1. A hybrid drive system (106), said hybrid drive system (106) comprising: an electric motor (108); a hybrid drivetrain assembly (110); a common output driveshaft (236) that transmits power from the hybrid drivetrain assembly (110) to at least one axle of the vehicle to drive a set of wheels (104) of the vehicle; wherein the hybrid drive system (106) is configured between a gear box (116) of an IC engine power pack (500) and the at least one axle of the vehicle for a front wheel drive or a rear wheel drive or an all-wheel drive vehicle; wherein the hybrid drive system (106) enables three different and independent driving modes, the three driving modes comprising: an IC engine mode with drive to the set of wheels from the IC engine power pack (500), an electric mode with drive to the set of wheels from the electric motor (108), and a combined mode with drive to the set of wheels collectively from the IC engine power pack (500) and the electric motor (108); wherein the hybrid drivetrain assembly (110) comprises a geartrain assembly (130) and a mode controller mechanism (140) that enable selective engagement and disengagement of the electric motor (108) and the IC engine power pack (500) to achieve the three driving modes; and wherein the mode controller mechanism (140) of the hybrid drivetrain assembly (110) comprises a synchronizing mechanism consisting of a control lever (418) and a bridge slider sleeve (420) that moves to different positions to enable selective engagement of a drive gear (402) of the geartrain assembly (130) with one of driven gears (404, 408) of the geartrain assembly (130), enabling different torque-speed ratios of drive from the electric motor (108) in the electric mode or in the combined mode of operation .

2. The hybrid drive system (106) as claimed in claim 1, wherein the geartrain assembly (130) comprises: the drive gear (402) with a conical hub arrangement and set of dog teeth on either side; the driven gears (404 and 408) having an externally splined hub rigidly attached thereto; the driven gears (404 and 408) are in constant mesh with their respective gear pairs (406 and 410) rigidly mounted on an intermediate drive shaft (312) that is coupled to the common output driveshaft (236); the bridge slider sleeve (420) having two sleeve sections (414 and 416), one each that slides on the externally splined hub of each of the driven gears (404 and 408): and a first series of pinion gears (422, 424, 426, 428 and 412) that transmit power from the electric motor (108) to the drive gear (402).

3. The hybrid drive system (106) as claimed in claim 2, wherein the mode controller mechanism (140) comprises: synchronizer rings (430 and 432) that help to match the speeds of the driven gears (404 and 408) with that of the drive gear (402); a control lever (418) that moves the two sleeve sections (414 and 416) of the bridge slider sleeve (420) on the externally splined hub of the driven gears (404 and 408); an actuation mechanism (610, 630, 650, 670) that controls the movement of the control lever (418).

4. The hybrid drive system (106) as claimed in claim 3, wherein, on receiving a command to engage the electric motor (108) with the common output drive shaft (236), the control lever (418) pushes sections of the bridge slider sleeve (414 or 416) towards the drive gear (402), the synchronizer ring (430 or 432) helping the driven gear (404 or 408) to match the speed of the drive gear (402) and then the dog teeth of that sleeve section engaging with the dog teeth of the drive gear and thus engaging the driven gear (404 or 408) with the drive gear (402); wherein, the selected driven gear (404 or 408) is in constant mesh with its paired gear (406 or 410) fixed on the intermediate drive shaft (312), resulting in the power from the electric motor (108) being transmitted to the common output drive shaft (236) through the intermediate driveshaft (312); wherein, the other half of the slider sleeve gets pushed away from the drive gear (402) and hence only one of the driven gears (404 or 408) gets engaged with the drive gear (402) at any given time; wherein, on receiving a command to disengage the electric motor (108) with the common output drive shaft (236), the control lever (418) brings the bridge slider sleeve (420) in a neutral position, where the drive gear (402) is disconnected from both the driven gears (404 and 408), thereby resulting in the power from the electric motor (108) not being transmitted from the drive gear (402) to the intermediate driveshaft (312) and disengagement of the electric motor (108) from the common output driveshaft (236).

5. The hybrid drive system (106) as claimed in claim 3, wherein the actuation mechanism is an electronically operated electric actuation mechanism (610) comprising: a linear electric actuator (612) mounted on a bracket (620); and a slider arm (614), shifter rod (616) and balancer link (618) that transmit movement from the linear electric actuator (612) to the control lever (418).

6. The hybrid drive system (106) as claimed in claim 5, wherein, when the linear electric actuator (612) is substituted by a hydraulic piston arrangement, or a pneumatic cylinder arrangement or a cable & hand lever arrangement, the actuation mechanism becomes a hydraulically operated actuator mechanism (630), or a pneumatically operated actuator mechanism (650) or a manually operated cable and lever mechanism (670), respectively.

7. The hybrid drive system (106) as claimed in claim 4, wherein for a first speed ratio in the electric mode, the electric motor (108) power is transmitted to the drive gear (402) through a first series of pinion gears (422, 424, 426, 428, 412) of the geartrain assembly (130) and the mode controller mechanism (140) engages the first driven gear (404) with the drive gear (402); wherein, the actuation mechanism (610, 630, 650, 670), on receiving a command, pushes the bridge slider sleeve (420) from the neutral position towards the drive gear (402) and the first sleeve (414) with the help of the synchronizer ring (428) helps the first driven gear (404) to match the speed of the drive gear (402) and then the dog teeth of the first sleeve (414) engage the dog teeth of the drive gear (402) thus engaging the first driven gear (404) with the drive gear (402) and the other half of the slider sleeve (416) gets pushed away from the drive gear (402) and towards the second driven gear (408); wherein, the electric motor (108) power is thus transmitted to the first driven gear (404) and the first driven gear (404) is in constant mesh with the first paired gear (406) of the intermediate drive shaft (312) and hence the electric motor (108) power is transmitted by the first driven gear (404) to the intermediate drive shaft (312) and then to the common output drive shaft (236) and the first ratio of the electric mode is enabled.

8. The hybrid drive system (106) as claimed in claim 4, wherein for the second ratio of the electric mode, the electric motor (108) power is transmitted to the drive gear (402) through a first series of pinion gears (422, 424, 426, 428, 412) of the geartrain assembly (130) and the mode controller mechanism (140) engages the second driven gear (408) with the drive gear (402); wherein, the actuation mechanism on receiving the necessary command pushes the bridge slider sleeve (420) from the neutral position towards the drive gear (402) and the second sleeve (416) with the help of the synchronizer ring (432) helps the second driven gear (408) to match the speed of the drive gear (402) and then the dog teeth of the second sleeve (416) engage the dog teeth of the drive gear (402) thus engaging the second driven gear (408) with the drive gear (402) and the other half of the slider sleeve (414) gets pushed away from the drive gear (402) and towards the first driven gear (404); wherein, the electric motor (108) power is thus transmitted to the second driven gear (408) and the second driven gear (408) is in constant mesh with the second paired gear (410) of the intermediate drive shaft (312) and hence the electric motor (108) power is transmitted by the second driven gear (408) to the intermediate drive shaft (312) and then to the common output drive shaft (236) and the second ratio of the electric mode is enabled.

9. The hybrid drive system (106) as claimed in claim 4, wherein for the IC engine mode, the actuation mechanism of the mode controller mechanism (140) on receiving the necessary command pushes the bridge slider sleeve (420) into the neutral position and thus disconnecting both the driven gears (404 and 408) from the drive gear (402); wherein, the electric motor (108) drive is thus not transmitted from the drive gear (402) to the intermediate driveshaft (312) and the electric motor (108) is also switched off and hence the electric motor (108) is thus disengaged entirely from the hybrid drivetrain assembly and the power from the IC engine powerpack (500) is sent to the common output driveshaft (236) through the intermediate drive shaft (312) and the IC engine mode is enabled.

10. The hybrid drive system (106) as claimed in claim 4, wherein for combined mode, the mode controller mechanism (140) actuates the actuation mechanism and engages the electric motor through the geartrain assembly (130); wherein, the power of the electric motor (108) is transmitted to the intermediate drive shaft (312) by connecting the drive gear (402) with either the first driven gear (404) and its paired gear (406) or with the second driven gear (408) and its paired gear (410) and the intermediate drive shaft (312) thus transmits the power from both the IC engine powerpack (500) and the electric motor (108) together to the common output drive shaft (236) thereby enabling the combined mode of operation.

11. The hybrid drive system (106) as claimed in claim 4, wherein the hybrid drive system (106) further enables a regeneration mode that allows a transfer of power from the wheel to the common output driveshaft (236) and then to the intermediate driveshaft (312) by switching off the traction electric motor (108) and also connecting either the first (404) or the second (408) driven gear with the drive gear (402) of the geartrain assembly (130) thereby enabling different levels of regeneration power to be fed back into the battery (114) by allowing the traction electric motor (108) to function as a generator motor.

12. The hybrid drive system (106) as claimed in claim 4, wherein to enable an electric power take off (e-PTO) option, the electric motor (108) is switched on and the IC engine powerpack (500) is either switched off or drives the common output driveshaft (236) and the mode controller mechanism commands the geartrain assembly (130) to keep the electric motor (108) disengaged with the intermediate shaft (312); wherein, the electric motor (108) power is transmitted to the pinion (412) and also to an e-PTO pulley (434); wherein, the actuation mechanism (610, 630, 650, 670) on receiving the necessary command, pushes the bridge slider sleeve (420) into the neutral position and thus disconnecting both the driven gears (404) and (408) from the drive gear (402) and the electric motor (108) drive is thus not transmitted from the drive gear (402) to the intermediate driveshaft (312) and hence the electric motor (108) is thus disengaged entirely from the common output driveshaft (236) that drives the wheels; wherein, the electric motor (108) now entirely drives the e-PTO pulley (434) and can power the accessories that are connected to the PTO drive thereby enabling the electric Power Take Off (e-PTO) to operate while the vehicle is stationary or driven only by the IC engine powerpack (500).

13. The hybrid drive system (106) as claimed in claim 4, wherein to enable an electric power take off (e-PTO) option, the electric motor (108) is switched on and the mode controller mechanism commands the geartrain assembly (130) to keep the electric motor (108) engaged with the intermediate shaft (312); wherein, the electric motor (108) power is transmitted to the pinion (412) and also to an e-PTO pulley (434) to power the accessories that are connected to the PTO drive; wherein, the actuation mechanism (610, 630, 650, 670) on receiving the necessary command, connects either the first (404) or the second (408) driven gear with the drive gear (402) of the geartrain assembly (130) thus transmitting the electric motor (108) drive to the intermediate driveshaft (312) and then to the common output driveshaft (236) that drives the wheels; wherein, the electric motor (108) now drives the e-PTO pulley (434) to power the accessories that are connected to the PTO drive thereby enabling the electric Power Take Off (e-PTO) and also provides drive to the common output driveshaft (236) to drive the wheels.

14. The hybrid drive system (106) as claimed in claim 1, wherein, the geartrain assembly (130) comprises more than one pair of driven gears, thereby enabling multiple torque speed gear ratios in the electric mode.

15. A vehicle (100) comprising the hybrid drive system (106) as claimed in claim 1.

16. A vehicle (100) having a transfer case with a four-wheel drive or an all-wheel drive option comprising the hybrid drive system (106) as claimed in claim 1.

17. The hybrid drive system (106) as claimed in claim 1, wherein the hybrid drive system (106) enables – (i) conversion of IC engine vehicle into its plug-in hybrid electric vehicle variant or (ii) a production of a new plug-in hybrid electric vehicle; wherein the IC engine is powered by at least one fuel selected from a group comprising diesel, petrol, CNG, LNG, ethanol and hydrogen; and wherein the electrical energy to operate the electric motor (108) is provided by at least one energy source selected from a group comprising a battery, a hydrogen fuel cells stack and an arrangement of ultra-capacitors or super capacitors.

18. The hybrid drive system (106) as claimed in claim 1, wherein the hybrid drive system (106) in a constrained design space of the prevalent ICE vehicle architecture enables conversion of the on-road ICE vehicle into its plug-in hybrid electric vehicle variant and then into a full electric vehicle variant in a phased manner.

Description:FIELD OF THE INVENTION
[0001] Present invention relates to the field of sustainable mobility. In particular, the present disclosure pertains to an alternative powertrain technology that optimizes integration of two independent drives such as ICE and Electric powertrains, on a vehicle.

BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] One of the greatest challenges being faced by human race today is undoubtedly the climate change and its potentially catastrophic consequences for humanity. The ever-rising greenhouse gas emissions coupled with massive urbanization trends create a further challenge where large-scale migration to urban areas is creating several high-density population clusters that require tremendous resources for survival such as round the clock availability of utilities, products and services to support such urban lifestyle. As a consequence, one of the highest contributors to global greenhouse gas emissions is transportation sector, responsible for nearly quarter of greenhouse gas emissions every year. The urban vehicular emissions not only affect the global temperature rise and the climate, but also the health of the urban populations as they inhale those harmful vehicular emissions that create health hazards including early deaths and COPD (chronic obstructive pulmonary disorders).
[0004] There has been a strong scientific evidence and record of such health hazards and ailments which need to be addressed with the sense of urgency, by providing more workable solutions for sustainable mobility which reduces the quantum of harmful emissions. At the same time, the consumers of automobile sector are used to certain conveniences with respect to ease of fueling, long range on a full fuel tank, as well as certain driving features which can’t be taken away from them in an instant by switching to non-IC engine vehicles such as fully electric vehicles, keeping in mind the mass affordability factor. The fully electric vehicles presently have specific shortcomings such as long recharge times, inconvenience of not having adequate charging facilities, range anxiety for drivers and passengers as a result of relatively short range on a single charge, etc. However, there is also an urgent need to move towards technology that can immediately start reducing the harmful tailpipe emissions from the mobility sector in general.
[0005] Therefore, it is pertinent to first migrate to an intermittent stage of hybrid electric mobility solutions such as a Plug-in Hybrid Electric Vehicle (PHEV) and/or Fuel Cell Electric Hybrid Vehicle (FC-HEV) whereby all shortcomings of a full electric vehicle or an ICE vehicle, can be effectively addressed. Such Plug-in Hybrid Vehicles (PHEVs), if by design are provided with an additional flexibility of proceeding to a full electric retrofit using the already installed electric powertrain, then such a solution would eventually accelerate the acceptance of full electric (zero tail-pipe emissions) vehicles into the mainstream mobility sector of transporting both people and goods.

OBJECTS OF THE DISCLOSURE
[0006] Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
[0007] It is an object of the present invention to provide a hybrid drive system for an internal combustion (IC) engine based vehicle, the hybrid drive system enables (i) quick, cost-effective and easy conversion of existing Internal Combustion Engine (ICE) vehicles into their Plug-in Hybrid Electric Vehicle (PHEV) variants, (ii) production of new Plug-in Hybrid Electric Vehicles (PHEVs) and (iii) an option to convert such Plug-in Hybrid Electric Vehicles into their zero-tailpipe emissions full Electric Vehicle (EV) versions in a sustainable and phased manner thereby providing a more inclusive and sustainable mobility solution.
[0008] It is another object of the present invention to provide a hybrid drive system that can be fitted on manufacturer’s assembly line to new vehicles being manufactured using the existing ICE vehicle architecture and platform thereby easily making those into Plug-in Hybrid Electric Vehicles (PHEVs) in a quick and cost-effective manner.
[0009] It is another object of the present invention to provide a hybrid drive system that can be retrofitted to convert an existing on-road vehicle powered by an ICE based power pack to a PHEV without modifying the vehicle’s architecture and platform thereby providing a solution that can be easily accommodated in a constrained design space of an existing on-road vehicle.
[0010] It is another object of the present invention to provide a hybrid drive system that can be easily installed on a rear-wheel-drive vehicle or an all-wheel drive vehicle.
[0011] It is another object of the present invention to provide a mode controller mechanism in the hybrid drive system that enables selection of various driving modes (Electric Mode, IC engine mode or combined mode) and their combinations in order to propel the vehicle by using a programmable logic controller based on the vehicle’s speed and load.
[0012] It is another object of the present invention to provide a compact, fail-safe and easy to operate mode controller mechanism in the hybrid drive system that can enable different driving modes of the hybrid drive system.
[0013] It is another object of the present invention to provide a hybrid drive system that allows one or more gear ratios and thereby allowing multiple torque-speed characteristics from the electric drive as well.
[0014] It is another object of the present invention to have an AI (Artificial Intelligence) based control system for the vehicle that can on the basis of the road conditions, traffic conditions, vehicular emission restrictions and route selected by the driver, select the various driving modes (Electric Mode, Range-extender Electric mode, IC engine mode or combined mode) and their combinations in order to propel the vehicle by using the best efficiency operating zones of either of the powertrains.
[0015] It is another object of the present invention to allow the option of power take-off (PTO) to be provided from the electric powertrain of a hybrid electric vehicle.
[0016] It is another object of the present invention to provide a hybrid drive system that is a Universal Hybridization Platform (UHP) that in a constrained design space of the prevalent ICE vehicle architecture, first enables conversion of the on-road ICE vehicle into its plug-in hybrid electric vehicle variant and then into a full electric vehicle variant in a phased manner.

SUMMARY
[0017] Present invention relates to a Hybrid Drive System that optimizes integration of two independent drives such as ICE and Electric powertrains, on a vehicle. More particularly, the present invention relates to a hybrid drive system that can quickly enable a cost-effective and sustainable conversion of an IC engine vehicle into its Plug-in Hybrid Electric Vehicle variant and then into a full Electric Vehicle variant in a phased manner. The hybrid drive system can be integrated with both, the existing vehicles on-road and newly manufactured vehicles that operate on an internal combustion engine-based power pack (ICE power pack, herein) thereby converting those into PHEVs that offer an optimum sustainable mobility solution. Specifically, the disclosed hybrid drive system can be integrated on rear-wheel-drive vehicles or all-wheel drive vehicles.
[0018] In an aspect, the proposed hybrid drive system includes an electric motor; a hybrid drivetrain assembly; and a common output driveshaft that transmits power from the hybrid drivetrain assembly to at least one axle of the vehicle to drive a set of wheels of the vehicle. The hybrid drive system is configured between a gear box of an IC engine power pack and the at least one axle of the vehicle for a front wheel drive or a rear wheel drive or an all-wheel drive vehicle. The hybrid drive system enables three different and independent driving modes comprising: an IC engine mode with drive to the set of wheels from the IC engine power pack, an electric mode with drive to the set of wheels from the electric motor, and a combined mode with drive to the set of wheels collectively from the IC engine power pack and the electric motor.
[0019] In an aspect, the hybrid drivetrain assembly include a geartrain assembly and a mode controller mechanism that enable selective engagement and disengagement of the electric motor and the IC engine power pack to achieve the there three independent driving modes. The mode controller mechanism of the hybrid drivetrain assembly includes a synchronizing mechanism consisting of a control lever and a bridge slider sleeve that moves to different positions to enable selective engagement of a drive gear of the geartrain assembly with one of driven gears of the geartrain assembly, enabling different torque-speed ratios of drive from the electric motor in the electric mode or in the combined mode of operation.
[0020] In one or more embodiments, the geartrain assembly may include the drive gear with a conical hub arrangement and set of dog teeth on either side; the driven gears having an externally splined hub rigidly attached thereto; the driven gears are in constant mesh with their respective gear pairs rigidly mounted on an intermediate drive shaft that is coupled to the common output driveshaft; the bridge slider sleeve includes two sleeve section, one each that slides on the externally splined hub of each of the driven gears: and a first series of pinion gears that transmit power from the electric motor to the drive gear.
[0021] In one or more embodiments, the mode controller mechanism includes synchronizer rings that help to match the speeds of the driven gears with that of the drive gear; a control lever that moves the two sleeve sections of the bridge slider sleeve on the externally splined hub of the driven gears; and an actuation mechanism that controls the movement of the control lever.
[0022] In one or more embodiments, on receiving a command to engage the electric motor with the common output drive shaft, the control lever pushes sections of the bridge slider sleeve towards the drive gear, the synchronizer ring helping the driven gear to match the speed of the drive gear and then the dog teeth of that sleeve section engaging with the dog teeth of the drive gear and thus engaging the driven gear with the drive gear. The selected driven gear is in constant mesh with its paired gear fixed on the intermediate drive shaft, resulting in the power from the electric motor being transmitted to the common output drive shaft through the intermediate driveshaft. The other half of the slider sleeve gets pushed away from the drive gear and hence only one of the driven gears gets engaged with the drive gear at any given time. On receiving a command to disengage the electric motor with the common output drive shaft, the control lever brings the bridge slider sleeve in a neutral position, where the drive gear is disconnected from both the driven gears, thereby resulting in the power from the electric motor not being transmitted from the drive gear to the intermediate driveshaft and disengagement of the electric motor from the common output driveshaft.
[0023] In one or more embodiments, the actuation mechanism may be an electronically operated electric actuation mechanism having a linear electric actuator mounted on a bracket; and a slider arm, shifter rod and balancer link that transmit movement from the linear electric actuator to the control lever.
[0024] In one or more embodiments, when the linear electric actuator is substituted by a hydraulic piston arrangement, or a pneumatic cylinder arrangement or a cable & hand lever arrangement, the actuation mechanism becomes a hydraulically operated actuator mechanism, or a pneumatically operated actuator mechanism or a manually operated cable and lever mechanism, respectively.
[0025] In one or more embodiments, for a first speed ratio in the electric mode, the electric motor power is transmitted to the drive gear through a first series of pinion gears of the geartrain assembly and the mode controller mechanism engages the first driven gear with the drive gear. The actuation mechanism, on receiving a command, pushes the bridge slider sleeve from the neutral position towards the drive gear and the first sleeve with the help of the synchronizer ring helps the first driven gear to match the speed of the drive gear and then the dog teeth of the first sleeve engage the dog teeth of the drive gear thus engaging the first driven gear with the drive gear and the other half of the slider sleeve gets pushed away from the drive gear and towards the second driven gear. The electric motor power is thus transmitted to the first driven gear and the first driven gear is in constant mesh with the first paired gear of the intermediate drive shaft and hence the electric motor power is transmitted by the first driven gear to the intermediate drive shaft and then to the common output drive shaft and the first ratio of the electric mode is enabled.
[0026] In one or more embodiments, for the second ratio of the electric mode, the electric motor power is transmitted to the drive gear through a first series of pinion gears of the geartrain assembly and the mode controller mechanism engages the second driven gear with the drive gear. The actuation mechanism on receiving the necessary command pushes the bridge slider sleeve from the neutral position towards the drive gear and the second sleeve with the help of the synchronizer ring helps the second driven gear to match the speed of the drive gear and then the dog teeth of the second sleeve engage the dog teeth of the drive gear thus engaging the second driven gear with the drive gear and the other half of the slider sleeve gets pushed away from the drive gear and towards the first driven gear. The electric motor power is thus transmitted to the second driven gear and the second driven gear is in constant mesh with the second paired gear of the intermediate drive shaft and hence the electric motor power is transmitted by the second driven gear to the intermediate drive shaft and then to the common output drive shaft and the second ratio of the electric mode is enabled.
[0027] In one or more embodiments, for the IC engine mode, the actuation mechanism of the mode controller mechanism on receiving the necessary command pushes the bridge slider sleeve into the neutral position and thus disconnecting both the driven gears from the drive gear. The electric motor drive is thus not transmitted from the drive gear to the intermediate driveshaft and the electric motor is also switched off and hence the electric motor is thus disengaged entirely from the hybrid drivetrain and the power from the IC engine powerpack is sent to the common output driveshaft through the intermediate drive shaft and the IC engine mode is enabled.
[0028] In one or more embodiments, for combined mode, the mode controller mechanism actuates the actuation mechanism and engages the electric motor through the geartrain assembly. The power of the electric motor is transmitted to the intermediate drive shaft by connecting the drive gear with either the first driven gear and its paired gear or with the second driven gear and its paired gear and the intermediate drive shaft thus transmits the power from both the IC engine powerpack and the electric motor together to the common output drive shaft thereby enabling the combined mode of operation.
[0029] In one or more embodiments, the hybrid drive system further enables a regeneration mode that allows a transfer of power from the wheel to the common output driveshaft and then to the intermediate driveshaft by switching off the traction electric motor and also connecting either the first or the second driven gear with the drive gear of the geartrain assembly thereby enabling different levels of regeneration power to be fed back into the battery by allowing the traction electric motor to function as a generator motor.
[0030] In one or more embodiments, to enable an electric power take off (e-PTO) option, the electric motor is switched on and the IC engine powerpack is switched off and the mode controller mechanism commands the geartrain assembly to keep the electric motor disengaged with the intermediate shaft. The electric motor power is transmitted to the pinion and also to an e-PTO pulley. The actuation mechanism on receiving the necessary command, pushes the bridge slider sleeve into the neutral position and thus disconnecting both the driven gears from the drive gear and the electric motor drive is thus not transmitted from the drive gear to the intermediate driveshaft and hence the electric motor is disengaged entirely from the common output driveshaft that drives the wheels. The electric motor now entirely drives the e-PTO pulley and can power the accessories that are connected to the PTO drive thereby enabling the electric Power Take Off (e-PTO). The e-PTO option can also be enabled while the IC engine powerpack is providing power to drive the wheels of the vehicle thus allowing the PTO accessories to be entirely driven by the electric motor and not by the IC engine and hence reducing the load on the IC engine powerpack. Alternatively, the e-PTO option can also be enabled while the electric motor is providing power to drive the wheels of the vehicle.
[0031] In one or more embodiments, the geartrain assembly and mode controller includes multiple synchronizing mechanisms working with more than one pair of driven gears and drive gears, thereby enabling multiple torque speed gear ratios in the electric mode.
[0032] An aspect of the present disclosure relates to a vehicle comprising the proposed hybrid drive system.
[0033] An aspect of the present disclosure relates to a vehicle having a transfer case with a four-wheel drive or an all-wheel drive option and having the disclosed hybrid drive system.
[0034] In one or more embodiments, the hybrid drive system enables – (i) conversion of IC engine vehicle into its plug-in hybrid electric vehicle variant or (ii) a production of a new plug-in hybrid electric vehicle. The IC engine is powered by at least one fuel selected from a group comprising diesel, petrol, CNG, LNG, ethanol and hydrogen; and the electrical energy to operate the electric motor is provided by at least one energy source selected from a group comprising a battery, a hydrogen fuel cells stack and an arrangement of ultra-capacitors or super capacitors.
[0035] In one or more embodiments, the hybrid drive system in a constrained design space of the prevalent ICE vehicle architecture enables conversion of the on-road ICE vehicle into its plug-in hybrid electric vehicle variant and then into a full electric vehicle variant in a phased manner.

BRIEF DESCRIPTION OF DRAWINGS
[0036] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
[0037] FIG. 1A illustrates an implementation of an electric mode in a vehicle, in accordance with one or more embodiments of the present disclosure.
[0038] FIG. 1B illustrates an implementation of an engine mode in the vehicle, in accordance with an embodiment of the present disclosure.
[0039] FIG. 1C illustrates an implementation of a combined mode in the vehicle, in accordance with an embodiment of the present disclosure.
[0040] FIG. 1D illustrates an implementation of a regeneration mode in the vehicle, in accordance with an embodiment of the present disclosure.
[0041] FIG. 2A, 2B & 2C illustrates an exemplary architecture of Hybrid Drive System in the vehicle, in accordance with an embodiment of the present disclosure.
[0042] FIG. 3A illustrates the hybrid drive system from engine side, in accordance with an embodiment of the present disclosure.
[0043] FIG. 3B illustrates the hybrid drive system from electric traction motor side, in accordance with an embodiment of the present disclosure.
[0044] FIG. 3C illustrates the hybrid drive system from engine side and also showing the internals of the geartrain assembly and mode controller mechanisms, in accordance with an embodiment of the present disclosure.
[0045] FIG. 4A & 4B illustrates the hybrid drivetrain assembly comprising the electric gear train and electric traction motor engagement and disengagement mechanism of the mode controller mechanism seen from engine side and electric motor side respectively, in accordance with an embodiment of the present disclosure.
[0046] FIG. 4C illustrates the detailed view of the synchronizing mechanism of the mode controller mechanism, in accordance with an embodiment of the present disclosure.
[0047] FIG. 4D illustrates the detailed view of the electric actuator mechanism used to control the synchronizing mechanism, in accordance with an embodiment of the present disclosure.
[0048] FIG. 4E illustrates the different actuator mechanisms used to control the synchronizing mechanism, in accordance with an embodiment of the present disclosure.
[0049] FIG. 5A illustrates an exemplary representation depicting working of the geartrain assembly in the electric mode, in accordance with an embodiment of the present disclosure.
[0050] FIG. 5B illustrates an exemplary representation depicting working of the geartrain assembly in the second ratio for electric mode, in accordance with an embodiment of the present disclosure.
[0051] FIG. 5C illustrates an exemplary representation depicting working of the hybrid drivetrain assembly in the IC Engine mode, in accordance with an embodiment of the present disclosure.
[0052] FIG. 6 illustrates an exemplary representation depicting the electric Power Take Off option of the hybrid drive system, in accordance with an embodiment of the present disclosure.
[0053] FIG. 7 illustrates an exemplary representation of a combined accelerator of the hybrid drive system, in accordance with an embodiment of the present disclosure.
[0054] FIG. 8A illustrates graphical representation of the vehicle with resultant torque-speed characteristics, in accordance with an embodiment of the present disclosure.
[0055] FIG. 8B illustrates graphical representation of the vehicle with resultant torque-speed characteristics under various drive cycles, in accordance with an embodiment of the present disclosure.
[0056] FIG. 8C illustrates graphical representation of the vehicle with resultant reduction in IC engine usage, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0057] The disclosed invention describes a Hybrid Drive System that helps to convert an existing ICE architecture vehicle into its Plug-in Electric Vehicle (PHEV) variant. Such a hybrid drive system also enables a quick, cost-effective and sustainable conversion of an IC engine vehicle into its PHEV variant and then into a full Electric Vehicle variant in a phased manner. The described hybrid drive system optimizes integration of two independent drives such as ICE and Electric powertrains, on a vehicle. Specifically, such a hybrid drive system can be integrated on rear-wheel-drive vehicles or all-wheel drive vehicles. The hybrid drive system can be integrated with both, (i) the existing vehicles on-road and (ii) newly manufactured vehicles; that operate on an internal combustion engine-based power pack (ICE power pack, herein) thereby converting those into PHEVs that offer an optimum sustainable mobility solution.
[0058] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0059] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
[0060] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0061] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0062] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. These exemplary embodiments are provided only for illustrative purposes and so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. The invention disclosed may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Also, the terminology and phraseology used is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
[0063] Thus, for example, it will be appreciated by those of ordinary skill in the art that the diagrams, schematics, illustrations, and the like represent conceptual views or processes illustrating systems and methods embodying this invention. The functions of the various elements shown in the figures may be provided through the use of dedicated hardware as well as hardware capable of executing associated software. Similarly, any switches shown in the figures are conceptual only. Their function may be carried out through the operation of program logic, through dedicated logic, through the interaction of program control and dedicated logic, or even manually, the particular technique being selectable by the entity implementing this invention. Those of ordinary skill in the art further understand that the exemplary hardware, software, processes, methods, and/or operating systems described herein are for illustrative purposes and, thus, are not intended to be limited to any particular named element.
[0064] Systems depicted in some of the figures may be provided in various configurations. In some embodiments, the systems may be configured as a distributed system where one or more components of the system are distributed across one or more networks in a cloud computing system.
[0065] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0066] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0067] FIG. 1A illustrate an implementation of the disclosed hybrid drive system on a vehicle showing operation in an electric mode where the electric motor 108 provides the drive to the axle through the hybrid drivetrain assembly 110, in accordance with an embodiment of the present disclosure.
[0068] According to an embodiment, a hybrid drive system 106 is implemented in a vehicle 100. The hybrid drive system 106 includes an electric motor 108 and a hybrid drivetrain assembly 110. The vehicle 100 includes an ICE power pack 500 having an internal combustion (IC) engine assembly 118 and a gearbox assembly 116, supplying power to rear wheels 104 of rear axle of the vehicle through the hybrid drive system 106. The electric motor 108 supplies power to the rear wheels 104 of rear axle of the vehicle through the hybrid drive system 106. The vehicle further includes a battery 114 to supply electric power to the electric motor 108, a motor controller 112 and a fuel unit 120 to supply fuel to the IC engine 118.
[0069] In an embodiment, the hybrid drivetrain assembly 110 of the hybrid drive system 106 includes an geartrain assembly 130 and mode controller mechanism 140, which facilitates in utilizing the torque generated from both the electric motor 108 and the IC engine assembly 118 either independently or in a combined way. The hybrid drive system 106 provides seamless synchronization of the IC engine drive and the electric drive by taking it from the IC power pack 500 and the electric motor 108 respectively. Further, the added or individual drives are transmitted to the common drive shaft 236 (refer to FIG. 2A) of the vehicle 100 and from there on to the final driven axle. The technical specification of the electric drive that includes the ratings and capacity of the electric motor 108, the related gear ratios of the geartrain assembly 130 and the configuration and capacity of the battery pack 114 can be customized as per the vehicle requirements and the user’s preferences.
[0070] In an embodiment, FIG. 1C illustrates an implementation of the disclosed hybrid drive system on a vehicle showing operation in an IC engine mode, where the IC engine assembly 118 of the IC power pack 500 provides the drive to the axle through the hybrid drivetrain assembly 110.
[0071] In an embodiment, FIG. 1D illustrates an implementation of the disclosed hybrid drive system on a vehicle showing operation in combined mode, where both the electric motor 108 and the IC engine assembly 118 of the IC power pack 500 provides the drive to the axle through the hybrid drivetrain assembly 110.
[0072] In an embodiment, FIG. 1E illustrates an implementation of the disclosed hybrid drive system on a vehicle showing operation in a regenerative braking mode, where the electric motor 108 acts as a generator and charges the battery 114 during braking, while the vehicle 100 may be driven by the IC engine assembly 118.
[0073] In another embodiment, the present invention includes an energy recuperation system that makes innovative use of mechanical power transfer from different elements of the hybrid drive system 106 to result in varying levels of regeneration current being fed back into the battery 114 when the vehicle 100 is decelerating or there is a need to apply brakes.
[0074] In an embodiment, the hybrid drive system 106 is based on the fact, that the existing internal combustion engine powerpack 500 is kept unaltered till the output of the IC engine gearbox 116. Further, the hybrid drive system 106 which includes the electric motor 108 and the hybrid drivetrain assembly 110, can be added between the gearbox 116 of the IC power pack 500 and a rear axle differential final drive unit 238. The power from both the IC engine 118 and electric motor 108 is transmitted by a common output driveshaft 236 to the rear axle differential and then to the rear wheels 104.
[0075] FIG. 2A, 2B and 2C illustrate an exemplary representation of general arrangement of the hybrid drive system in a rear-wheel-drive vehicle, in accordance with an embodiment of the present disclosure.
[0076] FIG. 2A illustrates a general arrangement of the hybrid drive system 106 of the rear-wheel-drive four-wheeler from passenger side. The vehicle 100 includes an electric traction motor controller 112, a generator-motor controller 126, a Vehicle Controller Unit (VCU) or programmable logic controller 122, an invertor and DC convertor 202, a battery 114, charging point 204, a Cable Harness (HV) 206, a gear lever 208, a hand brake 210, Cable Harness (LV) 212, a mode selector lever 214.
[0077] FIG. 2B illustrates a general arrangement of the hybrid drive system 106 of the rear-wheel-drive four-wheeler from driver side. The vehicle 100 includes an ICE gear box 116, a break safety switch 218, a combined accelerator 220, a hand brake 210, a mode indicator 222, a neutral safety switch 224, a Cable Harness (LV) 226, a EV Key Switch 228, a ICE Key Switch 230, an audio visual indication 232, a mode selector lever 214, a Cable Harness (HV) 206, a gear lever 208.
[0078] FIG. 2C illustrates a general arrangement of the hybrid drive system 106 of the rear-wheel-drive four-wheeler from under side. The vehicle 100 includes a motor controller 112, a vehicle controller unit or programmable logic controller 122, an inverter and DC convertor 202, a common output driveshaft (propeller shaft) 236, rear axle differential 238, ICE gear box 116, ICE gearbox output driveshaft 240, Cable Harness (LV) 226, Mode shifter 234, Battery 114, Cable Harness (HV) 206.
[0079] In an embodiment, FIG 2A indicates location of the motor controller 112. A 1k ohm pre charging resistor is added across the mains contactor. Similarly, 1K ohm resistor is also added across the key switch for electric mode. The vehicle control unit (VCU) 122 is operatively connected to the motor controller 112 and the IC engine control unit 124. Magnetically coupled accelerator 220 interacts with the mode selector lever 214 to provide desired speed control in various modes of operation. The motor controller 112 provides proportionate power as per the torque speed demand as directed by the combined accelerator 220. Thermister control is provided internally through the motor controller 112 for the protection of the electric motor 108 winding from over-heating during rotor lock situation. The brake safety switch 218 (also interchangeably referred as safety interlock switch) prevents accidental running of motor while brakes are engaged. The brake pedal is used to actuate the brake safety switch 218.
[0080] In another embodiment, when the vehicle 100 is enabled to run in electric mode in parallel hybrid configuration, the gearbox 116 connected to the IC engine assembly 118 must remain in “neutral mode”. This action has to be a foolproof system and is obtained by keeping the gear changing lever in a “neutral” position. A neutral safety switch 224 prevents activation of electric mode if the IC engine gearbox gear lever is not in the neutral position. Thus, protection interlocks are achieved. Further, the motor controller 112 provides a regeneration mode to conserve the free-wheeling rotational energy of the driven wheels and also to regenerate during braking done, thereby charging the batteries. Thus, this action is capable to further add extra miles as a result of regeneration. Further, the two independent electric key switches 228 and 230 are provided to isolate electric and engine mode. Speed and other display parameters are shown on custom build instrument cluster known as audio visual indication 232. The custom build cable harness 206 is provided for the power and control circuits and regeneration circuit of the motor controller 112, the generator motor controller 126, the vehicle control unit 122, the combined accelerator 220, brake safety switch interlock 218, neutral gear safety switch 224, charging circuit and vehicle operations.
[0081] In an embodiment, the electric power is derived from the battery 114, or the hydrogen fuel cell stack mounted on the chassis frame of the vehicle 100 under the passenger or cargo compartment. Thereby, the new additions are maintained within the bodyline of the vehicle 100 and preserving the centre of gravity of the vehicle 100 as low to the ground as possible for better dynamic behaviour and balancing. The charging point 204 is located at a very convenient and easily accessible point on the vehicle 100 and charging is done by an external battery charger. A three-phase charging adapter is also provided to aid in the fast charging of the vehicle 100.
[0082] FIG. 3A and 3B illustrate an exemplary representation of general arrangement of the hybrid drive system comprising the hybrid drivetrain assembly, the electric motor and the mode controller, in accordance with an embodiment of the present disclosure.
[0083] In an embodiment, the hybrid drive system 106 majorly comprises of the hybrid drivetrain assembly 110, the electric motor 108, the common output driveshaft 236 and the IC engine gearbox output driveshaft 240 as shown in FIG. 3A and 3B. The hybrid drivetrain assembly 110 comprises of a geartrain assembly 130 and mode controller mechanism 140. The mode controller mechanism 140 using a synchronizing mechanism operated by a control lever 418 that can be moved to different positions – (i) enables engagement and disengagement of the electric motor 108 drive with the common output driveshaft 236 and also (ii) enables the single or multiple torque-speed ratios during the electric mode and combined mode. The IC engine gearbox output driveshaft 240 connects the output of the IC engine gearbox 116 with the hybrid drivetrain assembly 110 and transmits the output of the IC engine powerpack 500 to the hybrid drivetrain assembly 110. The hybrid drivetrain assembly 110 performs the dual role of combining the drives and individually transmitting the drives from the two powertrains – the IC engine powertrain and the Electric motor powertrain. The common output driveshaft 236 (also referred as propeller shaft) transmits the output of the hybrid drivetrain assembly 110 to the rear axle differential unit 238 and then onto the rear wheels 104. The hybrid drivetrain assembly 110 and the electric motor 108 can be located as a single module mounted on the chassis frame of the vehicle between the output of the gearbox 116 of the IC engine powerpack 500 and the differential 238 of the rear axle.
[0084] FIG. 4A, 4B and 4C illustrate an exemplary representation of general arrangement of the hybrid drivetrain assembly comprising the geartrain assembly and the mode controller mechanism that controls the operations of the geartrain assembly, in accordance with an embodiment of the present disclosure.
[0085] FIG. 4A and 4B illustrate from the engine side and electric motor side respectively, the geartrain assembly 130 and part of the mode controller mechanism 140 that provide the engagement and disengagement of the electric motor 108 drive with the common output driveshaft 236 and enables the single or multiple torque-speed ratios during the electric mode using a synchronizing mechanism operated by a control lever 418. FIG. 4C illustrates a detailed view of the synchronizing mechanism of the mode controller 140.
[0086] The geartrain assembly 130 consists of a drive gear 402 and driven gears 404 & 408 mounted on a shaft. The electric motor shaft is connected to pinion 422, which then transmits the electric motor power to the drive gear 402 of the geartrain assembly through a series of pinion gears 424, 426, 428 and 412. The gear 412 is mounted on the shaft 436 and thus transmits the drive of the electric motor 108 further to the drive gear 402. Further, the mode controller mechanism 140 includes a control lever 418, a bridge slider sleeve 420 having two sections 414 & 416 and synchronizer rings 430 & 432. The drive gear 402 has a specialized construction with a set of dog teeth and a conical hub on either side of the gear. Each of the driven gears 404 and 408 also has a specialized construction wherein an externally splined hub is rigidly attached to the gears on one of the sides. The drive gear 402 and the driven gears 404 & 408 are mounted on the shaft using bearings and thus can independently rotate on the mounting shaft. The driven gears 404 & 408 are in constant mesh with their own respective gear pair 406 & 410 respectively. The gears 406 & 410 are rigidly mounted on the intermediate shaft 312 that is further connected to the common output driveshaft 236. The intermediate shaft 312 is connected to the IC engine gearbox output shaft 240 and thus receives the drive from the IC engine powerpack 500. The other end of the intermediate shaft 312 is connected to the common output driveshaft 236 and thus the intermediate shaft transmits the drive from both the IC engine powerpack 500 and the electric motor 108 either individually or combined together. The two sections of the slider sleeve 414 and 416 have mating internal splines corresponding to the externally splined hub of the driven gears 404 and 408. The slider sleeve sections 414 and 416 thus slide on the externally splined hub of the driven gears 404 and 408 respectively. The slider sleeve sections 414 and 416 also have a set of internal dog teeth that can mesh with the dog teeth on the drive gear 402 and the dog teeth of the synchronizer rings 430 & 432. The control lever 418 moves the two parts of the slider sleeve 420 on the externally splined hub of the driven gears 404 & 408. The movement of the control lever 418 is done by at least one of an electronically operated electric actuation mechanism 610, a hydraulically operated actuator mechanism 630, a pneumatically operated actuator mechanism 650 and a manually operated cable and lever mechanism 670. The synchronizer rings 430 & 432 with dog teeth and internal conical surface to mate with the conical hubs of the drive gear 402, help match the speeds of the driven gears 404 & 408 with that of the drive gear 402.
[0087] FIG. 4D shows the details of such an electronically operated electric actuation mechanism 610. The movement of the control lever 418 and thus the bridge slider sleeve 420 is controlled by the electric linear actuator 612. The movement of the actuator end is transmitted to the control lever 418 by the slider arm 614 through the shifter rod 616 and balancer link 618. The electric actuator 612 is mounted using a bracket 620 on the housing of the hybrid drivetrain assembly 110. In order to have a hydraulically operated actuator mechanism 630, the electric linear actuator 612 can be substituted by a hydraulic cylinder actuator 632 and similarly to have a pneumatically operated actuator mechanism 650, the electric linear actuator 652 can be substituted by a pneumatic cylinder actuator as shown in FIG. 4E. Alternatively, the movement of the slider arm can be managed manually by using a cable and hand lever mechanism 670 as shown in FIG. 4F.
[0088] On receiving the necessary command signal to engage the electric motor 108 with the common output driveshaft 236, the control lever 418 pushes either sections of the bridge slider sleeve 414 or 416 towards the drive gear 402, the synchronizer ring 430 or 432 helping the driven gear 404 or 408 to match the speed of the drive gear 402 and then the dog teeth of that sleeve section engaging with the dog teeth of the drive gear 402 and thus engaging the driven gear 404 or 408 with the drive gear 402. As the selected driven gear 404 or 408 is in constant mesh with its paired gear 406 or 410 respectively on the intermediate drive shaft 312, the electric motor 108 drive is transmitted to the common output drive shaft 236 by the intermediate driveshaft 312. The other half of the slider sleeve gets pushed away from the drive gear 402 and hence only one of the driven gear 404 or 408 gets engaged with the drive gear 402 at any given time.
[0089] On receiving the necessary command to disengage the electric motor 108 with the common output drive shaft 236, the control lever 418 brings the bridge slider sleeve 420 in the neutral position and thus disconnecting both the driven gears 404 & 408 from the drive gear 402. The electric motor 108 drive is thus not transmitted further from the drive gear 402 to the intermediate driveshaft 312 and hence the electric motor 108 is disengaged from the common output driveshaft 236.
[0090] FIG. 5A, 5B and 5C illustrate the working of the mode controller mechanism and the geartrain assembly when in electric drive mode, a second torque-speed gear ratio for electric mode, the combined mode, and IC engine mode in accordance with an embodiment of the present disclosure.
[0091] In an embodiment, FIG. 5A illustrates the gear train assembly 130 and mode controller mechanism 140 when in a first torque-speed gear ratio during the electric mode. In this mode, the electric motor 108 power is transmitted to the drive gear 402 through a first series of pinion gears 422, 424, 426, 428 and 412 of geartrain assembly 130 and the mode controller mechanism 140 engages the first driven gear 404 with the drive gear 402. The actuation mechanism, such as the actuation mechanism 610, 630, 650 or 670, on receiving the necessary command pushes the bridge slider sleeve 420 from the neutral position towards the drive gear 402. As the first half 414 of the sleeve 420 moves towards the drive gear 402, the sleeve 414 with the help of the synchronizer ring 430 helps the first driven gear 404 to match the speed of the drive gear 402 and then the dog teeth of the sleeve 414 engage the dog teeth of the drive gear 402 thus engaging the first driven gear 404 with the drive gear 402. The electric motor 108 power is thus transmitted to the first driven gear 404. The other half 416 of the slider sleeve 420 gets pushed away from the drive gear 402 and towards the second driven gear 408. The drive gear 402 is thus physically not engaged with the second driven gear 408. The first driven gear 404 is in constant mesh with its first paired gear 406 of the intermediate drive shaft 312 and hence the electric motor 108 power is transmitted by the first driven gear 404 to the intermediate drive shaft 312 and then to the common output drive shaft 236 and the first ratio of the electric mode is enabled.
[0092] In an embodiment, FIG. 5B illustrates the geartrain assembly 130 and mode controller mechanism 140 when in second torque-speed gear ratio during electric mode. In this mode, the electric motor 108 power is transmitted to the drive gear 402 through a first series of pinion gears 422, 424, 426, 428 and 412 of geartrain assembly 130 and the mode controller mechanism 140 engages the second driven gear 408 with the drive gear 402. The actuation mechanism 610, 630, 650 or 670, on receiving the necessary command pushes the bridge slider sleeve 420 from the neutral position towards the drive gear 402. As the second half 416 of the sleeve 420 moves towards the drive gear 402, the sleeve 416 with the help of the synchronizer ring 432 helps the second driven gear 408 to match the speed of the drive gear 402 and then the dog teeth of the sleeve 416 engage the dog teeth of the drive gear 402 thus engaging the second driven gear 408 with the drive gear 402. The electric motor 108 power is thus transmitted to the second driven gear 408. The other half 414 of the slider sleeve 420 gets pushed away from the drive gear 402 and towards the first driven gear 404. The drive gear 402 is thus physically not engaged with the first driven gear 404. The second driven gear 408 is in constant mesh with its paired gear 410 of the intermediate drive shaft 312 and hence the electric motor 108 power is transmitted by the second driven gear 408 to the intermediate drive shaft 312 and then to the common output drive shaft 236 and the second ratio of the electric mode is enabled.
[0093] FIG. 5C illustrates the geartrain assembly 130 and mode controller mechanism 140 in IC engine mode. In this mode, the mode controller mechanism 140 commands the actuation mechanism 610, 630, 650 or 670 of the geartrain assembly 130 wherein the actuation mechanism 610, 630, 650 or 670 on receiving the necessary command pushes the bridge slider sleeve 420 into the neutral position and thus disconnecting both the driven gears 404 and 408 from the drive gear 402. The electric motor 108 drive is thus not transmitted from the drive gear 402 to the intermediate driveshaft 312 and the electric traction motor 108 is also switched off and hence the electric motor 108 is thus disengaged entirely from the hybrid drivetrain assembly and the power from the IC engine powerpack 500 is sent to the common output driveshaft 236 through the intermediate drive shaft 312 and the IC engine mode is enabled.
[0094] For the combined mode of operation, the IC engine gearbox output driveshaft 240 is connected with the intermediate driveshaft 312 of the gear train assembly and mode controller mechanism 140 actuates the actuation mechanism 610, 630, 650 or 670 and engages the electric motor 108 with the geartrain assembly 130. The power of the electric motor 108 is transmitted to the intermediate drive shaft 312 by connecting the drive gear 402 with either the first driven gear 404 and its paired gear 406 as shown in FIG. 5A or with the second driven gear 408 and its paired gear 410 as shown in FIG. 5B. Thus, the intermediate drive shaft 312 transmits the power from both the IC engine powerpack 500 and the electric motor 108 to the common output drive shaft 236 thereby enabling the combined mode of operation.
[0095] The hybrid drive system 106 can also enable a regeneration mode that allows a transfer of power from the wheel to the common output driveshaft 236 and then to the intermediate driveshaft 312. For this the IC engine powerpack 500 can be kept in neutral position and the traction electric motor 108 is switched off. By connecting either the first driven gear 404, or the second driven 408 gear with the drive gear 402, the drive power can be fed back into the battery 114 by allowing the traction electric motor 108 to function as a generator motor. Engaging either of the driven gears 404 or 408 with the drive gear 402, enables different levels of regeneration power to be fed back into the battery 114.
[0096] FIG. 6 illustrates the hybrid drive system 106 with an e-PTO (Electric Power Take Off) option. In an embodiment, as shown in FIG. 6, a pulley or a drive gear 434 is attached to the shaft 436 on which are mounted the first series of pinion gears and the pinion gear 412. The electric motor 108 power is transmitted to the pinion 412 and also to the pulley through this shaft 436. For the e-PTO option to be used when the vehicle is stationary, the IC engine is switched off and the mode controller mechanism commands the geartrain assembly to keep the electric motor 108 disengaged with the intermediate shaft 312. The actuation mechanism 610, 630, 650 or 670 on receiving the necessary command, pushes the bridge slider sleeve 420 into the neutral position and thus disconnecting both the driven gears 404 and 408 from the drive gear 402. The electric motor 108 drive is thus not transmitted from the drive gear 402 to the intermediate driveshaft 312 and hence the electric motor 108 is thus disengaged entirely from the common output driveshaft 236 that drives the wheels. The electric motor 108 now entirely drives the e-PTO pulley 434 and can power the accessories that are connected to the PTO drive. The e-PTO option can also be used while the vehicle is in motion. The e-PTO pulley continues to receive the drive even when the actuation mechanism engages the electric motor 108 with the hybrid drivetrain assembly by connecting the electric motor drive to the intermediate shaft 312 during the electric mode or in the combined mode. The e-PTO option can also be used during the IC engine mode of driving the vehicle, thus reducing the load on the IC engine powerpack of driving the PTO accessories.
[0097] FIG. 7 illustrates an exemplary representation of the combined electro-mechanical accelerator 220 of the vehicle 100. The electro-mechanical accelerator 220 may include an accelerator fixture 702, which is used to fixedly mount the accelerator pedal 704 within the vehicle 100. The combined accelerator 220 serves as the accelerator for both the IC engine assembly 118 and the electric motor 108, providing ease of operation for the driver of the vehicle 100, allowing them to maintain their driving habits. The accelerator pedal 704 may be configured to operate both the electric and internal combustion engine accelerators simultaneously. A mechanical cable 708 operates a mechanism that provides the accelerator function for the IC engine assembly 118. The combined accelerator 220 may also include a connecting cable 706, which is operatively connected to the electric motor 108, and a magnetic coupling and sensor 712 that transmit a signal to the motor controller 112 based on the movement of the pedal 704, thereby providing the accelerator function for the electric motor 108. The combined accelerator 220 may include accelerator supports 714 and 718 to ensure proper fitment within the vehicle 100. Additionally, the combined accelerator 220 may feature a mechanical adjuster 710 adapted to adjust the positioning of the mechanical cable 708, which is coupled to the IC engine assembly 118, and a cable stretcher 716 configured to connect to a lever of the accelerator pedal 704. Thus, hybrid accelerator operation can be easily achieved through the common accelerator 220. The common accelerator 220 is configured with an optimized phase lag, allowing the IC engine assembly 118 to lag behind the electric motor 108 when the driver operates the accelerator pedal 704 while driving in combined mode.
[0098] FIG. 8A illustrates a graphical representation of the vehicle with resultant torque-speed characteristics, in accordance with an embodiment of the present disclosure.
[0099] In an embodiment, FIG. 8A represents the resultant representational torque speed characteristics delivered by the hybrid electric drive system 106. It can be seen that the resultant torque of the hybrid electric drive system 106 eclipses the maximum torque possible of the IC engine assembly 118 and this high resultant torque is available even at very low initial starting speed, thereby reducing the load on the IC engine assembly 118 significantly.
[00100] In an embodiment, FIG. 8A represents a graph, where x-axis is speed in revolutions per minute (rev/min) and y-axis is torque in N-m (newton-metre). The graph represents a torque speed characteristic of electric vehicle (EV) motor and a torque speed characteristic of an internal combustion engine (ICE). Further, the graph represents the resultant combined torque speed characteristics of ICE and EV motor.
[00101] FIG. 8B illustrates graphical representation of the vehicle with resultant torque-speed characteristics under various drive cycles, in accordance with an embodiment of the present disclosure.
[00102] In an embodiment, FIG. 8B represents a graph, the resultant representational torque speed characteristics delivered by the hybrid electric drive system 106 under various drive cycles like a start-up and heavy acceleration (power zone), partial load condition (eco zone), and a steady state cruise condition (cruise zone). It can be seen that the majority of the high torque from the resultant hybrid drive becomes available even from low initial speeds. This helps in keeping the engine speeds much lower than desired as the engine isn’t required to provide the complete torque needed to meet the load. By synchronizing the drives, the hybrid electric drive system 106 can reduce the load on the IC engine and thereby reduce the fossil fuel consumption and carbon and other harmful emissions by nearly up to 50%. Further reduction in harmful emissions can be achieved by improving the efficiency of the electric motor and battery pack.
[00103] In an embodiment, FIG. 8B represents a graph, where x-axis is speed in revolutions per minute (rev/min) and y-axis is torque in N-m (newton-metre). The graph includes representation of different gears such as 1st gear, 2nd gear, 3rd gear, etc of the IC engine gearbox along with various zones such as cruise zone, eco zone and power zone. It can be seen that the resultant torque-speed characteristics of the hybrid electric system allows the vehicle to be operated in 3rd or higher gears in the power zone unlike when in the IC engine mode where 1st or 2nd gear is needed in power zone. This translates to the engine being loaded less to provide the necessary drive when the vehicle is driven in combined mode, thereby resulting is savings of fuel and reduction in harmful emissions from the IC engine.
[00104] FIG. 8C illustrates a graphical representation of the vehicle with resultant reduction in IC engine usage, in accordance with an embodiment of the present disclosure.
[00105] In an embodiment, FIG. 8C represents the graph indicating a reduction in usage of IC engine power and in turn reduction in usage of fossil fuel and reduction in tail-pipe emissions by utilizing the uniquely designed Hybrid Drive System.
[00106] In an embodiment, FIG. 8C represents a graph which represents the saving in ICE Power in percentage (in %age) due to Hybrid Electric Drive System. When the vehicle 100 is operated at the 1st gear the maximum ICE power saving may be 73.68% and the minimum ICE power savings may be 68.42%. When the vehicle 100 is operated at the 2st gear the maximum ICE power saving may be 62.11% and the minimum ICE power savings may be 53.19%. When the vehicle 100 is operated at the 3rd gear the maximum ICE power saving may be 45.05% and the minimum ICE power savings may be 30.95%. The maximum ICE power saving in power zone may be 67.90% and the minimum ICE power saving in power zone may be 60.81%. The maximum ICE power saving in eco zone may be 53.58% and the minimum ICE power saving in eco zone may be 42.07%. The maximum ICE power saving in cruise zone may be 40.87% and the minimum ICE power saving in cruise zone may be 30.99%. Finally, the overall maximum ICE power saving may be 54.11% and the overall minimum ICE power saving may be 44.11%.
[00107] In an exemplary embodiment, the hybrid drive system 106 of the present invention synchronizes and transfers the torque generated by the two powertrains to the wheels of the vehicle 100. The hybrid drive system 106 serves the dual role of allowing the drive from each powertrain to be transmitted individually to the wheels of the vehicle 102/104 as demanded by the user, and of combining the drives from each powertrain and seamlessly transmitting them to the wheels of the vehicle 102/104 as required. The hybrid drive system 106 enables the true addition of the capabilities of the two distinct powertrains, preventing the splitting of the torque generated by either powertrain and instead adding the torque to meet the vehicle’s load demand by synchronizing the drives. This ensures the best utilization of the torque-speed characteristics of both powertrains. The hybrid drive system 106 makes unique use of the geartrain assembly 130 in combination with the mode controller mechanism 140 to provide the necessary synchronization between the drives from the two powertrains. The combined accelerator conveys the user’s demand to the hybrid drive system 106, and based on the total torque demand of the vehicle 100, the combination of the two powertrains is managed by the vehicle controller unit (VCU) 122 to deliver the required torque with the best possible efficiency. Such Hybrid Drive System can be installed on an IC engine vehicle without changing the existing IC engine architecture of the vehicle and thus rendering it as a bolt-on solution for converting existing IC engine vehicles into their Plug-in Hybrid Electric Vehicle (PHEV) variants.
[00108] The combined accelerator 220 is equipped with an optimized phase lag that allows the IC engine assembly 118 to lag behind the electric motor 108, taking advantage of the high initial starting torque of the electric motor 108 during the combined mode of operation. In this mode, the programmable vehicle control unit (VCU) 122 and the combined accelerator 220 allow the electric motor 108 to speed up earlier while the IC engine assembly 118 is still at idle speed, based on the programmable phase lag. The high starting torque of the electric motor 108 propels the vehicle 100 by providing the necessary torque up to a first programmable threshold speed of the vehicle. As the speed of the vehicle increases above this first programmable threshold speed, the IC engine assembly 118 begins providing the necessary torque to continue propelling the vehicle 100 as directed by the VCU 122. The geartrain assembly 130 and the mode controller mechanism 140 ensures a seamless addition of the two drives, with the electric motor 108 assisting the IC engine assembly 118 to propel the vehicle 100, while keeping the IC engine assembly 118 operating in its highest efficiency zones. At a second programmable threshold speed, the IC engine assembly 118 operates more efficiently than the electric motor 108. At this point, the VCU 122 shuts off the electric motor 108, and only the IC engine assembly 118 propels the vehicle 100. If the speed of the vehicle 100 drops below the second programmable threshold but remains above the first, the VCU 122 turns the electric motor 108 back on to assist the IC engine assembly 118 in propelling the vehicle 100. If the vehicle speed falls below the first programmable threshold, the VCU 122, with the help of the combined accelerator 220, enables the electric motor 108 to provide the necessary drive to propel the vehicle 100, while the IC engine assembly 118 operates at idle speed or can be switched OFF. Thus, during the combined mode of operation, the Vehicle Controller Unit (VCU) 122, along with the combined accelerator 220, enables propulsion of the vehicle 100 while ensuring the use of the highest efficiency zones of either powertrain.
[00109] The VCU 122 of the hybrid drive system 106 can be operated using a programmable logic. Such an operation of the VCU 122 would be primarily driven by vehicle speed thresholds (VSP) and State of Charge (SOC) of the battery 114. The Vehicle Control Unit 122 would need to be programmed or coded wherein the electronic / electrical commands would be issued to the motor controller 112, the engine control unit 124 and the various actuation mechanisms used in the hybrid drivetrain assembly 110. The VCU 122 would thus control the actuation of various drive modes of such a PHEV vehicle. One such algorithm for developing the program or code of the vehicle control unit 122 is described herein. Typically, there would be two vehicle speed (VSP) thresholds – VSPth1 & VSPth2 and one threshold for battery state of charge (SOC) as well – SOCth1. The values for these thresholds would depend on the type of vehicle and application and can be modified or re-programmed easily. Following are the steps of a typical algorithm used for programming the vehicle control unit 122 that operates the hybrid drive system 106.
 Vehicle to start in EV mode only if battery SOC > SOCth1 (e.g. 15%). This means the electric motor 108 would provide the drive to the wheels of the vehicle
 Upto threshold speed of VSPth1 (e.g. 40 kmph), vehicle to be driven by electric motor 108 only i.e. EV mode
 If SOC < SOCth1 then electric motor 108 to be switched off and shift to IC engine 500 drive, else continue in EV mode until vehicle speed VSP < VSPth1
 When the vehicle speed (VSP) increases and is in the range between the threshold values VSPth1(e.g. 40 kmph) and VSPth2 (e.g. 60 kmph), i.e. VSPth1 <= VSP <= VSPth2, the combined mode of operation is ON wherein both the Electric Motor 108 and IC Engine powerpack 500 drive the wheels of the vehicle together. In this mode the IC Engine powerpack 500 is operated under lower load as part of required power is contributed by Electric motor 108 and hence the fuel consumption is less
 If SOC < SOCth1 then electric motor 108 to be switched off and IC engine 500 to solely provide the drive, else continue in combined mode until vehicle speed VSPth1 <= VSP <= VSPth2
 If speed further increases above VSPth2, then only IC Engine powerpack 500 drives the wheels as it is the most efficient manner of driving the wheels at higher speeds. The electric motor 108 is disconnected from the common output driveshaft 236 by the VCU 122
 If vehicle speed VSP drops below VSPth2, then again combined mode operation needs to be started. For this though the important condition is whether battery SOC > SOCth1. If SOC < SOCth1 then IC Engine mode continues even at less than VSPth2 speeds. If SOC > SOCth1 then Electric motor 108 is engaged with the common output driveshaft 236 by the mode controller 140 as commanded by the VCU 122. So, both IC Engine powerpack 500 and Electric motor 108 continue to drive the wheels 104.
 If vehicle speed VSP again increases above that of SPth2, then, the mode of operation shifts to the pure IC Engine mode
 While if the vehicle speed VSP further drops lower and falls under the threshold VSPth1, then the IC engine powerpack 500 is switched OFF and the vehicle is now again driven in pure EV mode. However, the battery SOC should be higher than SOCth1 for EV mode to continue. If battery SOC < SOCth1, then IC engine powerpack is switched ON and the electric motor 108 is switched OFF and disconnected from the common output driveshaft 236 by the VCU 122.
[00110] Although this present invention has been described herein with respect to a number of specific illustrative embodiments, the foregoing description is intended to illustrate, rather than to limit the invention. Those skilled in the art will realize that many modifications of the illustrative embodiment could be made which would be operable. All such modifications, which are within the scope of the claims, are intended to be within the scope and of the present invention.

ADVANTAGES OF THE PRESENT DISCLOSURE
[00111] The present disclosure provides an efficient mechanism to build low emissions, fuel-saving hybrid drive system that can operate independently and in combined mode. Such a system would improve the fuel economy significantly and this would also mean a significant reduction in CO2 emissions per km.
[00112] The present disclosure provides a hybrid drive system that increases the life expectancy of the vehicle.
[00113] The present disclosure provides a hybrid drive system that provides a cost-effective solution to reduce the emissions from vehicles.
[00114] The present disclosure provides a hybrid drive system that helps in conserving the usage of fossil fuel thereby helping in reducing the import bills of such fuels for the nation.
[00115] The present disclosure provides a hybrid drive system which helps to re-purpose / upcycle the existing IC engine driven vehicle architectures into such cost-effective, low emissions, inclusive, consumer friendly mobility solutions; and also reduce the design and manufacturing costs for manufacturers.
[00116] Using this invention, OEM’s can either manufacture new PHEV or FC-HEV variants of their existing ICE vehicles in the portfolio, or can promote the retrofit conversion solutions through their authorized service / dealer network, both options offering huge additional revenue opportunities, besides leading to substantially higher green miles and achieving better CAFE regulatory norms. On a national level, the resulting savings of imported fossil fuels and the consequential benefits to national economy is certainly a huge advantage.
[00117] The present invention can be extremely beneficial for the consumers because it offers them the opportunity to recover substantial initial cost of vehicle due to reduced operating costs over the lifespan of vehicle. Since, the employment will be retained and can be grown further across ICE / EV / FCEV supply chains and multiple fuels eligible to be used, this invention is extremely inclusive for the economy.
[00118] Thus, the present invention would be a win-win solution for all the stakeholders such as Government, OEM, Consumers, Economy and Environment that we all have shared interests in.
, Claims:1. A hybrid drive system (106), said hybrid drive system (106) comprising:
an electric motor (108);
a hybrid drivetrain assembly (110);
a common output driveshaft (236) that transmits power from the hybrid drivetrain assembly (110) to at least one axle of the vehicle to drive a set of wheels (104) of the vehicle;
wherein the hybrid drive system (106) is configured between a gear box (116) of an IC engine power pack (500) and the at least one axle of the vehicle for a front wheel drive or a rear wheel drive or an all-wheel drive vehicle;
wherein the hybrid drive system (106) enables three different and independent driving modes, the three driving modes comprising: an IC engine mode with drive to the set of wheels from the IC engine power pack (500), an electric mode with drive to the set of wheels from the electric motor (108), and a combined mode with drive to the set of wheels collectively from the IC engine power pack (500) and the electric motor (108);
wherein the hybrid drivetrain assembly (110) comprises a geartrain assembly (130) and a mode controller mechanism (140) that enable selective engagement and disengagement of the electric motor (108) and the IC engine power pack (500) to achieve the three driving modes; and
wherein the mode controller mechanism (140) of the hybrid drivetrain assembly (110) comprises a synchronizing mechanism consisting of a control lever (418) and a bridge slider sleeve (420) that moves to different positions to enable selective engagement of a drive gear (402) of the geartrain assembly (130) with one of driven gears (404, 408) of the geartrain assembly (130), enabling different torque-speed ratios of drive from the electric motor (108) in the electric mode or in the combined mode of operation .
2. The hybrid drive system (106) as claimed in claim 1, wherein the geartrain assembly (130) comprises:
the drive gear (402) with a conical hub arrangement and set of dog teeth on either side;
the driven gears (404 and 408) having an externally splined hub rigidly attached thereto;
the driven gears (404 and 408) are in constant mesh with their respective gear pairs (406 and 410) rigidly mounted on an intermediate drive shaft (312) that is coupled to the common output driveshaft (236);
the bridge slider sleeve (420) having two sleeve sections (414 and 416), one each that slides on the externally splined hub of each of the driven gears (404 and 408): and
a first series of pinion gears (422, 424, 426, 428 and 412) that transmit power from the electric motor (108) to the drive gear (402).
3. The hybrid drive system (106) as claimed in claim 2, wherein the mode controller mechanism (140) comprises:
synchronizer rings (430 and 432) that help to match the speeds of the driven gears (404 and 408) with that of the drive gear (402);
a control lever (418) that moves the two sleeve sections (414 and 416) of the bridge slider sleeve (420) on the externally splined hub of the driven gears (404 and 408);
an actuation mechanism (610, 630, 650, 670) that controls the movement of the control lever (418).
4. The hybrid drive system (106) as claimed in claim 3,
wherein, on receiving a command to engage the electric motor (108) with the common output drive shaft (236), the control lever (418) pushes sections of the bridge slider sleeve (414 or 416) towards the drive gear (402), the synchronizer ring (430 or 432) helping the driven gear (404 or 408) to match the speed of the drive gear (402) and then the dog teeth of that sleeve section engaging with the dog teeth of the drive gear and thus engaging the driven gear (404 or 408) with the drive gear (402);
wherein, the selected driven gear (404 or 408) is in constant mesh with its paired gear (406 or 410) fixed on the intermediate drive shaft (312), resulting in the power from the electric motor (108) being transmitted to the common output drive shaft (236) through the intermediate driveshaft (312);
wherein, the other half of the slider sleeve gets pushed away from the drive gear (402) and hence only one of the driven gears (404 or 408) gets engaged with the drive gear (402) at any given time;
wherein, on receiving a command to disengage the electric motor (108) with the common output drive shaft (236), the control lever (418) brings the bridge slider sleeve (420) in a neutral position, where the drive gear (402) is disconnected from both the driven gears (404 and 408), thereby resulting in the power from the electric motor (108) not being transmitted from the drive gear (402) to the intermediate driveshaft (312) and disengagement of the electric motor (108) from the common output driveshaft (236).
5. The hybrid drive system (106) as claimed in claim 3, wherein the actuation mechanism is an electronically operated electric actuation mechanism (610) comprising:
a linear electric actuator (612) mounted on a bracket (620); and
a slider arm (614), shifter rod (616) and balancer link (618) that transmit movement from the linear electric actuator (612) to the control lever (418).
6. The hybrid drive system (106) as claimed in claim 5, wherein, when the linear electric actuator (612) is substituted by a hydraulic piston arrangement, or a pneumatic cylinder arrangement or a cable & hand lever arrangement, the actuation mechanism becomes a hydraulically operated actuator mechanism (630), or a pneumatically operated actuator mechanism (650) or a manually operated cable and lever mechanism (670), respectively.
7. The hybrid drive system (106) as claimed in claim 4, wherein for a first speed ratio in the electric mode, the electric motor (108) power is transmitted to the drive gear (402) through a first series of pinion gears (422, 424, 426, 428, 412) of the geartrain assembly (130) and the mode controller mechanism (140) engages the first driven gear (404) with the drive gear (402);
wherein, the actuation mechanism (610, 630, 650, 670), on receiving a command, pushes the bridge slider sleeve (420) from the neutral position towards the drive gear (402) and the first sleeve (414) with the help of the synchronizer ring (428) helps the first driven gear (404) to match the speed of the drive gear (402) and then the dog teeth of the first sleeve (414) engage the dog teeth of the drive gear (402) thus engaging the first driven gear (404) with the drive gear (402) and the other half of the slider sleeve (416) gets pushed away from the drive gear (402) and towards the second driven gear (408);
wherein, the electric motor (108) power is thus transmitted to the first driven gear (404) and the first driven gear (404) is in constant mesh with the first paired gear (406) of the intermediate drive shaft (312) and hence the electric motor (108) power is transmitted by the first driven gear (404) to the intermediate drive shaft (312) and then to the common output drive shaft (236) and the first ratio of the electric mode is enabled.
8. The hybrid drive system (106) as claimed in claim 4, wherein for the second ratio of the electric mode, the electric motor (108) power is transmitted to the drive gear (402) through a first series of pinion gears (422, 424, 426, 428, 412) of the geartrain assembly (130) and the mode controller mechanism (140) engages the second driven gear (408) with the drive gear (402);
wherein, the actuation mechanism on receiving the necessary command pushes the bridge slider sleeve (420) from the neutral position towards the drive gear (402) and the second sleeve (416) with the help of the synchronizer ring (432) helps the second driven gear (408) to match the speed of the drive gear (402) and then the dog teeth of the second sleeve (416) engage the dog teeth of the drive gear (402) thus engaging the second driven gear (408) with the drive gear (402) and the other half of the slider sleeve (414) gets pushed away from the drive gear (402) and towards the first driven gear (404);
wherein, the electric motor (108) power is thus transmitted to the second driven gear (408) and the second driven gear (408) is in constant mesh with the second paired gear (410) of the intermediate drive shaft (312) and hence the electric motor (108) power is transmitted by the second driven gear (408) to the intermediate drive shaft (312) and then to the common output drive shaft (236) and the second ratio of the electric mode is enabled.
9. The hybrid drive system (106) as claimed in claim 4, wherein for the IC engine mode, the actuation mechanism of the mode controller mechanism (140) on receiving the necessary command pushes the bridge slider sleeve (420) into the neutral position and thus disconnecting both the driven gears (404 and 408) from the drive gear (402);
wherein, the electric motor (108) drive is thus not transmitted from the drive gear (402) to the intermediate driveshaft (312) and the electric motor (108) is also switched off and hence the electric motor (108) is thus disengaged entirely from the hybrid drivetrain assembly and the power from the IC engine powerpack (500) is sent to the common output driveshaft (236) through the intermediate drive shaft (312) and the IC engine mode is enabled.
10. The hybrid drive system (106) as claimed in claim 4, wherein for combined mode, the mode controller mechanism (140) actuates the actuation mechanism and engages the electric motor through the geartrain assembly (130);
wherein, the power of the electric motor (108) is transmitted to the intermediate drive shaft (312) by connecting the drive gear (402) with either the first driven gear (404) and its paired gear (406) or with the second driven gear (408) and its paired gear (410) and the intermediate drive shaft (312) thus transmits the power from both the IC engine powerpack (500) and the electric motor (108) together to the common output drive shaft (236) thereby enabling the combined mode of operation.
11. The hybrid drive system (106) as claimed in claim 4, wherein the hybrid drive system (106) further enables a regeneration mode that allows a transfer of power from the wheel to the common output driveshaft (236) and then to the intermediate driveshaft (312) by switching off the traction electric motor (108) and also connecting either the first (404) or the second (408) driven gear with the drive gear (402) of the geartrain assembly (130) thereby enabling different levels of regeneration power to be fed back into the battery (114) by allowing the traction electric motor (108) to function as a generator motor.
12. The hybrid drive system (106) as claimed in claim 4, wherein to enable an electric power take off (e-PTO) option, the electric motor (108) is switched on and the IC engine powerpack (500) is either switched off or drives the common output driveshaft (236) and the mode controller mechanism commands the geartrain assembly (130) to keep the electric motor (108) disengaged with the intermediate shaft (312);
wherein, the electric motor (108) power is transmitted to the pinion (412) and also to an e-PTO pulley (434);
wherein, the actuation mechanism (610, 630, 650, 670) on receiving the necessary command, pushes the bridge slider sleeve (420) into the neutral position and thus disconnecting both the driven gears (404) and (408) from the drive gear (402) and the electric motor (108) drive is thus not transmitted from the drive gear (402) to the intermediate driveshaft (312) and hence the electric motor (108) is thus disengaged entirely from the common output driveshaft (236) that drives the wheels;
wherein, the electric motor (108) now entirely drives the e-PTO pulley (434) and can power the accessories that are connected to the PTO drive thereby enabling the electric Power Take Off (e-PTO) to operate while the vehicle is stationary or driven only by the IC engine powerpack (500).
13. The hybrid drive system (106) as claimed in claim 4, wherein to enable an electric power take off (e-PTO) option, the electric motor (108) is switched on and the mode controller mechanism commands the geartrain assembly (130) to keep the electric motor (108) engaged with the intermediate shaft (312);
wherein, the electric motor (108) power is transmitted to the pinion (412) and also to an e-PTO pulley (434) to power the accessories that are connected to the PTO drive;
wherein, the actuation mechanism (610, 630, 650, 670) on receiving the necessary command, connects either the first (404) or the second (408) driven gear with the drive gear (402) of the geartrain assembly (130) thus transmitting the electric motor (108) drive to the intermediate driveshaft (312) and then to the common output driveshaft (236) that drives the wheels;
wherein, the electric motor (108) now drives the e-PTO pulley (434) to power the accessories that are connected to the PTO drive thereby enabling the electric Power Take Off (e-PTO) and also provides drive to the common output driveshaft (236) to drive the wheels.
14. The hybrid drive system (106) as claimed in claim 1, wherein, the geartrain assembly (130) comprises more than one pair of driven gears, thereby enabling multiple torque speed gear ratios in the electric mode.
15. A vehicle (100) comprising the hybrid drive system (106) as claimed in claim 1.
16. A vehicle (100) having a transfer case with a four-wheel drive or an all-wheel drive option comprising the hybrid drive system (106) as claimed in claim 1.
17. The hybrid drive system (106) as claimed in claim 1, wherein the hybrid drive system (106) enables – (i) conversion of IC engine vehicle into its plug-in hybrid electric vehicle variant or (ii) a production of a new plug-in hybrid electric vehicle;
wherein the IC engine is powered by at least one fuel selected from a group comprising diesel, petrol, CNG, LNG, ethanol and hydrogen; and
wherein the electrical energy to operate the electric motor (108) is provided by at least one energy source selected from a group comprising a battery, a hydrogen fuel cells stack and an arrangement of ultra-capacitors or super capacitors.
18. The hybrid drive system (106) as claimed in claim 1, wherein the hybrid drive system (106) in a constrained design space of the prevalent ICE vehicle architecture enables conversion of the on-road ICE vehicle into its plug-in hybrid electric vehicle variant and then into a full electric vehicle variant in a phased manner.