DESC:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION

“POWER TRAIN FOR A HYDRAULIC HYBRID VEHICLE”

APPLICANTS:

Name Nationality Address
Mahindra & Mahindra Limited Indian Mahindra & Mahindra Ltd.,
MRV, Mahindra World City (MWC),Plot No. 41/1, Anjur Post, Chengalpattu,
Kanchipuram District – 603204 (TN) INDIA

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

TECHNICAL FIELD
[001] The embodiments herein generally relate to hybrid vehicles and more particularly, to hydraulic hybrid vehicles.

BACKGROUND
[002] Generally, a hybrid vehicle includes more than one propulsion system for propelling the vehicle. Some of the common hybrid vehicles are electric hybrid vehicles that include an internal combustion engine and an electric motor for propelling the vehicle.
[003] A hydraulic hybrid vehicle includes a high pressure accumulator, a low pressure accumulator and a pump/motor for propelling the vehicle in addition to the internal combustion engine. Packaging and arrangement of hydraulic components in the hydraulic hybrid vehicle is one of the challenges posed to the original equipment manufacturers (OEM). Further, providing manual transmission or automated manual transmission in hydraulic hybrid power train is complex and one of the major challenges posed to the OEM’s.
[004] Therefore, there exists a need for a compact hydraulic hybrid power train that can be implemented with manual or automated manual transmission. Furthermore, there exists a need for a hydraulic hybrid power train that can eliminate the aforementioned drawbacks.

OBJECTS
[005] The principal object of an embodiment of this invention is to provide a hydraulic hybrid power train for a vehicle that can be implemented with manual or automated manual transmission.
[006] Another object of an embodiment of this invention is to provide a compact hydraulic hybrid power train facilitating easier packaging in vehicles.
[007] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF DRAWINGS
[008] The embodiments of this invention are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[009] FIG. 1 depicts a schematic layout of a power train for a vehicle, according to a first embodiment of the invention as disclosed herein; and
[0010] FIG. 2 depicts a schematic layout of a power train for a vehicle, according to a second embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0011] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0012] The embodiments herein achieve a hydraulic hybrid power train for a vehicle that can be implemented with manual or automated manual transmission. Further, embodiments herein achieve a compact hydraulic hybrid power train facilitating easier packaging in vehicles. Referring now to the drawings, and more particularly to FIGS. 1 through 2, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0013] FIG. 1 depicts a schematic layout of a power train 100 for a vehicle (not shown), according to a first embodiment of the invention as disclosed herein. In an embodiment, the vehicle (not shown) includes a powertrain 100, a starter motor M, a battery B, a clutch pedal C, a throttle means (not shown) and a braking means (not shown). The vehicle (not shown) is a hydraulic hybrid vehicle.
[0014] In an embodiment, the powertrain 100 includes an engine 102, a flywheel 104, a first torque transfer assembly 106, a first shaft 108, a second torque transfer assembly 110, a power transmission unit 112, a hydraulic drive unit 114 and a drive mechanism 116.
[0015] The engine 102 serves as one of the power source for propelling the vehicle (not shown). The engine 102 includes a crankshaft (not shown) to transfer the torque produced by the engine 102 to rest of the power train components. The crankshaft (not shown) of the engine 102 can be used to mount at least one of the flywheel 104 and the first torque transfer assembly 106.
[0016] In an embodiment, a portion of the flywheel 104 is secured to a portion (not shown) of the crankshaft (not shown) of the engine 102. In an embodiment, the flywheel 104 includes an output member (not shown). The output member (not shown) of the flywheel 104 is used to transfer the torque from the crankshaft (not shown) of the engine 102 to the first torque transfer assembly 106. The output member (not shown) of the flywheel 104 can be integrated with the flywheel 104 or can be a separate shaft that is secured to the flywheel 104 for transferring the torque generated by the engine 102 to the first torque transfer assembly 106. Further, the flywheel 104 dampens the vibrations generated by the engine 102.
[0017] In an embodiment, the first torque transfer assembly 106 is a one way clutch. In an embodiment, the first torque transfer assembly 106 includes an input member (not shown), an output member 106s and other standard components of the one way clutch. In general terms, the input member (not shown) and the output member 106s of the first torque transfer assembly 106 refers to an inner race and an outer race of the one way clutch respectively. In one embodiment, the input member (not shown) of the first torque transfer assembly 106 is secured to one end (not shown) of the output member (not shown) of the flywheel 104. In other embodiment, the input member (not shown) of the first torque transfer assembly 106 is secured to a portion of the crankshaft (not shown) of the engine 102 i.e., the input member (not shown) of the first torque transfer assembly 106 is connected to the engine 102 through the flywheel 104. However, it is also within the scope of the invention to provide a coupling or any other connecting means for connecting the flywheel 104 to the input member (not shown) of the first torque transfer assembly 106. In an embodiment, the input member (not shown) is configured to rotate the output member 106s of the first torque transfer assembly 106 to transfer the torque generated by the engine 102 to the power transmission unit 112 through the first shaft 108 during engine drive mode. In an embodiment, the output member 106s is rotatably connected to the input member (not shown) of the first torque transfer assembly 106. In an embodiment, the output member 106s is configured to overrun the input member (not shown) of the first torque transfer assembly 106 during a hydraulic drive mode i.e., the output member 106s is configured to overrun (the output member 106s rotates faster than the input member (not shown) of the first torque transfer assembly 106) the input member (not shown) of the first torque transfer assembly 106 to transfer a torque produced by the hydraulic drive unit 114 to the power transmission unit 112 with engine 102 in off condition. It is also within the scope of the invention to provide a sprocket or pulley directly assembled to the output member 106s of the first torque transfer assembly 106 for receiving torque from the hydraulic drive unit 114 through a chain or belt respectively or also the output member 106s can have sprocket teeth or groove to receive torque from the hydraulic drive unit 114 through a chain or belt respectively. It is also within the scope of the invention to provide any other type of clutches without otherwise deterring the intended function of the first torque transfer assembly 106 as can be deduced from the description.
[0018] In an embodiment, the first shaft 108 is used to transfer the torque from at least one of the output member 106s of the first torque transfer assembly 106 (torque from engine 102) and the torque from the hydraulic drive unit 114 to the power transmission unit 112 through the second torque transfer assembly 110. In an embodiment, the first shaft 108 includes a first end (not shown) and a second end (not shown). In an embodiment, the first end (not shown) of the first shaft 108 is connected to the output member 106s of the first torque transfer assembly 106. In an embodiment, the first shaft 108 is a hollow shaft.
[0019] In an embodiment, the second torque transfer assembly 110 is used for engaging and disengaging at least one of the engine 102 and the hydraulic drive unit 114 with the power transmission unit 112. In an embodiment, the second torque transfer assembly 110 includes a driving member (not shown) and a driven member (not shown). The driving member (not shown) of the second torque transfer assembly 110 is connected to the second end (not shown) of the first shaft 108. In an embodiment, the second torque transfer assembly 110 is a friction coupling, or a friction clutch. Further, the second torque transfer assembly 110 includes other standard components of the friction clutch. However, it is also within the scope of the invention to provide any other type of clutches without otherwise deterring the intended function of the second torque transfer assembly 110 as can be deduced from the description.
[0020] The power transmission unit 112 is used for regulating the torque and speed of driving wheels (not shown) of the vehicle (not shown) in accordance to various driving conditions of the vehicle (not shown). In an embodiment, the power transmission unit 112 is a gearbox. In an embodiment, the power transmission unit 112 includes an input member 112i, an output member (not shown) and other standard components of the gearbox. In an embodiment, the input member 112i of the power transmission unit 112 is connected to the driven member (not shown) of the second torque transfer assembly 110. Further, the input member 112i is rotatably connected to the output member (not shown) of the power transmission unit 112. Furthermore, the output member (not shown) of the power transmission unit 112 is operably connected to at least one wheel (not shown) of the vehicle (not shown).
[0021] In an embodiment, the hydraulic drive unit 114 includes at least one accumulator 114a, at least one reservoir 114b, at least one turbine 114c, at least one compressor 114d, a shaft 114e, a first regulator controller 114f, a second regulator controller 114g, a plurality of first control valves 114h, a plurality of second control valves 114i and at least one pump (not shown). Further, the hydraulic drive unit 114 may include a plurality of bearings (not shown), a bearing housing (not shown) and a plurality of seals (not shown).
[0022] In an embodiment, the accumulator 114a is used to store a fluid at a high pressure. In an embodiment, the fluid from the accumulator 104a drives the turbine 114c to drive the first shaft 108 to drive the input member 112i of the power transmission unit 112 through the second torque transfer assembly 110 on engagement of the throttle means (not shown) of the vehicle (not shown). The accumulator 114a is provided in fluid communication with the turbine 114c and the compressor 114d. The accumulator 114a serves as a power source for powering the turbine 114c i.e., the fluid from the accumulator 114a drives the turbine 114c to generate the torque.
[0023] In an embodiment, the reservoir 114b is used to store the fluid at a low pressure. The reservoir 114b collects the fluid flowing from the turbine 114c. The reservoir 114b is provided in fluid communication with the turbine 114c and the compressor 114d.
[0024] The turbine 114c drives the first shaft 108 through the shaft 114e of the hydraulic drive unit 114. In an embodiment, the turbine 114c includes a housing (not shown) and at least one rotatable element (not shown). Further, the turbine 114c may include other standard components of the turbine for proper functioning of the turbine 114c. In an embodiment, the housing (not shown) is used to enclose and protect the rotatable element (not shown) of the turbine 114c. In an embodiment, the housing (not shown) of the turbine 114c includes at least one inlet (not shown) and at least one outlet (not shown). In an embodiment, at least one inlet (not shown) of the housing (not shown) of the turbine 114c is provided in fluid communication with the accumulator 114a. In an embodiment, at least one outlet (not shown) of the housing (not shown) of the turbine 114c is provided in fluid communication with the reservoir 114b. The rotatable element (not shown) of the turbine 114c is configured to rotate on receiving the fluid from the accumulator 114a. The rotatable element (not shown) of the turbine 114c is a turbine wheel in desired shape.
[0025] In an embodiment, the compressor 114d includes a housing (not shown) and at least one rotatable element (not shown). Further, the compressor 114d may include other standard components of the compressor for proper functioning of the compressor 114d. The housing (not shown) of the compressor 114d is used to enclose and protect the rotatable element (not shown) of the compressor 114d. The housing (not shown) of the compressor 114d includes at least one inlet (not shown) and at least one outlet (not shown). In an embodiment, at least one inlet (not shown) of the housing (not shown) of the compressor 114d is provided in fluid communication with the reservoir 114b. In an embodiment, at least one outlet (not shown) of the housing (not shown) of the compressor 114d is provided in fluid communication with the accumulator 114a. The rotatable element (not shown) of the compressor 114d is configured to rotate on receiving the fluid from the reservoir 114b. The rotatable element (not shown) of the compressor 114d is a compressor wheel in desired shape. The compressor 114d is driven by the kinetic energy of the braking through the power transmission unit 112 to compress the fluid that is flowing from the reservoir 114b and supply the same compressed fluid to the accumulator 114a i.e., the input member (not shown) of the power transmission unit 112 drives the first shaft 108 to drive the compressor 114d through the shaft 114e of the hydraulic drive unit 114 to compress the fluid flowing from the reservoir 114b to the accumulator 114a on engagement of the braking means (not shown) of the vehicle. It is also within the scope of the invention to provide a pump in the hydraulic drive unit 114 and is driven by the kinetic energy of the braking through standard powertrain members for compressing the fluid flowing from the reservoir 114b and supply the same compressed fluid to the accumulator 114a without otherwise deterring the intended function of the compressor 114d as can be deduced from the description.
[0026] It is within the scope of the invention to provide a housing that encloses both the rotating element of the turbine 114c and the compressor 114d without otherwise deterring the intended function of the housing (not shown) of the turbine 114c and housing (not shown) of the compressor 114d as can be deduced from the description.
[0027] The shaft 114e is configured to mount the rotatable element (not shown) of the turbine 114c, rotatable element (not shown) of the compressor 114d, each of the bearings (not shown) and each of the seals (not shown). The shaft 114e is connecting the rotatable element (not shown) of the turbine 114c and the rotatable element (not shown) of the compressor 114d. In one embodiment, the shaft 114e of the hydraulic drive unit 114 is rotatably connected to the first shaft 108 i.e., the shaft 114e of the hydraulic drive unit 114 is rotatably connected to the first shaft 108 through the drive mechanism 116. In another embodiment, the shaft 114e of the hydraulic drive unit 114 is rotatably connected to the output member 106s of the first torque transfer assembly 106 i.e., the shaft 114e of the hydraulic drive unit 114 is rotatably connected to the output member 106s of the first torque transfer assembly 106 through the drive mechanism 116. In an embodiment, the shaft 114e of the hydraulic drive unit 114 is used to generate a torque due to the rotation of rotatable element (not shown) of the turbine 114c provided by the fluid flowing from the accumulator 114a. The torque generated by shaft 114e of the hydraulic drive unit 114 is used to rotate at least one of the first shaft 108 and the output member 106s of the first torque transfer assembly 106 through the drive mechanism 116 for transferring the torque from the hydraulic drive unit 114 to the power transmission unit 112 during at least one of hybrid drive mode and the hydraulic drive mode (the engine 102 is switched off). In an embodiment, the shaft 114e of the hydraulic drive unit 114 is used to generate a braking torque or a negative torque due to rotation of the compressor 114d provided by pumping of the fluid from the reservoir 114b through the pump (not shown) for compressing the fluid to the accumulator 114a during vehicle braking condition. Furthermore, in an embodiment, the torque generated by the shaft 114e of the hydraulic drive unit 114 is used to facilitate cranking of the engine 102 in order to assist the starter motor M during the vehicle standstill condition or engine restarting condition.
[0028] In an embodiment, the first regulator controller 114f is used to regulate flow of the fluid from the accumulator 114a to the turbine 114c on receiving information or signal from the master controller (not shown).
[0029] In an embodiment, the second regulator controller 114g is used to regulate flow of the fluid from the compressor 114d to the accumulator 114a on receiving information or signal from the master controller (not shown).
[0030] In an embodiment, the master controller (not shown) is used to control the first regulator controller 114f and the second regulator controller 114g in accordance to various driving conditions of the vehicle (hydraulic hybrid vehicle).
[0031] In an embodiment, the plurality of first control valves 114h is used to direct the flow of fluid of the accumulator 114a i.e., one the first control valve 114h is used to direct the flow of fluid from the accumulator 114a to the inlet (not shown) of the housing (not shown) of the turbine 114c and the other first control valve 114h is used to direct the flow of fluid from the outlet (not shown) of the housing (not shown) of the compressor 114d to the accumulator 114a.
[0032] In an embodiment, the plurality of second control valves 114i is used to direct the flow of fluid of the reservoir 114b i.e., one the second control valve 114i is used to direct the flow of fluid from the outlet (not shown) of the housing (not shown) of turbine 114c to the reservoir 114b and the other first control valve 114i is used to direct the flow of fluid from the reservoir 114b to the inlet (not shown) of the housing (not shown) of the compressor 114d.
[0033] The pump (not shown) of the hydraulic drive unit 114 is used to pump the fluid from the reservoir 114b to the compressor 114d on engagement of the braking means (not shown) of the vehicle. The pump (not shown) is an electric pump.
[0034] Each of the bearings (not shown) is used to support the shaft 114e of the hydraulic drive unit 114. Each of the bearings (not shown) may include at least one sealing element (not shown). The bearing housing (not shown) is used to enclose each of the bearing (not shown). The bearing housing (not shown) may be connected between the housing (not shown) of the turbine 114c and the housing (not shown) of the compressor 114d. Each of the seals (not shown) is used to provide a sealing effect.
[0035] The drive mechanism 116 is used to transfer the torque from the turbine 114c of the hydraulic drive unit 114 to the first shaft 108. The drive mechanism 116 includes a first pulley (not shown), a second pulley (not shown) and a belt 116b. The first pulley (not shown) is mounted to a portion of the first shaft 108. The second pulley (not shown) is mounted to one end (not shown) of the shaft 114e of the hydraulic drive unit 114. The belt 116b is used to rotatably connect the first pulley (not shown) and the second pulley (not shown). However, it is also within the scope of the invention to provide a drive mechanism comprising sprockets and a chain for transferring the torque from the hydraulic drive unit 114 to the first shaft 108 without otherwise deterring the intended function of the first pulley (not shown), second pulley (not shown) and the belt 116b of the drive mechanism 116 as can be deduced from the description.
[0036] The starter motor M includes a pinion gear (not shown) that is in engagement with the flywheel 104. The starter motor M is used for starting the engine 102 through the flywheel 104 during engine starting condition or vehicle standstill condition. The load on the starter motor M is high during cranking of the engine 102. The torque generated by the hydraulic drive unit 114 is used to crank the engine 102 in order to assist the starter motor M (to reduce the load on the starter motor M) during engine starting condition. The battery B is used to power the starter motor M. The clutch pedal C is used for controlling the second torque transfer assembly 110. The throttle means (not shown) is used to accelerate the vehicle. In an embodiment, the throttle means (not shown) of the vehicle is at least one of a throttle pedal and a throttle lever. The braking means (not shown) is used to decelerate the vehicle or stop the motion of the vehicle (not shown). In an embodiment, the braking means (not shown) of the vehicle is at least one of a brake pedal and a brake lever.
[0037] The working of the powertrain 100 of the vehicle is as follows. During engine drive mode, the rotation of the crankshaft (not shown) of the engine 102 drives the input member (not shown) to rotate the output member (not shown) of the first torque transfer assembly 106 to drive the first shaft 108 to drive the output member (not shown) of the power transmission unit 112 to propel the vehicle. During hydraulic drive mode, fluid from the accumulator 114a drives the turbine 114c to drive the shaft 114e of the hydraulic unit 114 to drive the first shaft 108 to drive the input member of the power transmission unit to drive the output member (not shown) of the power transmission unit 112 on engagement of the throttle means (not shown) of vehicle for propelling the vehicle and at the same time the engine 102 in switched off. Further, in the hydraulic drive mode the output member (not shown) of the first torque transfer assembly 106 is rotating due to rotation of the shaft 114e of the hydraulic drive unit 114 and the input member (not shown) of the first torque transfer assembly 106 is substantially in stationary condition (no rotation). During, hybrid drive mode, power from the engine 102 and the power from the hydraulic drive unit 108 is used to drive the output member (not shown) of the power transmission unit 112 to propel the vehicle. During vehicle braking condition, the kinetic energy of braking drives the input member (not shown) of the power transmission unit 112 to drive the first shaft 108 to drive the compressor 114d through the shaft 114e of the hydraulic drive unit 114 to compress the fluid flowing from the reservoir 114b to the accumulator 114a on engagement of the braking means (not shown) of the vehicle that the accumulator 114a is charged and ready for next hydraulic drive mode or next hybrid drive mode. During engine restarting condition or to start the vehicle from a standstill condition, the torque generated by the hydraulic drive unit 114 is used to crank the engine 102 to assist the starter motor M so that load on starter motor M can be reduced. Therefore, an efficient powertrain 102 is provided for various driving conditions of the vehicle.
[0038] FIG. 2 depicts a schematic layout of a power train 200 for a vehicle (not shown), according to a second embodiment of the invention as disclosed herein. In an embodiment, the vehicle (not shown) includes a powertrain 200, a starter motor M, a battery B, a clutch pedal C, a throttle means (not shown) and a braking means (not shown). The vehicle (not shown) is a hydraulic hybrid vehicle.
[0039] In an embodiment, the powertrain 200 includes an engine 202, a flywheel 204, a first torque transfer assembly 206, a hydraulic drive unit 208, a second torque transfer assembly 210 and a power transmission unit 212.
[0040] The engine 202 serves as one of the power source for propelling the vehicle (not shown). The engine 202 includes a crankshaft (not shown) to transfer the torque produced by the engine 202 to rest of the power train components. The crankshaft (not shown) of the engine 202 can be used to mount at least one of the flywheel 204 and the first torque transfer assembly 206.
[0041] In an embodiment, a portion of the flywheel 204 is secured to a portion (not shown) of the crankshaft (not shown) of the engine 202. In an embodiment, the flywheel 204 includes an output member (not shown). The output member (not shown) of the flywheel 204 is used to transfer the torque from the crankshaft (not shown) of the engine 202 to the first torque transfer assembly 206. The output member (not shown) of the flywheel 204 can be integrated with the flywheel 204 or can be a separate shaft that is secured to the flywheel 204 for transferring the torque generated by the engine 202 to the first torque transfer assembly 206. Further, the flywheel 204 dampens the vibrations generated by the engine 202.
[0042] In an embodiment, the first torque transfer assembly 206 is a one way clutch. In an embodiment, the first torque transfer assembly 206 includes an input member (not shown), an output member (not shown) and other standard components of the one way clutch. In general terms, the input member (not shown) and the output member (not shown) of the first torque transfer assembly 206 refers to an inner race and an outer race of the one way clutch respectively. In one embodiment, the input member (not shown) of the first torque transfer assembly 206 is secured to one end (not shown) of the output member (not shown) of the flywheel 204. In other embodiment, the input member (not shown) of the first torque transfer assembly 206 is secured to a portion of the crankshaft (not shown) of the engine 202 i.e., the input member (not shown) of the first torque transfer assembly 206 is connected to the engine 202 through the flywheel 204. However, it is also within the scope of the invention to provide a coupling or any other connecting means for connecting the flywheel 204 to the input member (not shown) of the first torque transfer assembly 206. In an embodiment, the input member (not shown) is configured to rotate the output member (not shown) of the first torque transfer assembly 206 to transfer the torque generated by the engine 202 to the power transmission unit 212 through the hydraulic drive unit 208 during engine drive mode. In an embodiment, the output member (not shown) is rotatably connected to the input member (not shown) of the first torque transfer assembly 206. In an embodiment, the output member (not shown) is configured to overrun the input member (not shown) of the first torque transfer assembly 206 during a hydraulic drive mode i.e., the output member (not shown) is configured to overrun (the output member rotates faster than the input member of the first torque transfer assembly 206) the input member (not shown) of the first torque transfer assembly 206 to transfer a torque produced by the hydraulic drive unit 208 to the power transmission unit 212 with engine 202 in off condition. It is also within the scope of the invention to provide any other type of clutches without otherwise deterring the intended function of the first torque transfer assembly 206 as can be deduced from the description.
[0043] In an embodiment, the hydraulic drive unit 208 includes at least one accumulator 208a, at least one reservoir 208b, at least one turbine 208c, at least one compressor 208d, a shaft 208e, a first regulator controller 208f, a second regulator controller 208g, a plurality of first control valves 208h, a plurality of second control valves 208i and at least one pump (not shown). Further, the hydraulic drive unit 208 may include a plurality of bearings (not shown), a bearing housing (not shown) and a plurality of seals (not shown).
[0044] In an embodiment, the accumulator 208a is used to store a fluid at a high pressure. In an embodiment, the fluid from the accumulator 208a drives the turbine 208c to drive the shaft 208e of the hydraulic drive unit 208 to drive the input member 212i of the power transmission unit 212 through the second torque transfer assembly 210 on engagement of the throttle means (not shown) of the vehicle (not shown). The accumulator 208a is provided in fluid communication with the turbine 208c and the compressor 208d. The accumulator 208a serves as a power source for powering the turbine 208c i.e., the fluid from the accumulator 208a drives the turbine 208c to generate the torque.
[0045] In an embodiment, the reservoir 208b is used to store the fluid at a low pressure. The reservoir 208b collects the fluid flowing from the turbine 208c. The reservoir 208b is provided in fluid communication with the turbine 208c and the compressor 208d.
[0046] The turbine 208c drives the driving member (not shown) of the second torque transfer assembly 210 through the shaft 208e of the hydraulic drive unit 208. In an embodiment, the turbine 208c includes a housing (not shown) and at least one rotatable element (not shown). Further, the turbine 208c may include other standard components of the turbine for proper functioning of the turbine 208c. In an embodiment, the housing (not shown) is used to enclose and protect the rotatable element (not shown) of the turbine 208c. In an embodiment, the housing (not shown) of the turbine 208c includes at least one inlet (not shown) and at least one outlet (not shown). In an embodiment, at least one inlet (not shown) of the housing (not shown) of the turbine 208c is provided in fluid communication with the accumulator 208a. In an embodiment, at least one outlet (not shown) of the housing (not shown) of the turbine 208c is provided in fluid communication with the reservoir 208b. The rotatable element (not shown) of the turbine 208c is configured to rotate on receiving the fluid from the accumulator 208a. The rotatable element (not shown) of the turbine 208c is a turbine wheel in desired shape.
[0047] In an embodiment, the compressor 208d includes a housing (not shown) and at least one rotatable element (not shown). Further, the compressor 208d may include other standard components of the compressor for proper functioning of the compressor 208d. The housing (not shown) of the compressor 208d is used to enclose and protect the rotatable element (not shown) of the compressor 208d. The housing (not shown) of the compressor 208d includes at least one inlet (not shown) and at least one outlet (not shown). In an embodiment, at least one inlet (not shown) of the housing (not shown) of the compressor 208d is provided in fluid communication with the reservoir 208b. In an embodiment, at least one outlet (not shown) of the housing (not shown) of the compressor 208d is provided in fluid communication with the accumulator 208a. The rotatable element (not shown) of the compressor 208d is configured to rotate on receiving the fluid from the reservoir 208b. The rotatable element (not shown) of the compressor 208d is a compressor wheel in desired shape. The compressor 208d is driven by the kinetic energy of the braking through the power transmission unit 212 to compress the fluid that is flowing from the reservoir 208b and supply the same compressed fluid to the accumulator 208a i.e., the input member (not shown) of the power transmission unit 212 drives the shaft 208e of the hydraulic drive unit 208 through the second torque transfer assembly 210 to drive the compressor 208d to compress the fluid flowing from the reservoir 208b to the accumulator 208a on engagement of a braking means (not shown) of the vehicle. It is also within the scope of the invention to provide a pump in the hydraulic drive unit 208 and is driven by the kinetic energy of the braking through standard powertrain members for compressing the fluid flowing from the reservoir 208b and supply the same compressed fluid to the accumulator 208a without otherwise deterring the intended function of the compressor 208d as can be deduced from the description.
[0048] It is within the scope of the invention to provide a housing that encloses both the rotating element of the turbine 208c and the compressor 208d without otherwise deterring the intended function of the housing (not shown) of the turbine 208c and housing (not shown) of the compressor 208d as can be deduced from the description.
[0049] The shaft 208e is configured to mount the rotatable element (not shown) of the turbine 208c, rotatable element (not shown) of the compressor 208d, each of the bearings (not shown) and each of the seals (not shown). The shaft 208e is connecting the rotatable element (not shown) of the turbine 208c and the rotatable element (not shown) of the compressor 208d. In an embodiment, the shaft 208e of the hydraulic drive unit 208 includes a first end (not shown) and a second end (not shown). The first end (not shown) of the shaft 208e is connected to the output member (not shown) of the first torque transfer assembly 206. In an embodiment, the shaft 208e of the hydraulic drive unit 208 is used to generate a torque due to the rotation of the rotatable element (not shown) of the turbine 208c provided by the fluid flowing from the accumulator 208a. The torque generated by the shaft 208e of the hydraulic drive unit 208 is used to drive the input member 212i of the power transmission unit 212 through the second torque transfer assembly 210 during at least one of a hybrid drive mode (power from engine 202 and power from hydraulic drive unit 208) and the hydraulic drive mode (power from hydraulic drive unit 208 with the engine 202 in off condition). In an embodiment, the shaft 208e of the hydraulic drive unit 208 is used to generate a braking torque or a negative torque due to rotation of the compressor 208d provided by pumping of the fluid from the reservoir 208b through the pump (not shown) for compressing the fluid to the accumulator 208a during vehicle braking condition. Furthermore, in an embodiment, the torque generated by the shaft 208e of the hydraulic drive unit 208 is used to facilitate cranking of the engine 202 in order to assist the starter motor M during the vehicle standstill condition or engine restarting condition. Further, in an embodiment, the shaft 208e is a hollow shaft.
[0050] In an embodiment, the first regulator controller 208f is used to regulate flow of the fluid from the accumulator 208a to the turbine 208c on receiving information or signal from the master controller (not shown).
[0051] In an embodiment, the second regulator controller 208g is used to regulate flow of the fluid from the compressor 208d to the accumulator 208a on receiving information or signal from the master controller (not shown).
[0052] In an embodiment, the master controller (not shown) is used to control the first regulator controller 208f and the second regulator controller 208g in accordance to various driving conditions of the vehicle (hydraulic hybrid vehicle).
[0053] In an embodiment, the plurality of first control valves 208h is used to direct the flow of fluid of the accumulator 208a i.e., one the first control valve 208h is used to direct the flow of fluid from the accumulator 208a to the inlet (not shown) of the housing (not shown) of the turbine 208c and the other first control valve 208h is used to direct the flow of fluid from the outlet (not shown) of the housing (not shown) of the compressor 208d to the accumulator 208a.
[0054] In an embodiment, the plurality of second control valves 208i is used to direct the flow of fluid of the reservoir 208b i.e., one the second control valve 208i is used to direct the flow of fluid from the outlet (not shown) of the housing (not shown) of turbine 208c to the reservoir 208b and the other first control valve 208i is used to direct the flow of fluid from the reservoir 208b to the inlet (not shown) of the housing (not shown) of the compressor 208d.
[0055] The pump (not shown) of the hydraulic drive unit 208 is used to pump the fluid from the reservoir 208b to the compressor 208d on engagement of the braking means (not shown) of the vehicle. The pump (not shown) is an electric pump.
[0056] Each of the bearings (not shown) is used to support the shaft 208e of the hydraulic drive unit 208. Each of the bearings (not shown) may include at least one sealing element (not shown). The bearing housing (not shown) is used to enclose each of the bearing (not shown). The bearing housing (not shown) may be connected between the housing (not shown) of the turbine 208c and the housing (not shown) of the compressor 208d. Each of the seals (not shown) is used to provide a sealing effect.
[0057] In an embodiment, the second torque transfer assembly 210 is used for engaging and disengaging at least one of the engine 202 and the hydraulic drive unit 208 with the power transmission unit 212. In an embodiment, the second torque transfer assembly 210 includes a driving member (not shown) and a driven member (not shown). The driving member (not shown) of the second torque transfer assembly 210 is connected to the second end (not shown) of the shaft 208e of the hydraulic drive unit 208. In an embodiment, the second torque transfer assembly 210 is a friction coupling or a friction clutch. Further, the second torque transfer assembly 210 includes other standard components of the friction clutch. However, it is also within the scope of the invention to provide any other type of clutches without otherwise deterring the intended function of the second torque transfer assembly 210 as can be deduced from the description.
[0058] The power transmission unit 212 is used for regulating the torque and speed of driving wheels (not shown) of the vehicle (not shown) in accordance to various driving conditions of the vehicle (not shown). In an embodiment, the power transmission unit 212 is a gearbox. In an embodiment, the power transmission unit 212 includes an input member 212i, an output member (not shown) and other standard components of the gearbox. In an embodiment, the input member 212i of the power transmission unit 212 is connected to the driven member (not shown) of the second torque transfer assembly 210. Further, the input member 212i is rotatably connected to the output member (not shown) of the power transmission unit 212. Furthermore, the output member (not shown) of the power transmission unit 212 is operably connected to at least one wheel (not shown) of the vehicle (not shown).
[0059] The starter motor M includes a pinion gear (not shown) that is in engagement with the flywheel 204. The starter motor M is used for starting the engine 202 through the flywheel 204 during engine starting condition or vehicle standstill condition. The load on the starter motor M is high during cranking of the engine 202. The torque generated by the hydraulic drive unit 114 is used to crank the engine 202 in order to assist the starter motor M (to reduce the load on the starter motor M) during engine starting condition. The battery B is used to power the starter motor M. The clutch pedal C is used for controlling the second torque transfer assembly 210. The throttle means (not shown) is used to accelerate the vehicle. In an embodiment, the throttle means (not shown) of the vehicle is at least one of a throttle pedal and a throttle lever. The braking means (not shown) is used to decelerate the vehicle or stop the motion of the vehicle (not shown). In an embodiment, the braking means (not shown) of the vehicle is at least one of a brake pedal and a brake lever.
[0060] The working of the powertrain 200 of the vehicle is as follows. During engine drive mode, the rotation of the crankshaft (not shown) of the engine 202 drives the input member (not shown) to rotate the output member (not shown) of the first torque transfer assembly 206 to drive the shaft 208e of the hydraulic unit 208 to drive the input member of the power transmission unit to drive the output member (not shown) of the power transmission unit 212 to propel the vehicle. During hydraulic drive mode, fluid from the accumulator 208a drives the turbine 208c to drive the shaft 208e of the hydraulic unit 208 to drive the driving member of the second torque transfer assembly 210 to drive the output member (not shown) of the power transmission unit 212 on engagement of the throttle means (not shown) of vehicle for propelling the vehicle and at the same time the engine 202 in switched off. Further, in the hydraulic drive mode the output member (not shown) of the first torque transfer assembly 206 is rotating due to rotation of the shaft 208e of the hydraulic drive unit 208 and the input member (not shown) of the first torque transfer assembly 206 is substantially in stationary condition (no rotation). During, hybrid drive mode, power from the engine 202 and the power from the hydraulic drive unit 208 is used to drive the output member (not shown) of the power transmission unit 212 to propel the vehicle. During vehicle braking condition, the kinetic energy of braking drives the input member (not shown) of the power transmission unit 212 to drive the shaft 208e of the hydraulic drive unit 208 through the second torque transfer assembly 210 to drive the compressor 208d to compress the fluid flowing from the reservoir 208b to the accumulator 208a on engagement of the braking means (not shown) of the vehicle so that the accumulator 208a is charged and ready for next hydraulic drive mode or next hybrid drive mode. During, engine restarting condition or to start the vehicle from a standstill condition, the torque generated by the hydraulic drive unit 208 is used to crank the engine 202 to assist the starter motor M so that load on starter motor M can be reduced. Therefore, an efficient powertrain 202 is provided for various driving conditions of the vehicle.
[0061] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

CLAIMS
We claim,
1. A powertrain for a vehicle, said powertrain comprising:
an engine;
a first shaft having a first end and a second end;
a first torque transfer assembly comprising an input member connected to the engine and an output member rotatably connected to the input member, the output member is connected to the first end of the first shaft;
a power transmission unit comprising an input member and an output member rotatably connected to the input member, the output member is operably connected to at least one wheel of the vehicle;
a second torque transfer assembly comprising a driving member connected to the second end of the first shaft and a driven member connected to the input member of the power transmission unit; and
a hydraulic drive unit comprising at least one accumulator; at least one reservoir; at least one pump; at least one turbine; at least one compressor and a shaft connecting the turbine and the compressor, the shaft is rotatably connected to the first shaft,
wherein
the accumulator is adapted to store a fluid at a high pressure;
the reservoir is adapted to store the fluid at a low pressure;
the pump is adapted to pump the fluid from the reservoir to the compressor;
the compressor is adapted to compress the fluid;
the turbine is adapted to drive the first shaft through the shaft of the hydraulic drive unit;
the fluid from the accumulator drives the turbine to drive the first shaft to drive the input member of the power transmission unit through the second torque transfer assembly on engagement of a throttle means of the vehicle; and
the input member of the power transmission unit drives the first shaft to drive the compressor through the shaft of the hydraulic drive unit to compress the fluid flowing from the reservoir to the accumulator on engagement of a braking means of the vehicle.
2. The powertrain as claimed in claim 1, wherein the input member of the first torque transfer assembly is connected to the engine through a flywheel.
3. The powertrain as claimed in claim 1, wherein the first torque transfer assembly is a one way clutch.
4. The powertrain as claimed in claim 1, wherein the second torque transfer assembly is a friction clutch.
5. The powertrain as claimed in claim 1, wherein the power transmission unit is a gearbox.
6. The powertrain as claimed in claim 1, wherein the braking means of the vehicle is at least one of a brake pedal and a brake lever.
7. The powertrain as claimed in claim 1, wherein the throttle means of the vehicle is at least one of a throttle pedal and a throttle lever.
8. The powertrain as claimed in claim 1, wherein the first shaft is a hollow shaft.
9. The powertrain as claimed in claim 1, wherein the pump of the hydraulic drive unit is adapted to pump the fluid from the reservoir to the compressor on engagement of the braking means of the vehicle.
10. The powertrain as claimed in claim 1, wherein the hydraulic drive unit further comprising a first regulator controller, a second regulator controller, a master controller, a plurality of first control valves and a plurality of second control valves.
11. A powertrain for a vehicle, said powertrain comprising:
an engine;
a hydraulic drive unit comprising at least one accumulator; at least one reservoir; at least one pump; at least one turbine; at least one compressor and a shaft connecting the turbine and the compressor, the shaft having a first end and a second end,
a first torque transfer assembly comprising an input member connected to the engine and an output member rotatably connected to the input member, the output member is connected to the first end of the shaft of the hydraulic drive unit;
a power transmission unit comprising an input member and an output member rotatably connected to the input member, the output member is operably connected to at least one wheel of the vehicle; and
a second torque transfer assembly comprising a driving member connected to the second end of the shaft of the hydraulic drive unit and a driven member connected to the input member of the power transmission unit,
wherein
the accumulator is adapted to store a fluid at a high pressure;
the reservoir is adapted to store the fluid at a low pressure;
the pump is adapted to pump the fluid from the reservoir to the compressor;
the compressor is adapted to compress the fluid;
the turbine is adapted to drive the driving member of the second torque transfer assembly through the shaft of the hydraulic drive unit;
the fluid from the accumulator drives the turbine to drive the driving member of the second torque transfer assembly to drive the input member of the power transmission unit on engagement of a throttle means of the vehicle; and
the input member of the power transmission unit drives the shaft of the hydraulic drive unit through the second torque transfer assembly to drive the compressor to compress the fluid flowing from the reservoir to the accumulator on engagement of a braking means of the vehicle.
12. The powertrain as claimed in claim 11, wherein the input member of the first torque transfer assembly is connected to the engine through a flywheel.
13. The powertrain as claimed in claim 11, wherein the first torque transfer assembly is a one way clutch.
14. The powertrain as claimed in claim 1, wherein the second torque transfer assembly is a friction clutch.
15. The powertrain as claimed in claim 11, wherein the power transmission unit is a gearbox.
16. The powertrain as claimed in claim 11, wherein the braking means of the vehicle is at least one of a brake pedal and a brake lever.
17. The powertrain as claimed in claim 11, wherein the throttle means of the vehicle is at least one of a throttle pedal and a throttle lever.
18. The powertrain as claimed in claim 11, wherein the shaft of the hydraulic drive unit is a hollow shaft.
19. The powertrain as claimed in claim 11, wherein the pump of the hydraulic drive unit is adapted to pump the fluid from the reservoir to the compressor on engagement of the braking means of the vehicle.
20. The powertrain as claimed in claim 11, wherein the hydraulic drive unit further comprising a first regulator controller, a second regulator controller, a master controller, a plurality of first control valves and a plurality of second control valves.

Date: 29th April 2016 Signature:

Dr.Kalyan Ckahravarthy

ABSTRACT
Powertrain for a hydraulic hybrid vehicle includes an engine, a first torque transfer assembly, a first shaft, a second torque transfer assembly, a power transmission unit and a hydraulic drive unit. The hydraulic drive unit includes an accumulator, a reservoir, a turbine, a compressor, a shaft connecting the turbine and the compressor and a pump. The fluid from the accumulator drives the turbine to drive either the first shaft or driving member of second torque transfer assembly to drive the input member of the power transmission unit on engagement of a throttle means of the vehicle. The input member of power transmission unit drives the first shaft or shaft of the hydraulic drive unit to drive the compressor to compress the fluid flowing from reservoir to the accumulator on engagement of a braking means of the vehicle.

,CLAIMS:CLAIMS
We claim,
1. A powertrain for a vehicle, said powertrain comprising:
an engine;
a first shaft having a first end and a second end;
a first torque transfer assembly comprising an input member connected to the engine and an output member rotatably connected to the input member, the output member is connected to the first end of the first shaft;
a power transmission unit comprising an input member and an output member rotatably connected to the input member, the output member is operably connected to at least one wheel of the vehicle;
a second torque transfer assembly comprising a driving member connected to the second end of the first shaft and a driven member connected to the input member of the power transmission unit; and
a hydraulic drive unit comprising at least one accumulator; at least one reservoir; at least one pump; at least one turbine; at least one compressor and a shaft connecting the turbine and the compressor, the shaft is rotatably connected to the first shaft,
wherein
the accumulator is adapted to store a fluid at a high pressure;
the reservoir is adapted to store the fluid at a low pressure;
the pump is adapted to pump the fluid from the reservoir to the compressor;
the compressor is adapted to compress the fluid;
the turbine is adapted to drive the first shaft through the shaft of the hydraulic drive unit;
the fluid from the accumulator drives the turbine to drive the first shaft to drive the input member of the power transmission unit through the second torque transfer assembly on engagement of a throttle means of the vehicle; and
the input member of the power transmission unit drives the first shaft to drive the compressor through the shaft of the hydraulic drive unit to compress the fluid flowing from the reservoir to the accumulator on engagement of a braking means of the vehicle.
2. The powertrain as claimed in claim 1, wherein the input member of the first torque transfer assembly is connected to the engine through a flywheel.
3. The powertrain as claimed in claim 1, wherein the first torque transfer assembly is a one way clutch.
4. The powertrain as claimed in claim 1, wherein the second torque transfer assembly is a friction clutch.
5. The powertrain as claimed in claim 1, wherein the power transmission unit is a gearbox.
6. The powertrain as claimed in claim 1, wherein the braking means of the vehicle is at least one of a brake pedal and a brake lever.
7. The powertrain as claimed in claim 1, wherein the throttle means of the vehicle is at least one of a throttle pedal and a throttle lever.
8. The powertrain as claimed in claim 1, wherein the first shaft is a hollow shaft.
9. The powertrain as claimed in claim 1, wherein the pump of the hydraulic drive unit is adapted to pump the fluid from the reservoir to the compressor on engagement of the braking means of the vehicle.
10. The powertrain as claimed in claim 1, wherein the hydraulic drive unit further comprising a first regulator controller, a second regulator controller, a master controller, a plurality of first control valves and a plurality of second control valves.
11. A powertrain for a vehicle, said powertrain comprising:
an engine;
a hydraulic drive unit comprising at least one accumulator; at least one reservoir; at least one pump; at least one turbine; at least one compressor and a shaft connecting the turbine and the compressor, the shaft having a first end and a second end,
a first torque transfer assembly comprising an input member connected to the engine and an output member rotatably connected to the input member, the output member is connected to the first end of the shaft of the hydraulic drive unit;
a power transmission unit comprising an input member and an output member rotatably connected to the input member, the output member is operably connected to at least one wheel of the vehicle; and
a second torque transfer assembly comprising a driving member connected to the second end of the shaft of the hydraulic drive unit and a driven member connected to the input member of the power transmission unit,
wherein
the accumulator is adapted to store a fluid at a high pressure;
the reservoir is adapted to store the fluid at a low pressure;
the pump is adapted to pump the fluid from the reservoir to the compressor;
the compressor is adapted to compress the fluid;
the turbine is adapted to drive the driving member of the second torque transfer assembly through the shaft of the hydraulic drive unit;
the fluid from the accumulator drives the turbine to drive the driving member of the second torque transfer assembly to drive the input member of the power transmission unit on engagement of a throttle means of the vehicle; and
the input member of the power transmission unit drives the shaft of the hydraulic drive unit through the second torque transfer assembly to drive the compressor to compress the fluid flowing from the reservoir to the accumulator on engagement of a braking means of the vehicle.
12. The powertrain as claimed in claim 11, wherein the input member of the first torque transfer assembly is connected to the engine through a flywheel.
13. The powertrain as claimed in claim 11, wherein the first torque transfer assembly is a one way clutch.
14. The powertrain as claimed in claim 1, wherein the second torque transfer assembly is a friction clutch.
15. The powertrain as claimed in claim 11, wherein the power transmission unit is a gearbox.
16. The powertrain as claimed in claim 11, wherein the braking means of the vehicle is at least one of a brake pedal and a brake lever.
17. The powertrain as claimed in claim 11, wherein the throttle means of the vehicle is at least one of a throttle pedal and a throttle lever.
18. The powertrain as claimed in claim 11, wherein the shaft of the hydraulic drive unit is a hollow shaft.
19. The powertrain as claimed in claim 11, wherein the pump of the hydraulic drive unit is adapted to pump the fluid from the reservoir to the compressor on engagement of the braking means of the vehicle.
20. The powertrain as claimed in claim 11, wherein the hydraulic drive unit further comprising a first regulator controller, a second regulator controller, a master controller, a plurality of first control valves and a plurality of second control valves.