Description:RELATED ART

[0001] Embodiments of the present specification relate generally to geartrains, and more particularly to a dual speed geartrain for an electric vehicle.
[0002] An electric drive unit of a vehicle typically includes an electric motor, an inverter, and a geartrain. The geartrain may be a single speed geartrain or a multi-speed geartrain such as a dual speed geartrain. Generally, the dual speed geartrain includes a first set of gear components that provide a first gear ratio and a second set of gear components that provide a second gear ratio that is lesser than the first gear ratio. The dual speed geartrain typically uses the first set of gear components at lower speeds of the vehicle for providing superior torque to wheels and for improving the stability of the vehicle. Further, the dual speed geartrain uses the second set of gear components at higher speeds of the vehicle for delivering more power to the wheels of the vehicle.
[0003] Though existing dual speed geartrains claim to provide optimized torque and power to the wheels of the vehicle according to various driving conditions of the vehicle, such existing geartrains mostly use parallel geartrains that are complex and occupy more space. Further, such existing geartrains use a friction plate and multiple clutch packs, which lead to higher manufacturing costs of the geartrains and further unnecessarily increase packaging spaces typically required for accommodating the geartrains within electric drive units.
[0004] For example, US patent 9637127B1 describes one such dual speed geartrain that includes a dual clutch system and a dual actuator system for achieving a dual speed shifting of an electric drive unit of a vehicle. The dual clutch and the dual actuator used in an associated design of the geartrain make the geartrain more complex, increase a cost of manufacturing of the geartrain, and increase an overall weight and size of the geartrain.
[0005] In another example, a US patent 9366321B2 describes the dual speed geartrain including a planetary gear arrangement at a first reduction stage and a parallel gear arrangement at a second reduction stage for achieving a dual speed ratio. However, such a dual speed geartrain design generally achieves only a smaller gear ratio, which may not provide a sufficient amount of torque and stability to vehicles at very low speeds of the vehicles. Even attempts to modify the design of the dual speed geartrain described in the US9366321B2 to achieve a higher gear ratio by increasing the sizes of the planetary and parallel gear arrangements lead to increasing an overall size and a packaging volume of such dual speed geartrain.
[0006] Accordingly, there remains a need for an improved dual speed geartrain that is simple in design, compact, has less weight, is cost-effective, easy to manufacture and assemble, requires a lesser packaging space, and achieves a higher gear ratio.

BRIEF DESCRIPTION

[0007] It is an objective of the present disclosure to provide a dual speed geartrain of a vehicle. The dual speed geartrain includes a planetary gearset including a sun gear and a split planet carrier. The sun gear includes a set of inner teeth. Further, the dual speed geartrain includes a shifting sleeve disposed within a bore in the sun gear and includes a first set of teeth and a second set of teeth. Both the first set of teeth and the second set of teeth of the shifting sleeve are adapted to be disposed in a disengaged state with respect to the split planet carrier and the set of inner teeth of the sun gear, respectively, when the dual speed geartrain operates in a neutral gear mode. The first set of teeth of the shifting sleeve is adapted to be disposed in an engaged state with respect to the split planet carrier and the second set of teeth of the shifting sleeve is adapted to be disposed in the disengaged state with respect to the set of inner teeth of the sun gear when the dual speed geartrain operates in a first gear mode. The first set of teeth of the shifting sleeve is adapted to be disposed in the disengaged state with respect to the split planet carrier and the second set of teeth of the shifting sleeve is adapted to be disposed in the engaged state with respect to the set of inner teeth of the sun gear when the dual speed geartrain operates in a second gear mode.
[0008] The shifting sleeve includes an elongated body that passes through the bore in the sun gear, an outer face including the first set of teeth, a flange section including the second set of teeth, and inner splines. The inner splines are adapted to be disposed in a meshed state with respect to outer splines provided on a differential case associated with a differential unit of the vehicle when the dual speed geartrain is operating in one of the neutral gear mode, the first gear mode, and the second gear mode. The dual speed geartrain includes an input shaft that is operatively coupled to a motor shaft of a motor in the vehicle. The input shaft includes a first pinion gear. An intermediate shaft includes a second pinion gear and a first gear wheel. The first gear wheel in the intermediate shaft is disposed in a meshed state with respect to the first pinion gear in the input shaft. A sun gear shaft including a second gear wheel that is disposed in a meshed state with respect to the second pinion gear in the intermediate shaft.
[0009] The first pinion gear and the first gear wheel together form a first gearset. The second pinion gear and the second gear wheel together form a second gearset. A first gear reduction stage of the dual speed geartrain includes the first gearset and the second gearset disposed in parallel to each other. A second gear reduction stage of the dual speed geartrain includes the planetary gearset disposed co-axially to the first gearset and the second gearset. The dual speed geartrain including the first and second gearsets disposed co-axially to the planetary gearset provides space savings during installation of the dual speed geartrain within an electric drive unit of the vehicle.
[0010] The first gearset is adapted to reduce a speed provided as an output by the motor to a first reduced motor speed and to increase a torque output of the motor to a first increased torque output. The second gearset is adapted to reduce the first reduced motor speed from the first gearset to a second reduced motor speed and to increase the first increased torque output from the first gearset to a second increased torque output. The planetary gearset is adapted to reduce the second reduced motor speed from the second gearset to a third reduced motor speed and to increase the second increased torque output from the second gearset to a third increased torque output. The dual speed geartrain in the first gear mode is adapted to transfer the third reduced motor speed and the third increased torque output to one or more wheels of the vehicle via the split planet carrier and the shifting sleeve. The dual speed geartrain in the second gear mode is adapted to transfer the second reduced motor speed and the second increased torque output from the sun gear to the one or more wheels of the vehicle via the shifting sleeve.
[0011] The dual speed geartrain is adapted to provide a first gear ratio between a first half shaft and a second half shaft coupled to the differential unit in the vehicle when operating in the first gear mode. The dual speed geartrain is adapted to provide a second gear ratio between the first half shaft and the second half shaft when operating in the second gear mode. The first gear ratio is greater than the second gear ratio. The split planet carrier includes a left planet carrier plate and a right planet carrier plate that are coupled together using one or more fasteners. The left planet carrier plate is coupled to one or more planetary gears that are disposed in a meshed state with respect to the sun gear and a ring gear of the planetary gearset. The shifting sleeve is operatively coupled to a shifting fork. The shifting fork is operatively coupled to a linear actuator that is communicatively coupled to a control unit in the vehicle. The linear actuator includes one of a brushless direct current actuator including one or more of a leadscrew, a brushless direct current actuator including a cylindrical cam profile, a hydraulic piston actuator, a pneumatic piston actuator, a magnetic actuator, and a solenoid actuator. The control unit corresponds to an electronic control unit in the vehicle.
[0012] The control unit is communicatively coupled to an onboard sensor in the vehicle. The onboard sensor unit includes a motor speed sensor that measures the speed of the motor powering the one or more wheels of the vehicle. The control unit operates the dual speed geartrain in the neutral gear mode when there is no transfer of power from the motor to the one or more wheels of the vehicle. The control unit is adapted to actuate the linear actuator to switch an operational mode of the dual speed geartrain from the neutral gear mode to the first gear mode when the speed of the motor measured by the motor speed sensor corresponds to a value that falls within a designated speed range. The linear actuator linearly moves the shifting fork by a first distance in a first direction upon actuation by the control unit, thereby linearly moving the shifting sleeve from a neutral position to a pushed position, which disposes the first set of teeth of the shifting sleeve in an engaged state with respect to the split planet carrier and thereby switches the operational mode of the dual speed geartrain to the first gear mode.
[0013] The control unit is adapted to actuate the linear actuator to switch the operational mode of the dual speed geartrain from the first gear mode to the neutral gear mode when there is no transfer of power from the motor to the one or more wheels of the vehicle. The linear actuator linearly moves the shifting fork by the first distance in a second direction opposite to the first direction upon actuation by the control unit, thereby linearly moving the shifting sleeve from the pushed position to the neutral position, which disengages the first set of teeth of the shifting sleeve from the split planet carrier and disposes the dual speed geartrain in the neutral gear mode. The control unit is adapted to actuate the linear actuator to switch the operational mode of the dual speed geartrain from the first gear mode to the second gear mode when the speed of the motor measured by the motor speed sensor exceeds an upper limit of the designated speed range. The linear actuator linearly moves the shifting fork by a second distance greater than the first distance in a second direction opposite to the first direction upon actuation by the control unit, thereby linearly moving the shifting sleeve from the pushed position to a pulled position, which disengages the first set of teeth of the shifting sleeve from the split planet carrier and further engages the second set of teeth of the shifting sleeve with the set of inner teeth disposed within an inner surface of the sun gear, thereby disposing the dual speed geartrain in the second gear mode.
[0014] The control unit is adapted to actuate the linear actuator to switch the operational mode of the dual speed geartrain from the second gear mode to the first gear mode when the speed of the motor measured by the motor speed sensor corresponds to a value that falls within the designated speed range. The linear actuator linearly moves the shifting fork by the second distance in the first direction upon actuation by the control unit, which linearly moves the shifting sleeve disposed in the pulled position to the pushed position, thereby disengaging the second set of teeth of the shifting sleeve from the set of inner teeth of the sun gear and further engaging the first set of teeth of the shifting sleeve with the split planet carrier, which disposes the dual speed geartrain in the first gear mode. The control unit is adapted to actuate the linear actuator to switch the operational mode of the dual speed geartrain to the neutral gear mode from the second gear mode when there is no transfer of power from the motor to the one or more wheels of the vehicle. The linear actuator linearly moves the shifting fork by the first distance in the first direction upon actuation by the control unit, which linearly moves the shifting sleeve disposed in the pulled position to the neutral position, thereby disengaging the second set of teeth of the shifting sleeve from the set of inner teeth of the sun gear, which disposes the dual speed geartrain in the neutral gear mode.
[0015] The dual speed geartrain is integrated into an electric drive unit of the vehicle. The vehicle corresponds to one of a sport utility vehicle, a light-duty commercial vehicle, a medium-duty commercial vehicle, a heavy-duty commercial vehicle, a passenger vehicle, a pickup truck, a robotic vehicle, a train, a boat, an airplane, an industrial system, and a robotic system. The dual speed geartrain is retrofit to an electric drive unit of the vehicle. The vehicle corresponds to one of a sport utility vehicle, a light-duty commercial vehicle, a medium-duty commercial vehicle, a heavy-duty commercial vehicle, a passenger vehicle, a pickup truck, a robotic vehicle, a train, a boat, an airplane, an industrial system, and a robotic system.

BRIEF DESCRIPTION OF DRAWINGS

[0016] These and other features, aspects, and advantages of the claimed subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0017] FIG. 1 illustrates a block diagram depicting an exemplary architecture of a heavy-duty commercial electric vehicle having an electric drive unit including an embodiment of the present enhanced dual speed geartrain, in accordance with aspects of the present disclosure;
[0018] FIG. 2 illustrates an exploded view depicting various exemplary components of the dual speed geartrain of FIG. 1, in accordance with aspects of the present disclosure;
[0019] FIG. 3 illustrates a cross-section view depicting various components of the dual speed geartrain of FIG. 1 in an assembled state, in accordance with aspects of the present disclosure;
[0020] FIG. 4 illustrates a side perspective view of a sun gear in the dual speed geartrain of FIG. 1, in accordance with aspects of the present disclosure;
[0021] FIG. 5 illustrates a side perspective view of a shifting sleeve in the dual speed geartrain of FIG. 1, in accordance with aspects of the present disclosure;
[0022] FIG. 6 illustrates a front view of the dual speed geartrain of FIG. 1 operating in a neutral gear mode, in accordance with aspects of the present disclosure;
[0023] FIG. 7 illustrates a front view of the dual speed geartrain of FIG. 1 operating in a first gear mode, in accordance with aspects of the present disclosure; and
[0024] FIG. 8 illustrates a front view of the dual speed geartrain of FIG. 1 operating in a second gear mode, in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0025] The following description presents an exemplary dual speed geartrain for an electric vehicle. Particularly, embodiments described herein disclose a dual speed geartrain that includes a set of parallel gearsets at a first gear reduction stage that is coaxially coupled to a planetary gearset at a second gear reduction stage. The dual speed geartrain of the present disclosure operates in a plurality of gear modes including a neutral gear mode, a first gear mode and a second gear mode. The dual speed geartrain operates in the neural gear mode when an electric drive unit of a vehicle is not transferring power to wheels of the vehicle.
[0026] Further, the dual speed geartrain automatically switches an operational mode from the neutral gear mode to the first gear mode when the electric drive unit transfers power to the wheels and a speed of the vehicle is within a designated speed range. In the first gear mode, the dual speed geartrain offers a superior amount of torque to wheels of the vehicle, increases a load-carrying capacity of the vehicle, and improves an overall stability of the vehicle. Moreover, the dual speed geartrain automatically switches the operational mode from the first gear mode to the second gear mode when the speed of the vehicle exceeds the designated speed range. In the second gear mode, the dual speed geartrain transfers an increased amount of power to the wheels of the vehicle for facilitating the vehicle to move at higher speeds and for increasing driving performance of the vehicle. To that end, the dual speed geartrain of the present disclosure includes custom-designed components such as a split planet carrier and a single dog clutch mechanism including a shifting sleeve and a shifting fork that allow the dual speed geartrain to seamlessly switch between the neural, first, and second gear modes.
[0027] As noted previously, conventional dual speed geartrains are complex and use dual clutch and dual actuator systems to meet torque and power requirements according to various driving conditions of the vehicle. However, such conventional dual speed geartrains are bigger in size, heavier, require more packaging spaces, are difficult to manufacture, and are expensive. Certain other conventional dual speed geartrains use the planetary gearset at the first gear reduction stage and parallel gearsets at the second gear reduction stage, which generally cause the dual speed geartrains to achieve only a smaller gear ratio that may not provide a sufficient amount of torque to the vehicle at lower speeds.
[0028] In contrast to the complex conventional dual speed geartrains, the dual speed geartrain of the present disclosure uses only a single dog clutch mechanism and avoids the need for a friction plate based geartrain mechanism typically used in the conventional geartrains. Further, the dual speed geartrain of the present disclosure is simple and compact in design, lesser in weight, requires only a minimal amount of packaging space, and is cost-effective, and easy to manufacture. Further, in contrast to the conventional dual speed geartrains, the dual speed geartrain of the present disclosure uses the parallel gearsets in the first gear reduction stage and the planetary gearset in the second gear reduction stage that enable the dual speed geartrain to achieve a higher gear ratio when compared to gear ratios generally achievable using the conventional dual speed geartrains.
[0029] In certain embodiments, the dual speed geartrain described in the present disclosure may be deployed in different types of vehicles. Examples of such vehicles include sport utility vehicles, light, medium, or heavy-duty commercial vehicles, passenger vehicles, pickup trucks, robotic vehicles, trains, boats, and airplanes. In addition to the vehicles, the dual speed geartrain may also be deployed in any other types of systems that need to be operated at two different gear modes. Examples of such systems include industrial systems, and robotic systems used to move packages from one location to another location. Though the dual speed geartrain can be deployed in different types of vehicles and systems, certain embodiments of the dual speed geartrain are described herein in greater detail with reference to an associated deployment in a heavy-duty commercial vehicle.
[0030] FIG. 1 illustrates a block diagram depicting an architecture of a heavy-duty commercial electric vehicle (100) that includes an electric drive unit (102) including an enhanced dual speed geartrain (104). In certain embodiments, the electric drive unit (102) including the dual speed geartrain (104) is depicted to be deployed in a rear axle (106) of the vehicle (100) in FIG. 1. However, it is to be understood that the electric drive unit (102) including the dual speed geartrain (104) may additionally or alternatively be deployed in a front axle (108) of the vehicle (100).
[0031] In certain embodiments, the dual speed geartrain (104) is communicatively coupled to a control unit (110), which in turn, is communicatively coupled to an onboard sensor unit (112) in the vehicle (100). In one embodiment, the onboard sensor unit (112) includes a motor speed sensor (114) that measures speed of a motor (116) in the electric drive unit (102) and provides the measured motor speed as an input to the control unit (110). An example of the control unit (110) includes an electronic control unit in the vehicle (100). The control unit (110) selectively operates the dual speed geartrain (104) in one of a neutral gear mode, a first gear mode, and a second gear mode based on the motor speed received from the motor speed sensor (114).
[0032] In certain embodiments, the control unit (110) operates the dual speed geartrain (104) in the neutral gear mode in which the dual speed geartrain (104) functions as an axle disconnector while the vehicle (100) is operating either in a rear axle drive mode or in a front axle drive mode. Specifically, the control unit (110) operates the dual speed geartrain (104) in the neutral gear mode when the motor (116) is not transferring power to wheels (118A-B) of the vehicle (100).
[0033] Further, the control unit (110) automatically switches an operational mode of the dual speed geartrain (104) from the neutral gear mode to the first gear mode when the motor (116) powers the wheels (118A-B) of the vehicle (100) and the speed of the motor (116) is within a designated speed range, for example, within a range of 1-225 revolutions per minute. In one embodiment, the control unit (110) is communicatively coupled to a linear actuator (120) in the vehicle (100) for switching the operational mode to the first gear mode. Examples of the linear actuator (120) include a brushless direct current (BLDC) actuator with a leadscrew mechanism, a BLDC actuator with a cylindrical cam profile mechanism, a hydraulic piston actuator, a pneumatic piston actuator, a magnetic actuator, and a solenoid actuator.
[0034] When the speed of the motor (116) is within the designated speed range, the control unit (110) provides an instruction to the linear actuator (120) to linearly move a shifting fork (238) and a shifting sleeve (236) (shown in FIG. 2) in the dual speed geartrain (104) in a first direction (604) (shown in FIG. 6). The linear movement of the shifting fork (238) and the shifting sleeve (236) in the first direction (604) causes a first set of teeth (510) (shown in FIG. 5) disposed on an outer face (504) of the shifting sleeve (236) to engage with a custom-designed split planet carrier (222) (shown in FIG. 2), as described in detail subsequently with reference to FIG. 7. The engagement of the first set of teeth (510) of the shifting sleeve (236) with the split planet carrier (222) disposes the dual speed geartrain (104) in the first gear mode. In one embodiment, the dual speed geartrain (104), thus disposed in the first gear mode, transfers a superior amount of torque to the wheels (118A-B) of the vehicle (100), which increases a load-carrying capacity of the vehicle (100) and improves an overall stability of the vehicle (100).
[0035] In certain embodiments, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) from the first gear mode to the second gear mode when the motor (116) powers the wheels (118A-B) of the vehicle (100) and the speed of the motor (116) is greater than an upper limit of the designated speed range. For switching the dual speed geartrain (104) to the second gear mode, the control unit (110) provides another instruction to the linear actuator (120) to linearly move the shifting fork (238) and the shifting sleeve (236) in a second direction (706) (shown in FIG. 7) opposite to the first direction (604). The linear movement of the shifting fork (238) and the shifting sleeve (236) in the second direction (706) causes a second set of teeth (512) (shown in FIG. 5) disposed in a flange section (506) of the shifting sleeve (236) to engage with a set of inner teeth (402) of a sun gear (220) (shown in FIG. 4), as described in detail subsequently with reference to FIG. 8. The engagement of the second set of teeth (512) of the shifting sleeve (236) with the set of inner teeth (402) of the sun gear (220) disposes the dual speed geartrain (104) in the second gear mode. The dual speed geartrain (104), thus disposed in the second gear mode, transfers an increased amount of power to the wheels (118A-B) of the vehicle (100), which enables the vehicle (100) to move at higher speeds and further increases the driving performance of the vehicle (100), as noted previously.
[0036] FIG. 2 illustrates an exploded view depicting a set of components of the dual speed geartrain (104), described herein above with reference to FIG. 1. Additionally, FIG. 3 illustrates a cross-section view of the dual speed geartrain (104) of FIG. 1 in an assembled state. As depicted in FIGS. 2 and 3, the dual speed geartrain (104) includes an input shaft (202), which in turn, includes a first pinion gear (204). In one embodiment, the input shaft (202) is operatively coupled to a motor shaft (206) associated with the motor (116) when various components of the dual speed geartrain (104) are assembled together.
[0037] Further, the dual speed geartrain (104) includes an intermediate shaft (208) including a second pinion gear (210) and a first gear wheel (212). In one embodiment, the first pinion gear (204) coupled to the input shaft (202) is always disposed in a meshed state with respect to the first gear wheel (212) coupled to the intermediate shaft (208) in all three operational modes of the dual speed geartrain (104). Similarly, the second pinion gear (210) coupled to the intermediate shaft (208) is always disposed in a meshed state with respect to a second gear wheel (214) coupled to a sun gear shaft (216) in all three operational modes of the dual speed geartrain (104).
[0038] The first pinion gear (204) and the first gear wheel (212) that are meshed with each other form a first gearset (204, 212). Similarly, the second pinion gear (210) and the second gear wheel (214) that are meshed with each other form a second gearset (210, 214). The first gearset (204, 212) together with the second gearset (210, 214) form a first gear reduction stage. Thus, the first gear reduction stage includes the first gearset (204, 212) that is arranged in parallel with respect to the second gearset (210, 214), as depicted in FIGS. 2 and 3. In certain embodiments, the first pinion gear (204), the first gear wheel (212), the second pinion gear (210), and the second gear wheel (214) are all helical gears used to perform gear reduction and transfer torque and/or power to the wheels (118A-B) of the vehicle (100) according to the operational mode of the dual speed geartrain (104) at a particular instant of time.
[0039] In certain embodiments, a second gear reduction stage of the dual speed geartrain (104) includes a planetary gearset (218) that is coaxially arranged with respect to the first and second gearsets (204, 210, 212, 214) of the first gear reduction stage. In one embodiment, the planetary gearset (218) includes the sun gear (220), the split planet carrier (222), one or more planet gear pins (224), one or more planet gears (226), and a ring gear (228). In one embodiment, the sun gear (220) is operatively coupled to the sun gear shaft (216) that is disposed in a meshed state with respect to a spline (230) disposed in the second gear wheel (214) when various components of the dual speed geartrain (104) are assembled together. Further, the sun gear (220) includes a set of inner teeth (402) (clearly visible in FIG. 4) disposed within an interior surface of the sun gear (220). In one embodiment, the set of inner teeth (402) of the sun gear (220) is used for switching the operational mode of the dual speed geartrain (104) to the second gear mode as described subsequently with reference to FIG. 8.
[0040] In certain embodiments, the sun gear (220) is arranged in a meshed state with respect to the planet gears (226) that are held by the split planet carrier (222). In one embodiment, the split planet carrier (222) of the present disclosure is custom-designed as two different and separate plates. Specifically, the split planet carrier (222) is split into a left planet carrier plate (222A) and a right planet carrier plate (222B), which are assembled together as a single unit using one or more fasteners (232). Examples of the fasteners (232) include one or more bolts, screws, rivets, washers, and studs. The splitting of the split planet carrier (222) into left and right planet carrier plates (222A-B) enables vehicle servicing personnel to easily access the sun gear (220) and the planet gears (226) if these gears need to be replaced or serviced. The splitting of the planet carrier (222) into the left and right planet carrier plates (222A-B) also reduces the complexities involved in manufacturing and assembling of the planetary gearset (218).
[0041] In one embodiment, the left planet carrier plate (222A) includes the planetary gear pins (224) on which one or more needle bearings (234) are mounted. Further, the planetary gears (226) of the planetary gearset (218) are mounted on to the needle bearings (234). Moreover, the planetary gears (226) are disposed in a meshed state with respect to the ring gear (228), which is fixed and non-rotatable in all three operational modes of the dual speed geartrain (104).
[0042] In certain embodiments, the dual speed geartrain (104) further includes a single dog clutch unit including a shifting sleeve (236) and a shifting fork (238), which are custom components added to the dual speed geartrain (104) of the present disclosure. The shifting sleeve (236) and the shifting fork (238) are operatively coupled to each other as a single unit and are actuated by the linear actuator (120) for selectively switching the operational mode of the dual speed geartrain (104) between the neutral gear mode, the first gear mode, and the second gear mode. Specifically, the shifting sleeve (236) of the dual speed geartrain (104) includes an elongated body (502), the outer face (504), and the flange section (506), as depicted in FIG. 5.
[0043] In one embodiment, the elongated body (502) of the shifting sleeve (236) passes through a bore (404) (clearly visible in FIG. 4) disposed in the sun gear (220) when various components of the dual speed geartrain (104) are assembled together. In certain embodiments, the elongated body (502) includes inner splines (508) that are disposed in a meshed state with respect to outer splines (240) (clearly visible in FIG. 2) disposed on a differential case (242) of a differential unit (244) in all three operational modes of the dual speed geartrain (104). The outer face (504) of the shifting sleeve (236) includes a first set of teeth (510) that are adapted to engage with the split planet carrier (222) when the dual speed geartrain (104) operates in the first gear mode. Similarly, the flange section (506) of the shifting sleeve (236) includes a second set of teeth (512) that are adapted to engage with the set of inner teeth (402) of the sun gear (220) when the dual speed geartrain (104) operates in the second gear mode. The dual speed geartrain (104) further includes a first half shaft (246) and a second half shaft (248) that are operatively coupled to the differential unit (244) through which torque and/or power from the motor (116) is transferred to the wheels (118A-B) of the vehicle (100).
[0044] In certain embodiments, the dual speed geartrain (104) operates in the neutral gear mode when the motor (116) is not powering the wheels (118A-B) of the vehicle (100), as noted previously with reference to description of FIG. 1. FIG. 6 illustrates a front view of the dual speed geartrain (104) that is disposed in an assembled state and further that is operating in the neutral gear mode. In the neural gear mode, the shifting sleeve (236) is disposed in a neutral position (602) with respect to the first pinion gear (204) such that the first set of teeth (510) of the shifting sleeve (236) is disposed in a disengaged state with respect to the split planet carrier (222), as depicted in FIG. 6. In addition, the second set of teeth (512) of the shifting sleeve (236) is also disposed in a disengaged state with respect to the set of inner teeth (402) of the sun gear (220). In one embodiment, the shifting sleeve (236) acts an axle disconnector in the neutral gear mode as the shifting sleeve (236) is neither engaged with the split planet carrier (222), nor engaged with the sun gear (220) in the neutral gear mode of the dual speed geartrain (104).
[0045] In certain embodiments, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) from the neutral gear mode to the first gear mode when the motor (116) powers the wheels (118A-B) of the vehicle (100) and further when the speed of the motor (116) is within the designated speed range. Additionally, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) to the first gear mode in certain other scenarios where an increased amount of torque needs to be transferred to the wheels (118A-B) of the vehicle (100). Examples of such scenarios include when an amount of load in the vehicle (100) is greater than a designated load threshold, towing of another vehicle by the vehicle (100), and navigation of the vehicle via challenging terrains such as uphill terrains and/or off-road terrains.
[0046] Specifically, the control unit (110) provides a first instruction to a motor (606) operatively coupled to the linear actuator (120) when the dual speed geartrain (104) needs to be switched to the first gear mode from the neutral gear mode. An example of the motor (606) includes a brushless direct current motor. Upon receiving the first instruction, the linear actuator (120) that is operatively coupled to the shifting fork (238) moves the shifting fork (238) linearly by a first distance in a first direction (604) (depicted in FIG. 6) away from the first pinion gear (204). Examples of the linear actuator (120) that can be used for linearly moving the shifting fork (238) include a BLDC actuator with a leadscrew, a BLDC actuator with a cylindrical cam profile, a hydraulic piston actuator, a pneumatic piston actuator, a magnetic actuator, and a solenoid actuator.
[0047] The linear movement of the shifting fork (238) by the first distance in the first direction (604) causes the shifting sleeve (236) to move linearly from the neutral position (602) in the same first direction (604) by the same first distance away from the first pinion gear (204) to a pushed position (702) (depicted in FIG. 7). This linear movement of the shifting sleeve (236) away from the first pinion gear (204) from the neutral position (602) to the pushed position (702) causes the first set of teeth (510) disposed at the outer face (504) of the shifting sleeve (236) to engage with the split planet carrier (222). The engagement of the first set of teeth (510) of the shifting sleeve (236) with the split planet carrier (222) disposes the dual speed geartrain (104) in the first gear mode.
[0048] The dual speed geartrain (104), thus disposed in the first gear mode, receives a torque output from the motor (116), which causes the input shaft (202) coupled to the motor shaft (206) to rotate. The rotation of the input shaft (202) rotates the first pinion gear (204). The rotation of the first pinion gear (204), in turn, rotates the first gear wheel (212). The rotation of the first gear wheel (212) achieved by the rotation of the first pinion gear (204) reduces the speed of the motor (116) to a first reduced motor speed and further increases the torque output of the motor (116) to a first increased torque output. Further, the rotational motion of the first gear wheel (212) rotates the intermediate shaft (208). The rotation of the intermediate shaft (208) causes the second pinion gear (210) to rotate. The rotation of the second pinion gear (210), in turn, rotates the second gear wheel (214). The rotation of the second gear wheel (214) achieved by the rotation of the second pinion gear (210) reduces the first reduced motor speed to a second reduced motor speed and further increases the first increased torque output to a second increased torque output. In one embodiment, the second reduced motor speed is smaller than the first reduced motor speed. Further, the first increased torque output is smaller than the second increased torque output.
[0049] The second gear wheel (214) then transfers the second reduced motor speed to the planetary gearset (218). Subsequently, the planetary gearset (218) further reduces the second reduced motor speed to a third reduced motor speed and further increases the second increased torque output to a third increased torque output in the first gear mode. Further, the planetary gearset (218) outputs the third reduced motor speed and the third increased torque output via the split planet carrier (222) in the first gear mode. Specifically, the engagement of the first set of teeth (510) and the inner splines (508) of the shifting sleeve (236) with the split planet carrier (222) and the differential case (242), respectively causes the third reduced motor speed and the third increased torque output to be transferred to bevel gears (704) and to the wheels (118A-B) of the vehicle (100) in the first gear mode. In certain embodiments, the second reduced motor speed is smaller than the third reduced motor speed. Further, the second increased torque output is smaller than the third increased torque output.
[0050] In certain embodiments, the dual speed geartrain (104) provides a first gear ratio, for example of 23.25, between the first and second half shafts (246 and 248) of the differential unit (244) while operating in the first gear mode. Selecting a specific number of teeth in the first gearset (204, 212) including the first pinion gear (204) and the first gear wheel (212), the second gearset (210, 214) including the second pinion gear (210) and the second gear wheel (214), and the planetary gearset (218) enables the dual speed geartrain (104) to achieve the first gear ratio, for example of 23.25 in the first gear mode. In one embodiment, the first gear ratio provided by the dual speed geartrain (104) is substantially higher because of the use of custom-designed components of the dual speed geartrain (104) than gear ratios provided by conventional dual speed geartrains that use multiple clutch packs and/or friction based geartrain mechanisms. The dual speed geartrain (104) of the present disclosure is compact in size and yet achieves comparatively a higher gear ratio, which enables the dual speed geartrain (104) to transfer a superior amount of torque to the wheels (118A-B) even at very low speeds of the vehicle (100) and to provide an enhanced stability to the vehicle (100).
[0051] In certain embodiments, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) back to the neutral gear mode from the first gear mode when the motor (116) is not powering the wheels (118A-B) of the vehicle (100). To that end, the control unit (110) provides a second instruction to the motor (606) in the linear actuator (120) when the operational mode of the dual speed geartrain (104) needs to be switched back to the neutral gear mode from the first gear mode. Upon receiving the second instruction, the linear actuator (120) linearly moves back the shifting fork (238) towards the first pinion gear (204) by the first distance in a second direction (706) opposite to the first direction (604). The linear movement of the shifting fork (238) by the first distance in the second direction (706) causes the shifting sleeve (236) to move linearly towards the first pinion gear (204) from the pushed position (702) in the same second direction (706) by the same first distance to the neutral position (602). The linear movement of the shifting sleeve (236) towards the first pinion gear (204) from the pushed position (702) to the neutral position (602) disengages the first set of teeth (510) of the shifting sleeve (236) from the split planet carrier (222). The disengagement of the first set of teeth (510) of the shifting sleeve (236) from the split planet carrier (222) disposes the dual speed geartrain (104) in the neutral gear mode.
[0052] In certain other embodiments, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) to the second gear mode from the first gear mode when the motor (116) powers the wheels (118A-B) of the vehicle (100) and further when the speed of the motor (116) is greater than an upper limit of the designated speed range. In particular, the control unit (110) provides a third instruction to the motor (606) in the linear actuator (120) for switching the operational mode to the second gear mode from the first gear mode. Based on the third instruction, the linear actuator (120) linearly moves the shifting fork (238) by a second distance that is greater than the first distance in the second direction (706) towards the first pinion gear (204).
[0053] The linear movement of the shifting fork (238) by the second distance in the second direction (706) causes the shifting sleeve (236) to move linearly towards the first pinion gear (204) from the pushed position (702) in the same second direction (706) by the same second distance to a pulled position (802) (depicted in FIG. 8). In one embodiment, the first distance and the second distance by which the shifting sleeve (236) moves linearly during switching between various gear modes of the dual speed geartrain (104) are selected based on one or more of design and/or sizes of the first and second sets of teeth (510 and 512) of the shifting sleeve (236). Further, the first distance and the second distance by which the shifting sleeve (236) moves linearly during switching between various gear modes of the dual speed geartrain (104) may also vary based on a vehicle type and model in which the dual speed geartrain (104) is to be integrated. In certain embodiments, the linear movement of the shifting sleeve (236) towards the first pinion gear (204) from the pushed position (702) to the pulled position (802) causes the first set of teeth (510) of the shifting sleeve (236) to disengage from the split planet carrier (222), and further the second set of teeth (512) of the shifting sleeve (236) to engage with the set of inner teeth (402) of the sun gear (220), as depicted in FIG. 8. The engagement of the second set of teeth (512) of the shifting sleeve (236) with the set of inner teeth (402) of the sun gear (220) disposes the dual speed geartrain (104) in the second gear mode.
[0054] The dual speed geartrain (104), thus disposed in the second gear mode, receives the torque output from the motor (116), which causes the input shaft (202) coupled to the motor shaft (206) to rotate, as noted previously with reference to FIG. 7. The rotation of the input shaft (202) rotates the first pinion gear (204). The rotation of the first pinion gear (204), in turn, rotates the first gear wheel (212). The rotation of the first gear wheel (212) achieved by the rotation of the first pinion gear (204) reduces the speed of the motor (116) to the first reduced motor speed and further increases the torque output of the motor (116) to the first increased torque output. Further, the rotational motion of the first gear wheel (212) rotates the intermediate shaft (208). The rotation of the intermediate shaft (208) causes the second pinion gear (210) to rotate. The rotation of the second pinion gear (210), in turn, rotates the second gear wheel (214). The rotation of the second gear wheel (214) achieved by the rotation of the second pinion gear (210) reduces the first reduced motor speed to the second reduced motor speed and further increases the first increased torque output to a second increased torque output.
[0055] The rotation of the second gear wheel (214) then transfers the second reduced motor speed and the second increased torque output to the sun gear (220) in the planetary gearset (218). Subsequently, the sun gear (220) causes transfer of the second reduced motor speed and the second increased torque output to the bevel gears (704) and to the wheels (118A-B) of the vehicle (100) in the second gear mode via the engagement of the second set of teeth (512) and the inner splines (508) of the shifting sleeve (236) with the sun gear (220) and the differential case (242), respectively. In certain embodiments, the dual speed geartrain (104) provides a second gear ratio that is different from the first gear ratio between the first and second half shafts (246 and 248) of the differential unit (244) while operating in the second gear mode. In one embodiment, the second gear ratio provided by the dual speed geartrain (104) in the second gear mode is smaller than the first gear ratio provided by the dual speed geartrain (104) in the first gear mode. An example of the second gear ratio provided by the dual speed geartrain (104) in the second gear mode corresponds to 8.75.
[0056] Selecting a specific number of teeth in the first gearset (204, 212) including the first pinion gear (204) and the first gear wheel (212), and the second gearset (210, 214) including the second pinion gear (210) and the second gear wheel (214) enables the dual speed geartrain (104) to achieve the second gear ratio, for example of 8.75, in the second gear mode. With the comparatively smaller gear ratio achieved in the second gear mode, the dual speed geartrain (104) comparatively transfers an increased amount of motor speed to the wheels (118A-B) of the vehicle (100) that enables the vehicle (100) to move at higher speeds and further increases the driving performance of the vehicle (100) in the second gear mode.
[0057] In one embodiment, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) back to the first gear mode from the second gear mode when the motor (116) powers the wheels (118A-B) of the vehicle (100) and further the speed of the motor (116) is within the designated speed range. To that end, the control unit (110) provides a fourth instruction to the motor (606) in the linear actuator (120) when the operational mode of the dual speed geartrain (104) needs to be switched from the second gear mode to the first gear mode. Based on the fourth instruction, the linear actuator (120) linearly moves the shifting fork (238) by the second distance in the first direction (604) away from the first pinion gear (204). The linear movement of the shifting fork (238) by the second distance in the first direction (604) causes the shifting sleeve (236) to move linearly away from the first pinion gear (204) from the pulled position (802) in the same first direction by the same second distance to the pushed position (702). This linear movement of the shifting sleeve (236) away from the first pinion gear (204) from the pulled position (802) to the pushed position (702) causes the second set of teeth (512) of the shifting sleeve (236) to disengage from the set of inner teeth (402) of the sun gear (220), and further the first set of teeth (510) of the shifting sleeve (236) to engage with the split planet carrier (222), as depicted in FIG. 7. The engagement of the first set of teeth (510) of the shifting sleeve (236) with the split planet carrier (222) disposes the dual speed geartrain (104) back in the first gear mode.
[0058] In certain embodiments, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) back to the neutral gear mode from the second gear mode when there is no transfer of power from the motor (116to the wheels (118A-B) of the vehicle (100). To that end, the control unit (110) provides a fifth instruction to the motor (606) in the linear actuator (120) when the operational mode of the dual speed geartrain (104) needs to be switched from the second gear mode to the neutral gear mode. Based on the fifth instruction, the linear actuator (120) linearly moves the shifting fork (238) and the shifting sleeve (236) disposed in the pulled position (802) away from the first pinion gear (204) in the first direction (604) by the first distance, which causes the shifting sleeve (236) to move linearly from the pulled position (802) to the neutral position (602). The linear movement of the shifting sleeve (236) away from the first pinion gear (204) from the pulled position (802) to the neutral position (602) causes the second set of teeth (512) of the shifting sleeve (236) to disengage from the set of inner teeth (402) of the sun gear (220). In addition, the linear movement of the shifting sleeve (236) from the pulled position (802) to the neutral position (602) causes the first set of teeth (510) of the shifting sleeve (236) to remain in the disengaged state with respect to the split planet carrier (222), which disposes the dual speed geartrain (104) back in the neutral gear mode.
[0059] In one embodiment, the control unit (110) automatically switches the operational mode of the dual speed geartrain (104) directly from the neutral gear mode to the second gear mode when the motor (116) transmits power to the wheels (118A-B) of the vehicle (100) and the speed of the motor (116) is greater than the upper limit of the designated speed range. In one embodiment, the control unit (110) provides a sixth instruction to the motor (606) in the linear actuator (120) when the operational mode of the dual speed geartrain (104) needs to be directly switched to the second gear mode from the neutral gear mode. Based on the sixth instruction, the linear actuator (120) linearly moves the shifting fork (238) and the shifting sleeve (236) disposed in the neutral position (602) towards the first pinion gear (204) in the second direction (706) by the first distance, which causes the shifting sleeve (236) to move linearly from the neutral position (602) to the pulled position (802). The linear movement of the shifting sleeve (236) towards the first pinion gear (204) from the neutral position (602) to the pulled position (802) causes the second set of teeth (512) of the shifting sleeve (236) to engage with the set of inner teeth (402) of the sun gear (220), which disposes the dual speed geartrain in the second gear mode.
[0060] Thus, the control unit (110) switches the operational mode of the dual speed geartrain (104) to the neutral, first, and/or second gear modes by simply changing positions of the shifting sleeve (236) into neutral, pushed, and/or pulled positions (602, 702, 802), respectively. In certain embodiments, the dual speed geartrain (104) of the present disclosure can be easily retrofitted to existing vehicles with minimal modifications. For example, the dual speed geartrain (104) may be retrofitted by replacing existing electric drive units, electric beams, or axle systems in the vehicles with an embodiment of the present electric drive unit (102) including the dual speed geartrain (104) and the motor (116). Further, with minimal modifications made in vehicle assembly and manufacturing lines such as modifications made to vehicle chassis and axle components, the present dual speed geartrain (104) may be easily integrated in any upcoming vehicle variants.
[0061] In contrast to the conventional dual speed geartrains that have large and complex gearset arrangements, the dual speed geartrain (104) of the present disclosure includes the first and second gearsets (204, 212, 210, 214) that are parallel to each other at the first gear reduction stage. Further, the dual speed geartrain (104) includes the planetary gearset (218) at the second gear reduction stage such that the planetary gearset (218) is coaxially coupled to the first and second gearsets (204, 212, 210, 214). The dual speed geartrain (104) including such a gear architecture is compact in size, yet achieves comparatively higher gear ratios in both associated first and second gear modes. With the higher gear ratios achieved by the dual speed geartrain (104), the dual speed geartrain (104) transfers a superior amount of torque to the wheels (118A-B) even at very low speeds of the vehicle (100) and provides an enhanced stability to the vehicle (100). Further, with the higher gear ratios achieved by the dual speed geartrain (104), the dual speed geartrain (104) effectively manages the torque and speed requirements of the vehicle (100), provides optimistic vehicle performance, allows the motor (116) to operate with a maximum efficient operating range that ensures efficient utilization of battery energy, and thereby improves the range of the vehicle (100).
[0062] In addition, the present dual speed geartrain (104) includes a simple design using only a single dog clutch mechanism and avoids the usage of a friction plate based geartrain mechanism typically used in the conventional dual speed geartrains. Further, the preset dual speed geartrain (104) is compact, lesser in weight, requires only a minimal amount of packaging space, and is cost-effective and easy to manufacture, which makes the present dual speed geartrain (104) more suitable for both retrofitting to existing vehicles and integrating to new vehicle variants.
[0063] Although specific features of various embodiments of the present systems and methods may be shown in and/or described with respect to some drawings and not in others, this is for convenience only. It is to be understood that the described features, structures, and/or characteristics may be combined and/or used interchangeably in any suitable manner in the various embodiments shown in the different figures.
[0064] While only certain features of the present systems and methods have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes.

LIST OF NUMERAL REFERENCES:

100 Vehicle
102 Electric drive unit
104 Rear axle
108 Front axle
110 Control unit
112 Onboard sensor unit
114 Motor speed sensor
116 Motor
118A-D Vehicle wheels
120 Linear actuator
202 Input shaft
204 First pinion gear
206 Motor shaft
208 Intermediate shaft
210 Second pinion gear
212 First gear wheel
214 Second gear wheel
216 Sun gear shaft
218 Planetary gearset
220 Sun gear
222 Split planet carrier
222A Left planet carrier plate
222B Right planet carrier plate
224 Planetary gear pins
226 Planet gears
228 Ring gear
230 Second gear wheel bore
232 Fasteners
234 Needle bearings
236 Shifting sleeve
238 Shifting fork
240 Differential case outer splines
242 Differential case
244 Differential unit
246 First half shaft
248 Second half shaft
402 Set of inner teeth of sun gear
404 Sun gear bore
502 Elongated body
504 Outer face
506 Flange section
508 Inner splines of shifting sleeve
510 First set of teeth
512 Second set of teeth
602 Shifting sleeve in neutral position
604 First direction
606 Motor in linear actuator
702 Shifting sleeve in pushed position
704 Bevel gears
706 Second direction
802 Shifting sleeve in pulled position , Claims:We claim:

1. A dual speed geartrain (104) of a vehicle (100), comprising:
a planetary gearset (218) comprising a sun gear (220) and a split planet carrier (222), wherein the sun gear (220) comprises a set of inner teeth (402); and
a shifting sleeve (236) disposed within a bore (404) in the sun gear (220) and comprising a first set of teeth (510) and a second set of teeth (512);
wherein both the first set of teeth (510) and the second set of teeth (512) of the shifting sleeve (236) are adapted to be disposed in a disengaged state with respect to the split planet carrier (222) and the set of inner teeth (402) of the sun gear (220), respectively, when the dual speed geartrain (104) operates in a neutral gear mode;
wherein the first set of teeth (510) of the shifting sleeve (236) is adapted to be disposed in an engaged state with respect to the split planet carrier (222) and the second set of teeth (512) of the shifting sleeve (236) is adapted to be disposed in the disengaged state with respect to the set of inner teeth (402) of the sun gear (220) when the dual speed geartrain (104) operates in a first gear mode; and
wherein the first set of teeth (510) of the shifting sleeve (236) is adapted to be disposed in the disengaged state with respect to the split planet carrier (222) and the second set of teeth (512) of the shifting sleeve (236) is adapted to be disposed in the engaged state with respect to the set of inner teeth (402) of the sun gear (220) when the dual speed geartrain (104) operates in a second gear mode.

2. The dual speed geartrain (104) as claimed in claim 1, wherein the shifting sleeve (236) comprises an elongated body (502) that passes through the bore (404) in the sun gear (220), an outer face (504) comprising the first set of teeth (510), a flange section (506) comprising the second set of teeth (512), and inner splines (508) adapted to be disposed in a meshed state with respect to outer splines (240) provided on a differential case (242) associated with a differential unit (244) of the vehicle (100) when the dual speed geartrain (104) is operating in one of the neutral gear mode, the first gear mode, and the second gear mode.

3. The dual speed geartrain (104) as claimed in claim 2, wherein the dual speed geartrain (104) comprises:
an input shaft (202) that is operatively coupled to a motor shaft (206) of a motor (116) in the vehicle (100), wherein the input shaft (202) comprises a first pinion gear (204);
an intermediate shaft (208) comprising a second pinion gear (210) and a first gear wheel (212), wherein the first gear wheel (212) in the intermediate shaft (208) is disposed in a meshed state with respect to the first pinion gear (204) in the input shaft (202); and
a sun gear shaft (216) comprising a second gear wheel (214) that is disposed in a meshed state with respect to the second pinion gear (210) in the intermediate shaft (208).

4. The dual speed geartrain (104) as claimed in claim 3, wherein the first pinion gear (204) and the first gear wheel (212) together form a first gearset (204, 212), wherein the second pinion gear (210) and the second gear wheel (214) together form a second gearset (210, 214), wherein a first gear reduction stage of the dual speed geartrain (104) comprises the first gearset (204, 212) and the second gearset (210, 214) disposed in parallel to each other, wherein a second gear reduction stage of the dual speed geartrain (104) comprises the planetary gearset (218) disposed co-axially to the first gearset (204, 212) and the second gearset (210, 214), and wherein the dual speed geartrain (104) comprising the first and second gearsets (204, 212, 210, 214) disposed co-axially to the planetary gearset (218) provides space savings during installation of the dual speed geartrain (104) within an electric drive unit (102) of the vehicle (100).

5. The dual speed geartrain (104) as claimed in claim 4, wherein the first gearset (204, 212) is adapted to reduce a speed provided as an output by the motor (116) to a first reduced motor speed and to increase a torque output of the motor (116) to a first increased torque output, wherein the second gearset (210, 214) is adapted to reduce the first reduced motor speed from the first gearset (204, 212) to a second reduced motor speed and to increase the first increased torque output from the first gearset (204, 212) to a second increased torque output, wherein the planetary gearset (218) is adapted to reduce the second reduced motor speed from the second gearset (210, 214) to a third reduced motor speed and to increase the second increased torque output from the second gearset (210, 214) to a third increased torque output, wherein the dual speed geartrain (104) in the first gear mode is adapted to transfer the third reduced motor speed and the third increased torque output to one or more wheels (118A-B) of the vehicle (100) via the split planet carrier (222) and the shifting sleeve (236), and wherein the dual speed geartrain (104) in the second gear mode is adapted to transfer the second reduced motor speed and the second increased torque output from the sun gear (220) to the one or more wheels (118A-B) of the vehicle (100) via the shifting sleeve (236).

6. The dual speed geartrain (104) as claimed in claim 5, wherein the dual speed geartrain (104) is adapted to provide a first gear ratio between a first half shaft (246) and a second half shaft (248) coupled to the differential unit (244) in the vehicle (100) when operating in the first gear mode, wherein the dual speed geartrain (104) is adapted to provide a second gear ratio between the first half shaft (246) and the second half shaft (248) when operating in the second gear mode, and wherein the first gear ratio is greater than the second gear ratio.

7. The dual speed geartrain (104) as claimed in claim 6, wherein the split planet carrier (222) comprises a left planet carrier plate (222A) and a right planet carrier plate (22B) that are coupled together using one or more fasteners (232), wherein the left planet carrier plate (222A) is coupled to one or more planetary gears (226) that are disposed in a meshed state with respect to the sun gear (220) and a ring gear (228) of the planetary gearset (218).

8. The dual speed geartrain (104) as claimed in claim 7, wherein the shifting sleeve (236) is operatively coupled to a shifting fork (238), wherein the shifting fork (238) is operatively coupled to a linear actuator (120) that is communicatively coupled to a control unit (110) in the vehicle (100), wherein the linear actuator (120) comprises one of a brushless direct current actuator comprising one or more of a leadscrew, a brushless direct current actuator comprising a cylindrical cam profile, a hydraulic piston actuator, a pneumatic piston actuator, a magnetic actuator, and a solenoid actuator, and wherein the control unit (110) corresponds to an electronic control unit in the vehicle (100).

9. The dual speed geartrain (104) as claimed in claim 8, wherein the control unit (110) is communicatively coupled to an onboard sensor (112) in the vehicle (100), wherein the onboard sensor unit (112) comprises a motor speed sensor (114) that measures the speed of the motor (116) powering the one or more wheels (118A-B) of the vehicle (100), and wherein the control unit (110) operates the dual speed geartrain (104) in the neutral gear mode when there is no transfer of power from the motor (116) to the one or more wheels (118A-B) of the vehicle (100).

10. The dual speed geartrain (104) as claimed in claim 9, wherein the control unit (110) is adapted to actuate the linear actuator (120) to switch an operational mode of the dual speed geartrain (104) from the neutral gear mode to the first gear mode when the speed of the motor (116) measured by the motor speed sensor (114) corresponds to a value that falls within a designated speed range, wherein the linear actuator (120) linearly moves the shifting fork (238) by a first distance in a first direction (604) upon actuation by the control unit (110), thereby linearly moving the shifting sleeve (236) from a neutral position (602) to a pushed position (702), which disposes the first set of teeth (510) of the shifting sleeve (236) in an engaged state with respect to the split planet carrier (222), and thereby switches the operational mode of the dual speed geartrain (104) to the first gear mode.

11. The dual speed geartrain (104) as claimed in claim 10, wherein the control unit (110) is adapted to actuate the linear actuator (120) to switch the operational mode of the dual speed geartrain (104) from the first gear mode to the neutral gear mode when there is no transfer of power from the motor (116) to the one or more wheels (118A-B) of the vehicle (100), wherein the linear actuator (120) linearly moves the shifting fork (238) by the first distance in a second direction (706) opposite to the first direction (604) upon actuation by the control unit (110), thereby linearly moving the shifting sleeve (236) from the pushed position (702) to the neutral position (602), which disengages the first set of teeth (510) of the shifting sleeve (236) from the split planet carrier (222) and disposes the dual speed geartrain (104) in the neutral gear mode.

12. The dual speed geartrain (104) as claimed in claim 10, wherein the control unit (110) is adapted to actuate the linear actuator (120) to switch the operational mode of the dual speed geartrain (104) from the first gear mode to the second gear mode when the speed of the motor (116) measured by the motor speed sensor (114) exceeds an upper limit of the designated speed range, wherein the linear actuator (120) linearly moves the shifting fork (238) by a second distance greater than the first distance in a second direction (706) opposite to the first direction (604) upon actuation by the control unit (110), thereby linearly moving the shifting sleeve (236) from the pushed position (702) to a pulled position (802), which disengages the first set of teeth (510) of the shifting sleeve (236) from the split planet carrier (222) and further engages the second set of teeth (512) of the shifting sleeve (236) with the set of inner teeth (402) disposed within an inner surface of the sun gear (220), thereby disposing the dual speed geartrain (104) in the second gear mode.

13. The dual speed geartrain (104) as claimed in claim 12, wherein the control unit (110) is adapted to:
actuate the linear actuator (120) to switch the operational mode of the dual speed geartrain (104) from the second gear mode to the first gear mode when the speed of the motor (116) measured by the motor speed sensor (114) corresponds to a value that falls within the designated speed range, wherein the linear actuator (120) linearly moves the shifting fork (238) by the second distance in the first direction (604) upon actuation by the control unit (110), which linearly moves the shifting sleeve (236) disposed in the pulled position (802) to the pushed position (702), thereby disengaging the second set of teeth (512) of the shifting sleeve (236) from the set of inner teeth (402) of the sun gear (220) and further engaging the first set of teeth (510) of the shifting sleeve (236) with the split planet carrier (222), which disposes the dual speed geartrain (104) in the first gear mode; and
actuate the linear actuator (120) to switch the operational mode of the dual speed geartrain (104) to the neutral gear mode from the second gear mode when there is no transfer of power from the motor (116) to the one or more wheels (118A-B) of the vehicle (100), wherein the linear actuator (120) linearly moves the shifting fork (238) by the first distance in the first direction (604) upon actuation by the control unit (110), which linearly moves the shifting sleeve (236) disposed in the pulled position (802) to the neutral position (602), thereby disengaging the second set of teeth (512) of the shifting sleeve (236) from the set of inner teeth (402) of the sun gear (220), which disposes the dual speed geartrain (104) in the neutral gear mode.

14. The dual speed geartrain (104) as claimed in claim 1, wherein the dual speed geartrain (104) is integrated into an electric drive unit (102) of the vehicle (100), wherein the vehicle (100) corresponds to one of a sport utility vehicle, a light-duty commercial vehicle, a medium-duty commercial vehicle, a heavy-duty commercial vehicle, a passenger vehicle, a pickup truck, a robotic vehicle, a train, a boat, an airplane, an industrial system, and a robotic system.

15. The dual speed geartrain (104) as claimed in claim 1, wherein the dual speed geartrain (104) is retrofit to an electric drive unit (102) of the vehicle (100), wherein the vehicle (100) corresponds to one of a sport utility vehicle, a light-duty commercial vehicle, a medium-duty commercial vehicle, a heavy-duty commercial vehicle, a passenger vehicle, a pickup truck, a robotic vehicle, a train, a boat, an airplane, an industrial system, and a robotic system.