DESC:TECHNICAL FIELD
[001] The embodiments herein generally relate to powertrain in vehicles and more particularly, to a powertrain for a hybrid vehicle (hybrid electric vehicle and/or plug-in hybrid electric vehicle), which comprises an electric machine (electric motor or electric motor-generator) adapted to drive at least one of an output shaft of a power transmission unit and an input shaft of a differential unit on engagement of a gear shift lever adapted to be shifted to an electric drive gear position (E-gear position), where an engine is in non-operative condition when the gear shift lever is in electric drive gear position.

BACKGROUND
[002] Generally, a powertrain of a vehicle refers to a group of components used for generating and delivering power for driving the vehicle. A hybrid electric vehicle includes an internal combustion engine and an electric motor for propelling the vehicle. The powertrain of the hybrid electric vehicle comprises an engine, an electric machine (electric motor or electric motor-generator), a clutch unit, a power transmission unit (gear box assembly), a differential unit and a drive shaft which drive the wheels of the vehicle. Conventional hybrid electric powertrain includes an electric machine connected to a flywheel of the clutch unit. Some conventional hybrid electric powertrain includes an electric machine connected to the input side of power transmission unit. Other conventional hybrid electric powertrain includes an electric machine connected to the drive axle or even at the drive wheels. The arrangement and packaging of powertrain components, in particular for enabling electric drive functionality in the aforementioned hybrid electric power trains are complex and is one of the challenges posed to original equipment manufacturers (OEM’s). Further, for a manual transmission hybrid vehicle, it poses challenges of automating overall torque disconnection component which separate engine (the primary source of propulsion), from the driven wheels of the vehicle.
[003] Therefore, there exists a need for a powertrain arrangement for a hybrid vehicle, which comprises an electric machine (electric motor or electric motor-generator) adapted to drive at least one of an output shaft of a power transmission unit and an input shaft of a differential unit on engagement of a gear shift lever adapted to be shifted to an electric drive gear position (E-gear position), where an engine is in non-operative condition when the gear shift lever is in electric drive gear position. Further, there exists a need for a powertrain for a hybrid vehicle, which obviates the aforementioned drawbacks.

OBJECTS
[004] The principal object of an embodiment of this invention is to provide a powertrain for a hybrid vehicle (hybrid electric vehicle and/or plug-in hybrid electric vehicle), which comprises an electric machine (electric motor or electric motor-generator) adapted to drive at least one of an output shaft of a power transmission unit and an input shaft of a differential unit on engagement of a gear shift lever adapted to be shifted to an electric drive gear position (E-gear position), where an engine is in non-operative condition when the gear shift lever is in electric drive gear position.
[005] Another object of an embodiment of this invention is to provide a powertrain for a hybrid vehicle, which comprises an engine and an electric machine adapted to drive at least one of an output shaft of a power transmission unit and an input shaft of a differential unit during hybrid drive mode.
[006] 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
[007] The embodiments of the 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:
[008] FIG. 1 depicts a schematic view of a powertrain for a hybrid vehicle, according to a first embodiment of the invention as disclosed herein;
[009] FIG.2 depicts a schematic cross sectional view of a portion of the power train, according to the first embodiment of the invention as disclosed herein;
[0010] FIG. 3 depicts a schematic view of a powertrain for a hybrid vehicle, according to a second embodiment of the invention as disclosed herein; and
[0011] FIG. 4 depicts a schematic view of a gear shift lever position layout of a power transmission unit of the powertrain, according to the first and second embodiment of the invention as disclosed herein.

DETAILED DESCRIPTION
[0012] 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.
[0013] The embodiments herein achieve a powertrain for a hybrid vehicle (hybrid electric vehicle and/or plug-in hybrid electric vehicle), which comprises an electric machine (electric motor or electric motor-generator) adapted to drive at least one of an output shaft of a power transmission unit and an input shaft of a differential unit on engagement of a gear shift lever adapted to be shifted to an electric drive gear position (E-gear position), where an engine is in non-operative condition when the gear shift lever is in electric drive gear position. Referring now to the drawings, and more particularly to FIGS. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0014] FIG. 1 depicts a schematic view of a powertrain 100 for a hybrid vehicle, according to a first embodiment of the invention as disclosed herein. In the first embodiment, the powertrain 100 includes an engine 102, a clutch unit 104, a power transmission unit 106, an electric machine 108, a differential unit 110, a power electronics module 112 and a main battery 114, a gear shift lever position sensor (not shown), a clutch position sensor (not shown) and may include other standard components/system as present in standard powertrain.
[0015] The engine 102 serves as primary power source for propelling the vehicle. The engine 102 includes a crankshaft (not shown) and may include other standard components as present in standard engine. The crankshaft (not shown) of the engine 102 is adapted to transfer the torque generated/produced by the engine 102 to rest of the powertrain components.
[0016] The clutch unit 104 is used for engaging and disengaging the engine 102 with the power transmission unit 106. The clutch unit 104 is rotatably connected to the crankshaft (not shown) of the engine 102. The clutch unit 104 is also rotatably connected to an input shaft (not shown) of the power transmission unit 106.
[0017] The power transmission unit 106 is used for transmitting the torque from the engine 102 and/or the electric machine 108 to the wheels of the vehicle for propelling the vehicle, and for increasing and decreasing the speed of the vehicle. The power transmission unit 106 includes an input shaft (not shown), a counter shaft (not shown), an output shaft (not shown), a plurality of gears G (as shown in fig. 2), a plurality of synchronizer units S (as shown in fig. 2), a gear shift lever (not shown) and may include other standard components as present in standard power transmission unit (gear box assembly). The input shaft (not shown) of the power transmission unit 106 is rotatably connected to the clutch unit 104. The counter shaft (not shown) is rotatably connected to the input shaft (not shown) of the power transmission unit 106. The output shaft (not shown) is rotatably connected to the counter shaft of the power transmission unit 106. The output shaft (not shown) of the power transmission unit 106 is rotatably connected to the electric machine 108. The output shaft (not shown) of the power transmission unit 106 is rotatably connected to an input shaft (not shown) of the differential unit 110. The plurality of gears G is used to transmit the torque from the engine 102 and/or the electric machine 108 to the output shaft (not shown) of the power transmission unit 106. Each synchronizer unit S is used to facilitate smooth engagement or dis-engagement of corresponding gear G based on the movement of the gear shift lever (not shown) adapted to be shifted to corresponding gear position. Each synchronizer unit S includes at least one synchronizer sleeve (not shown), a synchronizer ring (not shown), a hub and may include other standard components as present in standard synchronizer unit. In the first embodiment, one synchronizer unit S (as shown in fig. 2) is used to engage the gear G driven by the electric machine 108 on engagement of the gear shift lever (not shown) adapted to be shifted to the electric drive gear position (E-gear position) thereby propelling the vehicle, where the gear G is mounted on the output shaft (not shown) of the power transmission unit 106. The gear shift lever (not shown) is selectively moveable between various gear positions that are required for various driving conditions of the vehicle. In the first embodiment, When, the gear shift lever (not shown) is engaged by the driver (user operating the vehicle) to be shifted to electric drive gear position (as shown in fig. 4, where ‘E’ represents E-gear position), the output shaft (not shown) of the power transmission unit 106 is driven by the electric machine 108 through the plurality of gears G, where the engine 102 is in non-operative condition (switch off condition) when the gear shift lever (not shown) is in electric drive gear position (E-gear position). The aforementioned operating condition is referred to as pure electric drive mode (E-drive mode). The power transmission unit 106 is at least a manual power transmission unit. It is also within the scope of the invention to provide the powertrain 100 with any other type of power transmission unit.
[0018] The electric machine 108 serves as secondary power source for propelling the vehicle. The electric machine 108 is used to drive the output shaft (not shown) of the power transmission unit 106 during at least one of an electric drive mode (E-drive mode) and a hybrid drive mode. In the first embodiment, the electric machine 108 is rotatably connected to the output shaft (not shown) of the power transmission unit 106 through the plurality of gears G (as shown in fig. 2), where one gear G is mounted to a shaft (not shown) of the electric machine 108, another gear G is mounted to the counter shaft (not shown) of the power transmission unit 106 and rotatably connected to the gear G mounted to the shaft (not shown) of the electric machine 108, and another gear G is mounted to the output shaft (not shown) of the power transmission unit 106 and rotatably connected to the gear G mounted to the counter shaft (not shown) of power transmission unit 106. In the first embodiment, the electric machine 108 is adapted to drive the output shaft (not shown) of the power transmission unit 106 on engagement of the gear shift lever (not shown) adapted to be shifted to the electric drive gear position (E-gear position), where the engine 102 is in non-operative condition (switch off condition) when the gear shift lever (not shown) is in electric drive gear position (E-gear position). The aforementioned operating condition is referred to as pure electric drive mode (E-drive mode). The electric machine 108 is connected to the main battery 114 through the power electronics module 112. In one embodiment, the electric machine 108 serves/acts as generator thereby recharging the main battery 114 during braking condition of the vehicle i.e., the shaft (not shown) of the electric machine 108 is driven by the differential unit 110 through the output shaft (not shown) of the power transmission unit 106, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112. In case if the state of charge of main battery 114 is low, then the main battery 114 can also be recharged by the engine 102 through the power transmission unit 106 during operation of the engine 102 i.e., the engine 102 drives the shaft (not shown) of the electric machine 108 through the countershaft (not shown) of the power transmission unit 106, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112 during the operation of the engine 102. In an embodiment, the electric machine 108 is an electric motor. In another embodiment, the electric machine 108 is an electric motor-generator.
[0019] The differential unit 110 is used to allow the drive wheels (not shown) to turn at different revolutions per minute (rpm) while both receiving power from the engine 102 and/or the electric machine 108. The differential unit 110 includes an input shaft (not shown) and may include other standard components as present in standard differential gear assembly. The input shaft (not shown) of the differential unit 110 is driven by the output shaft (not shown) of the power transmission unit 106 and transfers the motion to the wheels of the vehicle through a driveshaft (not shown). The driveshaft (not shown) is driven by the differential unit 110 to drive the wheels (not shown) of the vehicle.
[0020] The power electronics module 112 is used to control the speed and torque of the electric machine 108 by controlling the flow of electric power from or to the main battery 114 (high voltage main battery). Power electronics module 112 also has a DC-AC converter module which steps down or steps up the electric power from main battery 114 to 12V or vice-versa, to provide the LV board net and to charge the main battery 114 if state of charge is low, or if vehicle is in standstill condition. The power electronics module 112 acts as an inverter and rectifier and also consists of motor controls. The power electronics module 112 may also have other standard functions as present in standard power electronics module. The power electronics module 112 is connected to the electric machine 108 and the main battery 114.
[0021] The main battery 114 is used to provide electric power to the electric machine 108 through the power electronics module 112 and the electric machine 108 drives the output shaft (not shown) of the power transmission unit 106 thereby propelling the vehicle. The main battery 114 is connected to the power electronics module 112. The main battery 114 is either recharged by plugging in at a charging station or recharged by the electric machine 108 during braking condition of the vehicle i.e., the shaft (not shown) of the electric machine 108 is driven by the differential unit 110 through the output shaft (not shown) of the power transmission unit 106, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112.
[0022] The gear shift lever position sensor (not shown) is used to detect the position of the gear shift lever (not shown) of the power transmission unit 106. In the first embodiment, the gear shift lever position sensor (not shown) is used to detect the position of the gear shift lever (not shown) when the gear shift lever (not shown) is in electric drive gear position (E-gear position) and accordingly provides an output signal to an engine control unit (not shown) to switch off the engine 102 and to activate/energize (switch on) the electric machine 108 to drive the output shaft (not shown) of the power transmission unit 106 thereby propelling the vehicle.
[0023] The clutch position sensor (not shown) is used to detect the position of the clutch unit 104 and accordingly regulates the output speed and/or torque of the electric machine 108.
[0024] The working of the powertrain 100 is as follows. During hybrid drive mode, the output shaft (not shown) of the power transmission unit 106 is driven by the engine 102 and the electric machine 108 thereby propelling the vehicle. During electric drive mode (E-drive mode), the output shaft (not shown) of the power transmission unit 106 is driven by the electric machine 108 thereby propelling the vehicle on engagement of the gear shift lever (not shown) adapted to be shifted to electric drive gear position (E-gear position), where the engine 102 is in non-operative condition (switched off condition) when the gear shift lever (not shown) is in E-gear position.
[0025] FIG. 3 depicts a schematic view of a powertrain 100 for a hybrid vehicle, according to a second embodiment of the invention as disclosed herein. In the second embodiment, the powertrain 100 includes an engine 102, a clutch unit 104, a power transmission unit 106, an electric machine 108, a differential unit 110, a power electronics module 112 and a main battery 114, a gear shift lever position sensor (not shown), a clutch position sensor (not shown) and may include other standard components/system as present in standard powertrain.
[0026] The engine 102 serves as primary power source for propelling the vehicle. The engine 102 includes a crankshaft (not shown) and may include other standard components as present in standard engine. The crankshaft (not shown) of the engine 102 is adapted to transfer the torque produced by the engine 102 to rest of the powertrain components.
[0027] The clutch unit 104 is used for engaging and disengaging the engine 102 with the power transmission unit 106. The clutch unit 104 is rotatably connected to the crankshaft (not shown) of the engine 102. The clutch unit 104 is also rotatably connected to an input shaft (not shown) of the power transmission unit 106.
[0028] The power transmission unit 106 is used for transmitting the torque from the engine 102 to the wheels of the vehicle for propelling the vehicle, and for increasing and decreasing the speed of the vehicle. The power transmission unit 106 includes an input shaft (not shown), a counter shaft (not shown), an output shaft (not shown), a plurality of gears (not shown), a plurality of synchronizer units (not shown), a gear shift lever (not shown) and may include other standard components as present in standard power transmission unit (gear box assembly). The input shaft (not shown) of the power transmission unit 106 is rotatably connected to the clutch unit 104. The counter shaft (not shown) is rotatably connected to the input shaft (not shown) of the power transmission unit 106. The output shaft (not shown) is rotatably connected to the counter shaft of the power transmission unit 106. The output shaft (not shown) of the power transmission unit 106 is rotatably connected to an input shaft (not shown) of the differential unit 110. The plurality of gears (not shown) is used to transmit the torque from the engine 102 to the output shaft (not shown) of the power transmission unit 106. Each synchronizer unit (not shown) is used to facilitate smooth engagement or dis-engagement of corresponding gear (not shown) based on the movement of gear shift lever (not shown) adapted to be shifted to corresponding gear position. Each synchronizer unit (not shown) includes at least one a synchronizer sleeve (not shown), a synchronizer ring (not shown), a hub and may include other standard components as present in standard synchronizer unit. One synchronizer unit (not shown) is used to engage the gear (not shown) driven by the electric machine 108 through the input shaft (not shown) of the differential unit 110 on engagement of the gear shift lever (not shown) adapted to be shifted to the electric drive gear position (E-gear position) thereby propelling the vehicle, where the gear (not shown) is mounted on the output shaft (not shown) of the power transmission unit 106. The gear shift lever (not shown) is selectively moveable between various gear positions that are required for various driving conditions of the vehicle. In the second embodiment, When, the gear shift lever (not shown) is engaged by the driver (user operating the vehicle) to be shifted to electric drive gear position (as shown in fig. 4, where ‘E’ represents E-gear position), the input shaft (not shown) of the differential unit 110 is driven by the electric machine 108 thereby propelling the vehicle, where the engine 102 is in non-operative condition (switch off condition) when the gear shift lever (not shown) is in electric drive gear position (E-gear position). The aforementioned operating condition is referred to as pure electric drive mode (E-drive mode). The power transmission unit 106 is at least a manual power transmission unit. It is also within the scope of the invention to provide the powertrain 100 with any other type of power transmission unit
[0029] The electric machine 108 serves as secondary power source for propelling the vehicle. The electric machine 108 is used to drive the input shaft (not shown) of the differential unit 110 during at least one of an electric drive mode and a hybrid drive mode. In the second embodiment, the electric machine 108 is rotatably connected to the input shaft (not shown) of the differential unit 110 through the plurality of gears G, where one gear G is mounted to a shaft (not shown) of the electric machine 108 and another gear (not shown) is mounted to the input shaft (not shown) of the differential unit 110 and rotatably connected to the gear G mounted to the shaft (not shown) of the electric machine 108. In the second embodiment, the electric machine 108 is adapted to drive the input shaft of the differential unit 110 on engagement of the gear shift lever (not shown) adapted to be shifted to the electric drive gear position (E-gear position), where the engine 102 is in non-operative condition (switch off condition) when the gear shift lever (not shown) is in electric drive gear position (E-gear position. The aforementioned operating condition is referred to as pure electric drive mode (E-drive mode). The electric machine 108 is connected to the main battery 114 through the power electronics module 112. In one embodiment, the electric machine 108 serves/acts as generator thereby recharging the main battery 114 during braking condition of the vehicle i.e., the shaft (not shown) of the electric machine 108 is driven by input shaft (not shown) of the differential unit 110 through a driveshaft (not shown) of the vehicle, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112. In case if the state of charge of main battery 114 is low, then the main battery 114 can also be recharged by the engine 102 through the differential unit 110 during operation of the engine 102 i.e., the engine 102 drives the shaft (not shown) of the electric machine 108 through the input shaft (not shown) of the differential unit 110, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112 during the operation of the engine 102. In an embodiment, the electric machine 108 is an electric motor. In another embodiment, the electric machine 108 is an electric motor-generator.
[0030] The differential unit 110 is used to allow the drive wheels (not shown) to turn at different revolutions per minute (rpm) while both receiving power from the engine 102 and/or the electric machine 108. The differential unit 110 includes an input shaft (not shown) and may include other standard components as present in standard differential gear assembly. The input shaft (not shown) of the differential unit 110 is rotatably connected to the output shaft (not shown) of the power transmission unit 106 and the electric machine 108. The input shaft (not shown) of the differential unit 110 is driven by the electric machine 108 and transfers the motion to the wheels of the vehicle through the driveshaft (not shown). The driveshaft (not shown) is driven by the differential unit 110 to drive the wheels (not shown) of the vehicle.
[0031] The power electronics module 112 is used to control the speed and torque of the electric machine 108 by controlling the flow of electric power from or to the main battery 114 (high voltage main battery). Power electronics module 112 also has a DC-AC converter module which steps down or steps up the electric power from main battery 114 to 12V or vice-versa, to provide the LV board net and to charge the main battery 114 if state of charge is low, or if vehicle is in standstill condition. The power electronics module 112 acts as an inverter and rectifier and also consists of motor controls. The power electronics module 112 may also have other standard functions as present in standard power electronics module. The power electronics module 112 is connected to the electric machine 108 and the main battery 114.
[0032] The main battery 114 is used to provide electric power to the electric machine 108 through the power electronics module 112 and the electric machine 108 drives the input shaft (not shown) of the differential unit 110 thereby propelling the vehicle. The main battery 114 is connected to the power electronics module 112. The main battery 114 is either recharged by plugging in at a charging station or recharged by the electric machine 108 during braking condition of the vehicle i.e., the shaft (not shown) of the electric machine 108 is driven by the drive shaft (not shown) through the input shaft (not shown) of the differential unit 110, and the electric machine 108 converts the kinetic energy into electrical energy and recharges the main battery 114 through the power electronics module 112.
[0033] The gear shift lever position sensor (not shown) is used to detect the position of the gear shift lever (not shown) of the power transmission unit 106. In the second embodiment, the gear shift lever position sensor (not shown) is used to detect the position of the gear shift lever (not shown) when the gear shift lever (not shown) is in electric drive gear position (E-gear position) and accordingly provides an output signal to an engine control unit (not shown) to switch off the engine 102 and to activate/energize (switch on) the electric machine 108 to drive the input shaft (not shown) of the differential unit 110 thereby propelling the vehicle.
[0034] The clutch position sensor (not shown) is used to detect the position of the clutch unit 104 and accordingly regulates the output speed and/or torque of the electric machine 108.
[0035] The working of the powertrain 100 is as follows. During hybrid drive mode, the input shaft (not shown) of the differential unit 110 is driven by the engine 102 and the electric machine 108 thereby propelling the vehicle. During electric drive mode (E-drive mode), the input shaft (not shown) of the differential unit 110 is driven by the electric machine 108 thereby propelling the vehicle on engagement of the gear shift lever (not shown) adapted to be shifted to electric drive gear position (E-gear position), where the engine 102 is in non-operative condition (switched off condition) when the gear shift lever (not shown) is in E-gear position.
[0036] 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:STATEMENT OF CLAIMS
We claim,
1. A powertrain 100 for a vehicle, said powertrain 100 comprising:
an engine 102;
a power transmission unit 106 having an output shaft adapted to be operatively connected to said engine 102; and
an electric machine 108 adapted to be rotatably connected to the output shaft of said power transmission unit 106,
wherein
said electric machine 108 is adapted to drive the output shaft of said power transmission unit 106 on engagement of a gear shift lever adapted to be shifted to electric drive gear position, where said engine 102 is in non-operative condition when the gear shift lever is in electric drive gear position.

2. The powertrain 100 as claimed in claim 1, wherein said electric machine 108 is at least an electric motor.

3. The powertrain 100 as claimed in claim 1, wherein said electric machine 108 is at least an electric motor-generator.

4. The powertrain 100 as claimed in claim 1, wherein said electric machine 108 is adapted to be rotatably connected to the output shaft of said power transmission unit 106 through a plurality of gears G, where one gear G is mounted to a shaft of said electric machine 108, another gear G is mounted to a counter shaft of said power transmission unit 106 and rotatably connected to the gear G mounted to the shaft of said electric machine 108, and another gear G is mounted to an output shaft of said power transmission unit 106 and rotatably connected to the gear G mounted to the counter shaft of said power transmission unit 106.

5. The powertrain 100 as claimed in claim 1, wherein said engine 102 and said electric machine 108 is adapted to drive the output shaft of said power transmission unit 106 thereby propelling the vehicle during a hybrid drive mode.

6. The powertrain 100 as claimed in claim 1, further comprising a gear shift lever position sensor adapted to detect the position of the gear shift lever adapted to be shifted in electric drive gear position (E-gear position) and accordingly provides an output signal to an engine control unit to switch off said engine 102 and to activate (switch on) said electric machine 108 to drive the output shaft of said power transmission unit 106 thereby propelling the vehicle during pure electric drive mode (E-drive mode). 7. The powertrain 100 as claimed in claim 1, wherein the vehicle is at least one a hybrid electric vehicle and a plug-in hybrid electric vehicle.

8. A powertrain 100 for a vehicle, said powertrain 100 comprising:
an engine 102;
a power transmission unit 106 having an output shaft adapted to be operatively connected to said engine 102;
a differential unit 110 having an input shaft adapted to be rotatably connected to the output shaft of said power transmission unit 106; and
an electric machine 108 adapted to be rotatably connected to the input shaft of said differential unit 110,
wherein
said electric machine 108 is adapted to drive the input shaft of said differential unit 110 on engagement of a gear shift lever adapted to be shifted to electric drive gear position, where said engine 102 is in non-operative condition when the gear shift lever is in electric drive gear position.

9. The powertrain 100 as claimed in claim 8, wherein said electric machine 108 is at least an electric motor.

10. The powertrain 100 as claimed in claim 8, wherein said electric machine 108 is at least an electric motor-generator

11. The powertrain 100 as claimed in claim 8, wherein said electric machine 108 is adapted to be rotatably connected to the input shaft of said differential unit 110 through a plurality of gears G, where one gear is mounted to the input shaft of said differential unit 110, and another gear G is mounted to a shaft of said electric machine 108 and rotatably connected to the gear mounted to the input shaft of said differential unit 110.

12. The powertrain 100 as claimed in claim 8, wherein said engine 102 and said electric machine 108 is adapted to drive the input shaft of said differential unit 110 thereby propelling the vehicle during a hybrid drive mode.

13. The powertrain 100 as claimed in claim 8, further comprising a gear shift lever position sensor adapted to detect the position of the gear shift lever adapted to be shifted in electric drive gear position (E-gear position) and accordingly provides an output signal to an engine control unit to switch off said engine 102 and to activate (switch on) said electric machine 108 to drive the input shaft of said differential unit 110 thereby propelling the vehicle during pure electric drive mode (E-drive mode).
14. The powertrain 100 as claimed in claim 8, wherein the vehicle is at least one a hybrid electric vehicle and a plug-in hybrid electric vehicle.