WO2021152613A1

WO2021152613A1 - Powertrain assembly for a vehicle

Info

Publication number: WO2021152613A1
Application number: PCT/IN2021/050060
Authority: WO
Inventors: Meibalan Mugilan; Rawat ANKIT; Subramoniam Chithambaram
Original assignee: Tvs Motor Company Limited
Priority date: 2020-02-01
Filing date: 2021-01-21
Publication date: 2021-08-05
Also published as: MX2022008179A

Abstract

The present invention relates to a powertrain assembly (102), said powertrain assembly (102) connected to a frame assembly (F). The powertrain assembly(102) comprises a transmission housing (202), a cover member (208), a mount member (201) and a prime mover (101). The prime mover (101) is supported by the transmission housing (202) and mounted to the mount member thus ensures reliable mounting. Further mount member configured to have at least one air inlet window which allows fresh air to be directed towards the cooling and guide fins (205) provided on the prime mover housing (204) thus improves the cooling of the prime mover (101).

Description

POWERTRAIN ASSEMBLY FOR A VEHICLE TECHNICAL FIELD

[0001] The present subject matter relates to the vehicle. More particularly, the present subject matter relates to powertrain assembly.

BACKGROUND

[0002] Over the past few years, the investment and market viability of the electrical vehicle are growing in a wide range because of high costs of fossil based fuel and at the same time pressing need to be environment-friendly leading to alternative means of transportation. The alternative means includes electric vehicles, where these vehicle use motor as the prime mover. The electric vehicle is attractive in that the power unit in the form of a rechargeable battery pack is environmentally clean as it does not pollute the air during its operation and its operation is silent. Hence preference of most users is rapidly shifting towards electrical vehicle for their regular usage. But traction motors must withstand predetermined temperature ranges as well as shock, vibration and abuse hence optimal placement of motors without any compromise in space for luggage compartment or battery storage compartment and at the same time ensuring required torque and speed is always a challenge for automobile players.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The detailed description is described with reference to the accompanying figures. The same numbers are used throughout the drawings to reference like features and components.

[0004] Fig. 1 illustrates a left side view of the powertrain assembly, as per preferred embodiment of the present invention.

[0005] Fig. 2 illustrates an exploded view of the powertrain assembly where few parts are omitted from the Fig. 1 as per preferred embodiment of the present invention. [0006] Fig. 3(a) illustrates a perspective view of the powertrain assembly as per preferred embodiment of the present invention.

[0007] Fig. 3(b) illustrates an exploded view of the powertrain sub assembly as per preferred embodiment of the present invention.

[0008] Fig. 4(a) illustrates an exploded view of the power train sub assembly where few parts are omitted from the figure 3(a) as per preferred embodiment. [0009] Fig. 4(b) illustrates the rear cut section view of the powertrain assembly across the plane A-A’ as shown in the figure 1.

[00010] Fig. 5(a) illustrates a rear cut section view of powertrain assembly across the plane A-A’ as shown in the figure 1 as per alternative embodiment of the present invention.

[00011] Fig. 5(b) illustrates a rear cut section view of the powertrain assembly across the plane A-A’ as shown in the figure 1 as per another alternative embodiment of the present invention

DETAILED DESCRIPTION

[00012] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. It is contemplated that the concepts of the present invention may be applied to any type of vehicle employing the similar powertrain within the spirit and scope of this invention. The detailed explanation of the constitution of parts other than the present subject matter which constitutes an essential part has been omitted at suitable places. The word “prime mover” and “electric motor” used interchangeably throughout the specification.

[00013] As in automobiles torque and speed are important parameters, these can vary as per different segment of the vehicle; likewise, the vehicles are designed by keeping these two parameters in mind. It is always a challenge for the automobile manufactures to have appropriate balance between both torque and speed, so in order to achieve different speed at varying loads similarly different torque at different loads requires optimal transmission ratios / system. Power generated from the power unit when transmitted directly to rear wheel will lead to inappropriate torque since direct drive results in uncontrolled speed or sub-optimal speed and undesirable operating conditions thereby failing to achieve best power unit performance i.e., torque and rpm (revolutions per minute). Therefore, for best vehicle performance and optimal operating conditions, to transmit power from the power unit to rear wheel of the vehicle a transmission or gear box is typically provided. However, a trade-off between torque requirement and mileage is difficult since at higher torque requirements mileage of the vehicle drops. Further, high costs of fossil -based fuel lead to alternative means of transportation. Moreover, Original equipment manufacturer (OEMs) and customers are being driven down a path to reduce vehicular emissions by electrifying the drivetrain in that they have the capability to propel vehicles while leaving space inside the vehicles to allow packaging of large battery packs enabling adequate driving range in single charge. The alternative means including electric vehicles, where these vehicles use electric motor as a prime mover wherein hub motor is one of the promising technologies in automotive electrification. Typically, in-wheel hub motor drive type configuration is a rapidly developing solution along with variable speed drive. They are inherently variable speed drives featuring simple construction, a wide speed range, good efficiency but at the same time the inherent disadvantage of in-wheel hub motors is limited torque delivery to drive wheel independently. Thus, in order to get desired or higher torque, the size of in-wheel motor should be increased. Further, the increased size of in-wheel hub motor leads to increase in the size of the wheel assembly which is not desirable. So, there is trade off by moving the drivetrain mass from the sprung to the unsprung mass as well as space availability. This increased unsprung mass is often challenged with increased unsprung mass/sprung mass ratio which can result in dangerous, uncomfortable vehicles. Increasing wheel size brings in additional drawbacks in terms of packaging, inertia losses, seating height etc. Typically, in vehicles like two wheelers (like scooters) or three wheelers, the wheel assembly size is smaller and any increase in the wheel assembly size or addition of components leads to layout constraints in designing a compact low weight power train. Further, wheel rim may bend due to high inertia of motor and which can also cause the water to get inside the motor easily. This ingression of water inside motor may cause the motor short circuit. Moreover, it is difficult to provide motor cooling as it is disposed inside wheel hub, which tends to further decrease the efficiency of the motor because of heat and there by decrease the electric vehicle range, as more power or energy can get wastage in heat energy from the battery or energy source.

[00014] Typically, manufacturers need to cater to different market segments & users with product offerings & variants meeting demands of respective users. These could involve variants in form of size, capacity of vehicle, range of usage, cost, ease of manufacturing, etc. From manufacturers points of view, once a platform product is design, the product economics would be viable based on the numbers sold. Therefore, it is always a challenge for manufacturer to have vehicle layout & design which can be flexible to cater to the variants & the demands & enable modified versions with minimum changes in the vehicle layout, assembly time, manufacturing set-up etc. Additionally, from convenience of usage & utility space point of view, 2-wheeld vehicles with floorboard space have become more popular rather than conventional motorcycle type configuration. The challenge is further complicated when the vehicle architecture / platform requirement needs to cater to different powertrains like Internal combustion engine (ICE) to an Electric Powertrain or a Hybrid powertrain. Further, to create any alternate variant or upgrades etc., any major change in a layout of the vehicle can adversely affect its foot space or luggage space and also involves complete redesign of frame assembly to support the motor as well as its location/mountings. So, an electric drive assembly should be implementable with minimal changes in a base layout and minimum modification of frame component supporting the prime mover. Furthermore, there should be standardization of parts wherein electric drive can be introduced based on customer needs and requirements.

[00015] It is known in the art to have the transmission system with shaft motor mounted on the transmission case of the transmission system wherein motor is supported in an overhang manner on the transmission case which may cause the breakage of the transmission case or transmission cover or both. Further, it is difficult to do servicing of electric motor, as the electric motor is totally enclosed by the transmission case and to do service, the entire transmission assembly needs to be disassembled from the frame assembly. This leads to more service time and cost. More service time also includes disassembly of the sub-frame assembly like toggle link from the main frame assembly by removing bolt and entire sub-frame assembly along with the transmission assembly. Further, the service time includes the time to remove the electric motor from the transmission case and to assemble the same after the service. Thus, conventional transmission systems known in the art are complex and economically disadvantageous being unable to meet one or more requirements outlined above.

[00016] Moreover, solutions known in the art necessitate more assembly time as there are no guiding means to orient the motor and to lock it into the required position. Thus, the workmen need to hold the high inertia electric motor while aligning it to its required orientation in order to fasten it with the transmission case with plurality of fasteners.

[00017] Hence in light of increasing fossil-based fuel prices there is need to develop the electric drive assembly that can help to address above issues and which is affordable and within the means of the masses.

[00018] It is therefore an object of the invention to provide powertrain assembly which reduces the service time and assembly time.

[00019] It is another object of the invention is to provide powertrain assembly ensuring improved cooling for prime mover which will increase the range of the vehicle.

[00020] It is yet another object of the present invention to provide a powertrain assembly which ensures reliable mounting for the prime mover under extreme usage conditions.

[00021] the present invention describes a powertrain assembly layout & platform architecture overcoming all problems outlined earlier & other problems in known art. The powertrain assembly & layout as per the present invention is connected to the frame assembly of the vehicle. The powertrain assembly includes a mount member, a transmission housing, a cover member and a prime mover. The prime mover is supported on the transmission housing. The mount member is configured to have an at least one air inlet window, wherein the prime mover is at least partially covered and fixedly mounted to the mount member such that air inlet window allows fresh air to be directed towards the prime mover. A cover member is detachably attached to the transmission housing.

[00022] Furthermore, as per embodiment of the present invention, plurality of guide pins guide the workmen during sub assembly of the electric motor with transmission housing. The guide pin assembly aligns and makes the prime mover co-axial to the transmission housing.

[00023] As per embodiment of the present invention, the prime mover housing is configured to have annular bead surface at one of its side-end surface in the circumferential direction of the prime mover. The annular bead surface has predetermined thickness which forms an outwardly extending circular ring in a direction parallel to the shaft of the prime mover. The annular bead surface is centrally aligned with the prime mover shaft. The annular bead surface abuts in the corresponding groove formed in the transmission housing in the assembled condition. The annular bead surface and corresponding groove guides the transmission housing during the assembly.

[00024] The aforesaid and other advantages of the present subject matter would be described in greater detail in conjunction with the figures in the following description with an embodiment of the transmission assembly.

[00025] Fig. 1 illustrates the side view of powertrain assembly (102) as per preferred embodiment of the present invention. The present invention has a frame assembly (F) similar to a two or three wheelers (trike) frame known in the art. The present invention can have handle bars or steering wheel (not shown) and a seat assembly (not shown). The present invention has the feature that the drive wheel (100), as per preferred embodiment i.e. rear wheel (100) is operatively connected to the prime mover (101) through transmission means. The prime mover (101) as per preferred embodiment includes electric motor (101). A braking system (103) is attached to drive wheel (100). In alternative embodiment brake system (103) can be inbuilt in drive wheel (100). Further, as per one embodiment the vehicle configured to have a centre stand (104), used especially when the vehicle user is not on the vehicle. The centre stand (104) is operatively connected to at least portion of the powertrain assembly (102).

[00026] Fig. 2 illustrates the exploded view of the powertrain assembly (102) as per preferred embodiment. The powertrain assembly (102) includes a transmission housing (202), a mount member (201), a cover member (208) and prime mover assembly (101). The mount member (201) is provided with the at least one air inlet windows (203). The cooling medium, for example air, is directed circumferentially around the periphery of the prime mover housing (204) through air inlet windows (203) to remove heat therefrom being developed during its operation. The mount member (201) has mount member yokes (210) protruding from the surface at its ends, said mount member yokes (210) configured to have radially aligned bore (210A) portions. Further, the prime mover (101) has prime mover mount yokes (213) protruding from the surface at its ends, said prime mover mount yokes (213) configured to have radially aligned bore (213 A) portions. The prime mover yokes (213) and mount member yokes (210) provide a secure mounting for the prime mover (101) to the mount member (201) therefore protecting it from shocks that may occur during use and to prevent vertical and horizontal movement of the prime mover (101). Thus, ensuring reliable mounting of the prime mover (101) during extreme conditions. Further, the physical coupling of the prime mover (101) and mount member (201) is attached by inserting plurality of threaded fasteners (206) such as bolt, through the bore portion (210A) of the mount member yokes (210), and fastening it on the radially aligned threaded bore portion (213A) of the prime mover yokes (213). Furthermore, the transmission housing (202) has a transmission housing yokes (212) protruding from the surface at its ends, said transmission housing yokes (212) configured to have radially aligned bore (212 A) portions. The mount member (201) is attached to the transmission housing (202). The physical coupling of the transmission housing (202) and mount member (201) is provided by inserting plurality of threaded fasteners (207) through the bore portion (210A) of the mount member yokes (210), and screwing it on the radially aligned threaded bore portion (212A) of the transmission housing yokes (212). the transmission housing (202) is designed like a casing to receive transmission components which is covered by the cover member (208).

[00027] The physical coupling of the cover member (208) and transmission housing (202) is provided by inserting plurality of threaded fasteners (209) such as bolt, through the bore portion (211 A) of the cover member yokes (211), and screwing it on the radially aligned threaded bore portion (212A) of the transmission housing yokes (212). The transmission housing (202) is attached to the mount member (201), electric motor (101) and cover member (208) such that the transmission housing (202) is sandwiched between the cover member (208) and mount member (201) wherein the electric motor (101) is at least partially covered by mount member (201) and supported on the transmission housing

(202). Thus, the serviceability of prime mover (101) become easy as it can be removed directly from mount member (201), without disassembling the entire transmission assembly from the frame assembly (F).

[00028] Figure 3(a) illustrates the perspective view of the powertrain assembly (102) as per preferred embodiment of the present invention. The powertrain layout & architecture as per the present invention configured with an independent electric motor (101) enables implementation of heavy load capacity motor as compared to the in wheel motors & consequentially it requires a more efficient cooling system. To achieve this, the prime mover housing (204) configured to have cooling and guide fins (205). The air entering from the air inlet windows

(203) passes through the cooling and guide fins (205) which ensures effective cooling of the electric motor (101). The air inlet windows (203) configured to have predetermined geometry provided on a circumferential surface of the mount member (201). The predetermined geometry of air inlet windows as per preferred embodiment configured to have an elliptical or rectangular profile. Further, the size of air inlet windows varies with the size of electric motor. The air directed towards the electric motor (101) is guided through the cooling and guide fins (205). As shown below in equation, that the amount of heat transfer Q through convection directly depends on time for heat transfer. Equation - Q/t= h*A* \T

Where:

Q/t = rate of heat transfer (J/s) h = Convective heat transfer coefficient (Watt/(m²K)) A = surface area of heat transfer (m²)

DT = temperature difference(K)

Thus, as per the present invention, the surface area A is significantly increased to achieve a higher rate of convective heat transfer. Above construction & architecture leads to efficient cooling of the electric motor (101) by increasing the transfer of heat through convection. As air is in contact with electric motor (101) for longer duration due to predetermined geometry of the air inlet windows (203) provided on mount member (201) and cooling and guide fins (205) on the prime mover housing (204). more air is introduced in the mount member (201) through air inlet windows (203) thereby ensuring air is trapped inside the mount member (201) for longer duration such that air is forced to pass through the cooling and guide fins (205). The cooling and guide fins (205) configured to have zig-zag type of profile (in a circumferential direction around the mount member 201) which improves the cooling rate by increasing the rate of heat transfer. The zig-zag profile of the cooling and guide fins (205) in a side appears like a annular contour with a crest regions (205B) and a trough regions (205A) along the periphery wherein the crest region (205B) has a land portion width to be at least twice the circumferential width of the trough portion(205A)

[00029] As shown in fig. 3(b) the powertrain assembly (102) ensures ease of serviceability as there is no need of disassembly of the sub-frame assembly like toggle link from the main frame assembly because the prime mover (101) can be dismounted from the mount member (201) by removing plurality of threaded fasteners (206) which secure the prime mover (101) to the mount member (201). Furthermore, the service time of disassembly of the transmission housing (202) from the sub frame assembly is avoided. Hence, the present powertrain assembly (102) is easy to service with less assembly time which is economically advantageous over conventional systems.

[00030] Fig. 4(a) illustrates exploded view of the power train assembly as per preferred embodiment. The prime mover (101) having components such as the brush and holder assembly is enclosed within the prime mover housing (204). The shaft end of the prime mover (101) has a bearing (305) for rotatably supporting its shaft (303) about the axis. The prime mover housing (204) configured to have annular bead surface (301) at one of its side-end surface in the circumferential direction of the electric motor (101). Further, the electric motor (101) and transmission housing (202) are assembled with the help of plurality of guide pins (304). The prime mover housing (204) is configured to have plurality of holes (302) adapted to receive the guide pins (304). Further transmission housing (202) having corresponding plurality of holes (302A) receive guide pins (304). The guide pins (304) rest in the plurality of holes (302) provided in the prime mover housing (204) and corresponding holes (302A) in the transmission housing (202) in a direction parallel to the shaft (303) of the prime mover (101). This layout architecture enables ease of assembly as well as dismantling thereby improving the serviceability of the powertrain system while ensuring a large capacity motor can be packaged in the layout without any compromise on the rotary inertia of the wheel which additionally enables increase in the torque capacity of the powertrain. The present invention also achieves an efficient cooling configured within the single architecture as a whole by configuring an efficient convective heat transfer system thereby enhancing the cooling efficiency which leads to better durability & reliability of the powertrain as well as the energy source e.g., battery pack.

[00031] Fig. 4(b) illustrates the rear cut section view of the subassembly of prime mover and transmission assembly across the plane A-A’ as shown in the figure 1. The annular bead surface (301) is provided at shaft end of the prime mover (101). The annular bead surface (301) having predetermined thickness which forms like an outwardly extending circular annular ring in a direction parallel to the shaft (303) of the electric motor (101). The annular bead surface (301) is axially extended but shorter than the axial length of the motor shaft (303) to reduce the weight of the prime mover housing (204). The annular bead surface (301) engages in the corresponding groove (301 A) formed in the transmission housing (202) thereby ensuring ease of assembly and annular bead surface (301) rests in the corresponding groove (301 A) in assembled condition. The annular bead surface (301) and corresponding groove (301A) guides the prime mover (101) during the assembly and the guide pins (304) guides the sub assembly of the electric motor (101) with the mount member (201) and aligns and makes the prime mover (101) co-axial to the transmission housing (202). This configuration provides a self-aligning joint of the mating system which significantly reduces the strenuous effort of mounting as well as aligning the heavy motor to the transmission system; both during assembly at manufacturer as well as during service in workshop. Drastic reduction in the cycle time of assembly as well as reduction in effort are additional benefits derived from this architecture.

[00032] As per alternative embodiment of the present invention the Fig. 5(a) illustrates the rear cut section view of prime mover and transmission assembly across the plane A-A’ as shown in the figure 1. The prime mover (101) having components such as the brush and holder assembly, are enclosed within the prime mover housing (204). The shaft end of the prime mover (101) has a bearing (305) for rotatably supporting its shaft (303) about the axis. The prime mover housing (204) is configured to have annular bead surface (301) at one of its side end surface in the circumferential direction of the motor. The annular bead surface (301) which engages in the corresponding groove (301A) is provided in the transmission housing (202) to reduce the assembly time. Thus, annular bead surface (301) and corresponding groove (301A) guides the prime mover (101) during the assembly. Thus, the need for guide pins (304) is completely eliminated. [00033] As per another alternative embodiment of the present invention the Fig. 5(b) illustrates the rear cut section view of the prime mover and transmission assembly across the plane A-A’ as shown in the figure 1. The shaft end of the prime mover (101) has a bearing (305) for rotatably supporting the its shaft (303) about the axis. The guide pins (304) rests in the plurality of holes (302) (as shown in fig. 4) provided in the prime mover housing (204) and corresponding holes (302A) (as shown in fig. 4) in the transmission housing (202) to reduce the assembly time. Thus, the guide pins (304) guides the sub assembly of the electric motor (101) with transmission housing (202) as guide pins (304) align and make the transmission housing (202) co-axial to the prime mover (101). The side-end surface of the prime mover (101) can be simple in construction without the need of annular bear surface grooves (301 A) thereby further enhancing ease of manufacturing & assembly.

[00034] Thus, as per present subject matter the electric motor (101) is mounted on the mount member (201) with the series of fasteners and assembled on the transmission housing (202) with the help of guide pins (304) and/or annular bead surface (301) with corresponding groove (301A). This reduces the assembly time. Further the prime mover (101) is a platform architecture with a simply supported structure which in enclosed between mount member (201) and transmission housing (202) hence overhang support of the prime mover (101) is eliminated above layout & architecture design of the powertrain assembly along with its transmission ensures reliable mounting of the prime mover to the transmission assembly. Moreover, as the prime mover (101) is mounted from the one side (either left or right) of the transmission housing (202), so for the servicing requirement of the prime mover (101), the prime mover (101) can easily be removed from the powertrain assembly (102) without removing the complete powertrain assembly (102) from the vehicle.

[00035] While the present invention has been shown and described with reference to the foregoing preferred embodiments, it will be apparent to those skilled in the art that changes in form, connection, and detail may be made therein without departing from the spirit and scope of the invention.

List of references

101 - Prime mover/Electric motor 102- Powertrain assembly

103 - Brake system

104 - Centre stand

201 - Mount member

202 - Transmission housing 203- Air inlet window

204 - Prime mover housing/ electric motor housing 205- Cooling and guide Fins 205A- Trough region 205B - Crest region

206 - Plurality of threaded fasteners to couple prime mover to mount member

207- Plurality of threaded fasteners to couple mount member to the transmission housing

208 - Cover member

209 - Plurality of threaded fasteners to couple transmission housing to the cover member

210 - Mount member yoke

210A - Bore portion of the mount member yoke

211 - Cover member yoke

211A - Bore portion of the cover member yoke

212 - Transmission housing yoke

212A - Bore portion of the transmission housing yoke

213 - Prime mover yoke

213A - Bore portion of the prime mover yoke

301 - Annular bead surface

301 A - Groove in the transmission housing 302 - Plurality of holes

302A - Plurality of holes in transmission housing

303 - Shaft of the prime mover/ Motor shaft

304 - Guide pins 305 - Bearing

Claims

We Claim:

1. A powertrain assembly (102) for a vehicle, the powertrain assembly (102) supported by a frame assembly (F), said powertrain assembly (102) architecture comprising of a transmission housing (202), said transmission housing (202) supporting a prime mover (101); an mount member (201), said mount member (201) configured to have at least one air inlet window (203), said prime mover (101) is at least partially covered and fixedly mounted to the mount member (201), said air inlet windows (203) are configured to allow fresh air to be directed towards the prime mover (101); and, a cover member (208); said cover member (208) is detachably attached to the transmission housing (202).

2. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said prime mover (101) is configured to have cooling and guide fins (205) on said prime mover housing (204) to ensure effective cooling of said prime mover (101).

3. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said at least one air inlet window (203) is configured to have predetermined geometry provided on a circumferential surface of the mount member (201).

4. The powertrain assembly (102) as claimed in claim 1, wherein said cooling and guide fins (205) side appears like an annular contour with a crest regions (205B) and a trough regions (205A) along the periphery wherein the crest region (205B) has a land portion width to be at least twice the circumferential width of the trough portion(205A)

5. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said transmission housing (202) configured to have plurality of transmission housing yokes (212) protruding from the surfaces at its ends.

6. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said mount member (201) configured to have plurality of mount member yokes (210) protruding from the surface at its ends.

7. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said prime mover (101) configured to have plurality of prime mover yokes (213) protruding from the surface at its ends.

8. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said cover member (208) is configured to have plurality of cover member yokes (211) protruding from the surface at its ends.

9. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said prime mover (101) and the mount member (201) is coupled by inserting plurality of fasteners (206) through a bore portion (210A) of the mount member yokes (210), and fastening it on a radially aligned threaded bore portion (213A) of the prime mover yokes (213).

10. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said transmission housing (202) and mount member (201) is coupled by inserting plurality of fasteners (207) through the bore portion (210A) of the mount member yokes (210), and fastening it on a radially aligned threaded bore portion (212A) of the transmission housing yokes (212).

11. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said cover member (208) and transmission housing (202) is coupled by inserting plurality of fasteners (209) through the bore portion (210A) of the mount member yokes (210), and fastening it on a radially aligned threaded bore portion (211 A) of the cover member yokes (211).

12. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said the prime mover (101) and mount member (201) are assembled using plurality of guide pins (304).

13. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said transmission housing (202) configured to have plurality of holes (302A) to receive the guide pins (304).

14. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said prime mover (101) configured with plurality of holes (302) at one of its side-end surface to receive guide pins (304).

15. The powertrain assembly (102) for a vehicle as claimed in claim 1, wherein said guide pins (304) rests in the plurality of holes (302) provided in the prime mover (101) and corresponding holes (302A) in the transmission housing (202).

16. The powertrain assembly (102) for a vehicle as claimed in claim 1 or claim 12, wherein said prime mover (101) is configured to have annular bead surface (301) of predetermined thickness which forms like an outwardly extending circular annular ring in a direction parallel to the shaft (303) of the prime mover (101).

17. The powertrain assembly (102) for a vehicle as claimed in claim 16, wherein said annular bead surface (301) abuts in the corresponding groove (301A) formed in the transmission housing (202) in the assembled condition.