A housing assembly for an electric motor and a transmission unit

Abstract

Present invention provides a housing assembly (100). The housing assembly (100) comprises a motor casing (102) adapted to enclose an electric motor (104) and a transmission casing (106) integrated with the motor casing (102). The transmission casing (106) is extended outwardly from the motor housing (102). The transmission casing (106) is adapted to accommodate one or more transmission components. Such construction minimizes the number of components in the assembly (100), thereby simplifying construction, while reducing overall costs involved in manufacturing and maintenance.

Description

[0001] TITLE OF INVENTION:

[0002] A HOUSING ASSEMBLY FOR AN ELECTRIC MOTOR AND A TRANSMISSION UNIT

[0003] FIELD OF THE INVENTION

[0004]

[0001] Present invention generally relates to a housing assembly. More particularly, the present invention relates to an integrated housing assembly for enclosing an electric motor and a transmission unit.

[0005] BACKGROUND OF THE INVENTION

[0006]

[0002] An electric vehicle is a vehicle that is powered by electricity. The electric vehicle utilizes one or more electric motors powered by a power source such as a battery pack. The electric motors are coupled to one or more wheels of the vehicle. The electric motor is adapted to provide necessary motive force to the one or more wheels for vehicle movement. Typically, a transmission unit is connected between the electric motor and the one or more wheels. The transmission unit comprises a gear train that is adapted to control the torque transfer from the electric motor to the one or more wheels, thereby ensuring controlled vehicle movement.

[0007]

[0003] In conventional vehicles, the gear train of the transmission unit comprises a primary drive gear and a secondary gear drive. The primary gear drive is mounted on a motor shaft of the electric motor through a connecting shaft. The secondary gear is mounted on the transmission casing through another mounting shaft and bearings. This achieves a good noise level control in gears, due to controlled centre distance between the gears. However, this construction is complicated and involves a greater number of parts like bearings, casting profiles and increases the overall cost. Moreover, two additional bearings are used for mounting the connecting shaft on the transmission casing for the gear primary drive. To hold these bearings a provision is required to be provided in transmission casing, which increases overall design and manufacturing complexity, which is undesirable.

[0008]

[0004] Moreover, in conventional electric vehicles, the electric motor and the transmission unit are enclosed in separate housing. Such a construction furtherincreases overall costs in terms of materials and also increases the complexity of manufacturing and assembly process. Additionally, the separate housing for the electric motor and the transmission unit requires precise tolerances involving different manufacturing methods. The need for additional manufacturing stages increases overall labor costs and production time. Moreover, alignment issues persist between the motor housing and the transmission housing, leading to ineffective / inefficient performance. The alignment issues may also transfer uneven forces between the components placed in the motor and the transmission housing, leading to noise and accelerated wear and tear of components, resulting in premature failure of the components, which is undesirable.

[0009]

[0005] In view of the above, there is a need for a housing assembly which can overcome one or more limitations stated above in addition to provide additional technical advantages.

[0010] SUMMARY OF THE INVENTION

[0011]

[0006] In one aspect, a housing assembly for enclosing an electric motor and a transmission unit is disclosed. The housing assembly comprises a motor casing adapted to enclose an electric motor. A transmission casing is integrated with the motor casing. The transmission casing extends outwardly from the motor housing and adapted to accommodate one or more transmission components of a transmission unit.

[0012]

[0007] In an embodiment, a transmission cover is configured with the transmission casing. The transmission casing with the transmission cover defines a chamber therebetween for enclosing the one or more transmission components in the chamber.

[0013]

[0008] In an embodiment, the transmission cover is detachably secured to the transmission casing for enclosing the one or more transmission components.

[0014]

[0009] In an embodiment, the transmission casing comprises a first portion and a second portion. The first portion is oriented coaxially to an axis (X-X’) of the motor casing. The first portion is adapted to receive a portion of a motor shaft of the electricmotor. The second portion is configured to accommodate an output shaft. The output shaft is offset with respect to the axis (X-X’) of the motor shaft.

[0015]

[0010] In an embodiment, the output shaft is operatively coupled to the portion of the motor shaft through a gear train mechanism.

[0016] [Oil] In an embodiment, the gear train mechanism comprises one or more drive gears mounted onto the portion of the motor shaft and one or more driven gears mounted onto the output shaft. The one or more driven gears are engaged to the one or more drive gears.

[0017]

[0012] In an embodiment, the one or more drive gears are disposed in the first portion, and the one or more driven gears are disposed in the second portion.

[0018]

[0013] In an embodiment, the transmission casing comprises the first portion has one or more first flanges configured to receive a first bearing member. The first bearing member is adapted to rotatably support a motor shaft of the electric motor. The second portion has one or more second flanges configured to support a second bearing member. The second bearing member is adapted to rotatably support the output shaft.

[0019]

[0014] In an embodiment, the transmission cover comprises one or more third flanges configured to support a third bearing member. The third bearing member is adapted to rotatably support the motor shaft of the electric motor. Further, one or more fourth flanges are configured to support a fourth bearing member. The fourth bearing member is adapted to rotatably support the output shaft.

[0020]

[0015] In an embodiment, the motor casing comprises the first end portion and the second end portion. The transmission casing extends outwardly from the first end portion and wherein a side cover is provided for covering an opening defined in the second end portion of the motor casing.

[0021] BRIEF DESCRIPTION OF THE DRAWINGS

[0022]

[0016] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context ofthese embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.

[0023] Figure 1 illustrates a perspective view of a housing assembly, in accordance with an exemplary embodiment of the present invention.

[0024] Figure 2 illustrates a perspective view of the housing assembly without a transmission cover, in accordance with an exemplary embodiment of the present invention.

[0025] Figure 3 illustrates a top view of the housing assembly, in accordance with an exemplary embodiment of the present invention.

[0026] Figure 4 illustrates a left-side view of the housing assembly, in accordance with an exemplary embodiment of the present invention.

[0027] Figure 5 illustrates a sectional top view of the housing assembly, in accordance with an exemplary embodiment of the present invention.

[0028] Figure 6 illustrates an exploded view of the housing assembly, in accordance with an exemplary embodiment of the present invention.

[0029] Figure 7 illustrates a portion of the exploded view of the housing assembly depicting the gear train mechanism, in accordance with an exemplary embodiment of the present invention.

[0030] DETAILED DESCRIPTION OF THE INVENTION

[0031]

[0017] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.

[0032]

[0018] The present invention relates to a housing assembly for enclosing an electric motor and a transmission unit. The housing assembly comprises a motor casing adapted to enclose an electric motor. A transmission casing is integrated with the motor casing. The transmission casing extends outwardly from the motor housing and is adapted to accommodate one or more transmission components. Such a construction of the housing assembly ensures that the electric motor and the transmission casing are enclosed in single housing, thereby achieving precise alignment between a motor shaft of the electric motor and an output shaft of the transmission casing and also maintain a precise center distance between adjacentmessing gears of the transmission unit. The precise alignment ensures that even forces are transmitted between the motor shaft and the output shaft, thereby ensuring optimum performance, while minimizing noise and vibration. Moreover, the housing assembly minimizes additional components such as couplings, bearing and seals required for separate housing for the electric motor and the transmission casing, thereby minimizing complexity, potentially minimizing manufacturing and maintenance costs. Additionally, minimizing the number of components inherently reduces weight and size of the housing assembly, thereby enhancing space availability for installing other components in a vehicle.

[0033]

[0019] Figure 1 illustrates a perspective view of a housing assembly 100, in accordance with an exemplary embodiment of the present invention. The housing assembly 100 is adapted to enclose an electric motor 104 (shown in Figure 6) as well as a transmission unit (partially shown in Figure 5).

[0034]

[0020] The housing assembly 100 comprises a motor casing 102. The motor casing 102 is hollow cylindrical member that extends axially along an axis X-X’ that is extended along length of the motor shaft. The motor casing 102 is adapted to receive or enclose the electric motor 104. The electric motor 104 comprises a motor shaft 112 (shown in Figure 5) that is disposed coaxially to the axis X-X’ within the motor casing 102. A rotor 140 (shown in Figure 6) is coaxially and rotatably mounted onto the motor shaft 112. Further, a stator 138 is mounted coaxially over the rotor 140 with a thin gap therebetween. The stator 138 may be provided with a plurality of windings required for operation of the electric motor 104 upon receiving a power supply. In an embodiment, the rotor 140 may be mounted co-axially over the stator 138. As such, the positioning of the stator 138 and the rotor 140 is selected as per electric motor 104 design requirement. The stator 138 as well as the rotor 140 are enclosed within the motor casing 102.

[0035]

[0021] Further, the motor casing 102 comprises a plurality of mounting units 144. The plurality of mounting units 144 project outwardly from an outer circumferential surface 146 of the motor casing 102, and are adapted to engage / connect with a structural member such as, a frame member (not shown) of a vehicle (not shown) through conventional techniques such as fastening, clamping ... etc. Additionally,on the outer circumferential surface 146, a plurality of fins 142 are provided. The plurality of fins 142 may be annular fins that are adapted to dissipate heat generated in the electric motor 104 during operation. In an embodiment, the dimensions of the motor casing 102 are considered corresponding to dimensions of the electric motor 104. Accordingly, the dimensions of the motor casing 102 are considered corresponding to dimensions of at least the motor shaft 112 (for e.g. shown in Figure 5), the stator 138 (for e.g. shown in Figure 5) and the rotor 140 (for e.g. shown in Figure 5).

[0036]

[0022] Referring to Figures 2 and 3 in conjunction with Figure 1, the motor casing 102 comprises a first end portion 102a and a second end portion 102b on two opposite sides of the motor casing 102. In an exemplary embodiment, the first end portion 102a can be a left-side end portion of the outer circumferential surface 146, while the second end portion 102b can be a right-side end portion of the outer circumferential surface 146. In an embodiment, the first end portion 102a and the second end portion 102b can also be terminal edges on either side of the outer circumferential surface 146.

[0037]

[0023] The motor casing 102 further comprises a first cover 148. The first cover 148 is oriented laterally to the axis X-X’. The first cover 148 is an integral part of the motor casing 102 on the first end portion 102a, i.e., the motor casing 102 and the first cover 148 are an integral single casted part. In another embodiment, the first cover 148 can be mounted on the first end portion 102a through conventional mounting techniques such as fastening, welding, clamping ... etc. The first cover 148 encloses the electric motor 104 at the first end portion 102a. A slot 150 is provided coaxially to the axis X-X’ of the motor casing 102 on the first cover 148. The slot 150 is adapted to allow a portion 112a of the motor shaft 112 to protrude from the motor casing 102.

[0038]

[0024] In an embodiment, the first cover 148 is provided with a plurality of elongated fins 154 (as shown in Figure 4). The plurality of elongated fins 154 may be parallel to one another on the first cover 148. The plurality of elongated fins 154 facilitate dissipation of heat generated from operating the electric motor 104.

[0025] The motor casing 102 also comprises a second cover 152. The second cover 152 is oriented laterally to the axis X-X’ and is adapted to be mounted on the second end portion 102a through conventional mounting techniques such as fastening, welding, clamping...etc. The second cover 152 encloses the electric motor 104 at the second end portion 102b. In an embodiment, the second cover 152 is provided with a hole (not shown) for allowing electrical connection with an encoder unit (not shown) of the electric motor 104. In an embodiment, the motor casing 102 and the second cover 152 are an integral single casted part.

[0039]

[0026] Referring to Figure 3, the motor casing 102 is provided with a side cover 122. The side cover 122 is oriented laterally to the axis X-X’ of the motor casing 102. The side cover 122 is mounted on the second end portion 102b of the motor casing 102 through conventional mounting techniques such as fastening, clamping ... etc. In an embodiment, the side cover 122 is coaxial to the axis X-X’ of the motor casing 102. The side cover 122 is adapted to cover the encoder unit that is electrically connected to the electric motor 104. In an embodiment, dimensions of the side cover 122 are considered corresponding to the dimensions of the encoder unit to be enclosed.

[0040]

[0027] Referring to Figure 5 in conjunction with Figures 1-4, the housing assembly 100 further comprises a transmission casing 106. The transmission casing 106 is integrated with the motor casing 102. The transmission casing 106 extends outwardly from the motor casing 102. In the present embodiment, the transmission casing 106 extends outwardly from the first cover 148 provided on the first end portion 102a of the motor casing 102. The transmission casing 106 is adapted to enclose one or more transmission components such as gears, gear shafts...etc. of a transmission unit of the vehicle. The transmission casing 106 being integral to the motor casing minimizes additional parts required for separate housing for the electric motor 104 and the transmission components, thereby reducing weight, minimizing manufacturing and maintenance costs.

[0041]

[0028] The transmission casing 106 comprises a first portion 106a that is coaxial to the axis X-X’ of the motor casing 102. As such, the first portion 106a is adapted to receive the portion 112a of the motor shaft 112 that is protruded from the motorcasing 102. Also, the transmission casing 106 comprises a second portion 106b. The second portion 106b is radially offset or extends at a distance radially from the axis X-X’ . In an embodiment, the second portion 106b extends below the first portion 106a (as shown in Figure 5) and is radially offset with the axis X-X’. The second portion 106b is adapted to enclose an output shaft 114. Due to the radial offset disposition of the second portion 106b, the output shaft 114 is also offset or radially offset with respect to the axis X-X’ of the motor shaft 112. The output shaft 114 is disposed parallelly to the motor shaft 112, and is coupled to the portion 112a of the motor shaft 112 through a gear mechanism 116 (also shown in Figure 6 and 7). Also, the output shaft 114 is provided with splines 156 for receiving and supporting a pulley 158. The pulley 158 may be coupled to one or more wheels of the vehicle for movement.

[0042]

[0029] Referring to Figure 7, the gear train mechanism 116 comprises one or more drive gears 116a mounted onto the portion 112a of the motor shaft 112 and one or more driven gears 116b mounted onto the output shaft 114. Thus, the one or more drive gears 116a are disposed in the first portion 106a of the transmission casing 106, while the one or more driven gears 116b are disposed in the second portion 106a of the transmission casing 106. The gear mechanism 116 is adapted to control the torque transferred from the motor shaft 112 to the output shaft 114.

[0043]

[0030] In an embodiment, the portion 112a of the motor shaft 112 may be provided with a keyway (not shown) or splines (not shown) that match with the one or more drive gears 116a for facilitating mounting. In an embodiment, a fastener 160 or a circlip is fastened onto the portion 112a for securing the one or more drive gears 116a onto the portion 112a.

[0044]

[0031] In an embodiment, the output shaft 114 is provided with a keyway (not shown) or splines (not shown) that match with the one or more driven gears 116b for facilitating mounting. In an embodiment, suitable fasteners (not shown) or circlips may be provided for securing the one or more driven gears 116b onto the output shaft 114.

[0045]

[0032] The one or more driven gears 116b are coupled / meshed with the one or more drive gears 116a for transferring torque from the motor shaft 112 to the output shaft114, thereby rotating the pulley 158. In the present embodiment, one drive gear 116a and one driven gear 116b are provided in the gear mechanism 116. Alternatively, the number of drive gears 116a and the driven gears 116b is considered as per torque transmission requirement in the transmission unit 106. In an embodiment, the size of the drive gears 116a and the driven gears 116b is selected as per torque transmission requirement in the transmission unit 106. In the present embodiment, the driven gear 116b is larger in size than the drive gear 116a, thereby reducing the torque transferred to the output shaft 114.

[0046]

[0033] Referring back to Figure 5, the first portion 106a of the transmission casing 106 comprises one or more first flanges 126. The one or more first flanges 126 may define one or more annular grooves or one or more annular detent surfaces or one or more stepped surfaces provided to the transmission casing 106 at the first portion 106a. In the present embodiment, the one or more first flanges 126 are defined around the slot 150 of the first cover 148 provided at the first end portion 102a. Accordingly, the first cover 148 can be provided with stepped profile (not shown) to accommodate profile of the one or more flanges 126 provided at the first portion 106a. The one or more first flanges 126 are adapted to receive a first bearing member 118. The first bearing member 118 is adapted to rotatably support the motor shaft 112 of the electric motor 104 at the first portion 106a. Such a construction of the transmission casing 106 ensures that alignment of the motor shaft 112 is maintained and minimizes chances of misalignment of the motor shaft 112.

[0047]

[0034] Further, the second portion 106b of the transmission casing 106 has one or more second flanges 128. The one or more second flanges 128 may define one or more annular grooves or one or more annular detent surfaces or one or more stepped surfaces provided to the transmission casing 106 at the second portion 106b. In an embodiment, the first cover 148 can be provided with stepped profile (not shown) to accommodate profile of the one or more second flanges 128 provided at the second portion 106b. The one or more second flanges 128 are adapted to receive a second bearing member 120. The second bearing member 120 is adapted to rotatably support the output shaft 114 at the second portion 106b. Such a construction of the transmission casing 106 ensures that alignment of the outputshaft 114 is maintained and minimizes chances of misalignment of the output shaft 114. Moreover, the construction pertaining to the one or more first flanges 126 and the one or more second flanges 128 collectively maintain alignment of the motor shaft 112 and the output shaft 114 respectively, while the housing assembly 100 is integrating the electric motor 104 and the transmission casing 106. Thus, ensure accurate alignment, simplify construction and minimize parts in the housing assembly 100.

[0048]

[0035] In an embodiment, the transmission casing 106 comprises one or more ribs 168 (shown in Figure 2). The one or more ribs 168 surround the one or more second flanges 128. The one or more ribs 168 enhance structural rigidity of the one or more second flanges 128.

[0049]

[0036] Referring to Figures 6 and 7, the housing assembly 100 further comprises a transmission cover 110. The transmission cover 110 matches with the profile of the transmission casing 106, and is mounted to the transmission casing 106. In an embodiment, the transmission cover 110 is provided with one or more mounting holes 162 that align with mounting slots (not shown) provided along periphery of the transmission casing 106. Each of the one or more mounting holes 162 receive a fastener 164 for fastening the transmission cover 110 with the transmission casing 106. The transmission cover 110 upon mounting with the transmission casing 106 defines a chamber 124 (as shown in Figure 5) for enclosing the one or more transmission components, the gear train mechanism 116, the first bearing member 118 and the second bearing member 120.

[0050]

[0037] Further, the transmission cover 110 comprises one or more third flanges 130. The one or more third flanges 130 are aligned or in-line with the one or more first flanges 126. The one or more third flanges 130 may be one or more annular grooves or one or more annular detent surfaces or one or more stepped surfaces provided to the transmission cover 110. The one or more third flanges 130 are adapted to receive a third bearing member 132. The third bearing member 132 is adapted to rotatably support an outer end 166 of the motor shaft 112 that is disposed in the first portion 106a. Such construction further reinforces alignment and also optimal load distribution of the motor shaft 112.

[0038] The transmission cover 110 further comprises one or more fourth flanges 134. The one or more fourth flanges 134 are aligned or in-line with the one or more second flanges 128. The one or more fourth flanges 134 may be one or more annular grooves or one or more annular detent surfaces or one or more stepped surfaces provided to an inner surface of the transmission cover 110. The one or more fourth flanges 134 are adapted to receive a fourth bearing member 136. The fourth bearing member 136 is adapted to rotatably support a central portion 114b of the output shaft 114. Such construction further reinforces alignment and also optimal load distribution of the output shaft 114.

[0051]

[0039] In an embodiment, the transmission cover 110 comprises a hole 110a coaxial or inline with the one or more second flanges 128. The hole 110a is adapted to allow an end portion 114c of the output shaft 114 to be protruded out of the chamber 124. The pulley 158 engages / is mounted on the end portion 114c.

[0052]

[0040] In an embodiment, during assembly, the electric motor 104 is firstly disposed in the motor casing 102 such that, the portion 112a of the motor shaft 112 extends into the first portion 106a of the transmission casing 106 that is integrated to the motor casing 102. In an embodiment, the electric motor 104 is disposed in the motor casing 102 through the second end portion 102b by detaching the second cover 152. Upon disposing, the second cover 152 is fastened back to the second end portion 102b, for securing the electric motor 104 within the motor casing 102. At this juncture, the first bearing member 118 is disposed in the one or more first flanges 126, thereby supporting the portion 112a of the motor shaft 112. Subsequently, the output shaft 114 is disposed parallelly in the second portion 106b of the transmission casing 106, such that end 114a of the output shaft 114 is disposed in the one or more second flanges 128. At this juncture, the second bearing member 120 is disposed in the one or more second flanges 128 for engaging with the end 114a of the output shaft 114. The second bearing member 120 thus supports the output shaft 114. Subsequently, the one or more drive gears 116a are mounted to the portion 112a and fastened thereon, while the one or more driven gears 116b are mounted on the output shaft 114. The third bearing member 132 is then disposed on the one or more third flanges 130, while the fourth bearing member 136 is disposedon the one or more fourth flanges 134 of the transmission cover 110. At this juncture, the transmission cover 110 is aligned and fastened onto the transmission casing 106. Further, an end portion 114c protrudes through a hole 110a provided in the transmission cover 110. The pulley 158 is mounted onto the end portion 114c of the output shaft 114.

[0053]

[0041] The present invention as disclosed above is not routine, conventional, or well understood in the art, as the aspects enable the following solutions to the existing problems in conventional technologies. Specifically, the aspect of the housing assembly integrating the motor casing and the transmission casing, ensures that the electric motor and the transmission components are enclosed in single housing. Additionally, the aspect of providing the first bearing member, the second bearing member, the third bearing member and the fourth bearing member along with its respective flanges achieves precise alignment between the motor shaft of the electric motor and the output shaft of the transmission casing. The precise alignment ensures that even forces are transmitted between the motor shaft and the output shaft, thereby ensuring optimum performance, while minimizing noise and vibration. Moreover, the integration in the housing assembly minimizes additional components such as couplings, bearing and seals required for separate housing for the electric motor and the transmission casing, thereby minimizing complexity, potentially minimizing manufacturing and maintenance costs. Additionally, minimizing the number of components inherently reduces weight and size of the housing assembly, thereby enhancing space availability for installing other components in a vehicle.

[0054]

[0042] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

[0055] List of reference numerals:

[0056] 100 - Housing assembly

[0057] 102 - Motor casing104 - Electric motor

[0058] 106 - Transmission casing

[0059] 106a - First portion of the transmission casing 106b - Second portion of the transmission casing 110 - Transmission cover

[0060] 110a- Hole on the transmission cover

[0061] 112 - Motor shaft

[0062] 114 - Output shaft

[0063] 116 - Gear train mechanism

[0064] 116a- One or more drive gears

[0065] 116b - One or more driven gears

[0066] 118 - First bearing member

[0067] 120 - Second bearing member

[0068] 122 - Side cover

[0069] 124 - Chamber

[0070] 126 - One or more first flanges

[0071] 128 - One or more second flanges

[0072] 130 - One or more third flanges

[0073] 132 - Third bearing member

[0074] 134 - One or more fourth flanges

[0075] 136 - Fourth bearing member

[0076] 138 - Stator

[0077] 140 - Rotor

[0078] 142 - Fins

[0079] 144 - Mounting units

[0080] 146 - Outer circumferential surface

[0081] 148 - First cover

[0082] 150 - Slot on the first cover

[0083] 152 - Second cover

[0084] 154 - Plurality of elongated fins on first cover 156 - Splines on output shaft158 - Pulley connected to output shaft 160, 164 - Fastener

[0085] 162 - One or more mounting holes 166 - End of motor shaft

[0086] 168 - One or more ribs

Claims

WE CLAIM1. A housing assembly (100), comprising:a motor casing (102) adapted to enclose an electric motor (104); and a transmission casing (106) integrated with the motor casing (102), the transmission casing (106) being extended outwardly from the motor housing (102), andthe transmission casing (106) being adapted to accommodate one or more transmission components of a transmission unit.

2. The housing assembly (100) as claimed in claim 1 comprising a transmission cover (110) configured with the transmission casing (106), wherein the transmission casing (110) with transmission cover (106) defines a chamber (124) therebetween, for enclosing the one or more transmission components in the chamber (124)3. The housing assembly (100) as claimed in claim 2, wherein the transmission cover (110) is detachably secured to the transmission casing (106) for enclosing the one or more transmission components.

4. The housing assembly (100) as claimed in claim 1, wherein the transmission casing (106) comprises:a first portion (106a) oriented coaxially to an axis (X-X’) of the motor casing (102), wherein the first portion (106a) being adapted to receive a portion (112a) of a motor shaft (112) of the electric motor (104); anda second portion (106b) configured to accommodate an output shaft (114), the output shaft (114) being offset with respect to the axis (X-X’) of the motor shaft (112).

5. The housing assembly (100) as claimed in claim 4, wherein the output shaft (114) being operatively coupled to the portion (112a) of the motor shaft (112) through a gear train mechanism (116).

6. The housing assembly (100) as claimed in claim 5, wherein the gear train mechanism (116) comprises:one or more drive gears (116a) mounted onto the portion (112a) of the motor shaft (112); andone or more driven gears (116b) mounted onto the output shaft (114), the one or more driven gears (116b) being engaged to the one or more drive gears (116a).

7. The housing assembly (100) as claimed in claim 6, whereinthe one or more drive gears (116a) being disposed in the first portion (106a), andthe one or more driven gears (116b) being disposed in the second portion (106b).

8. The housing assembly (100) as claimed in claim 1, wherein the transmission casing (106) comprises:a first portion (106a) having one or more first flanges (126) configured to receive a first bearing member (118), the first bearing member (118) being adapted to rotatably support a motor shaft (112) of the electric motor (104); and a second portion (106b) having one or more second flanges (128) configured to support a second bearing member (120), the second bearing member (120) being adapted to rotatably support an output shaft (114).

9. The housing assembly (100) as claimed in claim 2, wherein the transmission cover (110) comprises:one or more third flanges (130) configured to support a third bearing member (132), the third bearing member (132) being adapted to rotatably support a motor shaft (112) of the electric motor (102); andone or more fourth flanges (134) configured to support a fourth bearing member (136), the fourth bearing member (136) being adapted to rotatably support an output shaft (114).

10. The housing assembly (100) as claimed in claim 1, whereinthe motor casing (102) comprises a first end portion (102a) and a second portion (102b),the transmission casing (106) being extended outwardly from the first portion (102), and wherein a side cover (122) being provided for covering an opening defined in the second portion (102b) of the motor casing (102).

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