Description:FIELD OF THE INVENTION

[1] The present disclosure generally relates to a saddle-type vehicle. More particularly, the present disclosure relates to a mid-frame assembly for assembling a motor and a gearbox of the saddle-type vehicle.

BACKGROUND

[2] The transmission drive in a saddle-type vehicle, for example, an electric scooter, includes a gearbox and an electric motor. The electric motor draws energy from a battery and converts it to mechanical energy. The gearbox transfers mechanical power from the electric motor to the wheel. The packaging and connection of the motor with transmission drive like gearbox, belt, and chain, is critical as the motor and the transmission drive will be prone to vibration, noise, power losses, and will affect the efficiency and reliability, service time/warranty, and durability.

[3] In existing electric scooter layout, the motor is assembled on a mid-frame structure. During this assembly, a tapered or wedge-shaped material is generally used to orient the motor in a particular fashion on the mid-frame structure with respect to an intermediate pulley. Only a highly skilled laborer can achieve this orientation. Gaps are generated between the motor and the mid-frame structure during this assembly process which are closed using shims. The motor to mid-frame mounting is through a flange bolting where the motor functions as a cantilever structure. The arrangement of the motor to mid-frame mounting through the flange increases motor vibration and noise. The vibration in turn affects the motor shaft alignment with belt and pulley that are connected to it, disturbing the alignment. Further, assembly stresses introduced during assembly of the motor and the transmission drive amplify these effects. Existing electric scooter layout of motor assembly has transmission power losses, noise and vibration, and frequent belt loosening and failure.

[4] Furthermore, every time the electric motor is disassembled from the mid-frame structure for servicing, a highly skilled laborer is required to reassemble the serviced motor to the mid-frame structure due to the complex assembly process as described earlier, which may not be feasible due to the dearth of highly skilled manual labor. This makes assembling the electric motor difficult, time consuming, and not cost-efficient.

[5] There is a need for a mid-frame assembly to accommodate motor and gearbox for improved and sustained performance of the motor and transmission, and easier serviceability and reduced warranty cost of the motor.

SUMMARY

[6] This summary is provided to introduce a selection of concepts, in a simplified format, that is further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.

[7] One objective of the present disclosure is to reduce noise and vibration of a motor in a saddle-type vehicle and improve performance of the motor and transmission.

[8] Another objective of the present disclosure is to provide a mid-frame assembly for accommodating a motor and a gearbox for better serviceability and to reduce warranty cost of the motor.

[9] Accordingly, an assembly is disclosed. The assembly includes a substantially U-shaped mid-frame. The substantially U-shaped mid-frame includes a front arm, a rear arm and a mid-portion extending between the front arm and the rear arm. The substantially U-shaped mid-frame includes an intermediate pulley shaft extending through the mid-portion of the substantially U-shaped mid-frame. The substantially U-shaped mid-frame includes a motor comprising a motor shaft and disposed partially within the substantially U-shaped mid-frame. The substantially U-shaped mid-frame includes a gearbox unit comprising a plurality of side flanges detachably coupled to a plurality of side flanges of the motor, respectively. The gearbox unit includes a pinion gear and an output gear, wherein the pinion gear is detachably coupled to the motor shaft and the output gear is detachably coupled to the intermediate pulley shaft.

[10] To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[11] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[12] Figure 1 illustrates a perspective side view of a saddle-type vehicle according to an embodiment of the present disclosure;

[13] Figure 2A illustrates a perspective view of an assembly according to an embodiment of the present disclosure;

[14] Figure 2B illustrates a perspective side view of a U-shaped mid-frame according to an embodiment of the present disclosure;

[15] Figure 2C illustrates perspective top view of a U-shaped mid-frame according to an embodiment of the present disclosure;

[16] Figure 2D illustrates a perspective side view of the U-shaped mid-frame with a motor according to an embodiment of the present disclosure;

[17] Figure 2E illustrates a perspective front view of the U-shaped mid-frame with the motor and a gearbox unit to be assembled, according to an embodiment of the present disclosure;

[18] Figure 2F illustrates a perspective front view of the U-shaped mid-frame with the assembled motor and the gearbox unit according to an embodiment of the present disclosure;

[19] Figure 2G illustrates a perspective side view of the U-shaped mid-frame with the assembled motor and the gearbox unit and a mid-frame bracket according to an embodiment of the present disclosure;

[20] Figure 2H illustrates a perspective top view of the U-shaped mid-frame with the assembled motor and the gearbox unit and fasteners according to an embodiment of the present disclosure; and

[21] Figure 2I illustrates a perspective side view of the assembled motor and gearbox unit in a saddle-type vehicle, according to an embodiment of the present disclosure.
[22] Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of vehicle, one or more components of the vehicle may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF FIGURES

[23] For the purpose of promoting an understanding of the principles of the present disclosure, reference will now be made to the various embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the present disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates.

[24] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof.

[25] Whether or not a certain feature or element was limited to being used only once, it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element.” Furthermore, the use of the terms “one or more” or “at least one” feature or element do not preclude there being none of that feature or element, unless otherwise specified by limiting language including, but not limited to, “there needs to be one or more…” or “one or more elements is required.”

[26] Reference is made herein to some “embodiments.” It should be understood that an embodiment is an example of a possible implementation of any features and/or elements of the present disclosure. Some embodiments have been described for the purpose of explaining one or more of the potential ways in which the specific features and/or elements of the proposed disclosure fulfil the requirements of uniqueness, utility, and non-obviousness.

[27] Use of the phrases and/or terms including, but not limited to, “a first embodiment,” “a further embodiment,” “an alternate embodiment,” “one embodiment,” “an embodiment,” “multiple embodiments,” “some embodiments,” “other embodiments,” “further embodiment”, “furthermore embodiment”, “additional embodiment” or other variants thereof do not necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or in the context of more than one embodiment, or in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.

[28] Any particular and all details set forth herein are used in the context of some embodiments and therefore should not necessarily be taken as limiting factors to the proposed disclosure.

[29] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

[30] Embodiments of the present disclosure will be described below in detail with reference to the accompanying drawings.

[31] For the sake of clarity, the first digit of a reference numeral of each component of the present disclosure is indicative of the Figure number, in which the corresponding component is shown. For example, reference numerals starting with digit “1” are shown at least in Figure 1. Similarly, reference numerals starting with digit “2” are shown at least in Figure 2.

[32] An Electric Vehicle (EV) or a battery powered vehicle including, and not limited to two-wheelers such as scooters, mopeds, motorbikes/motorcycles; three-wheelers such as auto-rickshaws, four-wheelers such as cars and other Light Commercial Vehicles (LCVs) and Heavy Commercial Vehicles (HCVs) primarily work on the principle of driving an electric motor using the power from the batteries provided in the EV. Furthermore, the electric vehicle may have at least one wheel which is electrically powered to traverse such a vehicle. The term ‘wheel’ may be referred to any ground-engaging member which allows traversal of the electric vehicle over a path. The types of EVs include Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV) and Range Extended Electric Vehicle. However, the subsequent paragraphs pertain to the different elements of a Battery Electric Vehicle (BEV).
[33] In construction, as illustrated in Figure 1, an EV (10) typically comprises a battery or battery pack (12) enclosed within a battery casing and includes a Battery Management System (BMS), an on-board charger (14), a Motor Controller Unit (MCU), an electric motor (16) and a transmission system (18). The primary function of the above-mentioned elements is detailed in the subsequent paragraphs: The battery of an EV (10) (also known as Electric Vehicle Battery (EVB) or traction battery) is re-chargeable in nature and is the primary source of energy required for the operation of the EV, wherein the battery (12) is typically charged using the electric current taken from the grid through a charging infrastructure (20). The battery may be charged using Alternating Current (AC) or Direct Current (DC), wherein in case of AC input, the on-board charger (14) converts the AC signal to DC signal after which the DC signal is transmitted to the battery via the BMS. However, in case of DC charging, the on-board charger (14) is bypassed, and the current is transmitted directly to the battery via the BMS.

[34] The battery (12) is made up of a plurality of cells which are grouped into a plurality of modules in a manner in which the temperature difference between the cells does not exceed 5 degrees Celsius. The terms “battery”, “cell”, and “battery cell” may be used interchangeably and may refer to any of a variety of different rechargeable cell compositions and configurations including, but not limited to, lithium-ion (e.g., lithium iron phosphate, lithium cobalt oxide, other lithium metal oxides, etc.), lithium-ion polymer, nickel metal hydride, nickel cadmium, nickel hydrogen, nickel-zinc, silver zinc, or other battery type/configuration. The term “battery pack” as used herein may be referred to multiple individual batteries enclosed within a single structure or multi-piece structure. The individual batteries may be electrically interconnected to achieve a desired voltage and capacity for a desired application. The Battery Management System (BMS) is an electronic system whose primary function is to ensure that the battery (12) is operating safely and efficiently. The BMS continuously monitors different parameters of the battery such as temperature, voltage, current and so on, and communicates these parameters to the Electronic Control Unit (ECU) and the Motor Controller Unit (MCU) in the EV using a plurality of protocols including and not limited to Controller Area Network (CAN) bus protocol which facilitates the communication between the ECU/MCU and other peripheral elements of the EV (10) without the requirement of a host computer.

[35] The MCU primarily controls/regulates the operation of the electric motor based on the signal transmitted from the vehicle battery, wherein the primary functions of the MCU include starting of the electric motor (16), stopping the electric motor (16), controlling the speed of the electric motor (16), enabling the vehicle to move in the reverse direction and protect the electric motor (16) from premature wear and tear. The primary function of the electric motor (16) is to convert electrical energy into mechanical energy, wherein the converted mechanical energy is subsequently transferred to the transmission system of the EV to facilitate movement of the EV. Additionally, the electric motor (16) also acts as a generator during regenerative braking (i.e., kinetic energy generated during vehicle braking/deceleration is converted into potential energy and stored in the battery of the EV). The types of motors generally employed in EVs include, but are not limited to DC series motor, Brushless DC motor (also known as BLDC motors), Permanent Magnet Synchronous Motor (PMSM), Three Phase AC Induction Motors and Switched Reluctance Motors (SRM). In an embodiment, the motor (16) may be disposed near the rear wheel (22b).

[36] The transmission system (18) of the EV (10) facilitates the transfer of the generated mechanical energy by the electric motor (16) to the wheels (22a,22b) of the EV. Generally, the transmission systems (18) used in EVs include single speed transmission system and/or multi-speed (i.e., two-speed) transmission system, wherein the single speed transmission system comprises a single gear pair whereby the EV is maintained at a constant speed. However, the multi-speed/two-speed transmission system comprises a compound planetary gear system with a double pinion planetary gear set and a single pinion planetary gear set, thereby resulting in two different gear ratios which facilitates higher torque and vehicle speed. In an embodiment, when the motor (16) is disposed near the rear wheel (22b), the transmission system (18) may be disposed between the motor (16) and the rear wheel (22b).

[37] In an embodiment, the motor (16) and the transmission system (18) may be collectively referred to as a powertrain.

[38] In one embodiment, all data pertaining to the EV (10) and/or charging infrastructure (20) are collected and processed using a remote server (known as cloud) (24), wherein the processed data is indicated to the rider/driver of the EV (10) through a display unit present in the dashboard (26) of the EV (10). In an embodiment, the display unit may be an interactive display unit. In another embodiment, the display unit may be a non-interactive display unit.

[39] Embodiments of the present disclosure describe a mid-frame assembly in the saddle-type vehicle (10) that includes the motor (16).

[40] Figure 2A illustrates a perspective view of an assembly (200), according to an embodiment of the present disclosure. The assembly (200) includes a substantially U-shaped mid-frame (205). The U-shaped mid-frame (205) is designed for accommodating bigger sized motor, gearbox, rear shock, battery, drive controller and also for higher durability, easier serviceability, and reducing assembly stress. The structure of the assembly (200) and the substantially U-shaped mid-frame (205) is explained in detail below in conjunction with Figures 2A to 2I.

[41] Structure of the U-shaped mid-frame (205):

[42] In one embodiment, the U-shaped mid-frame (205) is a cast mid frame base with three regions, a front portion, a mid-portion, and a rear portion. The substantially U-shaped mid-frame (205) includes a front arm (210) in the front portion. The front arm (210) structure has a substantially rectangular shaped member (210a) and a U-shaped member (210b) in the middle portion of the substantially rectangular shaped member (210a). Figure 2B illustrates a perspective side view of a U-shaped mid-frame (205), depicting the side view of the substantially rectangular shaped member (210a) and the U-shaped member (210b).

[43] The substantially rectangular shaped member (210a) functions as a support member to side channels (290) of the vehicle. The side channels (290) of the vehicle are bolted on to the substantially rectangular shaped member (210a) as illustrated in Figure 2I. The U-shaped member (210b) functions as an anchoring platform for mounting one flange (230a) of a motor (230). Further, the U-shaped member (210b) is used to mount a mid-frame bracket (265) as illustrated in Figure 2G. The mid-frame bracket (265) is detachably coupled to the front arm (210) of the substantially U-shaped mid-frame (205).

[44] The substantially U-shaped mid-frame (205) includes a rear arm (215) in the rear portion. The rear arm (215) includes a first arm (215a) and a second arm (215b) with space (S) in between the first arm (215a) and the second arm (215b) to accommodate a shock absorber (not shown), as illustrated in Figure 2C. Further, the first arm (215a) and the second arm (215b) provide support for a rear frame (not shown). The substantially U-shaped mid-frame (205) includes a mid-portion (220) extending between the front arm (210) and the rear arm (215) as illustrated in Figure 2B and Figure 2C. The mid-portion (220) is where the motor (230) is mounted. While the U-shaped member (210b) of the front arm (210) functions as an anchoring platform for mounting one flange (230a) of the motor (230), the mid-portion (220) functions as another anchoring platform for mounting the other flange (230b) of the motor (230).

[45] The substantially U-shaped mid-frame (205) includes an intermediate pulley shaft (225) extending through the mid-portion (220) of the substantially U-shaped mid-frame (205) as illustrated in Figure 2C and Figure 2D. The intermediate pulley shaft (225) comprises a stopper portion (225a) extending radially outwards and in contact with a one side of the mid-portion (220) of the substantially U-shaped mid-frame (205) as illustrated in Figure 2C. In existing vehicle layouts, the intermediate pulley shaft (225) is entered from the Left-hand side (LH) of the vehicle frame. However, in the present disclosure, in an embodiment, the intermediate pulley shaft (225) is entered into the substantially U-shaped mid-frame (205) by sliding it from the Right hand (RH) side. The stopper portion (225a) enables the intermediate pulley shaft (225) to be located in position when it is in contact with the right side of the mid-portion (220). In an alternate embodiment, the intermediate pulley shaft (225) may be entered into the substantially U-shaped mid-frame (205) by sliding it from the Left hand (LH) side so that the stopper portion (225a) is in contact with the left side of the mid-portion (220).

[46] In an embodiment, the intermediate pulley shaft (225) is a hollow shaft.

[47] The substantially U-shaped mid-frame (205) includes the motor (230) wherein the motor (230) is mounted or seated or housed on the U-shaped mid-frame (205). The motor (230) includes a motor shaft (235) and disposed partially within the substantially U-shaped mid-frame (205). The motor (230) includes front and rear flanges (230a, 230b), wherein the front and the rear flanges (230a, 230b) are detachably coupled to the front arm (210) and the rear arm (215) respectively through a plurality of fasteners (270a, 270b) oriented along a Z-axis as illustrated in Figure 2H. The substantially U-shaped mid-frame (205) includes a gearbox unit (240) comprising a plurality of side flanges (245) detachably coupled to a plurality of side flanges (250) of the motor (230) respectively as illustrated in Figure 2H. In an embodiment, the Z-axis is defined along a height of the vehicle, as shown in Figure 1.

[48] Referring to Figure 2E, the gearbox unit (240) includes a pinion gear (255). The gearbox unit (240) includes an output gear (260). The pinion gear (255) is detachably coupled to the motor shaft (235) and the output gear (260) is detachably coupled to the intermediate pulley shaft (225). The plurality of side flanges (245) of the gearbox unit (240) are detachably coupled to the plurality of side flanges (250) of the motor (230) respectively through a plurality of fasteners (275) oriented along a Y-axis as illustrated in Figure 2H. In an embodiment, the Y-axis is defined along a width of the vehicle, as shown in Figure 2G. The gearbox unit (240) comprises a pulley (240a) coupled to the output gear (260) as illustrated in Figure 2E. A slotted round nut (240b) is used to clamp the gearbox unit (240) to the U-shaped mid-frame (205). Figure 2F illustrates a perspective front view of the U-shaped mid-frame (205) with the assembled motor (230) and the gearbox unit (240).

[49] The assembly (200) includes a swingarm (280) coupled to the intermediate pulley shaft (225) using a hex bolt (292) that passes through the side channel (290), swingarm (280), and the intermediate pulley shaft (225) as illustrated in Figure 2I. The assembly (200) can also accommodate the drive controller (285) as illustrated in Figure 2I.

[50] Assembly method of the motor (230) and the gearbox unit (240):

[51] The method steps involved in assembling the motor (230), the gearbox unit (240) and other parts on the substantially U-shaped mid-frame (205) are further explained below.

[52] The first step in the assembly method is to slide an intermediate pulley shaft (225) from the first side, i.e., the RH side, to a second side, i.e., the LH side, of a mid-portion (220) of a substantially U-shaped mid-frame (205). The substantially U-shaped mid-frame (205) includes a front arm (210), a rear arm (215), and the mid-portion (220) extending between the front arm (210) and the rear arm (215). The intermediate pulley shaft (225) after sliding and projecting from the U-shaped mid-frame (205) is illustrated in Figure 2C.

[53] The next step is to partially mount a motor (230) onto the substantially U-shaped mid-frame (205) using fasteners (270b) such that the motor (230) is movable along X-axis and Y-axis. The movement of the motor (230) in the X-axis and the Y-axis is facilitated by the clearance hole defined in the side flanges (230a, 230b) of the motor (230). This is illustrated in Figure 2D.

[54] The next step is to slide a gearbox unit (240) on the intermediate pulley shaft (225) and a motor shaft (235), wherein the pinion gear (255) of the gearbox unit (240) is aligned with the motor shaft (235) by rotating the gearbox unit (240) about the intermediate pulley shaft (225) and moving the motor (230) along the X-axis.

[55] The method includes clamping the gearbox unit (240) to the mid-frame (210) using a slotted round nut (240b) as illustrated in Figure 2E.

[56] The method includes press-fitting an oil seal (240c) to an output gear (260) in the gearbox unit (240) and sliding it on the intermediate pulley shaft (225).

[57] The method includes clamping the gearbox unit (240) and the motor (230) through a plurality of fasteners (275) oriented along the Y-axis as illustrated in Figure 2G.

[58] The method includes clamping the motor (230) and the substantially U-shaped mid-frame (205) through a plurality of fasteners (270a, 270b) oriented along the Z-axis as illustrated in Figure 2H.

[59] Further, the method includes detachably coupling a mid-frame bracket (265) to the front arm (210) of the U-shaped mid-frame (205) using a plurality of fasteners oriented along the y-axis as illustrated in Figure 2G.

[60] Servicing the gearbox unit (240) and/or the motor (230):

[61] At times, there is a need to service the gearbox unit (240) and/or the motor (230). The U-shaped mid-frame (205) enables easy serviceability of the gearbox unit (240) and/or the motor (230).

[62] For servicing the gearbox unit (240), disassemble the gearbox unit (240) from the U-shaped mid-frame (205) as follows:

[63] First step involves removal of the oil seal (240c). Then, next step involves removal of the slotted round nut (240b). Further, remove the three bolts or fasteners (275) connecting the gearbox unit (240) and the motor (230). Then, slide the intermediate pulley shaft (225) towards RH side. Further, slide the gearbox unit (240) towards left till there is no contact with the motor shaft (235). Further, remove the gearbox unit (240) from bottom of the U-shaped mid-frame (205).

[64] For servicing the motor (230), disassemble the motor (230) from the U-shaped mid-frame (205) as follows:

[65] First step involves removal of the oil seal (240c). Then, the next step involves removal of the slotted round nut (240b) using a tool. Further, remove the three bolts or fasteners (275) connecting the gearbox unit (240) and the motor (230). Further, remove the four bolts or fasteners (270a, 270b) connecting the motor (230) and the U-shaped mid-frame (205). Further, slide the gearbox unit (240) towards left till there is no contact with the motor shaft (235). Further, remove the motor (230) from top of the U-shaped mid-frame (205).

[66] It is to be noted that the motor (230) is removed from the top while the gearbox unit (240) is removed from the bottom of the U-shaped mid-frame (205) for servicing.

[67] Design considerations:

[68] The following design considerations were considered for the U-shaped mid-frame (205).

[69] The joints or connections are designed to provide maximum stiffness in the mounting region in the U-shaped mid-frame (205). Critical parameters like Center distance (CD) between the intermediate pulley shaft (225) and the motor shaft (235) directly affects power transmission efficiency, wear and life of gear teeth, noise, and vibration. To achieve the CD with close tolerance, assembly procedure was set in synchronous with the design features of frame parts. Based on tolerance stack requirements for the assembly at worst case parts, sufficient provision like clearance holes at mounting locations are kept in design. Also, free rotation of gearbox unit (240) about intermediate pulley shaft (225) and sliding of the motor (230) helps in overcoming the misalignment of motor shaft axis and pinion axis due to the manufacturing variations of the components and its stack up at assembly level.

[70] It is to be noted that design of parts and assembly sequence and arrangement is such that unless all the parts are assembled and aligned, none of the bolting joints are fixed and kept in loose condition. Once loose assembly is over, clamping of parts are performed as per assembly procedure. In this way, assembly stresses induced in the components, especially gears, due to gaps generated during assembly due to tolerances are reduced to minimum.

[71] Mid-frame (205) along with gearbox unit (240) and the motor (230) are assembled such that the assembly is compact in nature to be accommodated within a constrained space. In an embodiment, the space to accommodate this assembly may be constrained by a drive controller at the top, swingarm, side channels, motor cover panels at the sides and the motor cover panels at the front. Also, this compact assembly allows bigger motors so as to improve motor performance.

[72] This compact assembly also results in improved durability, stiffness, and strength of the chassis of the vehicle, as the motor (230) and the gearbox unit (240) together act as a stiffening member.

[73] The motor (230) is mounted to the mid-frame (205) using side flanges (230a, 230b) as a simply supported beam structure whose bolting joint center lies close to the center of gravity (CG) of the motor (230). This mounting method significantly minimizes critical parameters such as vibration and noise of the motor (230). Also, since the gearbox unit (240) is connected to the motor (230) and the mid-frame (205), the vibrations of the motor (230) are further dampened. By reducing the vibrations, consistent and reduced noise can be achieved.

[74] Advantages:

[75] There are various advantages of the U-shaped mid-frame (205).

[76] The motor (230) and the gearbox unit (240) are arranged in the U-shaped mid-frame (205) such that assembly stress, vibration and noise are minimized to zero. Due to introduction of single stage compound gear drive in primary stage i.e., via the pinion gear (255) and the Output gear (260), the power transmission efficiency is improved, and noise and vibration is reduced. There is improved and sustained performance of the motor (230) and the gearbox unit (240). Further, there is easier serviceability and warranty cost reduction of the motor (230).

[77] In this application, unless specifically stated otherwise, the use of the singular includes the plural and the use of “or” means “and/or.” Furthermore, use of the terms “including” or “having” is not limiting. Any range described herein will be understood to include the endpoints and all values between the endpoints. Features of the disclosed embodiments may be combined, rearranged, omitted, etc., within the scope of the invention to produce additional embodiments. Furthermore, certain features may sometimes be used to advantage without a corresponding use of other features.

[78] List of reference numerals:

Components Reference numerals
Assembly 200
Substantially U-shaped mid-frame 205
Front arm 210
Rear arm 215
Mid-portion 220
Intermediate pulley shaft 225
Motor 230
Motor shaft 235
Gearbox unit 240
Side flanges 245
Side flanges 250
Pinion gear 255
Output gear 260
Mid-frame bracket 265
Front and rear flanges 230a, 230b
Fasteners 270a, 270b
Fasteners 275
Slotted round nut 240b
Oil seal 240c
Stopper portion 225a
Rectangular shaped member 210a
U-shaped member 210b
First arm 215a
Second arm 215b
Space S
Swingarm 280
drive controller 285
Pulley 240a
Side channels 290
Hex bolt 292 , Claims:1. An assembly (200) comprising:
a substantially U-shaped mid-frame (205) comprising:
a front arm (210);
a rear arm (215); and
a mid-portion (220) extending between the front arm (210) and the rear arm (215);
an intermediate pulley shaft (225) extending through the mid-portion (220) of the substantially U-shaped mid-frame (205);
a motor (230) comprising a motor shaft (235) and disposed partially within the substantially U-shaped mid-frame (205); and
a gearbox unit (240) comprising a plurality of side flanges (245) detachably coupled to a plurality of side flanges (250) of the motor (230) respectively, wherein the gearbox unit (240) comprises:
a pinion gear (255); and
an output gear (260), wherein the pinion gear (255) is detachably coupled to the motor shaft (235) and wherein the output gear (260) is detachably coupled to the intermediate pulley shaft (225).

2. The assembly (200) as claimed in claim 1, comprising a mid-frame bracket (265) detachably coupled to the front arm (210) of the substantially U-shaped mid-frame (205).

3. The assembly (200) as claimed in claim 1, wherein the motor (230) comprises front and rear flanges (230a, 230b), wherein the front and rear flanges (230a, 230b) are detachably coupled to the front arm (210) and the rear arm (215) respectively through a plurality of fasteners (270a, 270b) oriented along a z-axis.

4. The assembly (200) as claimed in claim 1, wherein the plurality of side flanges (245) of the gearbox unit (240) are detachably coupled to the plurality of side flanges (250) of the motor (230) respectively through a plurality of fasteners (275) oriented along a y-axis.

5. The assembly (200) as claimed in claim 1, wherein the gearbox unit (240) comprises a pulley (240a) coupled to the output gear (260).

6. The assembly (200) as claimed in claim 1, wherein the intermediate pulley shaft (225) comprises a stopper portion (225a) extending radially outwards and in contact with a right side of the mid-portion (220) of the substantially U-shaped mid-frame (205).

7. The assembly (200) as claimed in claim 1, wherein the front arm (210) comprises a substantially rectangular shaped member (210a) and a U-shaped member (210b) disposed on a middle portion of the substantially rectangular shaped member (210a).

8. The assembly (200) as claimed in claim 1, wherein the rear arm (215) comprises a first arm (215a), a second arm (215b), and space (S) formed between the first arm (215a) and the second arm (215b), wherein the space (S) is configured to accommodate a shock absorber, wherein the first arm (215a) and the second arm (215b) are configured to provide support for a rear frame.

9. The assembly (200) as claimed in claim 1, comprising a swingarm (280) coupled to the gearbox unit (240) using a hex bolt (292).

10. A method comprising:
sliding an intermediate pulley shaft (225) from a first side to a second side of a mid-portion (220) of a substantially U-shaped mid-frame (205), wherein the substantially U-shaped mid-frame (205) comprises a front arm (210), a rear arm (215), and the mid-portion (220) extending between the front arm (210) and the rear arm (215);
mounting a motor (230) partially within the substantially U-shaped mid-frame (205) such that the motor (230) is movable along two axes;
sliding a gearbox unit (240) along the intermediate pulley shaft (225) and a motor shaft (235), wherein the gearbox unit (240) is aligned with the motor (230) by rotating the gearbox unit (240) and moving the motor (230) along the y-axis;
clamping the gearbox unit (240) to the motor (230) by using a slotted round nut (240b);
press-fitting an oil seal (240c) between an output gear (260) in the gearbox unit (240) and the intermediate pulley shaft (225);
clamping the gearbox unit (240) to the motor (230) through a plurality of fasteners (275) oriented along the y-axis;
clamping the motor (230) to the substantially U-shaped mid-frame (205) through a plurality of fasteners (270a, 270b) oriented along a z-axis; and
detachably coupling a mid-frame bracket (265) to the front arm (210) of the U-shaped mid-frame (205), using a plurality of fasteners oriented along the y-axis.