Description:FORM 2

THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

A MULTI-MODE TRANSMISSION ASSEMBLY FOR AN ELECTRIC VEHICLE

APPLICANT:

TVS MOTOR COMPANY LIMITED, (an Indian Company)

at: “Chaitanya”, No. 12, Khader Nawaz Khan Road, Nungambakkam, Chennai – 600034, Tamil Nadu, India.

The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[0001] The present invention relates to a multi-mode transmission assembly for an electric vehicle.
BACKGROUND
[0002] It is known that in an electric vehicle, an electric motor is provided as a power source and this electric motor (hereinafter referred to as ‘motor’) is coupled to a single-speed gearbox with a reduction gear mechanism. The single-speed gearbox is responsible for transmitting a driving torque generated by the electric motor to the wheels of the vehicle. Further, the gear reduction mechanism helps in harnessing the high rotation produced by the motor so that it can propel the electric vehicle at a desired speed. Since the electric vehicle uses a single-speed transmission, it does not need to shift up and down between gears like a conventional vehicle powered by an internal combustion vehicle.
[0003] However, the single-speed transmissions unlike their multi-speed counterparts are not configured to change torque and speed based on various inputs from a user. This configuration of the single-speed transmission inevitably introduces a trade-off between load-carrying capacity and top speed. This limitation stems from the inherent challenge of balancing the requirements for both aspects within a single-speed configuration, when prioritizing load-carrying capacity, there is a consequential impact on top speed, and vice versa. Therefore, a single-speed transmission which is deployed for a high load-carrying capacity is geared in a high torque configuration and a single-speed transmission which is deployed for a high speed is geared in a high RPM configuration. For example, an electric vehicle requires high torque when it is carrying a load and in an unloaded scenario it requires high speed. Apart from the load conditions, the electric vehicle may require different torque and speed configurations based on the terrain. For example, in an offroad terrain, the electric vehicle may require a high torque configuration compared to a paved road where the electric vehicle may require a high-speed configuration, this is not possible with a single-speed transmission.
[0004] To overcome this problem, manufacturers often resort to increasing the motor size, an approach that not only escalates costs but also complicates the layout packaging of the electric vehicle. With a growing demand for electric vehicles having enhanced load-carrying capabilities without compromising speed, there arises a crucial need to rethink the transmission systems for electric vehicles.
[0005] Thus, there exists a need for a solution in the form of a multi-mode transmission assembly, which can achieve a superior load-carrying capacity and elevate top-speed performance, thereby enabling an optimum utilisation of a drivetrain of the electric vehicle. Therefore, the present invention proposes a multi-mode transmission assembly for an electric vehicle which will be able to overcome the above-mentioned problems.

SUMMARY OF THE INVENTION
[0006] The present invention relates to a multi-mode transmission assembly for an electrical vehicle. A multi-mode transmission assembly for an electric vehicle, the multi-mode transmission assembly comprises a countershaft, a drive shaft and a gear-shifting assembly. The countershaft is configured to receive a torque from an electric motor of the electric vehicle via a clutch assembly. The drive shaft is configured to receive the torque from the countershaft and rotatably mount a plurality of drive gears. The plurality of drive gears in a first configuration and a second configuration is configured to interchangeably transfer the torque to a plurality of rotating members of the electric vehicle via a differential assembly. The gear-shifting assembly is configured to interchangeably engage the plurality of drive gears to enable the first configuration and the second configuration.
[0007] The present invention also relates to a method of torque transfer in a multi-mode transmission assembly of an electric vehicle. The method comprises a first step, a second step and a third step. In the first step, disengages a countershaft from an electric motor of the electric vehicle via a clutch assembly of the multi-mode transmission assembly. The countershaft transfers a torque received from the electric motor to a plurality of drive gears via a first counter gear and a second counter gear. In the second step, select between a first configuration and a second configuration of a plurality of drive gears via a gear-shifting assembly. The plurality of drive gears is configured to transfer the torque to a drive shaft. The first configuration enables a high torque and a low-speed transmission to a differential assembly of the multi-mode transmission assembly, and the second configuration enables a high-speed and a low-torque transmission to the differential assembly. In the third step, engaging the countershaft with the electric motor via the clutch assembly thereby enabling the transfer of the torque from the drive shaft to the differential assembly.
[0008] The present invention also relates to an electric vehicle. The electric vehicle comprises an electric motor and a multi-mode transmission assembly. The electric motor is configured to generate a torque to propel the electric vehicle. The multi-mode transmission assembly is configured to transmit the torque from the electric motor to a plurality of rotating members of the electric vehicle. The multi-mode transmission assembly comprises a countershaft, a drive shaft and a gear-shifting assembly. The countershaft is configured to receive the torque from the electric motor of the electric vehicle via a clutch assembly. The drive shaft is configured to receive the torque from the countershaft and the drive shaft is configured to rotatably mount a plurality of drive gears. The plurality of drive gears in a first configuration and a second configuration is configured to interchangeably transfer the torque to the plurality of rotating members via a differential assembly. The gear-shifting assembly is configured to interchangeably engage the plurality of gears to enable the first configuration and the second configuration.

BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The proposed invention is described with reference to an exemplary embodiment of a multi-mode transmission assembly for an electric vehicle. The same reference numerals are used throughout the drawings to reference similar features and components. Description of certain details and implementations follow, including a description below, as well as a discussion of other potential embodiments described below, as well as a discussion of other potential embodiments or implementations of the inventive concepts provided below, followed by a more detailed description with reference to the drawings.
[0010] Figure 1: illustrates a perspective view of a multi-mode transmission assembly without one or more covers of the multi-mode transmission assembly as per another embodiment of the present disclosure.
[0011] Figure 2: illustrates an exploded view of a multi-mode transmission assembly as per another embodiment of the present disclosure.
[0012] Figure 3: illustrates a right perspective view of a multi-mode transmission assembly as per another embodiment of the present disclosure.
[0013] Figure 4: illustrates a left perspective view of a multi-mode transmission assembly as per another embodiment of the present disclosure.
[0014] Figure 5: illustrates a right-side view of a multi-mode transmission assembly along with an axis A-A being shown as per another embodiment of the present disclosure.
[0015] Figure 6: illustrates a cut-section view of a multi-mode transmission assembly along the axis A-A as per another embodiment of the present disclosure.
[0016] Figure 7: illustrates a method of operating a multi-mode transmission assembly as per another embodiment of the present disclosure.
[0017] Figure 8: illustrates a left side view of a vehicle as per another embodiment of the present disclosure.

DETAILED DESCRIPTION
[0018] 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 scope of the invention.
[0019] This written description uses examples to provide details on the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
[0020] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in light of the above disclosure.
[0021] In the following description, numerous specific details are set forth to provide a thorough understanding of the embodiments. One skilled in the relevant art will recognize, however, that the techniques described herein can be practised without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring certain aspects.
[0022] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. Further “front” and “rear”, and “left” and “right” referred to in the ensuing description of the illustrated embodiment refer to front and rear, and left and right directions as seen from a rear portion of the vehicle and looking forward. However, it is contemplated that the disclosure in the present invention may be applied to any vehicle without defeating the scope of the present subject matter. The detailed explanation of the constitution of parts other than the present invention which constitutes an essential part has been omitted at suitable places.
[0023] In order to address the one or more of the above-mentioned problems, the present invention provides a multi-mode transmission assembly for an electric vehicle.
[0024] As per one embodiment of the present invention, a multi-mode transmission assembly for an electrical vehicle is provided. In one embodiment, vehicle may be a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle, a multi-axle vehicle etc. A multi-mode transmission assembly for an electric vehicle, the multi-mode transmission assembly comprises a countershaft, a drive shaft and a gear-shifting assembly. The countershaft is configured to receive a torque from an electric motor of the electric vehicle via a clutch assembly. The drive shaft is configured to receive the torque from the countershaft and the drive shaft is configured to rotatably mount a plurality of drive gears. The plurality of drive gears in a first configuration and a second configuration is configured to interchangeably transfer the torque to a plurality of rotating members of the electric vehicle via a differential assembly. The gear-shifting assembly is configured to interchangeably engage the plurality of drive gears to enable the first configuration and the second configuration.
[0025] As per another embodiment of the present invention, in the first configuration, a dog drive of the gear-shifting assembly is engaged with a first drive gear of the plurality of drive gears to transfer the torque received from a first counter gear of the multi-mode transmission assembly to the drive shaft, and the drive shaft is configured to transfer the torque to a final gear drive of the differential assembly via a third drive gear.
[0026] As per another embodiment of the present invention, in the second configuration the dog drive is engaged with a second drive gear of the plurality of drive gears to transfer the torque received from a second counter gear of the multi-mode transmission assembly to the drive shaft and the drive shaft is configured to transfer the torque to a final gear drive of the differential assembly via a third drive gear.
[0027] As per another embodiment of the present invention, the clutch assembly is configured to be mounted to one or more covers of the multi-mode transmission assembly via a clutch shaft and the clutch assembly comprises a clutch plate assembly configured to engage and disengage the countershaft with the electric motor via a clutch housing and the clutch housing receive the clutch plate assembly.
[0028] As per another embodiment of the present invention, the gear-shifting assembly comprises a dog drive, a fork shaft and a stopping member. The dog drive is mounted on the drive shaft via a first gear and configured to engage the plurality of drive gears. In one embodiment, the dog drive is slidably mounted in the drive shaft. The fork shaft is configured to axially move the dog drive on the first gear via a fork member. The stopping member is configured to prevent the axial movement of the dog drive while the dog drive is engaged with the plurality of drive gears and a cam shift. The cam shift is configured to enable manual control of the gear-shifting assembly.
[0029] As per another embodiment of the present invention, the countershaft comprises a first counter gear, a second counter gear, a final gear drive and a transfer shaft mounting. The first counter gear is configured to rotatably enmeshed with a first drive gear of the plurality of drive gears. The second counter gear is configured to rotatably enmeshed with a second drive gear of the plurality of drive gears. The differential assembly comprises the final gear drive is configured to receive the torque from a third drive gear of the drive shaft and the transfer shaft mounting is configured to mount a transfer shaft of the electric vehicle.
[0030] As per another embodiment of the present invention, the drive shaft comprises a first gear and a third drive gear. The first gear is configured to slidably mount a dog drive of the gear-shifting assembly. The third gear is enmeshed with a final gear drive of the differential assembly. The drive shaft is configured to rotate the final gear drive in the first configuration enabled via a first drive gear of the plurality of drive gears and in the second configuration enabled via a second drive gear of the plurality of drive gears.
[0031] As per another embodiment of the present invention, the multi-mode transmission assembly comprises one or more covers configured to provide a sealed enclosure to the multi-mode transmission assembly.
[0032] As per another embodiment of the present invention a method of torque transfer in a multi-mode transmission assembly of an electric vehicle is provided. The method comprises a first step, a second step and a third step. In the first step, disengages a countershaft from an electric motor of the electric vehicle via a clutch assembly of the multi-mode transmission assembly. The countershaft transfers a torque received from the electric motor to a plurality of drive gears via a first counter gear and a second counter gear. In the second step, select between a first configuration and a second configuration of a plurality of drive gears via a gear-shifting assembly. The plurality of drive gears is configured to transfer the torque to a drive shaft. The first configuration enables a high torque and a low-speed transmission to a differential assembly of the multi-mode transmission assembly and the second configuration enables a high-speed and a low-torque transmission to the differential assembly. In the third step, engaging the countershaft with the electric motor via the clutch assembly thereby enabling the transfer of the torque from the drive shaft to the differential assembly.
[0033] As per another embodiment of the present invention, in the first configuration, a dog drive of the gear-shifting assembly is engaged with a first drive gear of the plurality of drive gears to transfer the torque received from a first counter gear of the multi-mode transmission assembly to the drive shaft. The drive shaft transfers the torque to a final gear drive of the differential assembly via a third drive gear.
[0034] As per another embodiment of the present invention, in the second configuration, the dog drive is engaged with a second drive gear of the plurality of drive gears to transfer the torque received from a second counter gear of the multi-mode transmission assembly to the drive shaft. The drive shaft transfers the torque to a final gear drive of the differential assembly via a third drive gear.
[0035] As per another embodiment of the present invention, an electric vehicle is provided. The electric vehicle comprises an electric motor and a multi-mode transmission assembly. The electric motor is configured to generate a torque to propel the electric vehicle. The multi-mode transmission assembly is configured to transmit the torque from the electric motor to a plurality of rotating members of the electric vehicle. The multi-mode transmission assembly comprises a countershaft, a drive shaft and a gear-shifting assembly. The countershaft is configured to receive the torque from the electric motor of the electric vehicle via a clutch assembly. The drive shaft is configured to receive the torque from the countershaft, and the drive shaft is configured to rotatably mount a plurality of drive gears. The plurality of drive gears in a first configuration and a second configuration is configured to interchangeably transfer the torque to the plurality of rotating members via a differential assembly. The gear-shifting assembly is configured to interchangeably engage the plurality of gears to enable the first configuration and the second configuration.
[0036] As per another embodiment of the present invention, the differential assembly is configured to transfer the torque to the plurality of rotating members via a plurality of transfer shafts connected to the differential assembly thereby enabling the movement of the electric vehicle.
[0037] As per another embodiment of the present invention, in the first configuration, a dog drive of the gear-shifting assembly is engaged with a first drive gear of the plurality of drive gears to transfer the torque received from a first counter gear of the multi-mode transmission assembly to the drive shaft and the drive shaft transfers the torque to a final gear drive of the differential assembly via a third drive gear.
[0038] As per another embodiment of the present invention, in the second configuration, a dog drive is engaged with a second drive gear of the plurality of drive gears to transfer the torque received from a second counter gear of the multi-mode transmission assembly to the drive shaft, and the drive shaft transfers the torque to a final gear drive of the differential assembly via a third drive gear.
[0039] The present subject matter is further described with reference to the accompanying figures. It should be noted that the description and figures merely illustrate the principles of the present subject matter. Various configurations may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0040] The foregoing disclosure is not intended to limit the present disclosure to the precise forms of particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure.
[0041] In the foregoing specification, the disclosure has been described with reference to specific embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description is to be considered illustrative and is for the purpose of teaching those skilled in the art the manner of making and using various embodiments of the disclosure. It is to be understood that the forms of the disclosure herein shown and described are to be taken as representative embodiments. Equivalent elements, materials processed or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, and “is”, used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components, or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.
[0042] Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and would in no way be construed as limiting the present disclosure. All joinder references (e.g., attached, affixed, coupled, connected, etc.) are only used to aid the reader’s understanding of the present invention, and may not create limitations, particularly as to the position orientation, or use of the system and/or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other.
[0043] Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken as identifiers, to assist the reader’s understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation, and/or modification relative to, or over, another element, embodiment, variation and/or modification.
[0044] It will also be appreciated that one or more of the elements depicted in the drawings/ figures can also be implemented in a more separated or integrated manner, or even removed, or rendered as inoperable in certain cases, as is useful in accordance with a particular application. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the disclosed invention is not limited to the present embodiments.
[0045] As shown in Figure 1, 2 and 6, the present invention relates to a multi-mode transmission assembly (200) for an electrical vehicle (100). The multi-mode transmission assembly (200) comprises a countershaft (201), a drive shaft (204) and a gear-shifting assembly (400). The countershaft (201) is configured to receive a torque from an electric motor of the electric vehicle (100) via a clutch assembly (300). The drive shaft (204) is configured to receive the torque from the countershaft (201) and the drive shaft (204) is configured to rotatably mount a plurality of drive gears (205, 206). The plurality of drive gears (205, 206) in a first configuration and a second configuration is configured to interchangeably transfer the torque to a plurality of rotating members (101) of the electric vehicle (100) via a differential assembly (207). The gear-shifting assembly (400) is configured to interchangeably engage the plurality of drive gears (205, 206) to enable the first configuration and the second configuration. Thus, by directly connecting the countershaft (201) to the electric motor, input power is efficiently received and transmitted without unnecessary energy loss, ensuring maximum utilization of available power. This direct linkage also minimizes the number of components involved, reducing potential points of failure and simplifying maintenance and troubleshooting procedures. In one embodiment the countershaft (201) has counter gears (202, 203) integrally mounted on it, therefore when the countershaft (201) receives torque from the electric motor, the counter gears (202, 203) rotate along with it. The counter gears (202, 203) are enmeshed with the plurality of drive gears (205, 206), which rotate freely on the drive shaft (204) when the counter gears (202, 203) transfer the torque.
[0046] The countershaft (201) comprises a first counter gear (202), a second counter gear (203) and a final gear drive (208). The first counter gear (202) is configured to rotatably enmeshed with a first drive gear (205) of the plurality of drive gears (205, 206). The second counter gear (203) is configured to rotatably enmeshed with a second drive gear (206) of the plurality of drive gears (205, 206). The differential assembly (207) comprises a final gear drive (208) and a transfer shaft mounting (212). The final gear drive (208) is configured to receive the torque from a third drive gear (210) of the drive shaft (204) and the transfer shaft mounting (212) is configured to rotatably mount a transfer shaft of the electric vehicle (100). During the operation of the electric vehicle (100), the transfer shaft receive the torque from the differential assembly (207) and transfers the received torque to the plurality rotating members (101, shown in Figure 8) of the vehicle and enable a movement of the electric vehicle (100).
[0047] The drive shaft (204) comprises a first gear (209) and the third drive gear (210). The first gear (209) is configured to slidably mount a dog drive (401) of the gear-shifting assembly (400). In an embodiment, the first gear (209) may be a spline gear (shown in Figure 2). The third gear (210) is enmeshed with a final gear drive (208) of the differential assembly (207). The drive shaft (204) is configured to rotate the final gear drive (208) in the first configuration enabled via the first drive gear (205) of the plurality of drive gears (205, 206) and in the second configuration enabled via the second drive gear (206) of the plurality of drive gears (205, 206).
[0048] In the first configuration, a dog drive (401) of the gear-shifting assembly (400) is configured to rotate the drive shaft (204) and engages the first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from the first counter gear (202) of the multi-mode transmission assembly (200) to the drive shaft (204), and the drive shaft (204) is configured to transfer the torque to a final gear drive (208) of the differential assembly (207) via the third drive gear (210). In the first configuration, the multi-mode transmission assembly (200) is configured to provide a high torque and a low-speed transmission to a plurality of rotating members (101, shown in Figure 1) of the electric vehicle (100), and the same is used when vehicle (100) needs higher torque for instance in starting vehicle (100) from stationary position, driving slow in heavy traffic, during higher laden weight, driving up an inclined road etc. .
[0049] Similarly in the second configuration, the dog drive (401) is engaged with the second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from the second counter gear (203) of the multi-mode transmission assembly (200) to the drive shaft (204) and the drive shaft (204) is configured to transfer the torque to a final gear drive (208) of the differential assembly (207) via the third drive gear (210). The plurality of drive gears (205, 206) comprises a grooved profile and the dog drive (401) comprises lugs which are confirming with the grooved profile of the plurality of drive gears (205, 206). In second configuration the multi-mode transmission assembly (200) provides a low torque high speed transmission to the plurality of rotating members (101), and the same is used when the requirement of power and torque is not high such as when vehicle (100) has already attained stable speed and inertia, on open highway or less traffic conditions. Thus, the interoperability between the first configuration and second configuration achieves efficiency in ensuring lower energy consumption in second configuration and yet maintaining desirable speed and supplying higher torque in first configuration only when needed. .
[0050] In an embodiment, the size of the first drive gear (205) is greater than the second drive gear (206), therefore the first drive gear (205) is configured for high torque configuration and the second drive gear (206) is configured for a high-speed configuration.
[0051] The clutch assembly (300) is configured to be mounted to one or more covers (200L, 200R, shown in Figures 3 – 5) of the multi-mode transmission assembly (200) via a clutch shaft (303) and the clutch assembly (300) comprises a clutch plate assembly (302) configured to engage and disengage the countershaft (201) with the electric motor via a clutch housing (301) and the clutch housing (301) receive the clutch plate assembly (302). The one or more covers (200L, 200R) configured to provide a sealed enclosure to the multi-mode transmission assembly (200). The one or more covers (200L, 200R) include a left cover (200L) that encloses and seals the multi-mode transmission assembly (200) from a left side. The one or more covers (200L, 200R) include a right cover (200R) that encloses and seals the multi-mode transmission assembly (200) from a right side.
[0052] The gear-shifting assembly (400) comprises a dog drive (401), a fork shaft (403), a stopping member (405) and a cam shift (402). The dog drive (401) is mounted on the drive shaft (204) via a first gear (209) and configured to engage the plurality of drive gears (205, 206). In one aspect of the invention, the dog drive (401) is slidably mounted on the drive shaft (204). The fork shaft (403) is configured to axially move the dog drive (401) on the first gear (209) via a fork member (404). The stopping member (405) is configured to prevent the axial movement of the dog drive (401) while the dog drive (401) is engaged with the plurality of drive gears (205, 206). In one embodiment, the stopping member is configured as a detent pin and helps in preventing gear slip. The cam shift (402) is configured to enable manual control of the gear-shifting assembly (400).
[0053] As shown in Figure 7, a method (500) of torque transfer in a multi-mode transmission assembly (200) of an electric vehicle (100) is disclosed herein. The method (500) comprises a first step (501), a second step (502) and a third step (503). In the first step (501), a user of the electric vehicle (100) disengages a countershaft (201) from the electric motor of the electric vehicle (100) via a clutch assembly (300) of the multi-mode transmission assembly (200). In an embodiment, the clutch assembly (300) may be operated either by a hand lever or a foot lever. The countershaft (201) transfers a torque received from the electric motor to a plurality of drive gears (205, 206) via a first counter gear (202) and a second counter gear (203) of the multi-mode transmission assembly (200).
[0054] In the second step (502), the user selects either between a first configuration or a second configuration of a plurality of drive gears (205, 206) via a gear-shifting assembly (400). In the first configuration, a dog drive (401) of the gear-shifting assembly (400) is slidably engaged with a first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from the first counter gear (202) to the drive shaft (204). The drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210), thereby enabling a high torque and a low-speed transmission to a plurality of rotating members (101) of the electric vehicle via a differential assembly (207) of the multi-mode transmission assembly (200).
[0055] In the second configuration, the dog drive (401) is engaged with a second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from the second counter gear (203) to the drive shaft (204). The drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via the third drive gear (210), thereby enabling a high-speed and a low-torque transmission to the plurality of rotating members (101) of the electric vehicle via a differential assembly (207) of the multi-mode transmission assembly (200).
[0056] In the third step (503), the user engages the countershaft (201) with the electric motor via the clutch assembly (300) thereby enabling the transfer of the torque from the drive shaft (204) to the plurality of rotating members (101) of the electric vehicle via the multi-mode transmission assembly (200) and allowing the electric vehicle (100) to move.
[0057] As shown in Figure 8, the present invention also relates to an electric vehicle (100). The electric vehicle (100) comprises an electric motor (not shown) and a multi-mode transmission assembly (200). The electric motor is configured to generate a torque to propel the electric vehicle (100). The electric vehicle (100) also includes one or more energy storage unit (not shown). The one or more energy storage unit may include but is not limited to rechargeable battery packs, swappable battery backs, a combination of rechargeable and swappable battery packs and the like. The one or more energy storage unit is the main source of electrical energy to the electric motor and other electrical components of the electric vehicle (100).
[0058] The multi-mode transmission assembly (200) is configured to transmit the torque from the electric motor to a plurality of rotating members (101) of the electric vehicle (100). The multi-mode transmission assembly (200) comprises a countershaft (201), a drive shaft (204) and a gear-shifting assembly (400). The countershaft (201) is configured to receive the torque from the electric motor of the electric vehicle (100) via a clutch assembly (300). The drive shaft (204) is configured to receive the torque from the countershaft (201), and the drive shaft (204) is configured to rotatably mount a plurality of drive gears (205, 206). The plurality of drive gears (205, 206) in a first configuration and a second configuration is configured to interchangeably transfer the torque to the plurality of rotating members (101) via a differential assembly (207). The gear-shifting assembly (400) is configured to interchangeably engage the plurality of gears (205, 206) to enable the first configuration and the second configuration.
[0059] The differential assembly (207) is configured to transfer the torque to the plurality of rotating members (101) via a plurality of transfer shafts connected to the differential assembly (207) thereby enable a movement of the electric vehicle (100).
[0060] In the first configuration, a dog drive (401) of the gear-shifting assembly (400) is engaged with a first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from a first counter gear (202) of the multi-mode transmission assembly (200) to the drive shaft (204) and the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210) thereby enabling a movement of the electric vehicle (100) via the plurality of rotating members (101).
[0061] In the second configuration, a dog drive (401) is engaged with a second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from a second counter gear (203) of the multi-mode transmission assembly (200) to the drive shaft (204), and the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via the third drive gear (210) thereby enabling a movement of the electric vehicle (100) via the plurality of rotating members (101).
[0062] According to the above disclosure, the present invention provides various advantages. The multi-mode transmission assembly (200) can be configured to varied load conditions such as varied weight being carried in the vehicle, various types of road conditions including inclined etc. Additionally, it allows a user of the electric vehicle (100) to select from different gear ratios ensuring optimal torque delivery, enhancing the vehicle's load-carrying capacity. The inclusion of manual gear shifting through the cam shift (402) and fork member (404) arrangement adds user control and adaptability to the system. This manual shifting capability enables operators to tailor gear ratios according to specific requirements, such as load conditions or terrain, thereby optimizing power delivery and fuel efficiency. Additionally, the presence of the stopping member (405) ensures secure gear engagement, preventing slip and maintaining the integrity of the transmission system during operation.
[0063] With multiple gear ratios, the electric vehicle (100) can efficiently navigate between high-speed scenarios and situations demanding increased load-bearing capability through efficient torque transfer in multiple modes. Thus, the multi-mode transmission assembly (200) solves the problem of the trade-off between top speed and torque in various ways. The present invention allows the electric vehicle (100) to efficiently navigate between situations demanding increased load-bearing capability and high-speed scenarios with the help of the first configuration and the second configuration respectively.
[0064] By directly connecting the countershaft (201) to the electric motor, input power is efficiently received and transmitted without unnecessary energy loss, ensuring maximum utilization of available power. This direct linkage also minimizes the number of components involved, reducing potential points of failure and simplifying maintenance and troubleshooting procedures.
[0065] Additionally, the utilization of free-running gears such as the counter gear (202) and the plurality of drive gears (205, 206) ensures smooth and continuous power transfer. These gears, operating in constant mesh, contribute to minimal friction losses, thereby enhancing overall system efficiency and reducing energy consumption. Moreover, the integration of the dog drive (401) into the gear selection mechanism adds versatility and precision to the transmission system. The ability to slide axially and engage with different driven gears provides flexibility in gear ratio selection, allowing for optimized performance in various operating conditions.
[0066] Moreover, by avoiding the single-speed transmission assembly, where improvements in speed/RPM compromise the torque, the multi-mode transmission assembly (200) strikes a balance. It allows for an improved top speed, load handling, efficient torque transmission paths and overall performance.
[0067] Departing from conventional designs utilizing one-way or dual clutches, the proposed clutch assembly (300) in the multi-mode transmission assembly (200) reduces complexity. This simplicity potentially translates to a more reliable and efficient transmission of torque. This feature is also responsible for improved reliability, reduced components, and enhanced performance compared to traditional one-way or dual clutches. Without the need for a one-way clutch, the transmission system may experience fewer instances of mechanical wear and failure associated with clutch engagement and disengagement, thereby potentially enhancing overall reliability and longevity. Moreover, the elimination of the one-way clutch in favor of a single clutch mechanism represents a departure from conventional transmission system, demonstrating innovation and adaptability in the field of automotive engineering. This innovative approach opens avenues for further advancements and optimizations in transmission technology, paving the way for more efficient, reliable, and versatile twin-speed transmission systems in the future. The multi-mode assembly (200) is also compact in nature because of its configuration and does not occupy much space and does not require substantially altering the vehicular design and configuration thereby saving cost of production which is also economically and environmentally beneficial.
[0068] Additionally, the multi-mode transmission assembly (200) provides a better load-carrying capacity, better top speed and better range to the electric vehicle (100). Especially, in case of electric vehicles, where the range of travel is a critical feature for users considering the single source of power is typically a battery pack. Thus, the multi-mode transmission assembly enables optimum usage of electric power based on different load and operating conditions for the user of the vehicle. The energy efficiency is not only environment friendly but also economically advantageous. This is especially true for three wheeled or smaller electric vehicles which is a cost conscious segment including passenger and goods vehicles.
[0069] Therefore, the present invention provides a multi-mode transmission assembly which has a smaller number of components, enhanced performance, better range, reliable configuration, and ease of serviceability because of simplistic configuration.
[0070] 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.
[0071] This written description uses examples to provide details on the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
[0072] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in light of the above disclosure.

List of references

Reference Numeral Meaning
100 An electric vehicle
101 A plurality of rotating members of an electric vehicle
200 A multi-mode transmission assembly for an electric vehicle
200L A left cover of one or more covers
200R A Right cover of one or more covers
201 A countershaft
202 A first counter gear
203 A second counter gear
204 A drive shaft
205 A first drive gear of a plurality of drive gears
206 A second drive gear of the plurality of drive gears
207 A differential assembly
208 A final gear drive
209 A first gear
210 A third drive gear of the drive shaft
300 A clutch assembly
301 A clutch housing
302 A clutch plate assembly
303 A clutch shaft
400 A gear-shifting assembly
401 A dog drive
402 A cam shift
403 A fork shaft
404 A fork member
405 A stopping member
500 A method of torque transfer in a multi-mode transmission assembly
501 a first step of the method of torque transfer in the multi-mode transmission assembly
502 a second step of the method of torque transfer in the multi-mode transmission assembly
503 a third step of the method of torque transfer in the multi-mode transmission assembly

, C , C , Claims:We claim:
1. A multi-mode transmission assembly (200) for an electric vehicle (100), the multi-mode transmission assembly (200) comprising:
a countershaft (201), the countershaft (201) being configured to receive a torque from an electric motor of the electric vehicle (100) via a clutch assembly (300);
a drive shaft (204), the drive shaft (204) being configured to receive the torque from the countershaft (201), the drive shaft (204) being configured to rotatably mount a plurality of drive gears (205, 206);
the plurality of drive gears (205, 206), in a first configuration and a second configuration, being configured to interchangeably transfer the torque to a plurality of rotating members (101) of the electric vehicle (100) via a differential assembly (207); and
a gear shifting assembly (400), the gear shifting assembly (400) being configured to interchangeably engage the plurality of drive gears (205, 206) to enable the first configuration and the second configuration.
2. The multi-mode transmission assembly (200) as claimed in claim 1, wherein in the first configuration:
a dog drive (401) of the gear shifting assembly (400) being engaged with a first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from a first counter gear (202) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) being configured to transfer the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).
3. The multi-mode transmission assembly (200) as claimed in claim 1, wherein in the second configuration:
the dog drive (401) being engaged with a second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from a second counter gear (203) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) being configured to transfer the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).
4. The multi-mode transmission assembly (200) as claimed in claim 1, wherein the clutch assembly (300) being configured to be mounted to one or more covers (200L, 200R) of the multi-mode transmission assembly (200) via a clutch shaft (303), the clutch assembly (300) comprising:
a clutch plate assembly (302), the clutch plate assembly (302) being configured to engage and disengage the countershaft (201) with the electric motor via a clutch housing (301); and
the clutch housing (301) being configured to receive the clutch plate assembly (302).
5. The multi-mode transmission assembly (200) as claimed in claim 1, wherein the gear shifting assembly (400) comprising:
a dog drive (401), the dog drive (401) being mounted on the drive shaft (204) via a first gear (209) and configured to engage the plurality of drive gears (205, 206);
a fork shaft (403), the fork shaft (403) being configured to axially move the dog drive (401) on the first gear (209) via a fork member (404);
a stopping member (405), the stopping member (405) being configured to prevent the axial movement of the dog drive (401) while the dog drive (401) being engaged with the plurality of drive gears (205, 206); and
a cam shift (402), the cam shift (402) being configured to enable manual control of the gear shifting assembly (400).
6. The multi-mode transmission assembly (200) as claimed in claim 1, wherein
the countershaft (201) comprising:
a first counter gear (202), the first counter gear (202) being configured to rotatably enmeshed with a first drive gear (205) of the plurality of drive gears (205, 206); and
a second counter gear (203), the second counter gear (203) being configured to rotatably enmeshed with a second drive gear (206) of the plurality of drive gears (205, 206) and
the differential assembly (207) comprising:
a final gear drive (208), the final gear drive (208) being configured to receive the torque from a third drive gear (210) of the drive shaft (204); and
a transfer shaft mounting (212) the transfer shaft mounting (212) being configured to mount a transfer shaft of the electric vehicle (100).
7. The multi-mode transmission assembly (200) as claimed in claim 1, wherein the drive shaft (204) comprising:
a first gear (209), the first gear (209) being configured to slidably mount a dog drive (401) of the gear shifting assembly (400); and
a third drive gear (210), the third drive gear (210) being enmeshed a final gear drive (208) of the differential assembly (207),
wherein the drive shaft (204) being configured to rotate the final gear drive (208) in the first configuration enabled via a first drive gear (205) of the plurality of drive gears (205, 206) and in the second configuration enabled via a second drive gear (206) of the plurality of drive gears (205, 206).
8. The multi-mode transmission assembly (200) as claimed in claim 1, wherein the multi-mode transmission assembly (200) comprising one or more covers (200L, 200R), the one or more covers (200L, 200R) being configured to provide a sealed enclosure to the multi-mode transmission assembly (200).
9. A method (500) of torque transfer in a multi-mode transmission assembly (200) of an electric vehicle (100), the method (500) comprising steps of:
as a first step (501), disengaging a countershaft (201) from an electric motor of the electric vehicle (100) via a clutch assembly (300) of the multi-mode transmission assembly (200),
the countershaft (201) transfers a torque received from the electric motor to a plurality of drive gears (205, 206) via a first counter gear (202) and a second counter gear (203);
as a second step (502), selecting between a first configuration and a second configuration of the plurality of drive gears (205, 206) via a gear shifting assembly (400), the plurality of drive gears (205, 206) being configured to transfer the torque to a drive shaft (204),
the first configuration enables a high torque and a low-speed transmission to a differential assembly (207) of the multi-mode transmission assembly (200), and
the second configuration enables a high-speed and a low-torque transmission to the differential assembly (207); and
as a third step (503), engaging the countershaft (201) with the electric motor via the clutch assembly (300) thereby enabling the transfer of the torque from the drive shaft (204) to the differential assembly (207).
10. The method (500) for operating the multi-mode transmission assembly (200) as claimed in claim 9, wherein in the first configuration:
A dog drive (401) of the gear shifting assembly (400) is engaged with a first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from the first counter gear (202) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).
11. The method (500) for operating the multi-mode transmission assembly (200) as claimed in claim 9 wherein in the second configuration,
the dog drive (401) is engaged with a second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from the second counter gear (203) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).
12. An electric vehicle (100), the electric vehicle (100) comprising:
an electric motor, the electric motor being configured to generate a torque to propel the electric vehicle (100);
a multi-mode transmission assembly (200), the multi-mode transmission assembly (200) being configured to transmit the torque from the electric motor to a plurality of rotating members (101) of the electric vehicle (100), the multi-mode transmission assembly (200) comprising:
a countershaft (201), the countershaft (201) being configured to receive the torque from the electric motor of the electric vehicle (100) via a clutch assembly (300);
a drive shaft (204), the drive shaft (204) being configured to receive the torque from the countershaft (201), the drive shaft (204) being configured to rotatably mount a plurality of drive gears (205, 206);
the plurality of drive gears (205, 206) in a first configuration and a second configuration being configured to interchangeably transfer the torque to the plurality of rotating members (101) via a differential assembly (207);
a gear shifting assembly (400), the gear shifting assembly (400) being configured to interchangeably engage the plurality of drive gears (205, 206) to enable the first configuration and the second configuration.
13. The electric vehicle (100) as claimed in claim 12, wherein the differential assembly (207) being configured to transfer the torque to the plurality of rotating members (101) via a plurality of transfer shafts connected to the differential assembly (207) thereby enable a movement of the electric vehicle (100).
14. The electric vehicle (100) as claimed in claim 12 wherein, in the first configuration:
a dog drive (401) of the gear shifting assembly (400) is engaged with a first drive gear (205) of the plurality of drive gears (205, 206) to transfer the torque received from a first counter gear (202) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).
15. The electric vehicle (100) as claimed in claim 12 wherein, in the second configuration:
a dog drive (401) is engaged with a second drive gear (206) of the plurality of drive gears (205, 206) to transfer the torque received from a second counter gear (203) of the multi-mode transmission assembly (200) to the drive shaft (204), and
the drive shaft (204) transfers the torque to a final gear drive (208) of the differential assembly (207) via a third drive gear (210).

Dated this 23rd day of March, 2024

(Digitally Signed)
Sudarshan Singh Shekhawat
IN/PA-1611
Agent for the Applicant