DESC:MOTOR FOR AN ELECTRIC VEHICLE
CROSS REFERENCE TO RELATED APPLICTIONS
The present application claims priority from Indian Provisional Patent Application No. 202321075058 filed on 03/11/2023, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
Generally, the present disclosure relates to an electric motor. Particularly, the present disclosure relates to a rotor assembly of the electric motor.
BACKGROUND
Recently, traction motors are increasingly being used due to adoption of electric vehicles. The high-power permanent magnet motors are widely applied to hybrid vehicles and new energy electric vehicles due to the characteristics of high torque, high power density, wide speed expansion range and the like. There has been a recent push to develop hybrid and fully electric consumer passenger vehicles. The growing availability of charging networks, along with declining battery costs, further accelerates the adoption of EVs, positioning as the future of sustainable transportation.
Generally, in an electric vehicle, the power is transmitted from an electric motor to a wheel of the electric vehicle by converting electrical energy into mechanical energy. The converted mechanical energy is transferred to the wheel via coupling mechanism provided between a motor shaft and a gearbox input shaft. Typically, while transmitting power from the motor shaft to the gearbox input shaft, a critical failure may occur at the coupling. Moreover, the coupling mechanism experiences high stress due to rotational forces occurring on the coupling mechanism. Such high stress may lead to wear or failure of the coupling mechanism over time. Furthermore, several mechanisms are employed to couple the motor shafts with the gearboxes in the electric vehicles (EVs). Such mechanisms comprise a rigid coupling, a keyed coupling, a friction coupling and a spline coupling. The rigid coupling involves direct mechanical connection of the motor shaft to the gearbox input shaft, ensuring that both the shafts rotate together without any relative motion. However, the rigid couplings unable to accommodate angular or axial differences between the motor shafts and the gearbox input shafts which potentially causes damage to the coupling mechanism. Also, even minor misalignments in the coupling mechanism leads to stress on the shaft, causing premature wear or failure of the rotor assembly. Moreover, the vibrations generated by the motor are directly transmitted to the gearbox through rigid couplings which may potentially cause noise and wear in the gearbox. Similarly, the keyed coupling is another type of coupling which incorporates the use of a key inserted into a keyway which is machined on both the motor shaft and the gearbox input shaft, locking together to transmit torque. However, the keyed coupling has certain limitations including the points of stress concentration on the motor shaft and gearbox input shaft, which may lead to fatigue and failure, especially under high torque loads. Also, the keyed coupling has limited durability and requires frequent maintenance. Furthermore, one of the commonly used coupling methods is the friction-based coupling which comprises clutches. The friction-based couplings rely on the friction generated between mating surfaces to transfer torque from the motor shaft to the gearbox input shafts. However, the reliance on friction-based coupling introduces the risk of slippage, particularly under high torque loads and leading to inefficiency in torque transmission. Furthermore, the spline coupling is one of the used mechanical couplings for two shafts i.e., the motor shaft and gearbox input shaft, which interlocks a teeth or grooves (splines) to transfer torque and rotational motion. The spline coupling allows the precise alignment and efficient torque transmission while accommodating minor axial and angular misalignments. However, the spline couplings require precise machining and alignment, making manufacturing and installation for the spline couplings more complex. Moreover, the spline coupling may manage minor misalignments but are sensitive to excessive misalignment, which may lead to wear or failure. Additionally, the high torque capacity and durability of the spline coupling comes with increased costs compared to simpler coupling methods.
Therefore, there is a need to provide an improved coupling mechanism for the rotor assembly that overcomes the one or more problems as set forth above.
SUMMARY
An object of the present disclosure is to provide a rotor assembly of an electric motor of a geared electric vehicle.
In accordance with an aspect of present disclosure there is provided a rotor assembly for an electric motor used in a geared electric vehicle. The rotor assembly comprises a rotor shaft, a rotor core, and at least one end plate. The rotor shaft is configured to act as an input shaft of the gearbox of the electric vehicle. The rotor core is mounted on the rotor shaft. The at least one end plate is mounted on the rotor shaft adjacent to the rotor core.
The present disclosure provides a rotor assembly for an electric motor. The rotor assembly as disclosed by present disclosure is advantageous in terms of providing an integrated rotor shaft for engaging the electric motor and the gearbox in the electric vehicle. Beneficially, the rotor shaft that is integrated with the gearbox eliminates the need for additional couplings or connectors. Beneficially, such integration reduces the mechanical complexity of the drivetrain. Furthermore, the elimination of additional coupling mechanism results in improved reliability and reduced maintenance requirements due to fewer components. The integrated rotor shaft of the motor as disclosed by present disclosure beneficially minimizes the chances for misalignment of engagement mechanism between the motor and the gearbox. Beneficially, the rotor assembly as disclosed by present disclosure is advantageous in terms of better power transfer efficiency between the motor and the gearbox. Beneficially, the rotor assembly of the present disclosure reduces the energy losses due to friction, slippage or vibrations. Beneficially, the rotor assembly of the present disclosure may enhance energy efficiency and range of the electric vehicle. Beneficially, the rotor assembly of the present disclosure reduces space requirement inside the drivetrain, thus, increasing the compactness and reducing weight of the drivetrain. Beneficially, the reduction in size also facilitates more flexible arrangement options of the drivetrain. Moreover, the rotor assembly of the present disclosure is advantageous in terms of smoother operation and less noise of the drivetrain.
Additional aspects, advantages, features and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
Figure 1 illustrates an exploded view of a rotor assembly of an electric motor, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates an exploded view of a rotor assembly of an electric motor, in accordance with another embodiment of the present disclosure.
Figure 3 illustrates an exploded view of a drivetrain of the electric vehicle, in accordance with another embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognise that other embodiments for carrying out or practising the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a rotor assembly and is not intended to represent the only forms that may be developed or utilised. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimised to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
As used herein, the terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings, and which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “electric motor”, “motor”, “AC motor” are used interchangeably and refer to electric motors capable of being implemented in an industrial and automobile application for high torque operations. In general, the electric motor converts electrical energy into mechanical energy through the interaction of magnetic fields, typically involving a rotor and stator assembly. The electric motor may operate on various principles, including but not limited to induction, synchronous, reluctance or synchronous reluctance mechanisms.
As used herein, the terms “electric vehicle”, “EV”, and “EVs” are used interchangeably and refer to any vehicle having stored electrical energy, including the vehicle capable of being charged from an external electrical power source. This may include vehicles having batteries which are exclusively charged from an external power source, as well as hybrid-vehicles which may include batteries capable of being at least partially recharged via an external power source. Additionally, it is to be understood that the ‘electric vehicle’ as used herein includes electric two-wheeler, electric three-wheeler, electric four-wheeler, electric pickup trucks, electric trucks and so forth.
As used herein, the terms “rotor” and “rotor assembly” are used interchangeably and refer to a rotating part of the motor which converts electrical energy supplied to the stator into mechanical energy. The rotor assembly may contain permanent magnets and reluctance core that generate the magnetic field used to drive the rotor. The rotor assembly may generate magnetic torque, reluctance torque or a combination thereof.
As used herein, the terms “rotor shaft”, “integrated rotor shaft”, “input shaft” and “shaft” are used interchangeably and refer to a power output mechanism of the motor, which transmits mechanical power to a load. The rotor shaft configured to act as an input shaft of a gearbox of the electric vehicle. The rotor shaft may be composed of various materials, including but not limited to steel, aluminium, or composite materials. The rotor shaft may incorporate design features that enables the integration with a gearbox of the electric vehicle.
As used herein, the term "stator" and “stator assembly” are used interchangeably and refer to a stationary component of the electric motor that houses the winding or permanent magnets and interacts with the rotor to create electromagnetic force or generate electrical power. The stator typically comprises a core made of laminated steel to reduce eddy current losses and may include slots or teeth to accommodate windings. The stator may also include insulation layers, cooling channels, and other structural features to enhance its mechanical robustness, thermal management, and electrical performance. While the stator is generally fixed in place, its design may allow for various mounting configurations and structural adaptations depending on the specific application of the motor.
As used herein, the terms “rotor core”, “rotor stack” and “stack” are used interchangeably and refers to an assembly of multiple laminated sheets or segments that collectively form the core structure of the rotor in an electric motor. The primary function of rotor core is to support the rotor magnets or windings and provide a path for magnetic flux to interact with the stator. Moreover, the rotor core facilitating the conversion of electrical energy into mechanical motion.
As used herein, the terms “rotor magnets”, “plurality of magnets”, and “magnets” are used interchangeably and refer to a permanent magnet present inside or on surface of the rotor core to generate magnetic field that interacts with the rotating magnetic field of the stator assembly resulting in rotational motion of the rotor.
As used herein, the terms “end plates”, “at least one end plate” and “finless end plate” are used interchangeably and refer to a disc like components of the rotor assembly that are placed on the ends of the rotor core to secure the plurality of the magnets inside the hollow cavities of the rotor core.
As used herein, the term “spacer spring” refers to a component of the rotor assembly that is designed to apply consistent axial force on the rotor stack, ensuring that the stack remains properly aligned and under the desired preload. Furthermore, the spacer spring compress or expand slightly, exerting force along the axis of the rotor assembly.
As used herein, the term “teeth” and “plurality of teeth” are used interchangeably and refer to design elements on the rotor shaft that enables the integration of the rotor shaft with the gearbox of the electric vehicle. Furthermore, the plurality of teeth enables the rotor shaft to act as an input shaft of the gearbox of the electric vehicle. Moreover, the teeth ensure a secure and precise engagement between the rotor shaft and the gearbox, thereby minimizing slippage during operation.
As used herein, the term “plurality of steps” refers to an axial variation in diameter or surface features on the rotor shaft designed to facilitate precise mounting of the rotor core and at least one end plate. The plurality of steps provides distinct seating positions, ensuring proper alignment, axial stability, and secure engagement of the rotor components.
As used herein, the terms “groove”, “locking groove” and “at least one groove” are used interchangeably and refer to the locking engagement inside a rotor core to engage the locking projection and facilitates the interlocking between the at least one end plate and the rotor core to secure the positions of rotor magnet.
As used herein, the term “casing” refers to the external protective enclosure that houses and supports the internal components of the motor, including the stator, rotor, and other critical elements. The casing is typically made from durable materials such as metal or high-strength polymers. The casing protects the internal components from environmental factors, provides structural integrity to the motor assembly, and aids in dissipating heat generated during operation.
As used herein, the terms “protrusion” and “at least one protrusion” are used interchangeably and refer to a protruding (extending above surface) design feature of the rotor core extended along length of the shaft hole that engage with the locking slit of the rotor shaft to interlock the rotor shaft with the rotor core.
As used herein, the term “hollow cavities” refers to hollow sections in the rotor core that are designed to accommodate the rotor magnets. The hollow cavities may be cut-through sections with both ends open. Alternatively, the hollow cavities may be closed at one end. It is to be understood that the plurality of the rotor magnets may be secured inside the hollow cavities by various means.
As used herein, the term “shaft hole” refers to a cylindrical opening or bore within the rotor core, designed to accommodate the insertion of the rotor shaft inside the rotor core. The shaft hole is precisely machined to match the diameter of the shaft, ensuring a secure fit.
As used herein, the terms “rivet hole” and “plurality of rivet holes” are used interchangeably and refer to holes in the rotor core designed to accommodate a rivet to secure the stacked electromagnetic sheets forming the rotor core.
As used herein, the terms “projection” and “locking projection” are used interchangeably and refer to a projection configured to secure the position of the locking plate on the rotor core. It is to be understood that the locking projection prevents slipping of the locking plate on the rotor core.
As used herein, the term “bearing” refers to a mechanical component in electric motor that is mounted on the rotor shaft to provide support, reduce friction, and facilitate smooth rotational movement of the rotor with respect to the motor casing.
As used herein, the term “drivetrain” refers to the system of components in a vehicle that work together to transmit power from the motor or engine to the wheels to enable motion. In electric vehicles, the drivetrain typically includes the electric motor, transmission, differential, driveshaft, axles, and other related components that convert the motor's electrical energy into mechanical energy for propulsion.
As used herein, the term “clutch” refers to a mechanical component that selectively engages or disengages the power transmission between the motor and the wheels. In electric vehicles, clutches can be used to connect or disconnect different parts of the drivetrain, such as engaging or disengaging a secondary motor, gearbox, or regenerative braking system. The clutch allows for smoother transitions between power sources, improved energy efficiency, and better control over torque delivery, enhancing the overall performance and responsiveness of the electric vehicle.
Figure 1, in accordance with an embodiment describes a rotor assembly 100 of an electric motor of a geared electric vehicle. The rotor assembly 100 comprises a rotor shaft 102, a rotor core 104, and at least one end plate 106a, 106b. The rotor shaft 102 is configured to act as an input shaft of a gearbox 320 (as shown in Fig. 3) of the electric vehicle. The rotor core 104 is mounted on the rotor shaft 102. The at least one end plate 106a, 106b is mounted on the rotor shaft 102 adjacent to the rotor core 104.
The present disclosure provides a rotor assembly 100 for an electric motor. The rotor assembly 100 as disclosed by present disclosure is advantageous in terms of providing an integrated rotor shaft 102 for engaging the electric motor and the gearbox 320 in the electric vehicle. Beneficially, the rotor shaft 102 that is integrated with the gearbox 320, eliminates the need for additional couplings or connectors. Beneficially, such integration reduces the mechanical complexity of the drivetrain. Furthermore, the elimination of additional coupling mechanism results in improved reliability and reduced maintenance requirements due to fewer components. The integrated rotor shaft 102 of the motor as disclosed by present disclosure beneficially minimizes the chances for misalignment of engagement mechanism between the motor and the gearbox 320. Beneficially, the rotor assembly 100 as disclosed by present disclosure is advantageous in terms of better power transfer efficiency between the motor and the gearbox 320. Beneficially, the rotor assembly 100 of the present disclosure reduces the energy losses due to friction, slippage or vibrations. Beneficially, the rotor assembly 100 of the present disclosure may enhance energy efficiency and range of the electric vehicle. Beneficially, the rotor assembly 100 of the present disclosure reduces space requirement inside the drivetrain, thus, increasing the compactness and reducing weight of the drivetrain. Beneficially, the reduction in size also facilitates more flexible arrangement options of the drivetrain. Moreover, the rotor assembly 100 of the present disclosure is advantageous in terms of smoother operation and less noise of the drivetrain.
It is to be understood that the rotor core 104 may be constructed by stacking multiple electromagnetic sheets. Beneficially, the rotor core 104 constructed by stacking multiple electromagnetic sheets may have lesser eddy current losses. Alternatively, the rotor core 104 may be constructed as a solid single component.
In an embodiment, the rotor shaft 102 comprises a first end 116a and a second end 116b. For instance, the first end 116a may be named as the second end 116b and vice versa, without affecting the function of both the ends of the rotor shaft 102. It is to be understood that the nomenclature of the first end 116a and the second end 116b of the rotor shaft 102 may be interchangeable. The function of the first end 116a and the second end 116b of the rotor shaft 102 depends on structural and mechanical design parameters associated with the first end 116a and the second end 116b of the rotor shaft 102, irrespective of the assigned names.
In an embodiment, the first end 116a of the rotor shaft 102 comprises a plurality of teeth 108. The first end 116a of the rotor shaft 102 engages with the gearbox 320 via the plurality of teeth 108. Beneficially, the plurality of teeth 108 at the first end 116a of the rotor shaft 102 are designed to establish mechanical engagement between the rotor shaft 102 and gearbox 320. Moreover, the plurality of teeth 108 on the at least one end of rotor shaft 102 improves torque transmission and rotational alignment in motor-gearbox assembly and reduces the risk of slippage or misalignment of rotor shaft 102 during high-load operations. Beneficially, the motor configuration with the rotor shaft 102 and the plurality of teeth 108 enables precise and efficient torque transfer from the rotor to the gearbox 320, ensuring optimal power delivery and minimized mechanical losses.
In an embodiment, the first end 116a of the rotor shaft 102 engages with a primary drive gear 318 (as shown in Fig. 3) of the gearbox 320 through the plurality of teeth 108. The engagement between motor shaft 102 and the primary drive gear 318 facilitates a direct power transmission from the motor to the gearbox 320 through primary drive gear 318, ensuring precise rotational movement and minimizing the power losses of the motor. The plurality of teeth 108 provides a secure mechanical interference, which enhances the load-bearing capacity and reduces the likelihood of slippage or misalignment under varying operational conditions. In an alternative embodiment, a motor drive gear may be mounted on the plurality of teeth 108 that engages with the primary drive gear 318 of the gearbox 320 to transfer power from the motor to the gearbox 320. Beneficially, the motor drive gear may enable enhanced torque output from the motor.
In an embodiment, the second end 116b of the rotor shaft 102 is fixed with a bearing on the casing of the electric motor. The fixing of rotor shaft 102 with the bearing ensures the rotor shaft 102 is securely supported within the motor housing, promoting smooth rotational movement and reducing frictional forces during operation. Moreover, the use of bearing enhances the stability and alignment of the rotor shaft 102, thereby minimizing wear and vibrations.
In an embodiment, the rotor assembly 100 comprises a plurality of rotor magnets 210 (as shown in Fig. 2) embedded within the rotor core 104. The plurality of rotor magnets 210 facilitate the electromagnetic interaction between the rotor assembly 100 and stator, thereby enhancing the overall performance of the electric motor. Beneficially, the strategic placement of the plurality of rotor magnets 210 ensures the uniform magnetic field, which improves torque production and operational efficiency. Also, the rotor assembly 100 achieves optimal magnetic flux distribution and stability and reduces cogging effects and vibrations. In an alternative embodiment, the plurality of rotor magnets 210 are present on cylindrical surface of the rotor core 104.
In an embodiment, at least one end plate 106a, 106b is a finless end plate. The at least one end plate 106a, 106b is configured to balance weight distribution of the rotor assembly 100. Beneficially, the finless end plate ensures the at least one end plate 106a, 106b does not introduce asymmetrical forces or imbalances, thereby contributing to a more stable and evenly distributed load during rotor operation. Moreover, at least one end plate 106a, 106b is configured to lock a plurality of rotor magnets 210 inside the rotor core 104. It is to be understood that the at least one end plate 106a, 106b may be etched to balance weight distribution of the rotor assembly 100.
In an embodiment, the rotor shaft 102 comprises a plurality of steps 112 configured to support the mounting of the rotor core 104 and at least one end plate 106a, 106b. Beneficially, the plurality of steps 112 provides distinct, precisely machined surfaces that ensure accurate positioning and secure engagement of the rotor core 104 and the at least one end plates 106a, 106b with the rotor shaft 102. Beneficially, the rotor shaft 102 with the plurality of steps 112 improves the mechanical integrity of the rotor assembly 100 and leads to better performance and reliability in electric motors.
In an embodiment, the rotor assembly 100 comprises at least one spacer spring 214 (as shown in Fig. 2) configured to exert a compressive force on either the at least one end plate 106a, 106b or the rotor core 104. The spacer spring 214 significantly restricts axial movement of the rotor core 104 on the rotor shaft 102. Beneficially, the spacer spring 214 ensures the rotor core 104 remains securely positioned along the rotor shaft 102 and minimizes unintended axial displacement during operation. Moreover, the compressive force exerted by the spacer spring 214 enhances the mechanical stability and alignment of the rotor assembly 100.
In an embodiment, the electric motor of a geared electric vehicle comprises a casing, a stator assembly, and a rotor assembly 100. The rotor shaft 102 of the rotor assembly 100 is mechanically engaged with the gearbox 320 of the electric vehicle and is configured to function as the input shaft for the gearbox 320. Beneficially, the rotor shaft 102 directly transfers rotational motion from the motor to the gearbox 320, thereby ensuring efficient power transmission for the electric vehicle. Moreover, the rotor shaft 102 acting as an input shaft beneficially reduces mechanical complexity, which improves overall reliability and performance of the electric motor.
Figure 2, in accordance with an embodiment describes the rotor assembly 100 of the electric motor. The rotor assembly 100 comprises the rotor shaft 102, the rotor core 104 and the at least one spacer spring 214. The rotor shaft 102 comprises the plurality of teeth 108 and the plurality of steps 112. The rotor shaft 102 configured to act as the input shaft of the gearbox 320 of the electric vehicle. The rotor shaft 102 further comprises the first end 116a and the second end 116. The first end 116a of the rotor shaft 102 is engaged with the primary drive gear 318 of the gearbox 320 via the plurality of teeth 108. The second end 116b of the rotor shaft 102 is fixed with a bearing on the casing of the electric motor. The plurality of steps 112 designed to support the mounting of the rotor core 104 ensures accurate positioning and secure attachment of the rotor core 104. Furthermore, the rotor core 104 is mounted on the rotor shaft 102. The rotor core 104 comprises a shaft hole designed to accommodate the rotor shaft 102 securely, a groove, a protrusion, a rivet holes and a plurality of hollow cavities to accommodate the plurality of rotor magnets 210. The at least one spacer spring 214 is mounted on the rotor shaft 102 along with the rotor core 104. The spacer spring 214 is configured to restrict axial movement of the rotor core 104 on the rotor shaft 102. Additionally, the rotor assembly 100 comprises at least one end plate 106a, 106b configured to lock the plurality of rotor magnets 210 placed in a plurality of the hollow cavities inside the rotor core 104. The at least one end plate 106a, 106b prevents any rotational movement by engaging a locking projection with the locking groove.
Figure 3, in accordance with an embodiment describes a drivetrain assembly 300 comprises the rotor shaft 102, the primary drive gear 318, the gearbox 320 and a clutch 322. The rotor shaft 102 configured to act as the input shaft of the gearbox 320 of the electric vehicle. The first end 116a of the rotor shaft 102 is engaged with the primary drive gear 318 of the gearbox 320 via the plurality of teeth 108. The engagement between motor shaft 102 and the primary drive gear 318 facilitates a direct power transmission from the motor to the gearbox 320 through primary drive gear 318, ensuring precise rotational movement and minimizing the power losses of the motor.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combination of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, “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 where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:We Claim:
1. A rotor assembly (100) of an electric motor of a geared electric vehicle, wherein the rotor assembly (100) comprises:
- a rotor shaft (102) configured to act as an input shaft of a gearbox (320) of the electric vehicle;
- a rotor core (104) mounted on the rotor shaft (102); and
- at least one end plate (106a, 106b), wherein the at least one end plate (106a, 106b) is mounted on the rotor shaft (102) adjacent to the rotor core (104).
2. The rotor assembly (100) as claimed in claim 1, wherein the rotor shaft (102) comprises a first end (116a) and a second end (116b).
3. The rotor assembly (100) as claimed in claim 2, wherein the first end (116a) of the rotor shaft (102) comprises a plurality of teeth (108), and wherein the first end (116a) of the rotor shaft (102) is engaged with the gearbox (320) via the plurality of teeth (108).
4. The rotor assembly (100) as claimed in claim 3, wherein the first end (116a) of the rotor shaft (102) is engaged with a primary drive gear (318) of the gearbox (320) via the plurality of teeth (108).
5. The rotor assembly (100) as claimed in claim 2, wherein the second end (116a) of the rotor shaft (102) is fixed with a bearing on a casing of the electric motor.
6. The rotor assembly (100) as claimed in claim 1, wherein the rotor assembly (100) comprises a plurality of rotor magnets (210) embedded in the rotor core (104).
7. The rotor assembly (100) as claimed in claim 1, wherein at least one end plate (106a, 106b) is a finless end plate configured to balance weight distribution of the rotor assembly (100).
8. The rotor assembly (100) as claimed in claim 1, wherein the rotor shaft (102) comprises a plurality of steps (112) to support mounting of the rotor core (104) and the least one end plate (106a, 106b).
9. The rotor assembly (100) as claimed in claim 1, wherein the rotor assembly (100) comprises at least one spacer spring (214) configured to exert a compressive force on the at least one end plate (106a, 106b) or the rotor core (104) to restrict movement of the rotor core (104) in the axial direction on the rotor shaft (102).
10. An electric motor of a geared electric vehicle, wherein the electric motor comprises:
- a casing;
- a stator assembly;
- a rotor assembly (100) as claimed in claim 1,
wherein a rotor shaft (102) of the rotor assembly (100) is mechanically engaged with a gearbox (320) of the electric vehicle and configured to act as an input shaft of the gearbox (320) of the electric vehicle.