DESC:TRANSMISSION SYSTEM FOR A VEHICLE
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202421021037 filed on 19/03/2024, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
Generally, the present disclosure relates to a transmission system of a vehicle. Particularly, the present disclosure relates to a clutch assembly in a transmission system of a vehicle.
BACKGROUND
Electric vehicles (EVs) represent a paradigm shift in automotive engineering, characterized by the reliance on electric motors for propulsion rather than traditional internal combustion engines. Unlike conventional vehicles with clutches playing a pivotal role in transmitting power from the engine to the transmission, most EVs adopt direct-drive systems that forego the need for clutches altogether. However, in certain contexts such as regenerative braking systems, hybrid electric vehicles (HEVs), and multi-speed transmission designs, clutches or clutch-like mechanisms retain importance in managing power flow, enhancing efficiency, optimizing traction, and ensuring safety.
Conventionally, the clutch operates through direct mechanical connection and disengagement without the need for additional cooling ducts. The clutch assembly, typically including friction plates, a pressure plate, and a flywheel, engages and disengages through the force applied via a linkage or hydraulic system. Specifically, as the clutch is engaged, the friction plates press against the flywheel, transmitting power from the motor to the rotor. The system relies on the heat generated by friction being naturally dissipated through the surrounding air or the materials used in the clutch itself. In the above-mentioned configuration, cooling is primarily managed by the material’s thermal properties and the heat resistance of the components, with the motor’s rotation generating enough airflow to prevent overheating.
However, there are certain problems associated with the existing or above-mentioned integrated motor assembly with the clutch. For instance, without dedicated cooling ducts or a more advanced cooling system, the friction generated during clutch engagement leads to excessive heat buildup. The generated heat causes premature wear of the friction plates, increased risk of clutch slippage, and even failure of components due to overheating. Additionally, the reliance on passive heat dissipation through air or material properties results in less efficient cooling, making the system less reliable in demanding applications, such as heavy-duty machinery or high-performance vehicles, as optimal heat management is crucial to ensure long-term durability and efficiency.
Therefore, there exists a need for a motor assembly that is safe, efficient, and overcomes one or more problems as mentioned above.
SUMMARY
An object of the present disclosure is to provide a transmission system capable of providing heat efficient clutch operation.
In accordance with an aspect of the present disclosure, there is provided a motor assembly of an electric vehicle, wherein the motor assembly comprises:
- a motor shaft;
- a cylindrical rotor stack having a plurality of slots for accommodating a plurality of permanent magnets;
- a stator; and
- a stator sleeve,
wherein the cylindrical rotor stack comprises a plurality of concentric ducts along the cylindrical surface of the cylindrical rotor stack.
The motor assembly, as described in the present disclosure, is advantageous in terms of enhanced cooling and thermal management. The inclusion of ducts allows for the directed flow of air or cooling fluids directly over the clutch components, effectively dissipating heat generated during the engagement and disengagement process. The improved cooling helps to prevent overheating, reduces wear on friction materials, and maintains the clutch's performance under heavy loads or extended use. Further, by maintaining optimal temperatures, the assembly experiences less friction-related damage, prolonging the lifespan of the clutch assembly and improving overall system reliability.
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 motor assembly, in accordance with an 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 recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
As used herein, the term “motor assembly” and “assembly” are used interchangeably and refer to an integrated structure of the motor and clutch mechanisms combined into a single, compact unit. Specifically, the rotor serves as the central rotating element of the motor, and the EM clutch is embedded within the rotor or attached in proximity. The integration of the motor assembly and the clutch system allows for efficient power transmission, as the combination enhances the motor's torque generation capabilities with the clutch’s function of engaging or disengaging rotational movement without the need for separate external components. The integrated setup reduces space requirements, enhances the system's reliability, and minimizes mechanical losses due to fewer moving parts. The types of integrated structure are Permanent Magnet Synchronous Motors (PMSMs), induction motors, and brushless DC motors. The mechanism for operating such an integrated system typically involves detecting the desired state (engaged or disengaged) and controlling the electromagnetic field around the rotor using a transmission control unit. The seamless interaction between motor and clutch within the rotor enables high-performance and compact drive.
As used herein, the terms “electric vehicle”, “vehicle”, and “EV” are used interchangeably and refer to a vehicle that is driven by an electric motor that draws its electrical energy from a battery and is charged from an external source. The electric vehicle includes both a vehicle that is only driven by the electric motor that draws electrical energy from the battery (all-electric vehicle) and a vehicle that may be powered by an electric motor that draws electricity from the battery and by an internal combustion engine (plug-in hybrid electric vehicle). Moreover, the ‘electric vehicle’ as mentioned herein may include electric two-wheelers, electric three-wheelers, electric four-wheelers, electric trucks, electric pickup trucks, and so forth.
As used herein, the terms “motor shaft” and “shaft” are used interchangeably and refer to a mechanical component that transmits rotational power from the electric motor to the vehicle's drivetrain for driving the wheels. The shaft is typically made of high-strength steel or durable materials to handle the forces and torque generated by the motor. The shaft is connected to the rotor and is designed to rotate at high speeds, converting the electrical energy from the motor into mechanical energy that propels the vehicle. The design of the shaft ensures smooth transmission of power while minimizing vibrations, noise, and wear over time. Types of motor shafts are solid shafts, hollow shafts, or spline shafts, depending on the specific application and power requirements. The key components of a motor shaft include the shaft, bearings to reduce friction and support rotation, a coupling to connect the shaft to other drivetrain components, and a flange or keyway for secure attachment. The shaft is designed to withstand high torque and operate efficiently across a range of conditions.
As used herein, the term “cylindrical rotor stack” refers to a collection of magnetic laminations or layers stacked together to form a rotor core. The laminations are typically made of high-grade electrical steel and are designed to reduce eddy current losses, improving the overall efficiency of the EM clutch assembly. In an EM clutch system, the rotor stack is responsible for generating the magnetic field when current is applied to the coil, which interacts with the stator or the clutch mechanism to engage or disengage the drive. The rotor stack is a crucial component in the electromagnetic system, enabling the rotor to convert electrical energy into rotational mechanical energy while minimizing heat generation and energy losses. The operation in an EM clutch system involves the rotor stack energized by an electromagnetic field generated by the control system. As the electromagnetic field is applied, a rotation is induced in the rotor stack, which in turn engages the clutch. The rotor stack's efficiency and design are key factors in the system's overall performance, affecting the responsiveness and power transmission capabilities of the EM clutch assembly.
As used herein, the term “permanent magnets” refers to magnetic components that generate a constant magnetic field without the need for an external power source. The PM magnets are typically made from high-energy materials such as neodymium or samarium-cobalt, which maintain the magnetic properties over a long period of time. The permanent magnets are used in EM clutch systems to provide a continuous magnetic field that interacts with the electromagnets or armature, enabling precise control of the clutch engagement and disengagement. By incorporating permanent magnets, the system achieves better efficiency, reduces power consumption, and provides more consistent performance without the need to continuously supply electricity to generate the magnetic field. Specifically, as the electromagnet is energized, the magnet either attracts or repels the permanent magnet, depending on the polarity of the field, which engages or disengages the clutch mechanism. The magnetic interaction between the permanent magnets and the electromagnets ensures smooth and reliable operation, allowing the clutch to engage and disengage as the current is reduced or removed from the electromagnet, maintaining efficient torque transfer.
As used herein, the term “stator” refers to a stationary part of the electric motor that generates a rotating magnetic field, which induces the rotor to rotate and produce mechanical power. The stator comprises a series of electromagnetic coils or windings that are energized by electric current to create a magnetic field. The magnetic field interacts with the rotor, initiating the rotor to rotate. The stator is typically mounted around the rotor and varies in size and design depending on the motor type and vehicle specifications. The stator is crucial for the conversion of electrical energy into mechanical energy, making it a central component in the operation of the EV motor. The different types of stators are based on the motor design, such as those used in permanent magnet motors, induction motors, or synchronous motors. The stator typically includes components such as, but not limited to, copper windings, laminated iron cores, and cooling systems to maintain efficiency and prevent overheating. The stator’s working principle involves applying electrical current to the coil, creating a magnetic field that rotates within the motor. The rotating magnetic field induces current in the rotor (in the case of induction motors) or interacts with the permanent magnets in the rotor (in the case of permanent magnet motors), triggering the rotor to spin. The rotational force is transferred to the motor shaft and subsequently to the vehicle's drivetrain, driving the wheels of the EV.
As used herein, the term “stator sleeve” refers to an external casing or housing that surrounds the stator in an electric motor, providing structural support, protection, and directs the flow of coolant to manage the thermal environment of the motor. The stator sleeve serves to maintain alignment between the rotor and stator, ensuring smooth and efficient operation by preventing excessive movement or wear between the components. The stator sleeve also acts as a barrier against contaminants or external environmental factors, contributing to the durability of the motor assembly. In a motor assembly, the stator sleeve is designed to accommodate and support additional components such as the clutch assembly. The sleeve is designed as a solid casing, perforated for cooling, or with specialized ducts to direct cooling fluids in some advanced systems, depending on the motor’s cooling requirements. The sleeve is engineered to maintain proper alignment and spacing between the components, ensuring that the clutch engages or disengages the rotor with precision when required. The stator sleeve’s design includes features such as cooling channels or ducts that ensure effective heat dissipation when the clutch assembly operates, which is especially important when it is engaged for long durations. Additionally, the stator sleeve helps direct coolant flow through the rotor stack and clutch assembly, preventing overheating and improving the efficiency of the motor system.
As used herein, the term “ducts” refers to pathways or channels designed to facilitate the flow of coolant or air to manage the heat generated during motor operation. The ducts are typically incorporated into the rotor stack, stator, or stator sleeve, ensuring efficient thermal regulation by allowing cooling material to circulate around the key motor components, such as the clutch assembly, rotor stack, and windings. The primary function of the ducts is to direct the flow of the coolant to critical areas of heat accumulation, thus preventing overheating and ensuring consistent motor performance. The types of ducts, include concentric ducts (arranged in multiple layers around the rotor), radial ducts (extending from the centre of the rotor to the outer edges), and axial ducts (which align with the rotor's axis), each offering distinct cooling advantages depending on the motor design and operational requirements. The ducts are positioned to ensure that coolant or air flows around the clutch assembly, rotor stack, and stator, absorbing the excess heat generated during engagement of the clutch. The method typically involves circulating the coolant through the ducts to carry away heat, which is then dissipated through the stator or the external motor casing. By directing the coolant flow to specific areas, particularly around the clutch assembly, the system prevents the clutch from overheating, which degrades the performance and reliability. Additionally, the ducts are designed to optimize the cooling process, ensuring an even distribution of coolant along the entire length of the rotor stack and clutch components.
As used herein, the term “clutch assembly” refers to a mechanical component that connects and disconnects the power transmission between the motor and the gearbox assembly. The clutch assembly allows for smooth engagement and disengagement of the motor power to the rotor, ensuring that the system operates efficiently under varying conditions, such as during startup, acceleration, or deceleration. The clutch assembly typically consists of a friction plate, pressure plate, and a flywheel, which work together to transfer torque from the engine to the rotor while preventing damage due to sudden or excessive force. The most common types are the centrifugal clutch, which uses the engine's speed to engage the clutch mechanism automatically, and the mechanical clutch, which requires manual input to engage or disengage. Another type is the electro-hydraulic clutch, which utilizes hydraulic force controlled by an electronic system for more precise control. The method of operation for the clutches involves varying the engagement and disengagement based on factors such as speed, load, and torque, ensuring that the rotor operates smoothly under different operating conditions.
As used herein, the term “friction plate” refers to a component that facilitates the transfer of torque between the motor and the rotor by creating friction when engaged. The plates are typically made from durable materials like steel, carbon, or composite materials that provide high resistance to wear and heat. In a rotor system, friction plates are positioned between the flywheel and the pressure plate. When the clutch engages, the friction plates press against the flywheel and pressure plate, allowing torque to be transmitted to the rotor while ensuring smooth operation. The plates are designed to withstand the stresses and heat generated during the engagement process without slipping, providing a reliable connection. Ceramic friction plates are used in high-performance applications due to the excellent heat resistance and durability under extreme conditions. Another type is sintered metal friction plates, made from compressed metal particles, which provide superior durability and heat resistance. The method of operation involves the friction plates engaging under pressure, transferring torque to the rotor while maintaining smooth power transmission without excessive slippage, ensuring efficient performance.
As used herein, the term “pressure plate” refers to a component that applies force to the friction plates to engage and disengage the power transmission between the engine and the rotor. The pressure plates works by pressing the friction plates against the flywheel, allowing torque to flow smoothly from the engine to the rotor. When the clutch is engaged, the pressure plate holds the friction plates tightly, ensuring that the power transfer is seamless and efficient. The pressure plate is typically made of high-strength steel or cast iron to withstand the pressure and heat generated during operation, ensuring durability and longevity. The most common type is the diaphragm spring pressure plate, which uses a single diaphragm spring to provide the required force for engaging and disengaging the clutch. Another type is the coil spring pressure plate, which uses multiple coil springs arranged around the perimeter to apply pressure evenly across the friction plates. A third type is the hydraulic pressure plate, which uses hydraulic fluid to control the force applied to the friction plates, allowing for smoother and more precise control in high-performance or heavy-duty systems. The method of operation involves the pressure plate working in conjunction with the friction plates and flywheel, ensuring that the clutch engages and disengages smoothly, effectively transferring power while reducing wear and tear on the components.
As used herein, the term “linkage panel” refers to a component that connects and transfers the motion or force between the friction plate and pressure plate. The linkage panel component plays a critical role in the engagement and disengagement of the clutch, translating the driver's input or automated system control into mechanical force that presses or releases the friction plates. The linkage panel typically includes rods, levers, springs, and bearings, depending on the specific design. The linkage panel function is to provide a reliable, efficient connection that ensures smooth operation of the clutch, facilitating the transfer of torque to the rotor when required and disengaging when needed to stop power transmission. In manual systems, a mechanical linkage panel is used, as a pedal or lever system is connected to the pressure plate through a series of rods and springs, allowing the driver to manually control the clutch engagement. In more advanced systems, such as hydraulic or electronic clutches, the linkage panel include hydraulic lines or electronic actuators that control the pressure applied to the friction plate and pressure plate. The method of operation in the systems involves the linkage panel transferring the input force to the pressure plate, which either engages or disengages the friction plates from the flywheel, thus controlling the power transfer to the rotor based on the system's demand to ensure smooth, controlled power delivery and preventing damage to the clutch components.
As used herein, the term “coolant material” refers to a component used to manage and dissipate the heat generated during the engagement and disengagement of the clutch components, particularly the friction plates. As the clutch engages, friction between the friction plate and the flywheel generates substantial heat, which lead to overheating, excessive wear, or even failure of components. The coolant material serves to absorb and transfer this heat away from critical components, maintaining the operational integrity and enhancing the overall efficiency of the clutch system. In rotor systems with high speeds and heavy loads, effective heat management is crucial to prevent performance degradation and component damage. The most common types of coolant materials used in clutch assemblies include liquid coolants, such as water-based or oil-based fluids, and air-based cooling systems. Liquid coolants, like glycol-water mixtures, are circulated through the clutch housing to absorb heat and dissipate it through heat exchangers or radiators. Oil-based coolants, such as synthetic or mineral oils, provide additional lubrication benefits while cooling, ensuring both heat dissipation and reducing friction wear. In some systems, air cooling is also employed, as ambient air is directed onto the clutch components to reduce temperature buildup. The method of cooling typically involves either circulating the coolant fluid or using air to absorb and carry away heat, thus maintaining optimal temperature ranges and prolonging the lifespan of the clutch assembly.
In accordance with an aspect of the present disclosure, there is provided a motor assembly of an electric vehicle, wherein the motor assembly comprises:
- a motor shaft;
- a cylindrical rotor stack having a plurality of slots for accommodating a plurality of permanent magnets;
- a stator; and
- a stator sleeve,
wherein the cylindrical rotor stack comprises a plurality of concentric ducts along the cylindrical surface of the cylindrical rotor stack.
Referring to figure 1, in accordance with an embodiment, there is described a motor assembly 100 of an electric vehicle, wherein the motor assembly 100 comprises a motor shaft 102, a cylindrical rotor stack 104 having a plurality of slots 106 for accommodating a plurality of permanent magnets 108, a stator 110 and a stator sleeve 112. Further, the assembly comprises the cylindrical rotor stack 104 comprises a plurality of concentric ducts 114 along the cylindrical surface of the cylindrical rotor stack 104. Furthermore, the cylindrical rotor stack 104 is integrated with a clutch assembly 116. Furthermore, the clutch assembly 116 comprises a plurality of friction plates 118, a plurality of pressure plates 120 and a linkage panel 122.
The motor assembly 100 for an electric vehicle as described herein comprises a motor shaft 102, a cylindrical rotor stack 104, a stator 110, and a stator sleeve 112, wherein the cylindrical rotor stack 104 is designed with a plurality of concentric ducts 106 along its cylindrical surface. The motor shaft 102, upon receiving power from the vehicle's powertrain, drives the cylindrical rotor stack 104, which is positioned concentrically with the stator 110. Further, the cylindrical rotor stack 104 includes multiple slots 106 that accommodate permanent magnets 108, which, upon rotation, create a dynamic magnetic field. Consequently, the magnetic field interacts with the stator's coils, which are energized to create a rotating magnetic field. The rotor 104 is induced to rotate within the stator 110, generating torque that drives the vehicle. Furthermore, the stator sleeve 112 is an outer casing that holds the stator 110 and rotor assembly together, providing structural integrity and protection to the internal components of the motor assembly. Advantageously, the inclusion of concentric ducts 114 along the cylindrical surface of the rotor stack 104 provides a critical thermal management solution. The ducts 114 enables the efficient circulation of cooling air or fluid through the rotor stack 104 during operation, thereby reducing the temperature of the motor assembly. The active cooling prevents overheating of the permanent magnets 108 and winding materials, thereby maintaining optimal performance. Further, the cooling mechanism allows the motor to operate at higher loads without risk of thermal failure, enhancing efficiency and reliability. The above-mentioned configuration leads to improved motor longevity, reduced power losses, and more compact motor designs, offering significant advantages in terms of space utilization and weight reduction, particularly for electric vehicles.
In an embodiment, the cylindrical rotor stack 104 is integrated with a clutch assembly 116. In the motor assembly, the cylindrical rotor stack 104 is integrated with a clutch assembly 116, providing an efficient mechanism to enhance the functionality and efficiency of the electric vehicle's drive system. The clutch assembly 116 is designed to engage or disengage the rotor stack 104 from the vehicle’s transmission or drivetrain system based on the vehicle’s operational needs. For instance, when engaged, the clutch assembly 116 ensures the transfer of rotational motion from the rotor stack 104 to the vehicle's drivetrain, thereby driving the wheels. Conversely, when disengaged, the clutch assembly 116 isolates the rotor stack 104, preventing unnecessary power loss and allowing the vehicle to coast or operate in a low-power mode. The integration of the clutch assembly 116 with the cylindrical rotor stack 104 is achieved through a coupling mechanism that ensures precise control over the engagement and disengagement process, minimizing mechanical wear and ensuring smooth transitions during vehicle operation. The integration of the clutch assembly 116 with the cylindrical rotor stack 104 offers several technical advantages. Primarily, the ability to modulate the torque transfer between the motor and the drivetrain is improved, thereby improving overall vehicle efficiency. By disengaging the motor during certain operating conditions (such as, coasting or cruising), energy consumption is reduced, thereby increasing the vehicle's range and reducing wear on the motor and other drivetrain components. Additionally, the clutch assembly 116 allows for a more flexible powertrain design, which accommodates varying driving conditions, such as heavy acceleration or deceleration, while minimizing energy losses. The ability to selectively engage or disengage the rotor stack 104 from the drivetrain also contributes to smoother driving dynamics, enhancing driver comfort and the vehicle's performance.
In an embodiment, the clutch assembly 116 comprises a plurality of friction plates 118, a plurality of pressure plates 120 and a linkage panel 122. The clutch assembly 116 comprises a plurality of friction plates 118, a plurality of pressure plates 120, and a linkage panel 122, all working together to engage or disengage the cylindrical rotor stack 104 from the vehicle's drivetrain. The friction plates 118 make direct contact with the pressure plates 120, facilitating the transfer of rotational motion from the rotor stack 104 to the transmission when engaged. The linkage panel 122, which connects the friction plates 118 and pressure plates 120, controls the movement and alignment of the above-mentioned components, ensuring a smooth and synchronized engagement or disengagement process. During engagement, the pressure plates 120 apply force to the friction plates 118, causing the plates to grip and transfer the rotational motion from the rotor stack 104 to the drivetrain. In the disengaged state, the pressure plates 120 are moved away from the friction plates 118, preventing any torque transmission and allowing the rotor stack 104 to operate independently from the drivetrain, reducing energy loss and improving vehicle efficiency. Advantageously, the inclusion of a plurality of friction plates 118, pressure plates 120, and a linkage panel 122 in the clutch assembly 116 provides enhanced control over the power transmission, resulting in smoother transitions between engaged and disengaged states. Further, the use of multiple friction and pressure plates allows for a higher torque capacity, ensuring that the clutch assembly 116 handles varying load conditions without slipping or excessive wear. The arrangement minimizes mechanical stress on both the motor and the drivetrain, contributing to longer lifespan and greater reliability of the vehicle’s powertrain. The linkage panel 122 ensures precise alignment and operation of the clutch components, reducing the risk of misalignment and improving the overall efficiency of the clutch system. Furthermore, the ability to effectively manage torque transfer between the rotor stack 104 and the drivetrain improves vehicle performance, reduces energy consumption, and offers the flexibility to optimize the driving experience based on varying driving conditions, such as acceleration, deceleration, or coasting.
In an embodiment, the plurality of slots 106 are arranged in a radially symmetric pattern along a length of the rotor stack 104. The radial symmetry ensures that the permanent magnets 108, which are housed within the slots 106, are evenly distributed around the rotor, maintaining uniform magnetic field generation. Specifically, as the rotor stack 104 rotates, the symmetry ensures a balanced interaction between the rotor’s magnetic field and the stator’s electrical coils. The arrangement of the slots in a consistent, radially symmetric pattern minimizes any imbalance or distortion in the magnetic field, leading to smoother operation and more efficient torque production. The design allows for optimal positioning of the permanent magnets 108, ensuring that the maximum amount of magnetic flux is used to induce a corresponding current in the stator windings, enhancing the motor's overall performance and efficiency. Further, by ensuring that the permanent magnets 108 are uniformly distributed around the rotor, the system minimizes the risk of torque ripple, which leads to vibrations and inefficient power delivery. Furthermore, the symmetric pattern also improves the thermal management of the motor, as heat is more evenly distributed along the rotor stack, allowing for more efficient cooling. Additionally, the uniform magnetic field generated by the arrangement increases the overall torque output of the motor while minimizing energy losses, thereby enhancing the motor's efficiency, extending its operational lifespan, and improving the overall performance of the electric vehicle.
In an embodiment, a coolant material is accommodated within the plurality of concentric ducts 114 and wherein the coolant material is configured to facilitate heat transfer from the rotor stack 104 to the stator 110. In the motor assembly, the plurality of concentric ducts 114 within the cylindrical rotor stack 104 are designed to accommodate a coolant material, which is circulated through the ducts 114 during operation. The coolant material facilitates efficient heat transfer by absorbing heat generated within the rotor stack 104 due to the movement of the rotor 104 and interaction with the stator’s magnetic field. Further, as the rotor stack 104 rotates, the coolant flows through the concentric ducts 114, effectively carrying away the heat from the rotor’s core and distributing it to the surrounding stator 110. The heat transfer process ensures that the motor remains within optimal operating temperatures, preventing overheating of the rotor stack and permanent magnets, which lead to performance degradation or thermal damage. The coolant material used is a liquid or gas, designed to have high thermal conductivity, allowing efficient absorbing and transferring heat to the stator for dissipation. Furthermore, the integration of the coolant material within the concentric ducts 114 provides a significant technical advantage in terms of thermal management. By facilitating effective heat transfer from the rotor stack 104 to the stator 110, the system helps to maintain stable motor temperatures under various operating conditions, preventing overheating and ensuring the motor operates at peak efficiency. The thermal stability enabled by the cooling method enhances the longevity of the motor components, particularly the permanent magnets and windings, which degrade under excessive heat. Moreover, the cooling mechanism contributes to the motor's overall performance by reducing power losses associated with heat generation, allowing the motor to operate at higher power densities without risk of thermal failure.
In an embodiment, the plurality of concentric ducts 114 are positioned perpendicular to the plurality of rotor slots 106 to facilitate an even distribution of cooling material along the length of the rotor stack 104. The plurality of concentric ducts 114 are positioned perpendicular to the plurality of rotor slots 106, which are arranged along the length of the rotor stack 104. The perpendicular arrangement ensures that the coolant material flows in a direction that allows for an even and uniform distribution of cooling material along the entire length of the rotor stack 104. As the motor operates, the coolant flows through the ducts 114, effectively reaching all parts of the rotor stack. The coolant material absorbs heat generated during rotor movement and magnetic interaction, which is carried through the ducts 114 to maintain uniform cooling across the rotor stack’s surface. By being positioned perpendicular to the rotor slots 106, the ducts 114 optimize the distribution of the coolant, ensuring that no area of the rotor stack overheats, and that heat is efficiently transferred to the stator for dissipation. The perpendicular positioning of the concentric ducts 114 relative to the rotor slots 106 provides a highly effective thermal management for the motor assembly. The arrangement ensures that the coolant material is distributed evenly across the entire length of the rotor stack 104, preventing localized overheating or thermal hotspots that could degrade motor performance. Further, the uniform cooling also reduces the risk of thermal expansion mismatches between the rotor 104 and the stator, which lead to mechanical stresses and operational inefficiencies. By optimizing the heat transfer process, this cooling method enhances the overall efficiency of the motor, reducing energy losses and maintaining stable performance across varying load conditions. Additionally, the even heat distribution contributes to the motor’s durability, extending lifespan by minimizing the thermal stress on the permanent magnets and windings, and improving the motor's reliability in long-term use.
In an embodiment, the stator sleeve 112 is configured to accommodate the motor shaft 102, the cylindrical rotor stack 104 and the clutch assembly 116. The stator sleeve 112 is an integral component of the motor assembly, designed to enclose and support the motor shaft 102, the cylindrical rotor stack 104, and the clutch assembly 116. The stator sleeve 112 acts as an outer housing that secures the rotor stack and the motor shaft in place, ensuring proper alignment and smooth rotation within the stator. Further, the cylindrical rotor stack 104, which houses permanent magnets, is situated concentrically within the stator sleeve 112, while the clutch assembly 116 is integrated to allow engagement and disengagement of the rotor from the drivetrain. The sleeve 112 provides structural support to all the components, preventing any axial or radial movement that could affect the motor's performance. Furthermore, the stator sleeve 112 is designed to house cooling pathways or ducts, which allow coolant to flow through the rotor stack, thus facilitating thermal regulation during operation. The stator sleeve 112 enhances the overall stability, alignment, and performance of the motor assembly by providing a secure and durable casing for the motor shaft 102, rotor stack 104, and clutch assembly 116. The inclusion of a stator sleeve 112 that integrates with the clutch assembly 116 also allows for more efficient torque transfer between the rotor 104 and the drivetrain, while ensuring that the clutch’s engagement and disengagement processes are not hindered by any misalignment. Additionally, by incorporating cooling pathways within the stator sleeve 112, the assembly enables efficient heat dissipation, ensuring the motor operates within optimal thermal conditions.
In an embodiment, the stator sleeve 112 is configured to direct the flow of the coolant material within the stator sleeve 112. The stator sleeve 112 is designed with specific features to direct the flow of the coolant material within its structure, ensuring efficient heat transfer throughout the motor assembly. The integrated channels or grooves are incorporated into the stator sleeve 112, guiding the coolant material along predefined paths as it circulates through the motor components. The channels are strategically positioned to align with the concentric ducts 114 within the cylindrical rotor stack 104, enabling the coolant to flow smoothly and evenly through the rotor stack 104 to absorb and carry away heat. The stator sleeve 112 also helps regulate the flow rate and distribution of the coolant, ensuring that heat is evenly dissipated from the rotor stack 104 and transferred to the surrounding stator for efficient cooling. The precise design of the stator sleeve 112, in terms of channel orientation and geometry, optimizes the cooling process by ensuring that no part of the rotor or stator experiences thermal imbalance during operation. Furthermore, the ability of the stator sleeve 112 to direct the flow of the coolant material results in enhanced thermal management within the motor assembly. By ensuring a controlled and uniform distribution of the coolant, the stator sleeve 112 prevents localized overheating of the rotor stack 104 and other critical components, which reduce efficiency or cause thermal damage. The optimized cooling process improves the overall performance of the motor by reducing power losses associated with excessive heat, allowing the motor to operate at higher efficiency levels for extended periods. Furthermore, the directed coolant flow reduces the risk of thermal degradation of sensitive motor components, such as the permanent magnets 108 and windings, leading to longer motor life and greater reliability. The stator sleeve's 112 design also contributes to the compactness of the motor assembly, ensuring that thermal management is achieved without adding significant bulk or complexity to the motor.
Based on the above-mentioned embodiments, the present disclosure provides significant advantages such as (but not limited to) enhanced cooling and thermal management by inclusion of ducts allows for the directed flow of air or cooling fluids directly over the clutch components, effectively dissipating heat generated during the engagement and disengagement process.
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 combinations 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”, 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 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 motor assembly (100) of an electric vehicle, wherein the motor assembly (100) comprises:
- a motor shaft (102);
- a cylindrical rotor stack (104) having a plurality of slots (106) for accommodating a plurality of permanent magnets (108);
- a stator (110); and
- a stator sleeve (112),
wherein the cylindrical rotor stack (104) comprises a plurality of concentric ducts (114) along the cylindrical surface of the cylindrical rotor stack (104).

2. The motor assembly (100) as claimed in claim 1, wherein the cylindrical rotor stack (104) is integrated with a clutch assembly (116).

3. The motor assembly (100) as claimed in claim 2, wherein the clutch assembly (116) comprises a plurality of friction plates (118), a plurality of pressure plates (120) and a linkage panel (122).

4. The motor assembly (100) as claimed in claim 1, wherein the plurality of slots (106) are arranged in a radially symmetric pattern along a length of the rotor stack (104).

5. The motor assembly (100) as claimed in claim 1, wherein a coolant material is accommodated within the plurality of concentric ducts (114) and wherein the coolant material is configured to facilitate heat transfer from the rotor stack (104) to the stator (110).

6. The motor assembly (100) as claimed in claim 1, wherein the plurality of concentric ducts (114) are positioned perpendicular to the plurality of rotor slots (106) to facilitate an even distribution of cooling material along the length of the rotor stack (104).

7. The motor assembly (100) as claimed in claim 1, wherein the stator sleeve (112) is configured to accommodate the motor shaft (102), the cylindrical rotor stack (104) and the clutch assembly (116).

8. The motor assembly (100) as claimed in claim 1, wherein the stator sleeve (112) is configured to direct the flow of the coolant material within the stator sleeve (112).