DESC:COOLING ARRANGEMENT IN ELECTRIC VEHICLE
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202221074280 filed on 21/12/2022, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to an electric motor. Particularly, the present disclosure relates to an electric motor with an integrated cooling mechanism.
BACKGROUND
Electric vehicles are rapidly gaining popularity in today's automotive marketplace as they offer economical as well as environmental benefits with several desirable features, such as eliminating pollutant emissions while having lower operating costs.
An eco-friendly vehicle such as a hybrid vehicle or an electric vehicle generates power through a drive motor, and includes the drive motor and power modules, such as inverters, LDCs (Low DC/DC Converters), and high-voltage batteries, to power the drive motor. Since such power modules have heating elements such as a variety of switching elements, transformers, windings, bearings, and IGBTs (Insulated Gate Bipolar Mode Transistors), there is a need for a cooling device to suppress the heat generated by operations of the power modules. The electric motor and the power pack are the most critical components that are required to be cooled as the rise in temperature of these components is safety critical and also adversely affects the performance of the electric vehicle. Particularly, the electric motor produces a variable amount of heat according to the operating parameters such as motor rpm and power output.
While the electric automobile is running in different environments, the temperature regulation of the electric motor is one of the most critical factors to be taken into consideration for the smooth operation of the vehicle. Under extreme temperature conditions, liquid cooling of the electric motor comes out to be most efficient, especially when active liquid cooling is employed. However, for active cooling, additional circuitries such as a low voltage pump, cooling controller, harnesses, sensors, and low voltage power supply are required. Such additional components increase the complexity of the system. Moreover, the manufacturing cost and maintenance complexity also increase due to the additional components required for active cooling of the electric motor.
Therefore, there exists a need for an improved motor design with active cooling that overcomes one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide an electric motor with an integrated active cooling mechanism.
In accordance with an aspect of the present disclosure, there is provided an electric motor for an electric vehicle, comprising a stator assembly, a rotor assembly, a motor shaft comprising a first end and a second end, a spiral cooling jacket, an impeller mounted on the second end of the motor shaft, and an enclosure enclosing the impeller and the second end of the motor shaft. The impeller rotates with the motor shaft during the operation of the motor to create a flow of a coolant through the spiral cooling jacket for cooling of the electric motor.
The present disclosure provides an electric motor with an integrated active cooling mechanism. Beneficially, the electric motor as disclosed by the prevent disclosure eliminates the requirement of additional pump active cooling using a flowing coolant in the electric vehicle. Beneficially, the rotation of the motor shaft is used as a means for creating pumping action of the flow of coolant. Beneficially, the impeller increases the pressure and flow rate of coolant. The electric motor as disclosed by the present disclosure is advantageous in terms of efficient active cooling, as the rotation speed of the impeller increases with the speed of rotation of the motor shaft increasing the flow of coolant in the spiral cooling jacket. Beneficially, the electric motor of the present disclosure is advantageous in terms of eliminating the requirement for any additional coolant controller.
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 an electric motor, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates a perspective view of the electric motor, in accordance with an embodiment of the present disclosure.
Figure 3 illustrates a sectional view of the electric motor, in accordance with another aspect 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.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a surface permanent magnet motor and is not intended to represent the only forms that may be developed or utilized. 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 minimized 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.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, or 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 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”, “surface permanent magnet motor”, “SPM motor”, “permanent magnet motor”, “permanent magnet synchronous reluctance motor” and “PMSRM” are used interchangeably and refer to type of electric motor in which the permanent magnets are attached to the surface of the rotor, in a radial or axial arrangement. The magnets generate a magnetic field that interacts with the magnetic flux generated by the stator windings to produce the rotational motion of the rotor. The permanent magnet motor has high efficiency, and compact design and is suitable for applications such as electric vehicles (EVs) and robotics.
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, “stator”, “stator structure” and “stator assembly” are used interchangeably and refer to the stationary part of a motor that houses the motor windings, designed to create a rotating magnetic field when an electrical current is applied to the windings. The magnetic field produced by the stator interacts with the permanent magnets on the rotor to induce rotation. The stator acts as a field magnet. The design of the stator is an important factor in deciding the performance of the motor such as its efficiency, power output, and torque.
As used herein, the terms “stator tooth”, and “stator teeth” are used interchangeably and refer to the tooth-like projections or raised portions of the stator core for holding the conductive windings. The stator teeth also help to reduce eddy currents and hysteresis losses in the motor or generator.
As used herein, the term “stator winding coil” refers to the winding of insulated copper wire wrapped around the stator tooth for generating magnetic flux in the stator assembly.
As used herein, “rotor” and “rotor assembly” are used interchangeably and refer to the rotating part of the electric motor that generates a magnetic field through permanent magnets, for interacting with the stator’s magnetic field for the generation of the torque on the rotor. The rotor serves as the structural support for the permanent magnets and provides a path for the magnetic flux to circulate within the rotor. The rotor core is often made of ferromagnetic materials like laminated iron or steel sheets. These materials have high magnetic permeability, which helps concentrate and direct the magnetic field. The physical dimensions of the rotor, including diameter and length, physical size determine the power output of the motor.
As used herein, the term “rotor stack” refers to the central component of the rotor that supports and houses the permanent magnets. The rotor core is typically made from a magnetic material, such as laminated iron or steel to concentrate and direct the magnetic flux generated by the magnets.
As used herein, the terms “permanent magnet” and “magnet” are used interchangeably and refer to pieces of permanent magnets held in the curved surface of the rotor’s core to generate constant magnetic flux in the rotor for interaction with the magnetic field of the stator. The magnets are typically made from materials with strong magnetic properties, such as neodymium-iron-boron (NdFeB) or samarium-cobalt (SmCo).
As used herein, the term “motor casing” is used to refer to the outer body of a motor enclosure made up of metal, which holds the entire motor components together.
As used herein, the term “motor shaft”, “shaft” and “shaft assembly” are used interchangeably and refer to a cylindrical rotating component for delivering mechanical output.
As used herein, the term “first end” refers to a front end of the motor shaft on which a mechanical load is connected for receiving power output of the electric motor.
As used herein, the term “second end” refers to a rear end of the motor on which an impeller is mounted for cooling of the electric motor.
As used herein, the terms “spiral cooling jacket” and “cooling jacket” are used interchangeably and refer to a heat exchange structure for cooling of electric motors by circulating a coolant, around the motor's exterior. The spiral cooling jacket comprises coolant flow path for the flow of coolant to absorb heat from the electric motor.
As used herein, the term “impeller” refers to a rotating component within the electric motor that imparts energy to a coolant, increasing its pressure and/or flow rate.
As used herein, the term “enclosure” refers to housing at the rear end of the motor forming a vacant area for drawing coolant inside.
As used herein, the term “enclosure cover” refers to a component of the enclosure covering the impeller circularly in radial direction.
As used herein, the term “enclosure plate” refers to a component of the enclosure covering the impeller in the axial direction.
As used herein, the term “casing inlet” refers to a coolant inlet in the casing of the motor. The casing inlet receives coolant from the enclosure coolant outlet.
As used herein, the term “casing outlet” refers to a coolant outlet in the casing of the motor. The casing outlet is connected to the coolant supply to send back the coolant after the heat is absorbed from the electric motor.
As used herein, the term “enclosure coolant inlet” refers to a coolant inlet in the enclosure for receiving coolant from the coolant supply.
As used herein, the term “enclosure coolant outlet” refers to a coolant outlet in the enclosure for supplying coolant to the spiral cooling jacket via the casing inlet.
Figure 1, in accordance with an embodiment, describes an exploded view of an electric motor 100 for an electric vehicle, comprising a stator assembly 102, a rotor assembly 104, a motor shaft 106 comprising a first end 106a and a second end 106b, a spiral cooling jacket 108, an impeller 110 mounted on the second end 106b of the motor shaft 106, and an enclosure 112 enclosing the impeller 110 and the second end 106b of the motor shaft 106. The impeller 110 rotates with the motor shaft 106 during the operation of the motor 100 to create a flow of a coolant through the spiral cooling jacket 108 for cooling of the electric motor 100.
The present disclosure provides an electric motor 100 with an integrated active cooling mechanism. Beneficially, the electric motor 100 eliminates the requirement of additional pump active cooling using a flowing coolant in the electric vehicle. Beneficially, the rotation of the motor shaft 106 is used as a means for creating pumping action of the flow of coolant. Beneficially, the impeller 110 increases the pressure and flow rate of the coolant. The electric motor 100 is advantageous in terms of efficient active cooling, as the rotation speed of the impeller 110 increases with the speed of rotation of the motor shaft 106 increasing the flow of coolant in the spiral cooling jacket 108. Beneficially, the electric motor 100 of the present disclosure is advantageous in terms of eliminating the requirement for any additional coolant controller.
In an embodiment, the stator assembly 102 comprises a plurality of stator tooth 102a to accommodate a plurality of stator winding coils. Beneficially, the stator assembly 102 generates a magnetic field which results in the rotation of the rotor assembly 104.
In an embodiment, the rotor assembly 104 comprises a rotor stack 104a and a plurality of permanent magnets 104b, and wherein the rotor assembly 104 is mounted on the motor shaft 106. Beneficially, the rotor assembly 104 generates a magnetic field that interacts with the magnetic field generated by the stator assembly 102 resulting in the rotation of the rotor assembly 104.
In an embodiment, the first end 106a of the motor shaft 106 is connected to a mechanical load. Beneficially, the output power of the electric motor 100 is delivered to the mechanical load via the first end 106a of the motor shaft 106.
In an embodiment, the enclosure 112 is two-part comprising an enclosure cover 112a and an enclosure plate 112b. Beneficially, the two-part enclosure 112 enables easier maintenance of the electric motor 100. It is to be understood that for the maintenance of the electric motor 100 only the enclosure plate 112b is required to be removed without removing the enclosure cover 112a.
In an embodiment, the motor 100 comprises a motor casing 114, wherein the motor casing 114 comprises a casing inlet 114a and a casing outlet 114b, wherein the spiral cooling jacket 108 is mounted within the motor casing 114 and connected to the casing inlet 114a and the casing outlet 114b to form a coolant flow path. It is to be understood that the spiral cooling jacket 108 forms the coolant flow path around the stator assembly 102 to absorb the heat generated by the electric motor 100 during the operation. The coolant passing through the coolant flow path in the spiral cooling jacket 108 absorbs the heat generated inside the electric motor 100.
In an embodiment, the enclosure 112 comprises an enclosure coolant inlet 116 and an enclosure coolant outlet 118, wherein the enclosure coolant inlet 116 is connected to a coolant supply reservoir and the enclosure coolant outlet 118 is connected to the casing inlet 114a. It is to be understood that the coolant enters the enclosure 112 via the enclosure coolant inlet 116 due to the rotation of the impeller 110. Simultaneously, the rotation of the impeller 110 pushes the coolant from the enclosure 112 to the spiral cooling jacket 108 via the enclosure coolant outlet 118 and the casing inlet 114a.
In an embodiment, the casing outlet 114b is connected to the coolant supply reservoir. It is to be understood that the coolant is sent back to the coolant supply from the spiral cooling jacket 108 via the casing outlet 114b after absorbing heat from the electric motor 100.
In an embodiment, the impeller 110 rotates with the motor shaft 106 during the operation of the motor 100 to draw the coolant inside the enclosure 112 from the coolant supply reservoir and simultaneously push the drawn coolant to the spiral cooling jacket 108 for cooling of the electric motor 100. Beneficially, the impeller 110 creates pressure inside the coolant flow path for the flow of coolant eliminating the need for an external pump. More beneficially, the impeller 110 rotates according to the speed of the motor shaft 106 resulting in increased coolant flow rate, thus eliminating the need for external coolant flow controller.
In an embodiment, the coolant exits the spiral cooling jacket 108 via the casing outlet 114b after absorbing heat from the electric motor 100.
Figure 2, in accordance with an embodiment, describes a perspective view of the electric motor 100 for the electric vehicle. The electric motor 100 comprises the stator assembly 102, the rotor assembly 104, the motor shaft 106 comprising the first end 106a and the second end 106b, the spiral cooling jacket 108, the impeller 110 mounted on the second end 106b of the motor shaft 106, and the enclosure 112 enclosing the impeller 110 and the second end 106b of the motor shaft 106. The impeller 110 rotates with the motor shaft 106 during the operation of the motor 100 to create the flow of the coolant through the spiral cooling jacket 108 for cooling of the electric motor 100.
Figure 3, in accordance with an embodiment, describes a sectional view of the electric motor 100 for the electric vehicle. The electric motor 100 comprises the stator assembly 102, the rotor assembly 104, the motor shaft 106 comprising the first end 106a and the second end 106b, the spiral cooling jacket 108, the impeller 110 mounted on the second end 106b of the motor shaft 106, and the enclosure 112 enclosing the impeller 110 and the second end 106b of the motor shaft 106. The impeller 110 rotates with the motor shaft 106 during the operation of the motor 100 to create the flow of the coolant through the spiral cooling jacket 108 for cooling of the electric motor 100. Furthermore, the enclosure 112 is two-part comprising the enclosure cover 112a and the enclosure plate 112b. Furthermore, the motor 100 comprises the motor casing 114, wherein the motor casing 114 comprises the casing inlet 114a and the casing outlet 114b, wherein the spiral cooling jacket 108 is mounted within the motor casing 114 and connected to the casing inlet 114a and the casing outlet 114b to form the coolant flow path. Furthermore, the enclosure 112 comprises the enclosure coolant inlet 116 and the enclosure coolant outlet 118, wherein the enclosure coolant inlet 116 is connected to the coolant supply reservoir and the enclosure coolant outlet 118 is connected to the casing inlet 114a. Furthermore, the casing outlet 114b is connected to the coolant supply reservoir. Furthermore, the impeller 110 rotates with the motor shaft 106 during the operation of the motor 100 to draw the coolant inside the enclosure 112 from the coolant supply reservoir and simultaneously push the drawn coolant to the spiral cooling jacket 108 for cooling of the electric motor 100. Furthermore, the coolant exits the spiral cooling jacket 108 via the casing outlet 114b after absorbing heat from the electric motor 100.
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. An electric motor (100) for an electric vehicle, comprising:
- a stator assembly (102);
- a rotor assembly (104);
- a motor shaft (106), comprising a first end (106a) and a second end (106b);
- a spiral cooling jacket (108);
- an impeller (110) mounted on the second end (106b) of the motor shaft (106); and
- an enclosure (112) enclosing the impeller (110) and the second end (106b) of the motor shaft (106),
wherein the impeller (110) rotates with the motor shaft (106) during the operation of the motor (100) to create a flow of a coolant through the spiral cooling jacket (108) for cooling of the electric motor (100).
2. The electric motor (100) as claimed in claim 1, wherein the stator assembly (102) comprises a plurality of stator tooth (102a) to accommodate a plurality of stator winding coils.
3. The electric motor (100) as claimed in claim 1, wherein the rotor assembly (104) comprises a rotor stack (104a) and a plurality of permanent magnets (104b), and wherein the rotor assembly (104) is mounted on the motor shaft (106).
4. The electric motor (100) as claimed in claim 1, wherein the first end (106a) of the motor shaft (106) is connected to a mechanical load.
5. The electric motor (100) as claimed in claim 1, wherein the enclosure (112) is two-part comprising an enclosure cover (112a) and an enclosure plate (112b).
6. The electric motor (100) as claimed in claim 1, wherein the motor (100) comprises a motor casing (114), wherein the motor casing (114) comprises a casing inlet (114a) and a casing outlet (114b), wherein the spiral cooling jacket (108) is mounted within the motor casing (114) and connected to the casing inlet (114a) and the casing outlet (114b) to form a coolant flow path.
7. The electric motor (100) as claimed in claim 1, wherein the enclosure (112) comprises an enclosure coolant inlet (116) and an enclosure coolant outlet (118), wherein the enclosure coolant inlet (116) is connected to a coolant supply reservoir and the enclosure coolant outlet (118) is connected to the casing inlet (114a).
8. The electric motor (100) as claimed in claim 1, wherein the casing outlet (114b) is connected to the coolant supply reservoir.
9. The electric motor (100) as claimed in claim 1, wherein the impeller (110) rotates with the motor shaft (106) during the operation of the motor (100) to draw the coolant inside the enclosure (112) from the coolant supply reservoir and simultaneously push the drawn coolant to the spiral cooling jacket (108) for cooling of the electric motor (100).
10. The electric motor (100) as claimed in claim 9, wherein the coolant exits the spiral cooling jacket (108) via the casing outlet (114b) after absorbing heat from the electric motor (100).