Rotor assembly, electric machine and vehicle

Abstract

The present disclosure provides a rotor assembly, a motor and a vehicle, and relates to the technical field of motors. The rotor assembly comprises a rotor core, a magnetic steel, two end plates and a rotating shaft. The rotor core is fixed between the two end plates, and the rotating shaft is arranged in the rotor core and the two end plates. The magnetic steel is fixed in a magnetic steel slot of the rotor core, and a cooling flow channel penetrating the rotor core in the axial direction is formed between the magnetic steel and the inner wall of the magnetic steel slot. The rotating shaft is used to pass in the cooling liquid and is thrown out through a liquid throwing port on the side wall. A first flow channel is formed between one of the end plates and the rotor core, and the first flow channel is connected with one end of the cooling flow channel and the liquid throwing port. A second flow channel is formed between the other end plate and the rotor core, and the second flow channel is connected with the other end of the cooling flow channel and the outside. When the rotor assembly works, the cooling liquid flows through the first flow channel, the cooling flow channel and the second flow channel in sequence through the liquid throwing port on the rotating shaft. In this way, the cooling liquid can directly cool the magnetic steel, the cooling effect of the magnetic steel is improved, and the risk of demagnetization of the magnetic steel is reduced.

Description

Technical Field

[0001] This disclosure relates to the field of electric motor technology, and in particular to a rotor assembly, an electric motor, and a vehicle. Background Technology

[0002] With the development of the new energy vehicle industry, the requirements for the power density, efficiency, and speed of vehicle electric drive systems are becoming increasingly stringent, which in turn places higher demands on motor cooling. The rotor assembly is the main heat source in the motor, making its cooling crucial.

[0003] The rotor assembly includes a rotor core and magnets, with the magnets embedded inside the rotor core. In related technologies, cooling of the rotor assembly often results in poor cooling of the magnets, leading to a significant risk of demagnetization. Summary of the Invention

[0004] This disclosure provides a rotor assembly, a motor, and a vehicle that can solve the technical problems existing in the related art. The technical solutions of the rotor assembly, motor, and vehicle are as follows.

[0005] In a first aspect, this disclosure provides a rotor assembly, the rotor assembly including a rotor core, magnets, two end plates and a shaft; The rotor core is fixed between the two end plates, and the rotating shaft passes through the rotor core and the two end plates. The magnet is fixed in the magnet slot of the rotor core, and a cooling channel that penetrates the rotor core axially is formed between the magnet and the inner wall of the magnet slot. The shaft is used to introduce coolant, which is then ejected from the outlet on the side wall. A first flow channel is formed between an end plate and the rotor core, and the first flow channel connects one end of the cooling flow channel and the liquid throwing port; A second flow channel is formed between the other end plate and the rotor core, and the second flow channel connects the other end of the cooling flow channel to the outside.

[0006] In one possible implementation, the first flow channel includes an inlet hole, a first guide groove, a second guide groove, and an inlet groove; The liquid inlet is connected to the liquid ejection port. The first guide groove and the second guide groove are distributed circumferentially on both sides of the liquid inlet. One end of the liquid inlet groove is connected to the liquid outlet of the first guide groove and the other end is connected to the liquid outlet of the second guide groove. The liquid inlet groove is also axially connected to a plurality of cooling channels.

[0007] In one possible implementation, both the first guide groove and the second guide groove are arc-shaped grooves; The first guide groove protrudes radially from the rotor core along a first direction, and the second guide groove protrudes radially from the rotor core along a second direction, wherein one of the first direction and the second direction is clockwise and the other is counterclockwise.

[0008] In one possible implementation, the end plate further has a sliding groove, the two ends of which are respectively connected to the liquid inlet end of the first guide groove and the liquid inlet end of the second guide groove; The rotor assembly also includes a slider located in the sliding groove. When the rotor assembly rotates clockwise, the slider blocks the liquid inlet end of the first guide groove. When the rotor assembly rotates counterclockwise, the slider blocks the liquid inlet end of the second guide groove.

[0009] In one possible implementation, the sliding groove is arc-shaped, and the center of the sliding groove is located on the axis of the rotating shaft.

[0010] In one possible implementation, the second flow channel includes an outlet and a return channel; The liquid outlet hole extends axially through the end plate, the opening of the liquid return groove faces the rotor core, and the cooling channel is connected to the liquid outlet hole through the liquid return groove.

[0011] In one possible implementation, the second flow channel further includes a third guide groove and a fourth guide groove; The third guide groove and the fourth guide groove are distributed circumferentially on both sides of the liquid outlet hole. One end of the return groove is connected to the liquid outlet end of the third guide groove, and the other end is connected to the liquid outlet end of the fourth guide groove.

[0012] In one possible implementation, the two end plates include a first end plate and a second end plate, with the first end plate forming a first flow channel and a second flow channel between one side of the rotor core and the second end plate forming the first flow channel and the second flow channel between the other side of the rotor core; The rotating shaft has at least two liquid ejection ports. One liquid ejection port is sequentially connected to the first flow channel of the first end plate, the cooling flow channel, and the second flow channel of the second end plate. The other liquid ejection port is sequentially connected to the first flow channel of the second end plate, the cooling flow channel, and the second flow channel of the first end plate.

[0013] In one possible implementation, there are multiple first flow channels and multiple second flow channels between the end plate and the rotor core, the first flow channels and the second flow channels being arranged alternately in the circumferential direction.

[0014] In a second aspect, this disclosure provides an electric motor comprising a rotor assembly as described in any of the first aspects.

[0015] Thirdly, this disclosure provides a vehicle that includes an electric motor as described in the second aspect.

[0016] The technical solution provided in this disclosure includes at least the following beneficial effects: This disclosure provides a rotor assembly in which coolant enters from the shaft and flows to the liquid ejector port during operation. The coolant then flows sequentially through a first flow channel, a cooling flow channel, and a second flow channel, finally exiting the rotor assembly, thus completing the cooling of the rotor assembly. Since the cooling flow channel is located between the magnet and the inner wall of the magnet slot, the coolant can directly cool the magnet through contact with it, thereby improving the cooling effect and reducing the risk of magnet demagnetization.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. In the drawings: Figure 1 This is a schematic diagram of the structure of a rotor assembly shown in an embodiment of this disclosure; Figure 2 This is an exploded view of a rotor assembly shown in an embodiment of this disclosure; Figure 3 This is a schematic diagram of the flow path of coolant in a rotor assembly according to an embodiment of the present disclosure; Figure 4 This is a front view of a rotor core and magnet shown in an embodiment of this disclosure; Figure 5 This is a schematic diagram of the structure of a rotating shaft shown in an embodiment of this disclosure; Figure 6 This is a schematic diagram of the structure of an end plate shown in an embodiment of this disclosure; Figure 7 This is a front view of an end plate shown in an embodiment of this disclosure; Figure 8 This is a schematic diagram illustrating the flow path of coolant in a first flow channel according to an embodiment of this disclosure; Figure 9 This is a schematic diagram illustrating the flow path of coolant in a second flow channel according to an embodiment of this disclosure.

[0019] Legend: 1. Rotor core; 11. Cooling channels; 11a. First cooling channel; 11b. Second cooling channel; 11c. Third cooling channel; 11d. Fourth cooling channel; 2. Magnet, 2a. First magnet, 2b. Second magnet; 3. End plate, 3a. First end plate, 3b. Second end plate, 31. First flow channel, 310. Liquid inlet hole, 311. First guide groove, 312. Second guide groove, 313. Liquid inlet groove, 3131. First sub-liquid inlet groove, 3132. Second sub-liquid inlet groove, 3133. Third sub-liquid inlet groove, 32. Second flow channel, 320. Liquid outlet hole, 321. Liquid return groove, 3211. First sub-liquid return groove, 3212. Second sub-liquid return groove, 3213. Third sub-liquid return groove, 322. Third guide groove, 323. Fourth guide groove, 33. Sliding groove; 4. Rotating shaft; 41. Liquid ejection port; 42. Liquid inlet; 5. Slider.

[0020] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings.

[0022] The terminology used in the embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used herein should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “a” or “one,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. It is understood that in this disclosure, “multiple” refers to two or more, and other quantifiers are similar. The singular forms “a,” “the,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It is further understood that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the two components; they can refer to a direct connection between two components without the presence of other components, or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0024] With the development of the new energy vehicle industry, the requirements for the power density, efficiency, and speed of vehicle electric drive systems are becoming increasingly stringent. This results in the motor generating more heat during operation, leading to increasingly demanding cooling requirements. The rotor assembly is the main heat source in the motor, making its cooling crucial.

[0025] The rotor assembly includes a rotor core, magnets, and a shaft. The magnets are embedded in magnet slots in the rotor core. The rotor core is annular, and the shaft is fixed to the inner side of the rotor core. During motor operation, the rotor assembly generates significant heat. In related technologies, the shaft has an oil inlet and an oil outlet, and the rotor core has cooling channels. The oil outlet of the shaft is connected to the cooling channels, allowing coolant to flow through the rotor core, thereby cooling the rotor core. The reduced temperature of the rotor core then cools the magnets.

[0026] However, in these technologies, the coolant only comes into direct contact with the rotor core and cannot directly cool the magnets. This results in poor cooling of the magnets, increasing the risk of demagnetization.

[0027] In view of the above-mentioned technical problems, embodiments of this disclosure provide a rotor assembly, such as... Figures 1-5 As shown, the rotor assembly includes a rotor core 1, magnets 2, two end plates 3, and a shaft 4. The rotor core 1 is fixed between the two end plates 3, and the shaft 4 passes through the rotor core 1 and the two end plates 3. The magnets 2 are fixed in the magnet slots of the rotor core 1, forming an axial cooling channel 11 between the magnets 2 and the inner wall of the magnet slots. The shaft 4 is used to introduce coolant, which is then ejected through a splash port 41 on its side wall. A first channel 31 is formed between one end plate 3 and the rotor core 1, connecting one end of the cooling channel 11 to the splash port 41. A second channel 32 is formed between the other end plate 3 and the rotor core 1, connecting the other end of the cooling channel 11 to the outside.

[0028] The rotor core 1 and the end plate 3 are both annular, and the rotating shaft 4 is fixed inside the rotor core 1 and the end plate 3. The rotating shaft 4 can be interference-fitted with the rotor core 1 and the end plate 3.

[0029] The rotor core 1 includes multiple rotor laminations stacked along the axial direction. Each rotor lamination has a magnet slot and a magnet 2 is embedded in each magnet slot. The cooling channels 11 on each rotor lamination are connected along the axial direction.

[0030] The magnet 2, also known as a permanent magnet, consists of multiple magnets arranged in an array along the circumference of the rotor core 1. Correspondingly, there are also multiple cooling channels 11, arranged in an array along the circumference of the rotor core 1. The magnet 2 can be made of ferrite, neodymium iron boron, or AlNiCo, etc.

[0031] End plate 3, also known as dynamic balancing end plate, is used to change the mass distribution of the rotor assembly, thereby achieving dynamic balance during rotor assembly rotation. Furthermore, end plate 3 also serves to limit the movement of magnet 2, preventing it from detaching from rotor core 1 during rotor assembly rotation. The first flow channel 31 can be a groove on end plate 3, and / or a groove on rotor core 1. Similarly, the second flow channel 32 can be a groove on end plate 3, and / or a groove on rotor core 1.

[0032] The shaft 4 is a hollow shaft, which allows for weight reduction and facilitates the flow of coolant to the end plate 3. An inlet 42 may be provided at one end or on the side wall of the shaft.

[0033] The technical solution provided in this disclosure embodiment allows coolant to enter the rotor assembly from the shaft 4 and flow to the liquid outlet 41 during operation. It then flows sequentially through the first flow channel 31 of one end plate 3, the cooling flow channel 11, and the second flow channel 32 of the other end plate 3, finally exiting the rotor assembly, thus completing the cooling of the rotor assembly. Since the cooling flow channel 11 is located between the magnet 2 and the inner wall of the magnet slot, the coolant can directly cool the magnet 2 by contacting it, thereby improving the cooling effect and reducing the risk of demagnetization of the magnet 2.

[0034] In addition, the coolant flowing through the cooling channel 11 can simultaneously contact the rotor core 1 and the magnet 2, thereby cooling the rotor core 1 and the magnet 2 at the same time. There is no need to open an additional cooling channel for cooling the rotor core, which makes the structure of the rotor assembly simpler and reduces the complexity of processing the rotor assembly.

[0035] As mentioned earlier, the first flow channel 31 is used to guide the coolant flowing from the slinger 41 to the cooling flow channel 11. When the rotor assembly rotates in different directions, the coolant will be subjected to inertial forces in different directions in the first flow channel 31. For example, when the rotor core 1 rotates clockwise, the coolant will be subjected to an inertial force in the counterclockwise direction. If the first flow channel 31 extends clockwise, it will guide the coolant in a clockwise direction, and the coolant will experience greater flow resistance in the first flow channel 31 due to the counterclockwise inertial force, resulting in a longer time for the coolant to enter the cooling flow channel 11 and lower cooling efficiency. Conversely, if the first flow channel 31 extends counterclockwise, the coolant will also experience greater flow resistance when the rotor core rotates counterclockwise.

[0036] Therefore, in order to ensure that the coolant does not encounter significant flow resistance when the rotor core 1 rotates in either a clockwise or counterclockwise direction, the present embodiment provides two guide grooves in the first flow channel 31, so that the coolant can flow in both clockwise and counterclockwise directions.

[0037] Specifically, such as Figure 6 and Figure 7 As shown, the first flow channel 31 includes a liquid inlet 310, a first guide groove 311, a second guide groove 312, and a liquid inlet tank 313. The liquid inlet 310 is connected to the liquid ejector port 41. The first guide groove 311 and the second guide groove 312 are distributed circumferentially on both sides of the liquid inlet 310. One end of the liquid inlet tank 313 is connected to the liquid outlet end of the first guide groove 311, and the other end is connected to the liquid outlet end of the second guide groove 312. The liquid inlet tank 313 is also axially connected to multiple cooling flow channels 11.

[0038] like Figure 7 As shown, the coolant can enter the inlet tank 313 clockwise through the first guide groove 311, or counterclockwise through the second guide groove 312. Thus, when the rotor core 1 rotates clockwise, the coolant flows smoothly to the inlet tank 313 through the second guide groove 312 under the action of the counterclockwise inertial force. When the rotor core 1 rotates counterclockwise, the coolant flows smoothly to the inlet tank 313 through the first guide groove 311 under the action of the clockwise inertial force.

[0039] In some examples, such as Figure 7 As shown, both the first guide groove 311 and the second guide groove 312 are arc-shaped grooves. The first guide groove 311 protrudes radially relative to the rotor core 1 along a first direction, and the second guide groove 312 protrudes radially relative to the rotor core 1 along a second direction. One of the first and second directions is clockwise, and the other is counterclockwise. This allows the coolant to smoothly rotate from radial to circumferential, thus facilitating its entry into the inlet groove 313.

[0040] For example, the first guide groove 311 protrudes counterclockwise relative to the radial direction of the rotor core 1, and the second guide groove 312 protrudes clockwise relative to the radial direction of the rotor core 1.

[0041] Of course, in other instances, the first guide groove 311 and the second guide groove 312 may also be linear, and this disclosure does not specifically limit this.

[0042] As mentioned above, since both the first guide groove 311 and the second guide groove 312 are connected to the liquid inlet hole 310, even when the rotor core 1 rotates clockwise, a small amount of coolant will still enter the liquid inlet tank 313 through the first guide groove 311. This results in less coolant entering the second guide groove 312, causing diversion, and also reduces the hydraulic pressure in the second guide groove 312, which is not conducive to the rapid flow of coolant to the liquid inlet tank 313. Therefore, in this embodiment of the present disclosure, the liquid inlet end of the first guide groove 311 is blocked when the rotor assembly rotates clockwise, and the second guide groove 312 is blocked when the rotor assembly rotates counterclockwise.

[0043] In some examples, such as Figure 7 As shown, the end plate 3 also has a sliding groove 33, the two ends of which are connected to the liquid inlet end of the first guide groove 311 and the liquid inlet end of the second guide groove 312, respectively. The rotor assembly also includes a slider 5, which is located in the sliding groove 33.

[0044] like Figure 8 As shown, when the rotor assembly rotates clockwise, the slider 5 slides counterclockwise under the action of inertia, thereby blocking the liquid inlet end of the first guide groove 311, so that the coolant can only flow to the second guide groove 312. Since the liquid inlet groove 313 is located counterclockwise from the second guide groove 312, the coolant will flow counterclockwise through the second guide groove 312 into the liquid inlet groove 313. It can be understood that since the rotor assembly rotates clockwise, the inertial force on the coolant is counterclockwise. In this way, the flow direction of the coolant is consistent with the direction of the inertial force, so the flow resistance of the coolant in the liquid inlet groove 313 is small, and it can flow smoothly.

[0045] Correspondingly, when the rotor assembly rotates counterclockwise, the slider 5 blocks the inlet end of the second guide groove 312, allowing the coolant to flow only into the first guide groove 311. Since the inlet groove 313 is located clockwise from the first guide groove 311, the coolant flows clockwise through the first guide groove 311 into the inlet groove 313. It can be understood that because the rotor assembly rotates counterclockwise, the inertial force on the coolant is clockwise. Thus, the flow direction of the coolant is consistent with the direction of the inertial force, resulting in less flow resistance and smoother flow in the inlet groove 313.

[0046] In some examples, such as Figure 6 and Figure 7 As shown, the sliding groove 33 is arc-shaped, and the center of the sliding groove 33 coincides with the axis of the rotating shaft 4, making the sliding trajectory of the slider 5 in the sliding groove 33 arc-shaped. Since the inertial force on the slider 5 is clockwise or counterclockwise when the rotor assembly rotates, setting the sliding groove 33 to an arc shape allows the slider 5 to slide smoothly in the sliding groove 33, avoiding jamming.

[0047] For example, the width of the slider 5 is greater than the width of the liquid inlet hole 310, thereby preventing the slider 5 from falling into the liquid inlet hole 310 when sliding in the sliding groove 33, thus ensuring that the slider 5 slides smoothly in the sliding groove 33.

[0048] For example, the side of the slider 5 facing the liquid inlet 310 is straight, so as to prevent part of the structure from extending into the liquid inlet 310 and getting stuck in the liquid inlet 310 when the slider 5 slides in the sliding groove 33, thereby ensuring that the slider 5 slides smoothly in the sliding groove 33.

[0049] In some examples, such as Figure 4 As shown, cooling channels 11 are formed between both ends of the magnet 2 and the inner wall of the magnet groove. In order to improve the cooling effect on the magnet 2, the liquid inlet tank 313 includes multiple sub-liquid inlet tanks, so that the liquid inlet tank 313 can be connected to each cooling channel.

[0050] For example, such as Figure 4 As shown, the rotor assembly includes multiple magnets 2. Each group of magnets 2 includes two first magnets 2a and two second magnets 2b arranged circumferentially, with the two first magnets 2a located between the two second magnets 2b. The length of the first magnets 2a is less than the length of the second magnets 2b. A first cooling channel 11a is formed between the end of the first magnet 2a near the rotor assembly axis and the magnet slot, a second cooling channel 11b is formed between the end of the first magnet 2a away from the rotor assembly axis and the magnet slot, a third cooling channel 11c is formed between the end of the second magnet 2b near the rotor assembly axis and the magnet slot, and a fourth cooling channel 11d is formed between the end of the second magnet 2b away from the rotor assembly axis and the magnet slot.

[0051] like Figure 7 and Figure 8 As shown, to ensure that the coolant can flow through the cooling channels of the first magnet 2a and the second magnet 2b, the inlet tank 313 includes a first sub-inlet tank 3131, a second sub-inlet tank 3132, and a third sub-inlet tank 3133, which are arranged sequentially along the axis away from the rotor assembly. The two ends of the first sub-inlet tank 3131 are connected to the first guide groove 311 and the second guide groove 312, respectively. The two ends of the second sub-inlet tank 3132 are also connected to the first guide groove 311 and the second guide groove 312, respectively. The third sub-inlet tank 3133 communicates with the second guide groove 312. The first sub-inlet tank 3131 is axially connected to the third cooling channel 11c, the second sub-inlet tank 3132 is axially connected to the first cooling channel 11a, and the third sub-inlet tank 3133 is axially connected to the second cooling channel 11b and the fourth cooling channel 11d. The third sub-inlet tank 3133 may have four branches, which are respectively connected to two second cooling channels 11b and two fourth cooling channels 11d.

[0052] like Figure 8 As shown ( Figure 8 (The solid arrows in the diagram indicate the rotation direction of end plate 3, and the dashed arrows indicate the flow path of the coolant.) When end plate 3 rotates clockwise, coolant enters sliding groove 33 through inlet hole 310. Sliding block 5 slides counterclockwise due to inertia, thus blocking the inlet end of first guide groove 311, allowing coolant to flow only to second guide groove 312. Then, coolant flows counterclockwise through second guide groove 312 to first sub-inlet groove 3131, second sub-inlet groove 3132, and third sub-inlet groove 3133. This allows coolant to flow to first cooling channel 11a, second cooling channel 11b, third cooling channel 11c, and fourth cooling channel 11d, thereby completing the cooling of first magnet 2a and second magnet 2b.

[0053] Correspondingly, when end plate 3 rotates counterclockwise, coolant enters sliding groove 33 through inlet hole 310. Sliding block 5 slides clockwise due to inertia, thus blocking the inlet end of second guide groove 312, allowing coolant to flow only to first guide groove 311. Then, coolant flows clockwise through first guide groove 311 to first sub-inlet groove 3131 and second sub-inlet groove 3132. Next, coolant in second sub-inlet groove 3132 flows through second guide groove 312 to third sub-inlet groove 3133, allowing coolant to flow to first cooling channel 11a, second cooling channel 11b, third cooling channel 11c, and fourth cooling channel 11d, thereby completing the cooling of first magnet 2a and second magnet 2b.

[0054] In some examples, the diameter of the inlet hole 310 is larger than the diameter of the first sub-inlet tank 3131, the second sub-inlet tank 3132, and the third sub-inlet tank 3133. This allows the coolant to have sufficient pressure in the first sub-inlet tank 3131, the second sub-inlet tank 3132, and the third sub-inlet tank 3133, ensuring that the coolant can flow smoothly in the inlet tank 313.

[0055] It should be noted that the structure and shape of the liquid inlet tank 313 are not specifically limited in this embodiment. In actual production, an adaptive design can be made according to the arrangement of the magnets 2 and the arrangement of the multiple cooling channels 11.

[0056] As mentioned above, the coolant flows through the first flow channel 31 to the cooling flow channel 11, and then flows out of the rotor assembly through the second flow channel 32. Therefore, the structural features of the second flow channel 32 also affect the flow of coolant in the rotor assembly, thereby affecting the cooling effect. The structural features of the second flow channel 32 are described below by way of example.

[0057] In some examples, such as Figure 9 As shown, the second flow channel 32 includes a liquid outlet 320 and a liquid return channel 321. The liquid outlet 320 extends axially through the end plate 3, and the opening of the liquid return channel 321 faces the rotor core 1. The cooling flow channel 11 is connected to the liquid outlet 320 through the liquid return channel 321. The liquid return channel 321 can collect the coolant on the end plate 3, so that the coolant is collected and then discharged from the rotor assembly through the liquid outlet 320.

[0058] In some examples, such as Figure 9 As shown, the second flow channel 32 also includes a third guide groove 322 and a fourth guide groove 323. The third guide groove 322 and the fourth guide groove 323 are distributed circumferentially on both sides of the liquid outlet hole 320. One end of the return groove 321 is connected to the liquid outlet end of the third guide groove 322, and the other end is connected to the liquid outlet end of the fourth guide groove 323. This allows the coolant to flow to the liquid outlet hole 320 through both the third guide groove 322 and the fourth guide groove 323, thereby enabling the coolant to be quickly discharged from the rotor assembly.

[0059] For example, such as Figure 9As shown, the return liquid tank 321 includes a first sub-return liquid tank 3211, a second sub-return liquid tank 3212, and a third sub-return liquid tank 3213, which are arranged sequentially along the axis away from the rotor assembly. The two ends of the first sub-return liquid tank 3211 are connected to the third guide groove 322 and the fourth guide groove 323, respectively. The two ends of the second sub-return liquid tank 3212 are connected to the third guide groove 322 and the fourth guide groove 323, respectively. One end of the third sub-return liquid tank 3213 is connected to the third guide groove 322. The first sub-return liquid tank 3211 is axially connected to the third cooling channel 11c, the second sub-return liquid tank 3212 is axially connected to the first cooling channel 11a, and the third sub-return liquid tank 3213 is axially connected to the second cooling channel 11b and the fourth cooling channel 11d. The third sub-return tank 3213 may have four branches, which are respectively connected to two second cooling channels 11b and two fourth cooling channels 11d.

[0060] like Figure 9 As shown ( Figure 9 The dashed arrows in the diagram indicate the flow path of the coolant. After flowing out of the cooling channel 11, the coolant enters the third sub-return tank 3213, and then flows to the third guide tank 322 and the second sub-return tank 3212 respectively. Part of the coolant in the third guide tank 322 flows directly to the outlet hole 320, and part of the coolant flows to the outlet hole 320 through the first sub-return tank 3211. The coolant in the second sub-return tank 3212 flows to the outlet hole 320 through the fourth guide tank 323.

[0061] In some examples, the inlet groove 313 on one end plate 3 and the return groove 321 on the other end plate 3 coincide along the axial projection.

[0062] The distribution of the first flow channel 31 and the second flow channel 32 on the two end plates will be illustrated below.

[0063] In some examples, such as Figure 2 and Figure 3 As shown, the two end plates 3 include a first end plate 3a and a second end plate 3b. A first flow channel 31 and a second flow channel 32 are formed between the first end plate 3a and one side of the rotor core 1, and a first flow channel 31 and a second flow channel 32 are formed between the second end plate 3b and the other side of the rotor core 1. The rotating shaft 4 has at least two liquid-throwing ports 41. One liquid-throwing port 41 is sequentially connected to the first flow channel 31 of the first end plate 3a, the cooling flow channel 11, and the second flow channel 32 of the second end plate 3b. The other liquid-throwing port 41 is sequentially connected to the first flow channel 31 of the second end plate 3b, the cooling flow channel 11, and the second flow channel 32 of the first end plate 3a.

[0064] like Figure 3 As shown ( Figure 3Cooling channel 11 is not shown. Figure 3 (The dashed arrows in the diagram indicate the flow path of the coolant.) When the rotor assembly rotates, the coolant in the shaft 4 enters the first flow channel 31 of the first end plate 3a through the splash port 41 opposite to the first end plate 3a, then flows axially through the cooling flow channel 11, and finally enters the second flow channel 32 of the second end plate 3b to exit the rotor assembly. Simultaneously, the coolant in the shaft 4 enters the first flow channel 31 of the second end plate 3b through the splash port 41 opposite to the second end plate 3b, then flows axially through the cooling flow channel 11, and finally enters the second flow channel 32 of the first end plate 3a to exit the rotor assembly.

[0065] In this way, the coolant can begin cooling both ends of the rotor assembly simultaneously, resulting in a more uniform cooling effect on the rotor assembly.

[0066] Furthermore, this allows the first end plate 3a and the second end plate 3b to have the same structure. When manufacturing the rotor assembly, only one type of end plate 3 needs to be manufactured, without the need to manufacture the first end plate 3a and the second end plate 3b separately, which is beneficial for the mass production of the rotor assembly.

[0067] In some examples, the inlet groove 313 and return groove 321 on the first end plate 3a are symmetrically distributed about the radius of the rotor core 1. This facilitates a more uniform mass distribution on the first end plate 3a and helps the rotor assembly achieve dynamic balance. Similarly, the inlet groove 313 and return groove 321 on the second end plate 3b can also be symmetrically distributed about the radius of the rotor core 1.

[0068] In other examples, the first end plate 3a may be configured to have only a first flow channel 31, and the second end plate 3b may have only a second flow channel 32. When the rotor assembly rotates, the coolant in the shaft 4 enters the first flow channel 31 of the first end plate 3a through the liquid ejector port opposite to the first end plate 3a, then flows axially through the cooling flow channel 11, and then enters the second flow channel 32 of the second end plate 3b to exit the rotor assembly.

[0069] At this time, the shaft 4 has a liquid inlet 42 at the end near the first flow channel 31. For example, when the first end plate 3a has only the first flow channel 31 and the second end plate 3b has only the second flow channel 32, the shaft 4 has a liquid inlet 42 at the end near the first end plate 3a, so that the coolant can quickly enter the first flow channel 31.

[0070] In some examples, there are multiple first flow channels 31 and multiple second flow channels 32 between the end plate 3 and the rotor core 1, with the first flow channels 31 and the second flow channels 32 arranged alternately in the circumferential direction. This makes the cooling effect of the coolant on the rotor assembly more uniform.

[0071] Correspondingly, the rotating shaft 4 has two sets of liquid ejection ports 41 arranged axially. Each set of liquid ejection ports 41 is distributed circumferentially, and each liquid ejection port 41 is connected to a liquid inlet 310. It can be understood that the number of liquid ejection ports 41 in each set of liquid ejection ports 41 is the same as the number of the first flow channels 31.

[0072] For example, the rotor core 1 is embedded with six sets of magnets 2, each set of magnets 2 including two first magnets 2a and two second magnets 2b, then each set of liquid ejection ports 41 has three liquid ejection ports 41.

[0073] The flow path of coolant in the rotor assembly will be illustrated below, taking the clockwise rotation of the rotor assembly as an example.

[0074] like Figure 3 As shown, the coolant enters the cavity of the rotating shaft 4 through the inlet 42 on the rotating shaft 4. Then, the coolant enters the first flow channel 31 of the first end plate 3a and the first flow channel 31 of the second end plate 3b through two sets of axially arranged splash ports 41.

[0075] like Figure 8 As shown, after the coolant enters the first flow channel 31 of the first end plate 3a, it enters the sliding groove 33 through the inlet hole 310. The slider 5 slides counterclockwise under inertia, thus blocking the inlet end of the first guide groove 311, allowing the coolant to flow only to the second guide groove 312. Then, the coolant flows counterclockwise through the second guide groove 312 to the first sub-inlet groove 3131, the second sub-inlet groove 3132, and the third sub-inlet groove 3133. This allows the coolant to flow to the first cooling flow channel 11a, the second cooling flow channel 11b, the third cooling flow channel 11c, and the fourth cooling flow channel 11d, and then to the second flow channel 32 of the second end plate 3b. Then, as... Figure 9 As shown, the coolant enters the third sub-return tank 3213, and then flows to the third guide tank 322 and the second sub-return tank 3212 respectively. Part of the coolant in the third guide tank 322 flows directly to the outlet hole 320, while part flows through the first sub-return tank 3211 to the outlet hole 320. The coolant in the second sub-return tank 3212 flows through the fourth guide tank 323 to the outlet hole 320. Correspondingly, after entering the first flow channel 31 of the second end plate 3b, the coolant also enters the second flow channel 32 of the first end plate 3a along the corresponding path, which will not be described further here.

[0076] Finally, the coolant is discharged from the rotor assembly through the outlet holes 320 on the first end plate 3a and the second end plate 3b, thus completing the cooling of the rotor core 1 and the magnet 2.

[0077] This disclosure also provides an electric motor, which includes a stator assembly and the aforementioned rotor assembly. The stator assembly includes a stator core and windings, with the windings wound around the stator core. When the motor is energized, the windings generate a rotating magnetic field. Under the influence of the stator's rotating magnetic field, the magnet 2 is subjected to electromagnetic torque and begins to rotate synchronously, thereby driving the rotor core to rotate as a whole.

[0078] The motor can be an internal rotor motor or an external rotor motor, and this disclosure does not specifically limit the specific type of motor.

[0079] The technical solution provided in this disclosure reduces the risk of demagnetization of the magnet 2 due to the better cooling effect of the rotor assembly, thereby enabling the motor to have good performance and making the motor less prone to failure.

[0080] This disclosure also provides a vehicle that includes the aforementioned motor.

[0081] When the vehicle moves forward, the motor's rotor assembly rotates in one direction (such as clockwise). When the vehicle reverses, the motor's rotor assembly rotates in another direction (such as counterclockwise).

[0082] This disclosure does not specifically limit the type of vehicle, such as: cars, buses, trucks, sport utility vehicles (SUVs), etc. The vehicle can be a pure electric vehicle (BEV, or EV) or a hybrid electric vehicle (HEV), such as range-extended or plug-in hybrid.

[0083] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary technical means in the art not disclosed in this disclosure. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the scope of claims.

Claims

1. A rotor assembly, characterized in that, The rotor assembly includes a rotor core (1), magnets (2), two end plates (3) and a shaft (4). The rotor core (1) is fixed between the two end plates (3), and the rotating shaft (4) passes through the rotor core (1) and the two end plates (3). The magnet (2) is fixed in the magnet slot of the rotor core (1), and a cooling channel (11) is formed between the magnet and the inner wall of the magnet slot, which penetrates the rotor core (1) axially. The rotating shaft (4) is used to introduce coolant and to eject it through the liquid ejection port (41) on the side wall; A first flow channel (31) is formed between one of the end plates (3) and the rotor core (1), and the first flow channel (31) connects one end of the cooling flow channel (11) and the liquid ejection port (41). A second flow channel (32) is formed between the other end plate (3) and the rotor core (1), the second flow channel (32) connecting the other end of the cooling flow channel (11) and the outside.

2. The rotor assembly according to claim 1, characterized in that, The first flow channel (31) includes an inlet hole (310), a first guide groove (311), a second guide groove (312), and an inlet groove (313). The liquid inlet (310) is connected to the liquid ejector (41). The first guide groove (311) and the second guide groove (312) are distributed circumferentially on both sides of the liquid inlet (310). One end of the liquid inlet groove (313) is connected to the liquid outlet of the first guide groove (311) and the other end is connected to the liquid outlet of the second guide groove (312). The liquid inlet groove (313) is also axially connected to a plurality of cooling channels (11).

3. The rotor assembly according to claim 2, characterized in that, Both the first guide groove (311) and the second guide groove (312) are arc-shaped grooves; The first guide groove (311) protrudes radially along a first direction relative to the rotor core (1), and the second guide groove (312) protrudes radially along a second direction relative to the rotor core (1), wherein one of the first direction and the second direction is a clockwise direction and the other is a counterclockwise direction.

4. The rotor assembly according to claim 2, characterized in that, The end plate (3) also has a sliding groove (33), the two ends of which are respectively connected to the liquid inlet end of the first guide groove (311) and the liquid inlet end of the second guide groove (312); The rotor assembly also includes a slider (5) located in the sliding groove (33). When the rotor assembly rotates clockwise, the slider (5) blocks the liquid inlet end of the first guide groove (311). When the rotor assembly rotates counterclockwise, the slider (5) blocks the liquid inlet end of the second guide groove (312).

5. The rotor assembly according to claim 1, characterized in that, The second flow channel (32) includes a liquid outlet (320) and a liquid return tank (321); The liquid outlet (320) passes through the end plate (3) axially, the opening of the return liquid groove (321) faces the rotor core (1), and the cooling channel (11) is connected to the liquid outlet (320) through the return liquid groove (321).

6. The rotor assembly according to claim 5, characterized in that, The second flow channel (32) also includes a third guide groove (322) and a fourth guide groove (323); The third guide groove (322) and the fourth guide groove (323) are distributed circumferentially on both sides of the liquid outlet (320). One end of the return groove (321) is connected to the liquid outlet end of the third guide groove (322), and the other end is connected to the liquid outlet end of the fourth guide groove (323).

7. The rotor assembly according to any one of claims 1-6, characterized in that, The two end plates (3) include a first end plate (3a) and a second end plate (3b). A first flow channel (31) and a second flow channel (32) are formed between the first end plate (3a) and one side of the rotor core (1), and the first flow channel (31) and the second flow channel (32) are formed between the second end plate (3b) and the other side of the rotor core (1). The rotating shaft (4) has at least two liquid ejection ports (41). One liquid ejection port (41) is sequentially connected to the first flow channel (31) of the first end plate (3a), the cooling flow channel (11), and the second flow channel (32) of the second end plate (3b). The other liquid ejection port (41) is sequentially connected to the first flow channel (31) of the second end plate (3b), the cooling flow channel (11), and the second flow channel (32) of the first end plate (3a).

8. The rotor assembly according to any one of claims 1-6, characterized in that, The end plate (3) and the rotor core (1) have a plurality of first flow channels (31) and a plurality of second flow channels (32), which are arranged alternately in the circumferential direction.

9. An electric motor, characterized in that, The motor includes a rotor assembly as described in any one of claims 1-8.

10. A vehicle, characterized in that, The vehicle includes the motor as described in claim 9.

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