Motor rotor and motor

Abstract

The utility model provides a motor rotor and a motor. The motor rotor comprises a rotating shaft, a rotor lamination and a first balance disc. The first balance disc is tightly attached to the rotor lamination on the axial side of the rotor lamination, a plurality of radial oil passing grooves are formed in the mounting surface, facing the rotor lamination, of the first balance disc, and the two ends of each radial oil passing groove are communicated with the oil guide hole of the rotating shaft and the oil passing channel of the rotor lamination respectively; wherein the mounting surface of the first balance disc is provided with a groove, the groove partially wraps the radial outer end of the radial oil passing groove on the radial outer side of the radial oil passing groove, and the groove is filled with a sealing material to form a sealing strip; or a sealing strip made of a sealing material is arranged on the lamination end face, facing the first balance disc, of the rotor lamination, the sealing material and the groove are oppositely arranged, and the radial outer side of the radial oil passing groove partially wraps the radial outer end of the radial oil passing groove and is used for preventing the cooling oil from flowing out to the radial outer side from the radial oil passing groove.

Description

Technical Field

[0001] This application relates to an electric motor rotor and an electric motor, which can be used, but is not limited to, as a drive motor for new energy vehicles. Background Technology

[0002] In the field of drive motors for new energy vehicles, drive motors require higher power density, efficiency, and smaller axial dimensions. For hybrid drive units, compactness is even more critical. To shorten the axial length of the motor, an oil passage design closer to the magnets is needed. This approach effectively improves heat transfer efficiency, controls magnet temperature, and reduces the risk of magnet demagnetization.

[0003] Typically, balance discs are installed on both sides of the rotor core. Currently, these balance discs are generally made of aluminum alloy with a thickness greater than 8mm. To further reduce the axial dimension, thinner balance discs are needed. However, when the thickness of the balance disc is reduced, deformation can easily occur after the balance disc and rotor core are assembled into the rotor assembly, resulting in a gap between the balance disc and the core. If this gap is too large, cooling oil will seep directly into the air gap of the motor, which not only affects the cooling effect but also increases the oil churning loss between the rotor and stator.

[0004] Current technical solutions aim to reduce post-assembly deformation by ensuring a sufficient thickness of the balance disc, thereby minimizing the gap between the balance disc and the core. However, a thicker balance disc increases the axial height of the rotor assembly and the overall weight of the motor. Furthermore, the mating surfaces of the balance disc and the core require precision machining to ensure flatness, further increasing the motor's manufacturing cost.

[0005] CN113629947A discloses a method and system for oil-cooled rotor laminations, wherein a closed-loop coolant path is formed between the gearbox, rotor shaft, encoder-end balance plate, rotor lamination stack, and output-end balance plate. By allowing the oil or coolant to directly contact the rotor laminations, the thermal path between the rotor laminations and the coolant is greatly reduced, thereby improving cooling performance. In the oil-cooling system disclosed in the above patent, a sealing ring groove is provided in the encoder balance plate, and the sealing ring forms a seal between the balance plate and the lamination stack. Utility Model Content

[0006] To reduce the axial height of the motor, a balance disc can be made from aluminum alloy with a thickness of less than, for example, 5mm, through stamping, without further finishing after stamping. The surface where the balance disc mates with the rotor laminations is the original surface after stamping, which has relatively poor flatness, resulting in a large gap between the balance disc and the rotor laminations. Therefore, it is necessary to solve the problem of radial oil leakage caused by the gap between the thin stamped balance disc and the rotor laminations.

[0007] For thin balance discs formed by stamping, such as the grooves in CN113629947A, it is difficult to form them in a single stamping operation, and subsequent machining of the balance disc is usually required. This increases the number of machining steps for the balance disc and also increases the manufacturing cost of the motor.

[0008] To overcome or mitigate the shortcomings of the prior art, one object of this application is to provide a motor rotor that effectively prevents cooling oil from leaking radially outward from the gap between the balance disc and the rotor laminations. Another object of this application is to provide a motor including the aforementioned motor rotor.

[0009] To achieve the above objectives, the present application may adopt the following technical solutions.

[0010] One embodiment of this application provides a motor rotor, which includes:

[0011] The rotating shaft, which is at least partially hollow, has an oil inlet chamber and an oil guide hole on its peripheral wall, one end of which communicates with the oil inlet chamber.

[0012] The rotor laminations are mounted to the rotating shaft, and the rotor laminations are provided with a plurality of oil passages that pass through the rotor laminations along the axial direction of the motor rotor.

[0013] The first balance disc is disposed close to the rotor lamination on one axial side of the rotor lamination. The mounting surface of the first balance disc facing the rotor lamination is provided with a plurality of radial oil passage grooves. The two ends of the radial oil passage grooves are respectively connected to the oil guide hole and the oil passage channel.

[0014] The mounting surface of the first balance disc is provided with a groove, which partially covers the radial outer end of the radial oil passage groove on its radial outer side. The groove is filled with a sealing strip made of sealing material to prevent cooling oil from flowing out of the radial oil passage groove to the radial outer side. Alternatively, a sealing strip made of sealing material is provided on the end face of the rotor laminations facing the first balance disc. The sealing material on the first balance disc is disposed opposite to the groove and partially covers the radial outer end of the radial oil passage groove on its radial outer side to prevent cooling oil from flowing out of the radial oil passage groove to the radial outer side.

[0015] In at least one embodiment, a plurality of radial oil grooves of the motor rotor are evenly distributed in the circumferential direction of the first balance disc, and a groove is provided on the radial outer side of each radial oil groove. The groove is "C" shaped and the opening of the "C" shape faces the radial oil groove.

[0016] In at least one embodiment, the sealing material filling the groove is rubber, which at least partially protrudes from the surface of the first balance disc surrounding the groove.

[0017] In at least one embodiment, the plurality of oil passages are evenly distributed in the circumferential direction of the rotor laminations, and a sealing strip is provided on the radial outer side of each oil passage. The sealing strip includes a "C"-shaped portion, which surrounds the radial outer portion of the oil passage.

[0018] In at least one embodiment, the sealing strip is formed by injection molding material that fixes the magnets in the magnet slots of the rotor laminations; the injection molding material in the magnet slots on at least one circumferential side of the oil passage is connected to the sealing strip.

[0019] In at least one embodiment, the injection molding material in two adjacent magnetic grooves on both sides of the oil passage is connected to the sealing strip.

[0020] In at least one embodiment, the injection molding material extends at least partially into the groove, such that the sealing strip formed by the injection molding material has a clearance fit with the groove.

[0021] In at least one embodiment, the first balance disc is further provided with an oil outlet, which is located between two adjacent radial oil grooves and connected to the oil passage.

[0022] In at least one embodiment, the motor rotor further includes a second balance disc, which is disposed close to the rotor laminations on the other side of the axial direction. The second balance disc has the same structure as the first balance disc and is disposed at a certain circumferential angle offset from the first balance disc, such that oil entering the oil passage from the radial oil groove of the first balance disc flows out from the oil outlet of the second balance disc, and oil entering the oil passage from the radial oil groove of the second balance disc flows out from the oil outlet of the first balance disc.

[0023] An embodiment of this application also provides an electric motor, which includes the motor rotor of this application.

[0024] By adopting the above technical solution, a groove is provided on the radially outer side of the radial oil passage of the first balance disc, and a sealing material is filled in the groove to form a sealing strip. Alternatively, a sealing strip made of sealing material is provided on the end face of the rotor laminations facing the first balance disc, with the sealing material positioned opposite the groove. When the first balance disc and the rotor laminations are assembled into a rotor assembly, the sealing material in the groove is compressed as the first balance disc and the rotor laminations are pressed together, thereby filling the gap on the radially outer side of the radial oil passage on the first balance disc, thus preventing cooling oil from leaking from the radial oil passage to the radially outer side. Attached Figure Description

[0025] Figure 1 A schematic diagram of the motor rotor of Embodiment 1 of this application is shown;

[0026] Figure 2 It shows Figure 1 A cross-sectional view of the motor rotor taken along the radial axis of the first balance disc through the center of the oil groove;

[0027] Figure 3 It shows Figure 2 A partially enlarged cross-sectional view of the motor rotor;

[0028] Figure 4 A top view of the first balancing disc of Embodiment 1 of this application is shown;

[0029] Figure 5 A schematic diagram of the rotor lamination structure of Embodiment 2 of this application is shown;

[0030] Figure 6 A schematic diagram of the structure of the first balancing disc in Embodiment 2 of this application is shown;

[0031] Explanation of reference numerals in the attached figures

[0032] 1. Shaft;

[0033] 11 Oil inlet chamber; 12 Oil guide hole;

[0034] 2. Rotor laminations;

[0035] 20 Mounting surface; 21 Oil passage; 22 Magnetic groove;

[0036] 3. First balance disc;

[0037] 30 Mounting surface; 31 Radial oil passage groove; 32 Groove; 33 Oil outlet hole; 34 Oil outlet groove; 35 Mounting hole;

[0038] 4. Second balance disc;

[0039] 5. Sealing materials;

[0040] 6. Injection molding materials;

[0041] A is axial; R is radial. Detailed Implementation

[0042] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaust all possible methods of this application, nor to limit the scope of this application.

[0043] In this application, unless otherwise specified, "axial," "radial," and "circumferential" refer to the axial, radial, and circumferential directions of the motor shaft, respectively. Further, "radial outer" refers to the side radially away from the central axis of the motor shaft, and "radial inner" refers to the side radially close to the central axis of the motor shaft.

[0044] Existing motor rotors use an oil-cooling structure for cooling. The cooling oil flows sequentially through the oil inlet chamber of the shaft, the radial oil grooves of the balance disc, and the oil passages within the rotor laminations, finally flowing out through the oil outlet of the balance disc. During the flow process, the cooling oil carries away the heat from the rotor laminations, thus cooling the motor rotor.

[0045] Because the flatness of the rotor laminations after machining is approximately 0.3mm, when the rotor laminations and balance disc are assembled and pressed together, there is a gap of about 0.3mm between their mating surfaces. This means the rotor laminations and balance disc are not completely fitted together after assembly. When cooling oil flows through the radial oil grooves of the balance disc and into the oil passages of the rotor laminations, some of the cooling oil will flow radially outward through this gap and enter the air gap of the motor. If the gap is too large, only a small amount of cooling oil can enter the oil passages of the rotor laminations, resulting in a reduction in the cooling effect of the motor rotor. Simultaneously, the cooling oil entering the air gap will also increase the oil churning losses between the rotor and stator.

[0046] To reduce the axial height of the motor, some current technologies use aluminum alloy with a thickness of less than 5mm to form the balance disc through stamping, without further finishing after stamping. Therefore, the surface where the balance disc mates with the rotor laminations is the original stamped surface, which has relatively poor flatness, resulting in a large gap between the balance disc and the rotor laminations. Therefore, it is necessary to solve the problem of radial oil leakage caused by the gap between the stamped thin balance disc and the rotor laminations. This application is made in consideration of these problems.

[0047] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] like Figure 1 As shown, Embodiment 1 of this application provides a motor rotor, which may include a rotating shaft 1, rotor laminations 2, a first balance disc 3, and a second balance disc 4.

[0049] In this embodiment, as Figure 2 As shown, the rotating shaft 1, rotor laminations 2, first balance disc 3 and second balance disc 4 are coaxially arranged, and the first balance disc 3, rotor laminations 2 and second balance disc 4 are sequentially installed on the rotating shaft 1.

[0050] Specifically, the shaft 1 is at least partially hollow inside and has an oil inlet chamber 11. An oil guide hole 12 is provided on its peripheral wall. One end of the oil guide hole 12 communicates with the oil inlet chamber 11, and the other end communicates with the radial oil passage groove 31 of the first balance disc 3. In this way, cooling oil enters the oil inlet chamber 11 inside the shaft 1, and the axially flowing cooling oil inside the shaft 1 is radially transported to the outside of the shaft 1 through the oil guide hole 12, preparing for the cooling oil to flow to the rotor laminations 2.

[0051] like Figure 2 and 3 As shown, rotor laminations 2 are installed between the first balance disc 3 and the second balance disc 4. The rotor laminations 2 are provided with several oil passages 21 extending axially A through the rotor laminations 2 for cooling the interior of the rotor laminations 2. For example, during assembly, one end of the oil passage 21 can be ensured to coincide with the radial oil groove 31 of the first balance disc 3; simultaneously, the other end of the oil passage 21 is aligned with the oil outlet groove or oil outlet hole of the second balance disc 4, so that the oil passage 21 communicates with the radial oil groove 31 of the first balance disc 3 and the oil outlet groove or oil outlet hole of the second balance disc 4, respectively. When cooling oil enters the interior of the rotor laminations 2 through the radial oil groove 31 of the first balance disc 3, it can flow out from the oil outlet hole of the second balance disc 4.

[0052] In this embodiment, as Figure 5 As shown, the rotor laminations 2 may also be provided with multiple axially penetrating magnet slots 22 for mounting magnets. The magnet slots 22 are evenly distributed in the circumferential direction of the rotor laminations 2, and the oil passage 21 is located between two adjacent magnet slots 22.

[0053] Furthermore, several oil passages 21 are evenly distributed in the circumferential direction of the rotor laminations 2. Preferably, in this embodiment, the number of oil passages 21 can be set to 8.

[0054] In this embodiment, as Figure 2 and 3 As shown, the first balance disc 3 is disposed close to the rotor lamination 2 on one axial side. Several radial oil passage grooves 31 are provided on the mounting surface 30 of the first balance disc 3 facing the rotor lamination 2. The two ends of the radial oil passage grooves 31 are connected to the oil guide hole 12 and the oil passage channel 21, respectively. Specifically, as shown... Figure 4 As shown, the radial oil groove 31 is connected to the mounting hole 35 of the first balance disc 3 at one end located on the radial inner side.

[0055] Here, the radial oil passage groove 31 can be directly connected to the oil guide hole 12, or an annular groove connecting the oil guide hole 12 and the radial oil passage groove 31 can be formed between the first balance disc 3 and the rotating shaft 1.

[0056] Furthermore, a groove 32 is provided on the mounting surface 30 of the first balance disc 3. The groove 32 can partially cover the radial outer end of the radial oil passage 31 on the radial outer side. A sealing strip made of sealing material 5 can be filled in the groove 32 to prevent cooling oil from flowing out of the radial oil passage 31 to the radial outer side.

[0057] When the first balance disc 3 is assembled and pressed with the rotor lamination 2, the sealing material 5 in the groove 32 will also be pressed accordingly, thereby filling the radial gap that may exist between the first balance disc 3 and the rotor lamination 2 on the radial outer side of the radial oil passage groove 31 to a certain extent, effectively preventing the cooling oil from being thrown out radially from the radial oil passage groove 31 to the radial outer side.

[0058] Furthermore, several radial oil passage grooves 31 are evenly distributed around the first balance disc 3. A groove 32 can be provided on the radial outer side of each radial oil passage groove 31. When the cooling oil circuit structure of the motor rotor changes, the shape of the groove 32 can be flexibly adjusted according to the specific cooling requirements of the motor rotor or according to the sealing material.

[0059] Preferably, in this embodiment, the groove 32 can be C-shaped. The opening of the C-shape faces the radial oil groove 31.

[0060] In this embodiment, the groove 32 can be integrally formed with the first balance disc 3 by stamping.

[0061] Furthermore, the sealing material 5 filling the groove 32 can be rubber, such as silicone rubber. In this embodiment, the filled rubber can locally protrude beyond the surface of the first balance disc 3 surrounding the groove 32.

[0062] In this embodiment, as Figure 4 As shown, the first balance disc 3 may also be provided with multiple oil outlet holes 33, which are located between two adjacent radial oil passage grooves 31 and connected to the oil passage channel 21.

[0063] Furthermore, in this embodiment, the first balance disc 3 is provided with four oil outlet holes 33.

[0064] As a preferred option, such as Figure 4 As shown, an oil outlet groove 34 can also be provided on the mounting surface 30 of the first balance disc 3. One end of the oil outlet groove 34 near the radial outer side is connected to the oil outlet hole 33, and the other end is connected to the oil passage 21. That is, the cooling oil passing through the oil passage 21 can enter the oil outlet groove 34 and then flow out through the oil outlet hole 33.

[0065] like Figure 5 and 6 As shown, Embodiment 2 of this application provides a motor rotor. The same reference numerals are used for structures in Embodiment 2 that are the same as or similar to those in Embodiment 1, and will not be described again.

[0066] like Figure 5 As shown, a sealing strip made of sealing material is provided on the end face 20 of the rotor lamination 2 facing the first balance disk 3. The sealing material is arranged opposite to the groove 32 of the first balance disk 3 and partially covers the radial outer end of the radial oil passage 31 to prevent the cooling oil from flowing out of the radial oil passage 31 to the radial outer side.

[0067] Furthermore, in this embodiment, a sealing strip may be provided on the radial outer side of each oil passage 21. The sealing strip may include a "C"-shaped portion, which may surround the radial outer side of the oil passage 21.

[0068] Furthermore, in this embodiment, the injection molding material 6 that fixes the magnet in the magnet groove 22 of the rotor lamination 2 forms a sealing strip, and the injection molding material 6 in the magnet groove 22 on at least one circumferential side of the oil passage 21 is connected to the sealing strip.

[0069] Preferably, in this embodiment, the injection molding material 6 in the two adjacent magnetic grooves 22 on both sides of the oil passage 21 is connected to the sealing strip.

[0070] In this embodiment, as Figure 6 As shown, the shape of the groove 32 can be consistent with the shape of the sealing strip formed by the injection molding material 6. When the first balance disc is assembled and pressed with the rotor laminations, the injection molding material 6 can partially extend into the groove 32, so that the sealing strip formed by the injection molding material 6 and the groove 32 are in clearance fit, thereby blocking the cooling oil from flowing out radially from the radial oil groove to the radial outside to a certain extent.

[0071] Here, in such Figure 5 , Figure 6 As shown, the sealing strip and groove 32 can be formed into a hat shape (axial section) with a brim. The two ends of the C-shaped structure of the sealing strip can be connected to the magnetic groove 22 by a straight line.

[0072] In the above embodiments, such as Figure 2 and 3As shown, the motor rotor also includes a second balance disc 4, which is disposed close to the rotor laminations 2 on the other side of the rotor laminations 2 along the axial direction. Specifically, the second balance disc 4 may have the same structure as the first balance disc 3, but is disposed at a certain circumferential angle offset from the first balance disc 3, for example, offset by 45 degrees. This allows oil entering the oil passage 21 from the radial oil groove 31 of the first balance disc 3 to flow out from the oil outlet 33 of the second balance disc 4, and oil entering the oil passage 21 from the radial oil groove 31 of the second balance disc 4 to flow out from the oil outlet 33 of the first balance disc 3.

[0073] It is understood that the above describes a scheme in which oil enters from and exits from two balance discs on both axial sides of the rotor lamination 2. However, this application is not limited to this.

[0074] Alternatively, oil can be supplied from one balancing disc on one axial side and discharged from the other axial side of the rotor laminations 2. Thus, the motor rotor may have only one balancing disc.

[0075] By adopting the above-mentioned scheme, in the motor rotor of this application, each radial oil passage groove 31 of the first balance disc 3 has a groove 32 on its radially outer side, and the groove 32 is filled with sealing material 5. Alternatively, a sealing strip made of sealing material is provided on the end face of the rotor lamination 2 facing the first balance disc 3, with the sealing material positioned opposite to the groove 32. The sealing strip partially covers the radially outer end of the radial oil passage groove 31, thus preventing the cooling oil from leaking radially outward from the radial oil passage groove 31 to a certain extent, allowing most of the cooling oil to enter the oil passage channel 21 of the rotor lamination 2, thereby effectively cooling the motor rotor.

[0076] The shape of the groove 32 can be flexibly designed, for example, it can be or include a "C" shape or a "U" shape.

[0077] Furthermore, the groove 32 can be integrally formed with the first balance disc 3 by stamping, thereby reducing the processing steps of the balance disc and lowering manufacturing costs. Moreover, the thickness of the balance disc can be further reduced, thereby reducing the axial length of the motor and improving its performance.

[0078] It should be understood that the above embodiments are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above embodiments under the teachings of this application without departing from the scope of this application.

[0079] It should be noted that the cross-sectional shapes of the oil inlet chamber 11, oil guide hole 12, oil passage 21, radial oil groove 31, and oil outlet groove 34 in the rotating shaft 1, rotor laminations 2, first balance disc 3, and second balance disc 4 are not limited, as long as the cooling oil can circulate inside the motor rotor. At the same time, in order to achieve better cooling effect, the shape, quantity, and structure of the oil passage can be adjusted accordingly.

[0080] This application also provides a motor including the aforementioned motor rotor, which can be used, but is not limited to, in new energy vehicles, such as pure electric vehicles, hybrid vehicles, and range-extended electric vehicles. In fact, the motor according to this application can also be applied to other fields, such as CNC machine tools, industrial electrical automation, and automated production lines, which will not be listed here.

Claims

1. A motor rotor, characterized in that, include: The rotating shaft, which is at least partially hollow, has an oil inlet chamber and an oil guide hole on its peripheral wall, one end of which communicates with the oil inlet chamber. The rotor laminations are mounted to the rotating shaft, and the rotor laminations are provided with a plurality of oil passages that pass through the rotor laminations along the axial direction of the motor rotor. The first balance disc is disposed close to the rotor lamination on one axial side of the rotor lamination. The mounting surface of the first balance disc facing the rotor lamination is provided with a plurality of radial oil passage grooves. The two ends of the radial oil passage grooves are respectively connected to the oil guide hole and the oil passage channel. The mounting surface of the first balance disc is provided with a groove, which partially covers the radial outer end of the radial oil passage groove on its radial outer side. The groove is filled with a sealing strip made of sealing material to prevent cooling oil from flowing out of the radial oil passage groove to the radial outer side. Alternatively, a sealing strip made of sealing material is provided on the end face of the rotor laminations facing the first balance disc. The sealing material on the first balance disc is disposed opposite to the groove and partially covers the radial outer end of the radial oil passage groove on its radial outer side to prevent cooling oil from flowing out of the radial oil passage groove to the radial outer side.

2. The motor rotor according to claim 1, characterized in that, Several radial oil passage grooves are evenly distributed in the circumferential direction of the first balance disc. Each radial oil passage groove has a groove on its radial outer side. The groove is "C" shaped and the opening of the "C" shape faces the radial oil passage groove.

3. The motor rotor according to claim 2, characterized in that, The sealing material filling the groove is rubber, which at least partially protrudes from the surface of the first balance disc surrounding the groove.

4. The motor rotor according to claim 1, characterized in that, The plurality of oil passages are evenly distributed in the circumferential direction of the rotor laminations. Each oil passage is provided with a sealing strip on the radial outer side. The sealing strip includes a "C"-shaped portion, which surrounds the radial outer portion of the oil passage.

5. The motor rotor according to claim 4, characterized in that, The sealing strip is formed by injection molding material that fixes the magnets in the magnet slots of the rotor laminations; the injection molding material in the magnet slots on at least one circumferential side of the oil passage is connected to the sealing strip.

6. The motor rotor according to claim 5, characterized in that, The injection molding material in the two adjacent magnetic grooves on both sides of the oil passage is connected to the sealing strip.

7. The motor rotor according to claim 5, characterized in that, The injection molding material extends at least partially into the groove, such that the sealing strip formed by the injection molding material has a clearance fit with the groove.

8. The motor rotor according to claim 1, characterized in that, The first balance disc is also provided with an oil outlet, which is located between two adjacent radial oil grooves and connected to the oil passage.

9. The motor rotor according to claim 8, characterized in that, It also includes a second balance disc, which is disposed close to the rotor laminations on the other side of the axial direction. The second balance disc has the same structure as the first balance disc and is disposed at a certain circumferential angle away from the first balance disc, so that oil entering the oil passage from the radial oil groove of the first balance disc flows out from the oil outlet of the second balance disc, and oil entering the oil passage from the radial oil groove of the second balance disc flows out from the oil outlet of the first balance disc.

10. An electric motor, characterized in that, The motor rotor includes any one of claims 1 to 9.

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