Rotor assembly, motor and vehicle

Abstract

The utility model provides a rotor assembly, a motor and a vehicle. The rotor assembly comprises a rotor. The rotor is provided with a magnetic steel groove penetrating through the rotor, and the magnetic steel groove comprises a first mounting surface; the magnetic steel is arranged in the magnetic steel groove; the magnetic steel comprises a first matching surface, and the first matching surface and the first mounting surface are opposite and arranged at an interval; an expansion coating is arranged on a part of the area of the first matching face and used for making contact with a part of the area of the first installation face after expansion. According to the rotor assembly, the motor and the vehicle, consumables are few, the process is simple, and the manufacturing cost is low. Moreover, the risk of rubbing or bumping between the expansion coating and the magnetic steel groove can be reduced, the cleanliness of the finished rotor assembly is improved, and the stability of the magnetic steel in the magnetic steel groove is ensured. And the expansion coating can be prevented from excessively extruding the magnetic steel grooves after expansion, so that the situation of deformation of the rotor caused by deformation of the magnetic steel grooves can be reduced, and the probability of chamber explosion in the rotating process of the rotor assembly can be reduced.

Description

Technical Field

[0001] The present application belongs to the technical field of magnetic steel fixing, and in particular relates to a rotor assembly, a motor and a vehicle. Background Art

[0002] With the rapid development of the new energy vehicle industry, price competition for automobiles and even parts is becoming increasingly fierce. Domestic new energy vehicle drive motors are mainly built-in permanent magnet synchronous motors. As an important component of the motor, the magnetic steel plays a major role in exerting the performance of the motor. In the prior art, the effect of fixing the magnetic steel is achieved by filling the gap between the magnetic steel and the magnetic steel slot with an expansion coating. However, the expansion coating fills the gap between the magnetic steel and the magnetic steel slot, which consumes a large amount of expansion coating materials and has a high cost. Moreover, after the expansion coating fills the gap between the magnetic steel and the magnetic steel slot, when the magnetic steel and the expansion coating are placed in the magnetic steel slot together, there is a risk of scratching or bumping between the expansion coating and the inner wall of the magnetic steel slot, which can easily cause the expansion coating to be scratched or fall off. Utility Model Content

[0003] In view of the shortcomings of the prior art, the present application provides a rotor assembly, motor and vehicle with less consumables, simple process and low production cost. Moreover, the rotor assembly, motor and vehicle provided by the present application can reduce the risk of scratching or bumping the expansion coating against the inner wall of the magnetic steel slot, thereby reducing the occurrence of the coating falling into the magnetic steel slot, which is beneficial to improving the cleanliness of the finished rotor assembly, and can also reduce the risk of the magnetic steel falling from the magnetic steel slot due to the failure of the expansion coating to provide sufficient clamping force on the magnetic steel, so as to ensure the stability of the magnetic steel in the magnetic steel slot. It can also prevent the expansion coating from excessively squeezing the inner wall of the magnetic steel slot after expansion, thereby reducing the occurrence of deformation of the rotor caused by deformation of the magnetic steel slot, which is beneficial to reducing the probability of the rotor assembly exploding during rotation.

[0004] In one aspect, the present application provides a rotor assembly, comprising:

[0005] A rotor having a magnetic steel slot extending through the rotor, wherein the magnetic steel slot includes a first mounting surface; and

[0006] A magnetic steel is arranged in the magnetic steel groove; the magnetic steel includes a first mating surface, the first mating surface is opposite to the first mounting surface and is spaced apart; a partial area of ​​the first mating surface is provided with an expansion coating, and the expansion coating is used to contact a partial area of ​​the first mounting surface after expansion.

[0007] In a possible implementation, assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the expansion coating before heating is I, and the thickness of the expansion coating after heating is L, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I of the expansion coating before heating, and the thickness L of the expansion coating after heating satisfy: H+I<D, H+L≥A*D, where A is a constant, A≥1.015.

[0008] In a possible implementation manner, a groove is provided on the first matching surface of the magnetic steel, the groove extends along the thickness direction of the magnetic steel, and the expansion coating is provided in the groove.

[0009] In a possible embodiment, the expansion coating includes a first expansion layer and a second expansion layer, the first expansion layer is arranged on a partial area of ​​the first mating surface, and the first expansion layer is used to contact a partial area of ​​the first mounting surface after thermal expansion; the magnetic steel also includes a second mating surface arranged opposite to the first mating surface, and the magnetic steel slot also includes a second mounting surface arranged opposite to the first mounting surface, the second mating surface is opposite to the second mounting surface and is arranged at an interval, the second expansion layer is arranged on a partial area of ​​the second mating surface, and the second expansion layer is used to contact a partial area of ​​the second mounting surface after thermal expansion.

[0010] In a possible implementation, assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the first expansion layer before heating is I1, and the thickness of the first expansion layer after heating is L1, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I1 of the first expansion layer before heating, and the thickness L1 of the first expansion layer after heating satisfy: H+I1<D, H+L1≥A1*D, wherein A1 is a constant, A1≥0.5075.

[0011] In a possible implementation, assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the second expansion layer before heating is I2, and the thickness of the second expansion layer after heating is L2, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I2 of the second expansion layer before heating, and the thickness L2 of the second expansion layer after heating satisfy: H+I2<D, H+L2≥A2*D, where A2 is a constant, A2≥0.5075.

[0012] In a possible implementation, there are multiple expansion coatings, the first mating surface includes multiple sub-mating surfaces, and any two adjacent sub-mating surfaces are spaced apart, and each expansion coating is disposed on one of the sub-mating surfaces.

[0013] In a possible implementation, the orthographic projection of the expansion coating on the first mating surface is any one of a polygonal shape, a circular shape, and an elliptical shape, and the orthographic projection of the expansion coating on the first mating surface covers a partial area of ​​the first mating surface.

[0014] On the other hand, the present application provides a motor, comprising:

[0015] The rotor assembly described above; and

[0016] A stator and a housing, wherein the stator and the rotor assembly are fixed in the housing, and the rotor assembly is rotatably arranged in the stator.

[0017] In another aspect, the present application provides a vehicle, comprising:

[0018] The above-mentioned motor; and

[0019] The vehicle body is connected to the motor and is used to drive the vehicle to move.

[0020] The rotor assembly, motor and vehicle provided by the present application, on the one hand, by providing an expansion coating on the magnetic steel, and the expansion coating has the characteristic of thermal expansion, when the magnetic steel and the expansion coating provided on the magnetic steel are thermally expanded, the expansion coating can press the magnetic steel against the inner wall of the magnetic steel slot, so that the magnetic steel is fixed in the magnetic steel slot. The rotor assembly provided by the present application consumes less material and has a low cost of material consumption by providing the expansion coating. Moreover, the rotor assembly of the present application presses and fixes the magnetic steel in the magnetic steel slot by providing the expansion coating, without the need for additional injection molds and tooling, so that the process of fixing the magnetic steel is simpler and the manufacturing cost is lower. On the other hand, by providing the expansion coating on a partial area of ​​the first mating surface of the magnetic steel, the expansion coating can contact a partial area of ​​the first mounting surface of the magnetic steel slot after expansion, so as to fix the magnetic steel in the magnetic steel slot. Because the expansion coating does not completely cover the first mating surface of the magnetic steel. When the magnetic steel and the expansion coating are assembled into the magnetic steel slot, the magnetic steel can be assembled into the magnetic steel slot before the expansion coating, which can reduce the risk of the expansion coating and the inner wall of the magnetic steel slot being scratched or bumped, thereby reducing the occurrence of the coating falling into the magnetic steel slot, which is beneficial to improving the cleanliness of the finished rotor assembly, and can also reduce the risk of the magnetic steel falling from the magnetic steel slot due to the expansion coating falling and being unable to provide sufficient pressing force to the magnetic steel, so as to ensure the stability of the magnetic steel in the magnetic steel slot. On the other hand, since the expansion coating does not completely cover the first mating surface of the magnetic steel, after the expansion coating expands due to heat, the expansion coating can extend into the gap between the first mating surface and the first mounting surface of the magnetic steel slot, which can prevent the expansion coating from excessively squeezing the inner wall of the magnetic steel slot after expansion, thereby reducing the occurrence of deformation of the rotor caused by deformation of the magnetic steel slot, which is beneficial to reducing the probability of the rotor assembly exploding during rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some implementation methods provided by the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a front view of a rotor assembly provided in one embodiment of the present application;

[0023] Figure 2 yes Figure 1 An enlarged view of the rotor assembly at P is shown;

[0024] Figure 3 is a front view of a magnetic steel provided in the first embodiment of the present application;

[0025] Figure 4 It is a front view of a magnetic steel and an expansion coating assembly provided in the first embodiment of the present application;

[0026] Figure 5 It is a side view of a magnetic steel and an expansion coating assembled before being heated provided by the first embodiment of the present application;

[0027] Figure 6 It is a side view of a magnetic steel and an expansion coating assembled after being heated provided by the first embodiment of the present application;

[0028] Figure 7 is a cross-sectional view of a magnetic steel and an expansion coating assembled before heating provided in the second embodiment of the present application;

[0029] Figure 8 is a cross-sectional view of a magnetic steel and an expansion coating assembled after heating provided by the second embodiment of the present application;

[0030] Fig. 9 is a front view of a magnetic steel provided in the third embodiment of the present application;

[0031] Fig.10 It is a front view of a magnetic steel and an expansion coating assembly provided in the third embodiment of the present application;

[0032] Fig.11 is a front view of a magnetic steel provided in the fourth embodiment of the present application;

[0033] Fig.12 It is a front view of a magnetic steel and an expansion coating assembly provided in the fourth embodiment of the present application;

[0034] Fig.13is a front view of a magnetic steel provided in the fifth embodiment of the present application;

[0035] Fig.14 is a rear view of a magnetic steel provided in the fifth embodiment of the present application;

[0036] Fig.15 It is a side view of a magnetic steel and an expansion coating assembled before being heated provided by the fifth embodiment of the present application;

[0037] Fig.16 It is a side view of the assembly of a magnetic steel and an expansion coating after heating provided by the fifth embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solution of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described implementation methods are only part of the implementation methods of the present application, rather than all the implementation methods. Based on the implementation methods in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0039] This embodiment provides a vehicle, the vehicle includes a motor and a vehicle body, the motor is connected to the vehicle body, and the motor is used to drive the vehicle to move. For example, the motor can drive the wheels of the vehicle to rotate so that the vehicle can travel normally.

[0040] It is understandable that in some other embodiments, the motor can also be used in other equipment, such as engineering machinery, medical equipment, etc., and the present application does not limit this.

[0041] This embodiment also provides a motor, which includes a rotor assembly, a stator and a housing, wherein the stator and the rotor assembly are fixed in the housing, and the rotor assembly is rotatably disposed in the stator. The rotor assembly can rotate in the housing so that the motor can output rotational power.

[0042] The rotor assembly provided by the present application is described in detail below.

[0043] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 is a front view of a rotor assembly provided in one embodiment of the present application, Figure 2 yes Figure 1 An enlarged view of the rotor assembly at P is shown, Figure 3 is a front view of a magnetic steel provided in the first embodiment of the present application, Figure 4 It is a front view of a magnetic steel and expansion coating assembly provided in the first embodiment of the present application.

[0044] The present embodiment provides a rotor assembly 100, which includes a rotor 10, a magnetic steel 30 and an expansion coating 50. The rotor 10 can rotate around its own axis, the magnetic steel 30 is embedded in the rotor 10, and the expansion coating 50 is arranged between the rotor 10 and the magnetic steel 30. The expansion coating 50 is used to press and fix the magnetic steel 30 on the rotor 10.

[0045] Specifically, the rotor 10 has a magnetic steel slot 11 that runs through the rotor 10, and the magnetic steel slot 11 is used to accommodate the magnetic steel 30 and the expansion coating 50. The magnetic steel slot 11 includes a first mounting surface (not shown in the figure), which is a surface on the inner side wall of the magnetic steel slot 11. The magnetic steel 30 is arranged in the magnetic steel slot 11, and the magnetic steel 30 includes a first mating surface (not shown in the figure), which is a surface on the circumferential side wall of the magnetic steel 30. The first mating surface is opposite to the first mounting surface and is arranged at a distance, and a partial area of ​​the first mating surface is provided with an expansion coating 50, and the expansion coating 50 is used to contact with a partial area of ​​the first mounting surface after expansion, so as to fix the magnetic steel 30 in the magnetic steel slot 11 after the expansion coating 50 expands.

[0046] The first mating surface includes a first area 31 and a second area 32 connected to each other, the first area 31 is spaced apart from a partial area of ​​the first mounting surface of the magnetic steel slot 11, and the second area 32 is provided with an expansion coating 50 in contact with another partial area of ​​the first mounting surface of the magnetic steel slot 11. The expansion coating 50 can expand when heated. When the expansion coating 50 is in the original state, that is, before the expansion coating 50 is heated and expanded, the magnetic steel 30 and the expansion coating 50 arranged in the second area 32 of the peripheral side wall of the magnetic steel 30 can be arranged in the magnetic steel slot 11 of the rotor 10, and at this time, there is a gap between the expansion coating 50 and the first mounting surface of the magnetic steel slot 11. Then, the expansion coating 50 is heated to expand the expansion coating 50, and the expansion coating 50 fills the aforementioned gap, so that the magnetic steel 30 is pressed and fixed in the magnetic steel slot 11, and at this time, the expansion coating 50 is in contact with a partial area of ​​the first mounting surface of the magnetic steel slot 11.

[0047] The rotor assembly 100, motor and vehicle provided in the present application, on the one hand, by providing an expansion coating 50 on the magnetic steel 30, and the expansion coating 50 has the characteristic of thermal expansion, when the magnetic steel 30 and the expansion coating 50 provided on the magnetic steel 30 are thermally expanded, the expansion coating 50 can press the magnetic steel 30 against the first mounting surface of the magnetic steel slot 11, so that the magnetic steel 30 is fixed in the magnetic steel slot 11. By providing the expansion coating 50 on a partial area of ​​the first mating surface, the material consumption of the expansion coating 50 is small, and the material consumption cost of the expansion coating 50 is low. Moreover, the rotor assembly 100 of the present application presses and fixes the magnetic steel 30 in the magnetic steel slot 11 by providing the expansion coating 50, without the need for additional injection molds and tooling, so that the process of fixing the magnetic steel 30 is simpler and the manufacturing cost is lower. On the other hand, the first mating surface of the magnetic steel 30 includes a first area 31 and a second area 32 connected to each other, the first area 31 is spaced apart from a part of the first mounting surface of the magnetic steel slot 11, and the expansion coating 50 is arranged in the second area 32, that is, the expansion coating 50 does not completely cover the first mating surface of the magnetic steel 30. When the magnetic steel 30 and the expansion coating 50 are assembled into the magnetic steel slot 11, the magnetic steel 30 can be assembled into the magnetic steel slot 11 before the expansion coating 50, which can reduce the risk of scratching or bumping between the expansion coating 50 and the first mounting surface of the magnetic steel slot 11, thereby reducing the phenomenon of the expansion coating 50 falling into the magnetic steel slot 11, which is conducive to improving the cleanliness of the finished rotor assembly 100, and can also reduce the risk of the magnetic steel 30 falling from the magnetic steel slot 11 due to the expansion coating 50 falling and failing to provide sufficient pressing force to the magnetic steel 30, so as to ensure the stability of the magnetic steel 30 in the magnetic steel slot 11. On the other hand, since the expansion coating 50 does not completely cover the first mating surface with the magnetic steel 30, after the expansion coating 50 expands due to heat, the expansion coating 50 can extend into the gap between the first region 31 and the first mounting surface of the magnetic steel slot 11, which can prevent the expansion coating 50 from excessively squeezing the first mounting surface of the magnetic steel slot 11 after expansion, thereby reducing the deformation of the magnetic steel slot 11 and causing deformation of the rotor 10, which is beneficial to reducing the probability of the rotor assembly 100 exploding during rotation.

[0048] It should be understood that the rotor assembly 100 can coat the expansion coating 50 on the second region 32 of the first mating surface of the magnetic steel 30 through a coating process. However, when the expansion coating 50 is coated on the second region 32 of the outer wall of the magnetic steel 30 through a coating process, the coating process is not convenient for controlling the thickness of the expansion coating 50, and the thickness of the expansion coating 50 is likely to be large, which makes it inconvenient to install the magnetic steel 30 and the expansion coating 50 into the magnetic steel slot 11 of the rotor 10. At the same time, there is also a risk that the first installation surface of the magnetic steel slot 11 may cause scratches and bumps on the expansion coating 50, which may easily lead to unstable pressing force of the expansion coating 50 on the magnetic steel 30 after the expansion is heated. At the same time, the expansion coating 50 is coated on the second area 32 of the first mating surface of the magnetic steel 30 through the coating process. The coating process is not convenient for controlling the shape of the expansion coating 50, and is not convenient for accurately forming the expansion coating 50 on the second area 32 of the first mating surface of the magnetic steel 30. This may easily lead to a larger area of ​​the expansion coating 50 on the first mating surface of the magnetic steel 30, and the expansion coating 50 may exceed the second area 32. It is easy for the expansion coating 50 to over-compress the first mounting surface 2 of the magnetic steel slot 11 after expansion, causing the magnetic steel slot 11 to deform, thereby increasing the probability of the rotor assembly 100 exploding during rotation.

[0049] Based on the above reasons, in the rotor assembly 100 provided by the present application, the expansion coating 50 is formed on the second area 32 of the first mating surface of the magnetic steel 30 by a printing process. The expansion coating 50 is printed on the second area 32 of the first mating surface of the magnetic steel 30 by a printing process, and the printing process can accurately form the expansion coating 50 on the second area 32 of the first mating surface of the magnetic steel 30. At the same time, the printing process can accurately grasp the thickness of the expansion coating 50 on the second area 32, so as to facilitate the installation of the magnetic steel 30 and the expansion coating 50 into the magnetic steel slot 11 of the rotor 10, and can reduce the risk of scratches and bumps caused by the first installation surface of the magnetic steel slot 11 to the expansion coating 50, thereby making the pressing force of the expansion coating 50 on the magnetic steel 30 more stable after the heat expansion. The printing process can also accurately grasp the shape of the expansion coating 50 on the second area 32 of the first mating surface of the magnetic steel 30, without causing waste of the expansion coating 50 material, which is conducive to reducing the manufacturing cost of the rotor assembly 100. Moreover, since the expansion coating 50 does not completely cover the first mating surface with the magnetic steel 30, after the expansion coating 50 expands due to heat, the expansion coating 50 can extend into the gap between the first region 31 and the first mounting surface of the magnetic steel slot 11, which can prevent the expansion coating 50 from excessively squeezing the first mounting surface of the magnetic steel slot 11 after expansion, thereby reducing the deformation of the magnetic steel slot 11 and causing deformation of the rotor 10, which is beneficial to reducing the probability of the rotor assembly 100 exploding during rotation.

[0050] In a specific embodiment, Figure 3 and Figure 4 As shown, the second area 32 of the first mating surface is rectangular, the first area 31 of the first mating surface is arranged around the circumference of the second area 32 of the first mating surface, and the expansion coating 50 covering the second area 32 of the first mating surface is also rectangular. Each side of the first area 31 is spaced from the circumference of the surface of the magnetic steel 30 provided with the expansion coating 50, that is, each side of the expansion coating 50 is spaced from the circumference of the surface of the first mating surface of the magnetic steel 30. In other words, the shape of the orthographic projection of the expansion coating 50 on the first mating surface is rectangular, and the circumference of the first mating surface is spaced from the circumference of the orthographic projection of the expansion coating 50 on the first mating surface, that is, the orthographic projection of the expansion coating 50 on the first mating surface only covers a partial area of ​​the first mating surface.

[0051] It can be understood that in some other embodiments, the first area 31 of the first mating surface can be arranged side by side with the second area 32 of the first mating surface, or the first area 31 of the first mating surface surrounds the two sides of the second area 32 of the first mating surface, or the first area 31 of the first mating surface surrounds the three sides of the second area 32 of the first mating surface, and the present application does not impose any restrictions on this.

[0052] See also Figure 1 , Figure 2 , Figure 5 and Figure 6 , Figure 5 This is a side view of a magnetic steel and an expansion coating assembly before heating provided by the first embodiment of the present application. Figure 6 It is a side view of the assembly of a magnetic steel and an expansion coating after heating provided by the first embodiment of the present application.

[0053] In a specific embodiment, assuming that the thickness of the magnetic steel 30 is H, the width of the magnetic steel slot 11 is D, the thickness of the expansion coating 50 before heating is I, and the thickness of the expansion coating 50 after heating is L, the thickness H of the magnetic steel 30, the width D of the magnetic steel slot 11, the thickness I of the expansion coating 50 before heating, and the thickness L of the expansion coating 50 after heating satisfy: H+I<D, H+L≥A*D, where A is a constant, A≥1.015.

[0054] It should be understood that in the above formula, the thickness L of the expansion coating 50 after being heated is the expansion of the expansion coating 50 without restraint. When the magnetic steel 30 and the expansion coating 50 are installed in the magnetic steel slot 11, due to the limitation of the magnetic steel slot 11, the sum of the thickness L of the expansion coating 50 after expansion and the thickness H of the magnetic steel 30 should be equal to the width D of the magnetic steel slot 11.

[0055] In order to prevent the magnetic steel 30 from being squeezed and deformed by the expansion coating 50 after heating, the shear load F of the magnetic steel 30 is 磁 Greater than or equal to the expansion load F of the expansion coating 50膨 .

[0056] According to the calculation formula of the shear load of magnetic steel 30: And the calculation formula of the expansion load of the expansion coating 50 is:

[0057] Among them, σ is the stress of the radial magnetic isolation bridge, k1 is the tangential stress constant, k2 is the radial stress constant, θ 12 is the circumferential division occupied by a group of magnetic steel 30, θ 22 is the angle formed by a group of magnetic steel grooves 11; δ is the expansion interference, S is the area of ​​the expansion coating 50, K is the compression force coefficient of the magnetic steel 30, and μ is the friction coefficient.

[0058] It can be obtained that in this embodiment, A=1.105 is preferred. When A=1.105, that is, H+L≥1.105D, it can not only ensure that the magnetic steel 30 can be stably set in the magnetic steel groove 11, but also avoid the magnetic steel 30 being excessively squeezed and deformed.

[0059] See also Figure 7 and Figure 8 , Figure 7 is a cross-sectional view of a magnetic steel and an expansion coating assembly before heating provided in the second embodiment of the present application. Figure 8 It is a cross-sectional view of the assembly of a magnetic steel and an expansion coating after heating provided in the second embodiment of the present application.

[0060] The rotor assembly 100 provided in the second embodiment of the present application is substantially the same as the rotor assembly 100 provided in the first embodiment of the present application, except that in the rotor assembly 100 provided in the second embodiment of the present application, a groove 33 is provided on the first mating surface of the magnetic steel 30, the groove 33 is provided at a position corresponding to the second region 32, the groove 33 extends along the thickness direction of the magnetic steel 30, and the expansion coating 50 is provided in the groove 33. Before the expansion coating 50 is heated, the expansion coating 50 is completely contained in the groove 33. After the expansion coating 50 is heated, the expansion coating 50 protrudes out of the groove 33 and abuts against a partial region of the first mounting surface of the magnetic steel slot 11, so that the magnetic steel 30 and the expansion coating 50 can be fixed in the magnetic steel slot 11. Through the design of the groove 33, the expansion coating 50 is completely contained in the groove 33 before being heated. During the process of installing the magnetic steel 30 and the expansion coating 50 in the magnetic steel groove 11, the expansion coating 50 will not scratch or collide with the first installation surface of the magnetic steel groove 11, which can reduce the occurrence of the expansion coating 50 falling into the magnetic steel groove 11, which is beneficial to improving the cleanliness of the finished rotor assembly 100, and can also reduce the risk of the magnetic steel 30 falling from the magnetic steel groove 11 due to the failure of the expansion coating 50 to provide sufficient clamping force to the magnetic steel 30, so as to ensure the stability of the magnetic steel 30 in the magnetic steel groove 11.

[0061] See also Fig. 9 and Fig.10 , Fig. 9 is a front view of a magnetic steel provided in the third embodiment of the present application, Fig.10 It is a front view of a magnetic steel and expansion coating assembly provided in the third embodiment of the present application.

[0062] The rotor assembly 100 provided in the third embodiment of the present application is substantially the same as the rotor assembly 100 provided in the first embodiment of the present application, with the difference being that in the rotor assembly 100 provided in the third embodiment of the present application, the number of expansion coatings 50 is multiple, the second region 32 of the first mating surface includes multiple sub-regions 320, and the multiple sub-regions 320 are arranged on the same surface (first mating surface) of the magnetic steel 30, and any two adjacent sub-regions 320 are spaced apart, and each expansion coating 50 is arranged on a sub-region 320.

[0063] See also Fig.11 and Fig.12 , Fig.11 is a front view of a magnetic steel provided in the fourth embodiment of the present application, Fig.12 It is a front view of a magnetic steel and expansion coating assembly provided in the fourth embodiment of the present application.

[0064] The rotor assembly 100 provided in the fourth embodiment of the present application is substantially the same as the rotor assembly 100 provided in the first embodiment of the present application, except that in the rotor assembly 100 provided in the fourth embodiment of the present application, the second area 32 of the first mating surface is circular, the first area 31 of the first mating surface is arranged around the second area 32 of the first mating surface, and the expansion coating 50 covering the second area 32 of the first mating surface is also circular. The edge of the second area 32 of the first mating surface is spaced apart from the edge of the first mating surface of the magnetic steel 30, that is, the edge of the expansion coating 50 is spaced apart from the edge of the first mating surface of the magnetic steel 30. In other words, the shape of the orthographic projection of the expansion coating 50 on the first mating surface is circular, and the circumference of the first mating surface is spaced apart from the circumference of the orthographic projection of the expansion coating 50 on the first mating surface, that is, the orthographic projection of the expansion coating 50 on the first mating surface only covers a partial area of ​​the first mating surface.

[0065] It is understandable that in some other embodiments, the second area 32 of the first mating surface may be elliptical or other polygonal shapes, and the corresponding orthographic projection shape of the expansion coating 50 on the first mating surface is elliptical or other polygonal shapes, and the present application does not impose any limitation on this.

[0066] See also Figure 1 , Figure 2 , Fig.13 , Fig.14 , Fig.15 and Fig.16 , Fig.13 is a front view of a magnetic steel provided in the fifth embodiment of the present application, Fig.14 is a rear view of a magnetic steel provided in the fifth embodiment of the present application, Fig.15 This is a side view of a magnetic steel and an expansion coating assembly before heating provided in the fifth embodiment of the present application. Fig.16 It is a side view of the assembly of a magnetic steel and an expansion coating after heating provided by the fifth embodiment of the present application.

[0067] The rotor assembly 100 provided in the fifth embodiment of the present application is substantially the same as the rotor assembly 100 provided in the first embodiment of the present application, except that in the rotor assembly 100 provided in the fifth embodiment of the present application, the expansion coating 50 includes a first expansion layer 51 and a second expansion layer 52. The magnetic steel 30 includes a first mating surface and a second mating surface, and the first mating surface and the second mating surface are arranged opposite to each other. The magnetic steel slot 11 includes a first mounting surface and a second mounting surface, and the first mounting surface and the second mounting surface are arranged opposite to each other. The first mating surface is opposite to the first mounting surface and is arranged at intervals, and the second mating surface is opposite to the second mounting surface and is arranged at intervals. The first mating surface includes a first area 31 and a second area 32 connected, and the second mating surface includes a third area 34 and a fourth area 35 connected, the first area 31 is spaced from the first mounting surface of the magnetic steel slot 11, and the third area 34 is spaced from the second mounting surface of the magnetic steel slot 11. The first expansion layer 51 is arranged in the second area 32 of the first mating surface, and the second expansion layer 52 is arranged in the fourth area 35 of the second mating surface. By arranging the first expansion layer 51 on a partial area of ​​the first mating surface of the magnetic steel 30, and arranging the second expansion layer 52 on a partial area of ​​the second mating surface of the magnetic steel 30, the first expansion layer 51 and the second expansion layer 52 can both expand after being heated, and the first expansion layer 51 can abut against a partial area of ​​the first mounting surface after being heated and the second expansion layer 52 can abut against a partial area of ​​the second mounting surface after being heated, that is, the first expansion layer 51 and the second expansion layer 52 can fix the magnetic steel 30 in the magnetic steel groove 11 after being heated and expanded.

[0068] In a specific embodiment, the magnetic steel 30 includes a first surface 30a and a second surface 30b that are arranged opposite to each other, and the first mating surface is arranged on the first surface 30a, that is, the first area 31 and the second area 32 are arranged on the first surface 30a. The second mating surface is arranged on the second surface 30b, that is, the third area 34 and the fourth area 35 are arranged on the second surface 30b. That is, the first expansion layer 51 is arranged on the first surface 30a, and the second expansion layer 52 is arranged on the second surface 30b. By arranging the first surface 30a and the second surface 30b back to back, the first expansion layer 51 and the second expansion layer 52 are arranged on two opposite surfaces of the magnetic steel 30. The first expansion layer 51 and the second expansion layer 52 can both expand after being heated, and the first expansion layer 51 and the second expansion layer 52 can fix the magnetic steel 30 in the magnetic steel slot 11 after being heated and expanded. Therefore, the magnetic steel 30 is fixed in the magnetic steel slot 11 through the first expansion layer 51 and the second expansion layer 52, which is more stable, and is conducive to improving the overall stability of the rotor assembly 100.

[0069] More specifically, assuming that the thickness of the magnetic steel 30 is H, the width of the magnetic steel slot 11 is D, the thickness of the first expansion layer 51 before heating is I1, and the thickness of the first expansion layer 51 after heating is L1, the thickness H of the magnetic steel 30, the width D of the magnetic steel slot 11, the thickness I1 of the first expansion layer 51 before heating, and the thickness L1 of the first expansion layer 51 after heating satisfy: H+I1<D, H+L1≥A1*D, where A1 is a constant, A1>0.5075. The thickness of the second expansion layer 52 before heating is I2, and the thickness of the second expansion layer 52 after heating is L2, the thickness H of the magnetic steel 30, the width D of the magnetic steel slot 11, the thickness I2 of the second expansion layer 52 before heating, and the thickness L2 of the second expansion layer 52 after heating satisfy: H+I2<D, H+L2≥A2*D, where A2 is a constant, A2>0.5075.

[0070] It should be understood that in the above formula, the thickness L1 of the first expansion layer 51 after being heated is the expansion of the first expansion layer 51 without restraint. When the magnetic steel 30 and the first expansion layer 51 are installed in the magnetic steel slot 11, due to the limitation of the magnetic steel slot 11, the sum of the thickness L1 of the first expansion layer 51 after expansion and the thickness H of the magnetic steel 30 should be equal to the width D of the magnetic steel slot 11.

[0071] It should be understood that in the above formula, the thickness L2 of the second expansion layer 52 after heating is the expansion of the second expansion layer 52 without restraint. When the magnetic steel 30 and the second expansion layer 52 are installed in the magnetic steel slot 11, due to the limitation of the magnetic steel slot 11, the sum of the thickness L2 of the second expansion layer 52 after expansion and the thickness H of the magnetic steel 30 should be equal to the width D of the magnetic steel slot 11.

[0072] In order to prevent the magnetic steel 30 from being squeezed and deformed by the expansion coating 50 after heating, the shear load F of the magnetic steel 30 is 磁 Greater than or equal to the expansion load F of the expansion coating 50 膨 . According to the calculation formula of the shear load of magnetic steel 30: And the calculation formula of the expansion load of the expansion coating 50 is: It can be obtained that in this embodiment, preferably A1=0.5075, preferably A2=0.5075. When A1=0.5075, A2=0.5075. That is, H+L1≥0.5075D, H+L2≥0.5075D, it can not only satisfy that the magnetic steel 30 can be stably arranged in the magnetic steel slot 11, but also avoid the magnetic steel 30 from being excessively squeezed and deformed.

[0073] The above are some implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications are also considered to be within the scope of protection of the present application.

Claims

1. A rotor assembly, characterized in that: include: A rotor having a magnetic steel slot extending through the rotor, wherein the magnetic steel slot includes a first mounting surface; as well as A magnetic steel is arranged in the magnetic steel slot; The magnetic steel comprises a first mating surface, which is opposite to and spaced from the first mounting surface; a partial area of ​​the first mating surface is provided with an expansion coating, which is used to contact a partial area of ​​the first mounting surface after expansion.

2. The rotor assembly according to claim 1, characterized in that Assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the expansion coating before heating is I, and the thickness of the expansion coating after heating is L, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I of the expansion coating before heating, and the thickness L of the expansion coating after heating satisfy: H+I<D, H+L≥A*D, where A is a constant, A≥1.

015.

3. The rotor assembly according to claim 1, characterized in that: A groove is arranged on the first matching surface of the magnetic steel, the groove extends along the thickness direction of the magnetic steel, and the expansion coating is arranged in the groove.

4. The rotor assembly according to claim 1, wherein: The expansion coating comprises a first expansion layer and a second expansion layer, the first expansion layer being disposed on a partial area of ​​the first mating surface, the first expansion layer being used to contact a partial area of ​​the first mounting surface after thermal expansion; The magnetic steel also includes a second mating surface arranged opposite to the first mating surface, and the magnetic steel slot also includes a second mounting surface arranged opposite to the first mounting surface, the second mating surface is opposite to the second mounting surface and is arranged at an interval, and the second expansion layer is arranged on a partial area of ​​the second mating surface, and the second expansion layer is used to contact a partial area of ​​the second mounting surface after thermal expansion.

5. The rotor assembly according to claim 4, characterized in that Assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the first expansion layer before heating is I1, and the thickness of the first expansion layer after heating is L1, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I1 of the first expansion layer before heating, and the thickness L1 of the first expansion layer after heating satisfy: H+I1<D, H+L1≥A1*D, where A1 is a constant, A1≥0.5075.

6. The rotor assembly according to claim 4, characterized in that Assuming that the thickness of the magnetic steel is H, the width of the magnetic steel groove is D, the thickness of the second expansion layer before heating is I2, and the thickness of the second expansion layer after heating is L2, the thickness H of the magnetic steel, the width D of the magnetic steel groove, the thickness I2 of the second expansion layer before heating, and the thickness L2 of the second expansion layer after heating satisfy: H+I2<D, H+L2≥A2*D, where A2 is a constant, A2≥0.5075.

7. The rotor assembly according to claim 1, wherein: The number of the expansion coatings is multiple, the first mating surface includes multiple sub-mating surfaces, and any two adjacent sub-mating surfaces are arranged at intervals, and each expansion coating is arranged on one of the sub-mating surfaces.

8. The rotor assembly according to claim 1, wherein: The orthographic projection of the expansion coating on the first mating surface is any one of a polygonal shape, a circular shape, and an elliptical shape, and the orthographic projection of the expansion coating on the first mating surface covers a partial area of ​​the first mating surface.

9. A motor, characterized in that: include: A rotor assembly as claimed in any one of claims 1 to 8; as well as A stator and a housing, wherein the stator and the rotor assembly are fixed in the housing, and the rotor assembly is rotatably arranged in the stator.

10. A vehicle, characterized in that: include: The motor as claimed in claim 9; as well as The vehicle body is connected to the motor and is used to drive the vehicle to move.

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