Rotor lamination, rotor, electric machine, electric power steering system, and vehicle

Abstract

The application provides a rotor lamination, a rotor, an electric machine, an electric power steering system and a vehicle. The rotor lamination comprises a lamination body and a plurality of permanent magnet grooves. The lamination body is provided with a shaft hole. The plurality of permanent magnet grooves are arranged on the lamination body at intervals around the shaft hole. Each of the plurality of permanent magnet grooves comprises a permanent magnet section and a magnetic isolation section which are in communication with each other. The permanent magnet section is used for accommodating a permanent magnet of the rotor. A part of the lamination body between the magnetic isolation section and an outer circumferential edge of the lamination body is a magnetic isolation bridge. The width W1 of the permanent magnet section, the width W2 of the magnetic isolation bridge and the number P of pole pairs satisfy 0.5≤(W2×P / W1)≤0.9. The application can significantly inhibit the magnetic leakage phenomenon of the rotor permanent magnet magnetic field through the magnetic isolation bridge, reduce the leakage flux density at the magnetic isolation bridge, increase the utilization rate of the permanent magnet, thereby improving the quality of the output torque of the electric machine on the basis of improving the performance of the electric machine, inhibiting torque pulsation, and realizing high power density and high efficiency.

Description

[0001] This application is a divisional application of Chinese patent application filed on December 8, 2021, with application number “202111491567.X” and invention title “Rotor Lamination, Rotor, Motor, Electric Power Steering System and Vehicle”. Technical Field

[0002] This application relates to the field of electrical equipment technology, and more specifically, to a rotor lamination, a rotor, an electric motor, an electric power steering system, and a vehicle. Background Technology

[0003] Currently, with the rapid development of society, electric motors can generate driving torque and serve as a power source for electrical appliances or various machines, thus gaining more and more attention and developing towards higher power density and higher speed.

[0004] However, the existing lamination structure is not reasonable, resulting in poor torque output quality of the motor, leakage flux, high torque pulsation, and the motor performance needs to be improved. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art or related technologies.

[0006] Therefore, the first aspect of this application is to propose a rotor lamination.

[0007] The second aspect of this application is to propose a rotor.

[0008] The third aspect of this application is to propose an electric motor.

[0009] The fourth aspect of this application is to propose an electric power steering system.

[0010] The fifth aspect of this application is to propose a vehicle.

[0011] In view of the above, according to the first aspect of this application, a rotor lamination is provided, including a lamination body and a plurality of permanent magnet slots. The lamination body is provided with a shaft hole, and the plurality of permanent magnet slots are spaced around the shaft hole on the lamination body. Each of the plurality of permanent magnet slots includes a permanent magnet segment and a magnetic isolation segment that are interconnected. The permanent magnet segment is used to accommodate the permanent magnet of the rotor. The portion of the lamination body located between the magnetic isolation segment and the outer periphery of the lamination body is a magnetic isolation bridge. The width W1 of the permanent magnet segment, the width W2 of the magnetic isolation bridge, and the number of pole pairs P satisfy 0.5≤(W2×P / W1)≤0.9.

[0012] The rotor lamination provided in this application includes a lamination body and multiple permanent magnet slots. The lamination body has a shaft hole in its center for accommodating a rotating shaft. Multiple permanent magnet slots are arranged at intervals around the shaft hole on the lamination body, each slot extending axially to accommodate a permanent magnet. Each permanent magnet slot includes a permanent magnet section and a magnetic isolation section, which are interconnected. The permanent magnet section accommodates the rotor's permanent magnets, which are embedded within it. The magnetic isolation section is empty, containing no permanent magnets. There are two magnetic isolation sections, each connected to one side of a permanent magnet section. The portion of the lamination body located between the magnetic isolation section and the outer periphery of the lamination body is called the magnetic isolation bridge. The width of the magnetic isolation bridge is related to the width of the permanent magnet section and the number of pole pairs of the motor. This allows the width of the magnetic isolation bridge to be set within a reasonable range, avoiding excessively small widths that would make the manufacturing process too difficult and increase the possibility of rotor lamination deformation during motor operation. It can significantly suppress the leakage magnetic field of the rotor permanent magnet through the magnetic isolation bridge, reduce the leakage magnetic flux density at the magnetic isolation bridge, and increase the utilization rate of the permanent magnet. Thus, it can improve the quality of the motor output torque while improving motor performance, suppress torque pulsation, and achieve high power density and high efficiency.

[0013] In one possible design, further, on the axial end face of the lamination body, there are inter-pole center lines between adjacent permanent magnet slots in a plurality of permanent magnet slots. The permanent magnet slots are provided with opposing first and second vertices. A first radial extension line passing through the center of the shaft hole intersects or is tangent to the first vertex, and a second radial extension line passing through the center of the shaft hole intersects or is tangent to the second vertex. The permanent magnet slots are located between the first and second radial extension lines, wherein the included angle β between the first and second radial extension lines and the included angle α between adjacent inter-pole center lines satisfy 0.9 ≤ β / α ≤ 0.98.

[0014] In this design, on the axial end face of the lamination body, the line connecting the center of each permanent magnet slot and the center of the shaft hole is the magnetic pole center line. The angle bisector of two adjacent magnetic pole center lines is the inter-pole center line. The included angle formed between adjacent inter-pole center lines is the central angle α occupied by each magnetic pole. The central angle α represents the proportion of each magnetic pole in the lamination body, α = 360° / 2P.

[0015] Furthermore, the permanent magnet slot includes a first vertex and a second vertex, which are located at opposite ends of the permanent magnet slot. The first vertex and the center of the shaft hole are respectively located on the first radial extension line, and the second vertex and the center of the shaft hole are respectively located on the second radial extension line. The included angle formed by the first radial extension line and the second radial extension line is the central angle β corresponding to the permanent magnet slot. That is, the permanent magnet slot is completely located within the area formed by the first radial extension line and the second radial extension line. By limiting the ratio of the central angle α corresponding to each magnetic pole to the central angle β corresponding to the permanent magnet slot, the relative position of the permanent magnet slot in each magnetic pole can be determined, making the arrangement of the permanent magnet slot more rational, thereby helping to improve the motor performance.

[0016] In one possible design, the portion of the lamination body between adjacent permanent magnet slots in the multiple permanent magnet slots is a magnetic rib, wherein the minimum width W3 of the magnetic rib satisfies W2≤W3≤W1.

[0017] In this design, the part of the lamination body located between two adjacent permanent magnet slots is a magnetic rib. The specific shape of the magnetic rib is related to the specific shape of the permanent magnet slot. The width of the magnetic rib is related to the width of the magnetic isolation bridge and the width of the permanent magnet segment, which makes the arrangement of various positions on the periphery of the lamination body more reasonable, thereby helping to improve the leakage magnetic phenomenon, improve the quality of the motor output torque, and thus improve the motor performance.

[0018] In one possible design, the permanent magnet segment further includes opposing straight groove walls and bent groove walls, with the straight groove walls positioned away from the shaft hole relative to the bent groove walls.

[0019] In this design, the permanent magnet section includes straight groove walls and bent groove walls, which are distributed radially. The straight groove walls are positioned away from the shaft hole relative to the bent groove walls, i.e., the straight groove walls are located on the outside, while the bent groove walls are located on the inside. The bent groove walls have a bending angle, and when the permanent magnet comes into contact with the bent groove walls, it will be restricted by the bent groove walls, thus ensuring the positional stability of the permanent magnet within the permanent magnet section. The straight groove walls are located on the outside, which facilitates the dimensional processing of the magnetic bridge and reduces the processing difficulty of the rotor laminations.

[0020] In one possible design, further, on the axial end face of the lamination body, the outer periphery of the portion of the lamination body located between adjacent inter-pole center lines includes an outer arc line, which includes a first arc segment, a second arc segment, and a third arc segment. The second arc segment is connected to the first arc segment and the third arc segment, respectively. The radius R2 of the circle containing the second arc segment and the maximum radius R1 of the lamination body satisfy 0.3≤(R1-R2) / R1≤0.7.

[0021] In this design, on the axial end face of the lamination body, the outer periphery of the portion of the lamination body located between adjacent pole center lines includes an outer arc. That is, for each magnetic pole, the outer periphery of the lamination body has an outer arc corresponding to the magnetic pole. The outer arc includes a first arc segment, a second arc segment, and a third arc segment connected sequentially. The second arc segment is located between the first and third arc segments. The radius R2 of the circle containing the second arc segment and the maximum radius R1 of the lamination body satisfy 0.3 ≤ (R1-R2) / R1 ≤ 0.7. When the value of (R1-R2) / R1 is within the above range, the torque ripple of the motor is at a low level, and the torque ripple further decreases as the value of (R1-R2) / R1 increases. At the same time, the motor's output torque is in a stable state without significant fluctuations. In other words, when the value of (R1-R2) / R1 is within a reasonable range, it will not affect the motor's output torque, but will keep the torque ripple at a low level and reduce it to a certain extent. By weakening the torque ripple, the noise and vibration of the motor can be improved, thus enhancing the motor's performance.

[0022] It is worth noting that the permanent magnet groove includes a permanent magnet segment and two magnetic isolation segments, namely the first magnetic isolation segment and the second magnetic isolation segment, which are connected to the two ends of the permanent magnet segment. Therefore, along the circumferential direction, the correspondence between the permanent magnet groove and the outer arc is as follows: the first magnetic isolation segment corresponds to the first arc segment, the permanent magnet segment corresponds to the second arc segment, and the second magnetic isolation segment corresponds to the third arc segment. Thus, there are two magnetic isolation bridges: the first magnetic isolation bridge formed by the first arc segment and the second magnetic isolation bridge formed by the second arc segment. When the first and second magnetic isolation segments have the same structure, and the first and third arc segments have the same curvature, then the first and second magnetic isolation bridges have the same structure, resulting in a symmetrical structure for each magnetic pole, which facilitates quality control during the production process.

[0023] In one possible design, the central angle γ corresponding to the second arc segment and the angle α between the adjacent interpolar center lines satisfy 0.6≤γ / α≤0.8.

[0024] In this design, by limiting the ratio of the central angle α corresponding to each magnetic pole and the central angle γ corresponding to the second arc segment, the approximate shape of the outer circumference of the lamination body can be determined. The curvature distribution of the outer periphery corresponding to each magnetic pole can be rationally designed, making the structure of the lamination body more rational and thus helping to improve motor performance.

[0025] In one possible design, the rotor lamination further includes multiple weight-reduction holes, which are located on the lamination body and respectively on the magnetic pole center line and / or the inter-pole center line of the lamination body.

[0026] In this design, a rotor lamination has a magnetic pole centerline and an inter-pole centerline. The line connecting the center of the permanent magnet slot and the center of the shaft hole forms the magnetic pole centerline, referred to as the d-axis. The angle bisector of two adjacent magnetic pole centerlines is the inter-pole centerline, also known as the adjacent magnetic pole centerline, referred to as the q-axis. Multiple weight-reduction holes are located on the magnetic pole centerline and / or the inter-pole centerline. While ensuring that motor performance is not affected, the weight-reduction holes can reduce the moment of inertia and lighten the overall weight of the motor.

[0027] The number of weight-reducing holes is multiple. All weight-reducing holes are located on the center line of the magnetic poles, or all weight-reducing holes are located on the center line between the poles, or a portion of the weight-reducing holes are located on the center line of the magnetic poles and another portion of the weight-reducing holes are located on the center line between the poles.

[0028] It is conceivable that for the lamination body, there are multiple magnetic pole center lines and multiple inter-pole center lines. One weight reduction hole can be set on a magnetic pole center line, or multiple relatively independent weight reduction holes can be set on a magnetic pole center line. However, for a weight reduction hole, it can only be located on one of the magnetic pole center lines or the inter-pole center lines; there is no case where a weight reduction hole is located on both the magnetic pole center line and the inter-pole center line at the same time.

[0029] In one possible design, the weight reduction hole is further located between the permanent magnet groove and the shaft hole, wherein the minimum distance W4 between the weight reduction hole and the permanent magnet groove and the minimum distance W5 between the weight reduction hole and the shaft hole satisfy 0.8≤W4 / W5≤1.2.

[0030] In this design, the weight-reduction hole is located between the permanent magnet slot and the shaft hole. The weight-reduction hole is independently positioned relative to the permanent magnet slot and shaft hole, and the centers of the weight-reduction hole, the permanent magnet slot, and the shaft hole are all located on the magnetic pole centerline. The minimum distances W4 between the weight-reduction hole and the permanent magnet slot, and W5 between the weight-reduction hole and the shaft hole, satisfy the condition 0.8 ≤ W4 / W5 ≤ 1.2. By rationally selecting the position of the weight-reduction hole, the moment of inertia is reduced, and the motor weight is lightened without affecting the motor's performance.

[0031] In one possible design, the minimum distance W4 between the weight reduction hole and the permanent magnet slot, the minimum distance W5 between the weight reduction hole and the shaft hole, the maximum radius R1 of the lamination body, and the radius R3 of the shaft hole satisfy 0.4≤(W4+W5) / (R1-R3)≤0.6.

[0032] In this design, the minimum distance between the weight-reducing hole and the permanent magnet slot is W4, the minimum distance between the weight-reducing hole and the shaft hole is W5, the maximum radius of the lamination body is R1, and the radius of the shaft hole is R3. The dimensional relationships of these four components satisfy the aforementioned relationship, thus achieving the goal of reducing rotational inertia and motor weight without affecting motor performance. When the value of (W4+W5) / (R1-R3) is within the above range, the motor's rotational inertia is at a low level. As (W4+W5) / (R1-R3) increases, the increase in rotational inertia is relatively small, meaning that within the above range, the motor's rotational inertia can remain stably at a low level.

[0033] In one possible design, the weight reduction hole further includes an arc-shaped hole wall, which includes a circular arc on the axial end face. The radius R4 of the circle containing the circular arc and the maximum radius R1 of the lamination body satisfy 0.05≤R4 / R1≤0.3.

[0034] In this design, the weight reduction hole includes at least one arc-shaped hole wall. The arc-shaped hole wall has a circular arc on the axial end face perpendicular to the axial direction. The radius R4 of the circle containing the circular arc and the maximum radius R1 of the lamination body satisfy the above relationship, thereby associating the shape of the weight reduction hole with the lamination body, making the size and shape selection of the weight reduction hole more reasonable, and thus optimizing the overall structural arrangement of the rotor lamination, which helps to improve the motor performance.

[0035] In one possible design, the weight-reducing hole is further provided with a third vertex and a fourth vertex opposite to each other. The third radial extension line passing through the center of the shaft hole intersects or is tangent to the third vertex, and the fourth radial extension line passing through the center of the shaft hole intersects or is tangent to the fourth vertex. The weight-reducing hole is located between the third radial extension line and the fourth radial extension line. The included angle θ between the third radial extension line and the fourth radial extension line and the included angle α between the adjacent interpole center lines satisfy 0.6≤θ / α≤0.8.

[0036] In this design, the weight-reducing hole includes a third vertex and a fourth vertex, which are located at opposite ends of the weight-reducing hole. The third vertex and the center of the shaft hole are respectively located on the third radial extension line, and the fourth vertex and the center of the shaft hole are respectively located on the fourth radial extension line. The angle formed by the third radial extension line and the fourth radial extension line is the central angle θ corresponding to the weight-reducing hole. That is, the weight-reducing hole is completely located within the area formed by the third radial extension line and the fourth radial extension line. By limiting the ratio of the central angle α corresponding to each magnetic pole to the central angle θ corresponding to the weight-reducing hole, the relative position of the weight-reducing hole in each magnetic pole can be determined, making the arrangement of the weight-reducing hole more rational, thereby helping to improve the motor performance.

[0037] In one possible design, the number of weight-reducing holes is further 4, 6, 8, 12, 16 or 20.

[0038] In this design, the number of weight-reducing holes can be varied and set according to actual needs. However, regardless of the number of weight-reducing holes, they can be located only on the inter-pole centerline. Alternatively, weight-reducing holes can be located only on the magnetic pole centerline, or at least one of the multiple weight-reducing holes can be located on the inter-pole centerline, and at least one of the multiple weight-reducing holes can be located on the magnetic pole centerline.

[0039] For example, when the number of weight-reducing holes is 16, the weight-reducing holes include 8 first weight-reducing holes and 8 second weight-reducing holes. The 8 first weight-reducing holes are arranged circumferentially at intervals, and each first weight-reducing hole is located on the center line of each magnetic pole. The 8 second weight-reducing holes are arranged circumferentially at intervals, and can be located outside or inside the first weight-reducing holes. Each second weight-reducing hole is located on a center line between poles. The opening areas of the first weight-reducing holes and the second weight-reducing holes are different. For example, when the first weight-reducing holes are located further away from the shaft hole relative to the second weight-reducing holes, the opening area of ​​the first weight-reducing holes is larger than that of the second weight-reducing holes.

[0040] It should be noted that the shape of the first weight-reducing hole and the shape of the second weight-reducing hole may be the same or different.

[0041] In one possible design, the rotor lamination further includes a rivet portion, which is located on the lamination body and situated on the magnetic pole centerline or the inter-pole centerline.

[0042] In this design, each lamination body is also provided with a rivet part. Multiple rotor laminations are stacked axially to form a rotor core. The rivet parts on adjacent rotor laminations can be matched to connect multiple rotor laminations axially, thereby forming a whole rotor core. The weight reduction holes and rivet parts are independently formed on the lamination body and do not interfere with each other. By setting rivet parts and weight reduction holes on the lamination body, and by associating the positions of the rivet parts and weight reduction holes with the positions of the magnetic pole center line and the inter-pole center line, this application can improve the quality of the motor output torque while improving motor performance, reduce magnetic leakage and suppress torque pulsation, achieve high power density and high efficiency, reduce rotational inertia and reduce motor weight.

[0043] It should be noted that, for the lamination body, there are multiple magnetic pole center lines and multiple inter-pole center lines. There are also multiple rivet parts, with one rivet part corresponding to one magnetic pole center line or one inter-pole center line. In one possible design, the number of rivet parts is further half the number of permanent magnet slots; or, the number of rivet parts is equal to the number of permanent magnet slots.

[0044] In this design, the number of rivet parts is related to the number of permanent magnet slots. The number of rivet parts can be half the number of permanent magnet slots, or the number of rivet parts can be equal to the number of permanent magnet slots. Specifically, when the number of permanent magnet slots is 8, the number of rivet parts can be 4 or 8. Regardless of whether the number of rivet parts and the number of permanent magnet slots are in a multiple or equal relationship, the rivet parts need to be located on the inter-pole centerline and / or the magnetic pole centerline.

[0045] When multiple weight-reducing holes and multiple rivet parts are provided on the lamination body, the weight-reducing holes and rivet parts must follow the principle of being arranged on the inter-pole center line and the magnetic pole center line. The weight-reducing holes and rivet parts are relatively independent and each forms its own reasonable arrangement position.

[0046] In one possible design, further, when the number of rivet parts and the number of weight-reducing holes are equal, the weight-reducing holes and rivet parts are alternately arranged in the circumferential direction.

[0047] In this design, when the number of rivet parts and the number of weight-reducing holes are equal—for example, both being half the number of permanent magnet slots—or when their numbers are the same as the number of permanent magnet slots, their arrangement follows an alternating pattern. Specifically, when there are four rivet parts and four weight-reducing holes, they are arranged alternately, with the centers of the four rivet parts and the four weight-reducing holes located within the same circle. When there are eight rivet parts and eight weight-reducing holes, one of the weight-reducing holes and rivet parts is located on the center line of the magnetic poles, and the other is located on the center line between the poles, forming concentric circles of different radii along the circumference. The weight-reducing holes are positioned closer to the shaft holes than the rivet parts. This is because during high-speed rotation of the rotor laminations, the centrifugal force on the outer periphery of the rotor laminations is significant. Positioning the rivet parts further outward better ensures that the rotor laminations do not deform, improving structural reliability.

[0048] According to a second aspect of this application, a rotor is provided, comprising rotor laminations provided by any of the above designs.

[0049] The rotor provided in this application includes the rotor laminations provided in any of the above designs, and therefore has all the beneficial effects of the rotor laminations, which will not be repeated here.

[0050] The rotor laminations are stacked axially to form a rotor core, and the permanent magnet slots of the rotor laminations are connected axially to form a magnetic slot, with the permanent magnets inserted into the magnetic slot.

[0051] According to a third aspect of this application, an electric motor is provided, comprising a rotor provided by any of the above-described designs.

[0052] The motor provided in this application includes the rotor provided by any of the above designs, and therefore has all the beneficial effects of that rotor, which will not be repeated here.

[0053] It is worth noting that the motor is a permanent magnet motor.

[0054] According to a fourth aspect of this application, an electric power steering system is provided, comprising a motor provided by any of the above designs.

[0055] The electric power steering system provided in this application includes the motor provided in any of the above designs, and therefore has all the beneficial effects of that motor, which will not be repeated here.

[0056] It should be noted that Electric Power Steering (EPS) is a power steering system that directly relies on an electric motor to provide auxiliary torque. Compared with the traditional Hydraulic Power Steering (HPS) system, EPS has many advantages. EPS mainly consists of a torque sensor, a vehicle speed sensor, an electric motor, a reduction gear, and an electronic control unit (ECU).

[0057] According to a fifth aspect of this application, a vehicle is provided, including rotor laminations, rotor, motor, or electric power steering system provided by any of the above designs.

[0058] The vehicle provided in this application includes the rotor laminations, rotor, motor or electric power steering system provided by any of the above designs, and therefore has all the beneficial effects of the rotor laminations, rotor, motor or electric power steering system, which will not be repeated here.

[0059] It should be noted that the vehicles can be either traditional gasoline-powered vehicles or new energy vehicles. New energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid electric vehicles, fuel cell electric vehicles, and hydrogen engine vehicles.

[0060] Additional aspects and advantages of this application will become apparent in the following description or may be learned by practice of this application. Attached Figure Description

[0061] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0062] Figure 1 A schematic diagram of the rotor lamination structure according to the first embodiment of this application is shown;

[0063] Figure 2 One of the partial structural schematic diagrams of the rotor laminations according to the first embodiment of this application is shown;

[0064] Figure 3 A second schematic diagram of a portion of the rotor lamination structure according to the first embodiment of this application is shown;

[0065] Figure 4 A schematic diagram showing the variation of motor torque and stress at the magnetic bridge as a function of variable (W2×P / W1) in one embodiment of this application is shown.

[0066] Figure 5 A schematic diagram showing the variation of motor torque and torque ripple with variable (R1-R2) / R1 in one embodiment of this application is shown.

[0067] Figure 6 A schematic diagram showing the change of the moment of inertia of the motor as a function of the variable (W4+W5) / (R1-R3) in one embodiment of this application is shown.

[0068] Figure 7 A schematic diagram of the rotor lamination structure according to a second embodiment of this application is shown;

[0069] Figure 8 A schematic diagram of the rotor lamination structure according to a third embodiment of this application is shown;

[0070] Figure 9 A schematic diagram of the rotor lamination structure according to the fourth embodiment of this application is shown;

[0071] Figure 10 A schematic diagram of the rotor lamination structure according to the fifth embodiment of this application is shown;

[0072] Figure 11 A schematic diagram of an electric power steering system according to one embodiment of this application is shown.

[0073] Figure label:

[0074] 100 rotor laminations,

[0075] 110 punch body,

[0076] 111 is a magnetic isolation bridge, 111a is the first magnetic isolation bridge, and 111b is the second magnetic isolation bridge.

[0077] 112 magnetic ribs,

[0078] 113 First arc segment, 114 Second arc segment, 115 Third arc segment

[0079] 120 shaft hole,

[0080] 130 permanent magnet slots,

[0081] 131 Permanent magnet section, 1311 Straight groove wall, 1312 Bending groove wall.

[0082] 132 magnetic shielding section, 132a first magnetic shielding section, 132b second magnetic shielding section.

[0083] 140 rivet part,

[0084] 150 weight reduction hole,

[0085] 200 Electric Power Steering System

[0086] 211 Steering wheel, 212 Steering shaft, 213 Universal coupling, 214 Rotary shaft, 215 Rack and pinion mechanism, 216 Rack and pinion shaft, 217 Wheel.

[0087] 221 Steering torque sensor, 222 Control unit, 223 Reduction mechanism. Detailed Implementation

[0088] To better understand the above-mentioned objectives, features, and advantages of this application, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0089] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0090] The following reference Figures 1 to 11 The present application describes a rotor lamination 100, a rotor, a motor, an electric power steering system 200, and a vehicle provided according to some embodiments thereof.

[0091] According to an embodiment of the first aspect of this application, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, a rotor lamination 100 is provided, including a lamination body 110 and a plurality of permanent magnet slots 130. The lamination body 110 is provided with a shaft hole 120. The plurality of permanent magnet slots 130 are arranged at intervals around the shaft hole 120 on the lamination body 110. Each of the plurality of permanent magnet slots 130 includes a permanent magnet segment 131 and a magnetic isolation segment 132 that are interconnected. The permanent magnet segment 131 is used to accommodate the permanent magnets of the rotor. The portion of the lamination body 110 located between the magnetic isolation segment 132 and the outer periphery of the lamination body 110 is a magnetic isolation bridge 111. The width W1 of the permanent magnet segment 131 and the width W2 of the magnetic isolation bridge 111 satisfy the following for the number of pole pairs P: 0.5≤(W2×P / W1)≤0.9.

[0092] The rotor lamination 100 provided in this application includes a lamination body 110, a plurality of permanent magnet slots 130, a rivet portion 140, and a weight reduction hole 150. A shaft hole 120 is provided in the middle of the lamination body 110 to accommodate a rotating shaft. The plurality of permanent magnet slots 130 are arranged at intervals around the shaft hole 120 on the lamination body 110, and each permanent magnet slot 130 is axially penetrating to accommodate a permanent magnet. Each permanent magnet slot 130 includes a permanent magnet section 131 and a magnetic isolation section 132, which are interconnected. The permanent magnet section 131 accommodates the permanent magnet of the rotor, and the permanent magnet is embedded within the permanent magnet section 131. The magnetic isolation section 132 does not contain a permanent magnet; that is, the magnetic isolation section 132 is empty. There are two magnetic isolation sections 132, which are respectively connected to both sides of the permanent magnet section 131. The portion of the lamination body 110 located between the magnetic isolation section 132 and the outer periphery of the lamination body 110 is called the magnetic isolation bridge 111. The width of the magnetic isolation bridge 111 is related to the width of the permanent magnet section 131 and the number of pole pairs of the motor. This allows the width of the magnetic isolation bridge 111 to be set within a reasonable range, avoiding the problem of the magnetic isolation bridge 111 being too small, which would make the manufacturing process too difficult and increase the possibility of deformation of the rotor lamination 100 during motor operation. It can significantly suppress the leakage magnetic field of the rotor permanent magnet through the magnetic isolation bridge 111, reduce the leakage magnetic flux density at the magnetic isolation bridge 111, increase the utilization rate of the permanent magnet, and thus improve the quality of the motor output torque while ensuring motor performance, improve the leakage magnetic phenomenon and suppress torque pulsation, and achieve high power density and high efficiency.

[0093] like Figure 4 As shown, when (W2×P / W1) is less than 0.5, the stress on the magnetic bridge is relatively high, making it prone to deformation during motor operation. When (W2×P / W1) is greater than 0.9, although the stress at the magnetic bridge shows a decreasing trend, the motor's output torque also decreases, resulting in compromised output quality. However, when (W2×P / W1) falls within the range of [0.5, 0.9], the stress at the magnetic bridge is at a low level, while the torque remains relatively stable without significant reduction. Therefore, within this range, both the stress at the magnetic bridge and the motor's output torque are within optimal limits, thus improving the quality of the motor's output torque while maintaining performance, mitigating magnetic leakage, suppressing torque pulsation, and achieving high power density and high efficiency.

[0094] Furthermore, such as Figure 1 , Figure 2 and Figure 3As shown, on the axial end face of the lamination body 110, there are inter-pole center lines between adjacent permanent magnet slots 130. Each permanent magnet slot 130 has a first vertex and a second vertex. A first radial extension line passing through the center of the shaft hole 120 intersects or is tangent to the first vertex, and a second radial extension line passing through the center of the shaft hole 120 intersects or is tangent to the second vertex. The permanent magnet slot 130 is located between the first and second radial extension lines. The included angle β between the first and second radial extension lines and the included angle α between adjacent inter-pole center lines satisfy 0.9 ≤ β / α ≤ 0.98.

[0095] In this embodiment, on the axial end face of the lamination body 110, the line connecting the center of each permanent magnet slot 130 and the center of the shaft hole 120 is the magnetic pole center line, the angle bisector of two adjacent magnetic pole center lines is the inter-pole center line, and the included angle formed between adjacent inter-pole center lines is the central angle α occupied by each magnetic pole. The central angle α represents the proportion of each magnetic pole in the lamination body 110, and α = 360° / 2P.

[0096] Furthermore, the permanent magnet slot 130 includes a first vertex and a second vertex, which are located at opposite ends of the permanent magnet slot 130. The first vertex and the center of the shaft hole 120 are respectively located on the first radial extension line, and the second vertex and the center of the shaft hole 120 are respectively located on the second radial extension line. The included angle formed by the first radial extension line and the second radial extension line is the central angle β of the permanent magnet slot 130. That is, the permanent magnet slot 130 is completely located within the area formed by the first radial extension line and the second radial extension line. By limiting the ratio of the central angle α corresponding to each magnetic pole to the central angle β corresponding to the permanent magnet slot 130, the relative position of the permanent magnet slot 130 in each magnetic pole can be determined, making the position arrangement of the permanent magnet slot 130 more reasonable, thereby helping to improve the motor performance.

[0097] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the portion of the lamination body 110 between adjacent permanent magnet slots 130 is a magnetic rib 112, wherein the minimum width W3 of the magnetic rib 112 satisfies W2≤W3≤W1.

[0098] In this embodiment, the portion of the lamination body 110 located between two adjacent permanent magnet slots 130 is a magnetic rib 112. The specific shape of the magnetic rib 112 is related to the specific shape of the permanent magnet slot 130. The width of the magnetic rib 112 is related to the width of the magnetic isolation bridge 111 and the width of the permanent magnet segment 131, making the arrangement of various positions on the periphery of the lamination body 110 more rational, thereby helping to improve the leakage magnetic phenomenon, improve the quality of the motor output torque, and thus improve the motor performance.

[0099] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the permanent magnet segment 131 includes opposing straight groove walls 1311 and bent groove walls 1312, with the straight groove wall 1311 disposed away from the shaft hole 120 relative to the bent groove wall 1312.

[0100] In this embodiment, the permanent magnet segment 131 includes a straight groove wall 1311 and a bent groove wall 1312. The straight groove wall 1311 and the bent groove wall 1312 are distributed radially. The straight groove wall 1311 is located away from the shaft hole 120 relative to the bent groove wall 1312, that is, the straight groove wall 1311 is located on the outside and the bent groove wall 1312 is located on the inside. The bent groove wall 1312 has a bending angle. When the permanent magnet comes into contact with the bent groove wall 1312, it will be restricted by the bent groove wall 1312, thereby ensuring the positional stability of the permanent magnet in the permanent magnet segment 131. The straight groove wall 1311 is located on the outside, which facilitates the dimensional processing of the magnetic isolation bridge 111 and reduces the processing difficulty of the rotor lamination 100.

[0101] Furthermore, such as Figure 5 As shown, on the axial end face of the lamination body 110, the outer periphery of the portion of the lamination body 110 located between adjacent inter-pole center lines includes an outer arc line. The outer arc line includes a first arc segment 113, a second arc segment 114, and a third arc segment 115. The second arc segment 114 is connected to the first arc segment 113 and the third arc segment 115, respectively. The radius R2 of the circle containing the second arc segment 114 and the maximum radius R1 of the lamination body 110 satisfy 0.3≤(R1-R2) / R1≤0.7.

[0102] In this embodiment, on the axial end face of the lamination body 110, the outer periphery of the portion of the lamination body 110 located between adjacent inter-pole center lines includes an outer arc line. That is, for each magnetic pole, the outer periphery of the lamination body 110 has an outer arc line corresponding to the magnetic pole. The outer arc line includes a first arc segment 113, a second arc segment 114, and a third arc segment 115 connected in sequence. The second arc segment 114 is located between the first arc segment 113 and the third arc segment 115. The radius R3 of the circle containing the second arc segment 114 and the maximum radius R1 of the lamination body 110 satisfy 0.3≤(R1-R2) / R1≤0.7. Figure 5As shown, when the value of (R1-R2) / R1 is within the above range, the torque ripple of the motor is at a low level, and the torque ripple shows a decreasing trend as the value of (R1-R2) / R1 increases. At the same time, the output torque of the motor is in a stable state without significant fluctuations. In other words, when the value of (R1-R2) / R1 is within a reasonable range, it will not affect the output torque of the motor, but will keep the torque ripple at a low level and reduce it to a certain extent. By weakening the torque ripple, the noise and vibration of the motor are improved, thus enhancing motor performance.

[0103] It is worth noting that the permanent magnet groove 130 includes a permanent magnet segment 131 and two magnetic isolation segments 132, namely the first magnetic isolation segment 132a and the second magnetic isolation segment 132b, which are respectively connected to the two ends of the permanent magnet segment 131. Therefore, along the circumferential direction, the correspondence between the permanent magnet groove 130 and the outer arc is as follows: the first magnetic isolation segment 132a corresponds to the first arc segment 113, the permanent magnet segment 131 corresponds to the second arc segment 114, and the second magnetic isolation segment 132b corresponds to the third arc segment 115. Thus, there are two magnetic isolation bridges 111, namely the first magnetic isolation bridge 111a formed by the first arc segment 113 and the second magnetic isolation bridge 111b formed by the second arc segment 114. When the first magnetic isolation segment 132a and the second magnetic isolation segment 132b have the same structure, and the first arc segment 113 and the third arc segment 115 have the same curvature, then the first magnetic isolation bridge 111a and the second magnetic isolation bridge 111b have the same structure, making each magnetic pole a symmetrical structure, which is easy to control the quality of the production process.

[0104] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the angle α between the central angle γ corresponding to the second arc segment 114 and the adjacent interpolar center line satisfies 0.6≤γ / α≤0.8.

[0105] In this embodiment, by limiting the ratio of the central angle α corresponding to each magnetic pole and the central angle γ corresponding to the second arc segment 114, the approximate shape of the outer circumference of the lamination body 110 can be determined, and the curvature distribution of the outer periphery corresponding to each magnetic pole can be rationally designed, making the structure of the lamination body 110 more rational, thereby helping to improve the motor performance.

[0106] In some embodiments of this application, the rotor lamination further includes a plurality of weight reduction holes 150, which are disposed on the lamination body 110 and are respectively located on the magnetic pole center line and / or the inter-pole center line of the lamination body 110.

[0107] In this embodiment, a rotor lamination 100 has a magnetic pole centerline and an inter-pole centerline. The line connecting the center of the permanent magnet slot 130 and the center of the shaft hole 120 forms the magnetic pole centerline, referred to as the d-axis. The angle bisector of two adjacent magnetic pole centerlines is the inter-pole centerline, also called the adjacent magnetic pole centerline, referred to as the q-axis. Multiple weight-reducing holes 150 are respectively provided on the magnetic pole centerline and / or inter-pole centerline of the lamination body 110. Without affecting motor performance, the weight-reducing holes 150 can reduce the moment of inertia and lighten the overall weight of the motor.

[0108] The number of weight-reducing holes 150 is multiple. All of the weight-reducing holes 150 are located on the center line of the magnetic pole, or all of the weight-reducing holes 150 are located on the center line between the poles, or a portion of the weight-reducing holes 150 are located on the center line of the magnetic poles, and another portion of the weight-reducing holes 150 are located on the center line between the poles.

[0109] It is conceivable that for the lamination body 110, there are multiple magnetic pole center lines and multiple inter-pole center lines. One weight reduction hole 150 can be set on one magnetic pole center line, or multiple relatively independent weight reduction holes 150 can be set on one magnetic pole center line. However, for a weight reduction hole 150, it will only be located on one of the magnetic pole center lines or the inter-pole center lines; there is no case where a weight reduction hole 150 is located on both the magnetic pole center line and the inter-pole center line at the same time.

[0110] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the weight reduction hole 150 is located between the permanent magnet groove 130 and the shaft hole 120. The minimum distance W4 between the weight reduction hole 150 and the permanent magnet groove 130 and the minimum distance W5 between the weight reduction hole 150 and the shaft hole 120 satisfy the condition 0.8≤W4 / W5≤1.2.

[0111] In this embodiment, the weight-reducing hole 150 is formed between the permanent magnet slot 130 and the shaft hole 120. The weight-reducing hole 150 is independently set relative to the permanent magnet slot 130 and the shaft hole 120. The center of the weight-reducing hole 150, the center of the permanent magnet slot 130, and the center of the shaft hole 120 are all located on the magnetic pole center line. The minimum distance W4 between the weight-reducing hole 150 and the permanent magnet slot 130 and the minimum distance W5 between the weight-reducing hole 150 and the shaft hole 120 satisfy 0.8≤W4 / W5≤1.2. By reasonably selecting the position of the weight-reducing hole 150, the moment of inertia is reduced, the weight of the motor is reduced, and the performance of the motor is not affected.

[0112] Furthermore, such as Figure 6As shown, the minimum distance W4 between the weight reduction hole 150 and the permanent magnet groove 130, the minimum distance W5 between the weight reduction hole 150 and the shaft hole 120, the maximum radius R1 of the lamination body 110, and the radius R3 of the shaft hole 120 satisfy the condition 0.4≤(W4+W5) / (R1-R3)≤0.6.

[0113] In this embodiment, the minimum distance between the weight reduction hole 150 and the permanent magnet slot 130 is W4, the minimum distance between the weight reduction hole 150 and the shaft hole 120 is W5, the maximum radius of the lamination body 110 is R1, and the radius of the shaft hole 120 is R3. The dimensional relationship of these four components satisfies the above relationship, thereby achieving the goal of reducing rotational inertia and lightening the motor weight without affecting the motor's performance. Figure 6 As shown, when the value of (W4+W5) / (R1-R3) is within the above range, the moment of inertia of the motor is at a low level. As (W4+W5) / (R1-R3) increases, the increase in moment of inertia is relatively small. That is, within the above range, the moment of inertia of the motor can remain at a low level.

[0114] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the weight reduction hole 150 includes an arc-shaped hole wall, which includes a circular arc on the axial end face. The radius R4 of the circle containing the circular arc and the maximum radius R1 of the lamination body 110 satisfy 0.05≤R4 / R1≤0.3.

[0115] In this embodiment, the weight reduction hole 150 includes at least one arc-shaped hole wall. The arc-shaped hole wall has an arc on the axial end face perpendicular to the axial direction. The radius R4 of the circle containing the arc and the maximum radius R1 of the lamination body 110 satisfy the above-mentioned relationship, thereby associating the shape of the weight reduction hole 150 with the lamination body 110, making the size and shape selection of the weight reduction hole 150 more reasonable, thereby optimizing the overall structural arrangement of the rotor lamination 100 and helping to improve motor performance.

[0116] Furthermore, such as Figure 1 , Figure 2 and Figure 3 As shown, the weight reduction hole 150 has a third vertex and a fourth vertex opposite to each other. The third radial extension line passing through the center of the shaft hole 120 intersects or is tangent to the third vertex, and the fourth radial extension line passing through the center of the shaft hole 120 intersects or is tangent to the fourth vertex. The weight reduction hole 150 is located between the third radial extension line and the fourth radial extension line. The included angle θ between the third radial extension line and the fourth radial extension line and the included angle α between the adjacent interpole center lines satisfy 0.6≤θ / α≤0.8.

[0117] In this embodiment, the weight reduction hole 150 includes a third vertex and a fourth vertex, which are located at opposite ends of the weight reduction hole 150. The third vertex and the center of the shaft hole 120 are respectively located on the third radial extension line, and the fourth vertex and the center of the shaft hole 120 are respectively located on the fourth radial extension line. The angle formed by the third radial extension line and the fourth radial extension line is the central angle θ corresponding to the weight reduction hole 150. That is, the weight reduction hole 150 is completely located within the area formed by the third radial extension line and the fourth radial extension line. By limiting the ratio of the central angle α corresponding to each magnetic pole to the central angle θ corresponding to the weight reduction hole 150, the relative position of the weight reduction hole 150 in each magnetic pole can be determined, making the arrangement of the weight reduction hole 150 more reasonable, thereby helping to improve the motor performance.

[0118] Furthermore, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, the number of weight-reducing holes 150 is 4, 6, 8, 12, 16 or 20.

[0119] In this embodiment, the number of weight-reducing holes 150 is 4. Alternatively, the number of weight-reducing holes 150 is 6. Alternatively, the number of weight-reducing holes 150 is 8. Alternatively, the number of weight-reducing holes 150 is 12. Alternatively, the number of weight-reducing holes 150 is 16. Alternatively, the number of weight-reducing holes 150 is 20. Regardless of the number of weight-reducing holes 150, the weight-reducing holes 150 need to be located on the inter-pole centerline and / or the magnetic pole centerline.

[0120] For example, when the number of weight-reducing holes 150 is 16, the weight-reducing holes 150 include 8 first weight-reducing holes and 8 second weight-reducing holes. The 8 first weight-reducing holes are arranged circumferentially at intervals, and each first weight-reducing hole is located on the center line of each magnetic pole. The 8 second weight-reducing holes are arranged circumferentially at intervals, and can be located outside or inside the first weight-reducing holes. Each second weight-reducing hole is located on a center line between poles. The opening area of ​​the first weight-reducing holes is different from that of the second weight-reducing holes. For example, when the first weight-reducing holes are located away from the shaft hole 120 relative to the second weight-reducing holes, the opening area of ​​the first weight-reducing holes is larger than that of the second weight-reducing holes.

[0121] It should be noted that the shape of the first weight-reducing hole and the shape of the second weight-reducing hole may be the same or different.

[0122] In some embodiments of this application, the rotor lamination 100 further includes a rivet portion 140, which is disposed on the lamination body 110 and is located on the magnetic pole center line or the inter-pole center line of the lamination body 110.

[0123] In this embodiment, each lamination body 110 is further provided with a rivet portion 140. Multiple rotor laminations 100 are stacked axially to form a rotor core. The rivet portions 140 on adjacent rotor laminations 100 can be matched to connect the multiple rotor laminations 100 axially, thereby forming a complete rotor core. The weight-reducing hole 150 and the rivet portion 140 are independently formed on the lamination body 110 and do not interfere with each other. The weight-reducing hole 150 is located on the magnetic pole center line and / or the inter-pole center line. By providing the rivet portion 140 and the weight-reducing hole 150 on the lamination body 110, and by associating the positions of the rivet portion 140 and the weight-reducing hole 150 with the positions of the magnetic pole center line and the inter-pole center line, this application can improve the quality of the motor output torque while improving motor performance, improve magnetic leakage and suppress torque pulsation, achieve high power density and high efficiency, reduce rotational inertia and reduce motor weight.

[0124] It should be noted that, for the lamination body 110, there are multiple magnetic pole center lines and multiple inter-pole center lines. There are multiple rivet parts 140, with one rivet part 140 corresponding to one magnetic pole center line or one inter-pole center line.

[0125] Furthermore, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 10 As shown, the number of rivet portions 140 is half the number of permanent magnet slots 130; or, the number of rivet portions 140 is equal to the number of permanent magnet slots 130.

[0126] In this embodiment, the number of rivet portions 140 is related to the number of permanent magnet slots 130. The number of rivet portions 140 can be half the number of permanent magnet slots 130, or the number of rivet portions 140 can be equal to the number of permanent magnet slots 130. For example, when the number of permanent magnet slots 130 is 8, the number of rivet portions 140 can be 4 or 8. Regardless of whether the number of rivet portions 140 and the number of permanent magnet slots 130 are a multiple or equal, the rivet portions 140 need to be located on the inter-pole centerline and / or the magnetic pole centerline.

[0127] When multiple weight-reducing holes 150 and multiple rivet parts 140 are provided on the stamping body 110, the weight-reducing holes 150 and rivet parts 140 need to follow the principle of being arranged on the inter-pole center line and the magnetic pole center line. The weight-reducing holes 150 and rivet parts 140 are relatively independent and each forms its own reasonable arrangement position.

[0128] Furthermore, such as Figure 1 , Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, when the number of rivet parts 140 and the number of weight-reducing holes 150 are equal, the weight-reducing holes 150 and the rivet parts 140 are alternately arranged in the circumferential direction.

[0129] In this embodiment, when the number of rivet portions 140 and the number of weight-reducing holes 150 are equal—for example, both are half the number of permanent magnet slots 130—or when their numbers are the same as the number of permanent magnet slots 130, their arrangement follows an alternating pattern. Specifically, when there are four rivet portions 140 and four weight-reducing holes 150, the four rivet portions 140 and four weight-reducing holes 150 are arranged alternately, with the centers of the four rivet portions 140 and the centers of the four weight-reducing holes 150 located within the same circle. When there are eight rivet portions 140 and eight weight-reducing holes 150, one of the weight-reducing holes 150 and the rivet portion 140 is located on the magnetic pole centerline, and the other is located on the inter-pole centerline, with both forming concentric circles of different radii along the circumferential direction. The weight reduction hole 150 is located closer to the shaft hole 120 than the rivet part 140. This is because during the high-speed rotation of the rotor lamination 100, the centrifugal force on the outer periphery of the rotor lamination 100 is relatively large. Setting the rivet part 140 outward can better ensure that the rotor lamination 100 does not deform and improve the reliability of the structure.

[0130] According to an embodiment of the second aspect of this application, a rotor is provided, comprising rotor laminations 100 provided by any of the above designs.

[0131] The rotor provided in this application includes the rotor lamination 100 provided in any of the above designs, and therefore has all the beneficial effects of the rotor lamination 100, which will not be repeated here.

[0132] The rotor laminations 100 are multiple, and the multiple rotor laminations 100 are stacked along the axial direction to form a rotor core. The permanent magnet slots 130 of the multiple rotor laminations 100 are axially connected to form magnetic slots, and permanent magnets are inserted in the magnetic slots.

[0133] According to an embodiment of a third aspect of this application, an electric motor is provided, comprising a rotor provided by any of the above designs.

[0134] The motor provided in this application includes the rotor provided by any of the above designs, and therefore has all the beneficial effects of that rotor, which will not be repeated here.

[0135] It is worth noting that the motor is a permanent magnet motor.

[0136] According to an embodiment of the fourth aspect of this application, such as Figure 11 As shown, an electric power steering system 200 is provided, including a motor provided by any of the above designs.

[0137] The electric power steering system 200 provided in this application includes the motor provided by any of the above designs, and therefore has all the beneficial effects of the motor, which will not be repeated here.

[0138] It should be noted that Electric Power Steering (EPS) is a power steering system that directly relies on an electric motor to provide auxiliary torque. Compared with the traditional Hydraulic Power Steering (HPS) system, EPS has a simpler structure, is more flexible in assembly, saves energy, and protects the environment. Most modern vehicles are equipped with EPS systems.

[0139] Specifically, the EPS system of this embodiment includes a steering system and an auxiliary torque mechanism that generates auxiliary torque. The EPS system generates auxiliary torque, which assists the steering torque of the steering system generated by the driver operating the steering wheel. This auxiliary torque reduces the driver's workload.

[0140] The steering system specifically includes a steering wheel 211, a steering shaft 212, a universal coupling 213, a rotating shaft 214, a rack and pinion mechanism 215, a rack and pinion shaft 216, and left and right steering wheels 217, etc.

[0141] The auxiliary torque mechanism specifically includes a steering torque sensor 221, an automotive electronic control unit (ECU) 222, a motor, and a reduction gear 223. Specifically, the steering torque sensor 221 detects the steering torque of the steering system. The control unit 222 generates a drive signal based on the detection signal from the steering torque sensor 221. The motor generates an auxiliary torque corresponding to the steering torque based on the drive signal. The motor transmits the generated auxiliary torque to the steering system via the reduction gear 223.

[0142] According to an embodiment of the fifth aspect of this application, a vehicle is provided, including a rotor lamination 100, a rotor, a motor, or an electric power steering system provided by any of the above designs.

[0143] The vehicle provided in this application includes the rotor lamination 100, rotor, motor or electric power steering system provided by any of the above designs, and therefore has all the beneficial effects of the rotor lamination 100, rotor, motor or electric power steering system, which will not be repeated here.

[0144] It should be noted that the vehicles can be either traditional gasoline-powered vehicles or new energy vehicles. New energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid electric vehicles, fuel cell electric vehicles, and hydrogen engine vehicles.

[0145] In this application, the term "multiple" refers to two or more unless otherwise expressly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0146] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0147] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rotor lamination, characterized in that, include: A lamination body, wherein the lamination body is provided with a shaft hole; Multiple permanent magnet slots are spaced around the shaft hole on the lamination body; Each of the plurality of permanent magnet slots includes an interconnected permanent magnet segment and a magnetic isolation segment, wherein the permanent magnet segment is used to accommodate a permanent magnet; Multiple weight-reducing holes are provided on the lamination body, and the multiple weight-reducing holes are respectively located on the magnetic pole center line and / or the inter-pole center line of the lamination body; On the axial end face of the lamination body, there is a pole center line between adjacent permanent magnet slots in the plurality of permanent magnet slots; On the axial end face of the lamination body, the outer periphery of the portion of the lamination body located between adjacent inter-pole center lines includes an outer arc line. The outer arc line includes a first arc segment, a second arc segment, and a third arc segment. The second arc segment is connected to the first arc segment and the third arc segment, respectively. Wherein, the maximum radius R1 of the lamination body and the radius R2 of the circle containing the second arc segment satisfy: 0.3≤(R1-R2) / R1≤0.7; The weight-reducing hole has opposing third and fourth vertices. A third radial extension line passing through the center of the shaft hole intersects or is tangent to the third vertex, and a fourth radial extension line passing through the center of the shaft hole intersects or is tangent to the fourth vertex. The weight-reducing hole is located between the third and fourth radial extension lines. Wherein, the angle θ between the third radial extension line and the fourth radial extension line and the angle α between the adjacent interpole center lines satisfy the following conditions: 0.6≤θ / α≤0.

8.

2. The rotor lamination according to claim 1, characterized in that, The permanent magnet slot has a first vertex and a second vertex facing each other. A first radial extension line passing through the center of the shaft hole intersects or is tangent to the first vertex, and a second radial extension line passing through the center of the shaft hole intersects or is tangent to the second vertex. The permanent magnet slot is located between the first radial extension line and the second radial extension line. Wherein, the included angle α between adjacent interpolar centerlines and the included angle β between the first radial extension line and the second radial extension line satisfy the following conditions: 0.9≤β / α≤0.98。 3. The rotor lamination according to claim 2, characterized in that, The portion of the lamination body located between the magnetic isolation section and the outer periphery of the lamination body is a magnetic isolation bridge. The width W1 of the permanent magnet section and the width W2 of the magnetic isolation bridge are defined. The portion of the lamination body between adjacent permanent magnet slots in the plurality of permanent magnet slots is a magnetic rib. The minimum width W3 of the magnetic rib satisfies W2≤W3≤W1.

4. The rotor lamination according to claim 2, characterized in that, The permanent magnet segment includes opposing straight groove walls and bent groove walls, with the straight groove walls positioned away from the shaft hole relative to the bent groove walls.

5. The rotor lamination according to claim 1, characterized in that, The central angle γ corresponding to the second arc segment and the angle α between the adjacent interpolar center lines satisfy the following condition. 0.6≤γ / α≤0.

8.

6. The rotor lamination according to claim 1, characterized in that, The weight-reducing hole is located between the permanent magnet groove and the shaft hole, wherein the minimum distance W4 between the weight-reducing hole and the permanent magnet groove, the minimum distance W5 between the weight-reducing hole and the shaft hole, the maximum radius R1 of the lamination body, and the radius R3 of the shaft hole satisfy the following conditions: 0.4≤(W4+W5) / (R1-R3)≤0.

6.

7. The rotor lamination according to claim 6, characterized in that, The minimum distance W4 between the weight reduction hole and the permanent magnet groove, and the minimum distance W5 between the weight reduction hole and the shaft hole are satisfied. 0.8≤W4 / W5≤1.

2.

8. The rotor lamination according to claim 6, characterized in that, The weight-reducing hole includes an arc-shaped hole wall, which comprises a circular arc on the axial end face. The radius R4 of the circle containing the circular arc and the maximum radius R1 of the lamination body satisfy the following condition. 0.05≤R4 / R1≤0.

3.

9. The rotor lamination according to claim 1, characterized in that, The number of weight-reducing holes is 4, 6, 8, 12, 16 or 20.

10. The rotor lamination according to any one of claims 6 to 9, characterized in that, The rotor laminations also include: A rivet is provided on the lamination body, and the rivet is located on the magnetic pole center line or the inter-pole center line.

11. The rotor lamination according to claim 10, characterized in that, The number of the rivet portions is half the number of the permanent magnet slots; or The number of the rivet portions is equal to the number of the permanent magnet slots.

12. The rotor lamination according to claim 10, characterized in that, When the number of rivet portions and the number of weight-reducing holes are equal, the weight-reducing holes and the rivet portions are alternately arranged in the circumferential direction.

13. A rotor, characterized in that, include: The rotor lamination as described in any one of claims 1 to 12.

14. An electric motor, characterized in that, include: The rotor as described in claim 13.

15. An electric power steering system, characterized in that, include: The motor as described in claim 14.

16. A vehicle, characterized in that, include: Rotor laminations as described in any one of claims 1 to 12; or The rotor as described in claim 13; or The motor as described in claim 14; or The electric power steering system as described in claim 15.

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