Electric power steering motor, electric power steering system and vehicle

Abstract

The utility model provides an electric power steering motor, an electric power steering system and a vehicle. The electric power-assisted steering motor comprises a shell assembly, and a first bearing cavity and a second bearing cavity are formed in the shell assembly; the rotor core is located between the first bearing cavity and the second bearing cavity; the rotating shaft penetrates through the shaft hole; the first bearing is arranged in the first bearing cavity; the second bearing is arranged in the second bearing cavity, the first bearing and the second bearing are both in interference fit with the rotating shaft, and at least one of the first bearing and the second bearing is a four-point contact ball bearing; the first elastic part is abutted between one side, deviating from the rotor iron core, of the first bearing and the cavity wall of the first bearing cavity, and the first elastic part is used for applying axial pre-tightening force to the first bearing; the second elastic part abuts against the side, facing the rotor iron core, of the second bearing, and the second elastic part is used for limiting the axial displacement of the second bearing. And the rotating shaft is matched with the second elastic part, so that the vibration performance of the motor during operation is further improved.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to an electric power steering motor, an electric power steering system and a vehicle. Background Art

[0002] With the advancement of technology, new energy vehicles are accepted and sought after by more and more families. In the related technology, the structure of the motor of the new energy vehicle is unreasonable, the vibration noise of the motor is large, resulting in a large noise when the vehicle is running. Utility Model Content

[0003] The present application aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present application provides an electric power steering motor.

[0005] A second aspect of the present application provides an electric power steering system.

[0006] A third aspect of the present application provides a vehicle.

[0007] In view of this, the present application provides an electric power steering motor, comprising: a housing assembly, a first bearing cavity and a second bearing cavity are provided in the housing assembly; a rotor core, arranged in the housing assembly, the rotor core is located between the first bearing cavity and the second bearing cavity, the rotor core comprises a plurality of core segments, the plurality of core segments are stacked, any two adjacent core segments are staggered in a clockwise direction or in a counterclockwise direction, the rotor core is provided with an axial hole, the axial hole penetrates the plurality of core segments along the axial direction of the rotor core; a rotating shaft, which is passed through the axial hole; a first bearing, which is arranged in the first bearing cavity, and a first bearing sleeve is arranged on the rotating shaft ; The second bearing is arranged in the second bearing cavity, the second bearing sleeve is arranged on the rotating shaft, the first bearing and the second bearing are both interference fit with the rotating shaft, and at least one of the first bearing and the second bearing is a four-point contact ball bearing; the first elastic part is arranged around the rotating shaft, and the first elastic part abuts between the side of the first bearing away from the rotor core and the cavity wall of the first bearing cavity, and the first elastic part is used to apply axial preload to the first bearing; the second elastic part is arranged around the rotating shaft, the second elastic part abuts against the side of the second bearing facing the rotor core, and the second elastic part is used to limit the axial displacement of the second bearing.

[0008] An electric power steering motor provided by the present application includes a housing assembly, a rotor core, a rotating shaft, a first bearing, a second bearing, a first elastic part, and a second elastic part.

[0009] The rotor core includes a plurality of core segments stacked axially along the rotor core. Among them, any two adjacent core segments are arranged staggeredly in the clockwise direction, or any two adjacent core segments are arranged staggeredly in the counterclockwise direction. That is to say, any two adjacent core segments are arranged staggeredly in the circumferential direction of the rotor core to form a skewed pole of the rotor. The segmented modular setting of the rotor core has the advantages of being convenient for installation and maintenance, and skewed poles can be formed between multiple core segments.

[0010] Defining that any two adjacent core segments are arranged staggeredly in the clockwise direction or in the counterclockwise direction can reduce the cogging torque and torque ripple, thereby reducing the electromagnetic vibration. That is to say, by dividing the rotor core into multiple core segments and making any two adjacent core segments arranged staggeredly in the clockwise direction or in the counterclockwise direction, the specific harmonic content in the electric power steering motor can be effectively suppressed, the torque ripple and cogging torque of the electric power steering motor can be improved, and thus the vibration and noise of the electric power steering motor can be reduced.

[0011] Furthermore, the rotor core is provided with a shaft hole, the shaft hole axially penetrates through multiple core segments along the rotor core, a rotating shaft is inserted into the shaft hole, a first bearing is sleeved on the rotating shaft, a second bearing is sleeved on the rotating shaft, the first bearing is located outside the rotor core, and the second bearing is located outside the rotor core. Among them, at least one of the first bearing and the second bearing is a four-point contact ball bearing. That is to say, the first bearing is a four-point contact ball bearing, and / or the second bearing is a four-point contact ball bearing.

[0012] The four-point contact ball bearing can enhance the overall anti-deformation ability of the electric power steering motor, is beneficial to improving the structural stiffness of the electric power steering motor, can reduce the axial runout amount during the operation of the electric power steering motor. In this way, the vibration performance during the operation of the electric power steering motor is further improved, the vibration and noise of the electric power steering motor can be further reduced, and the service performance and market competitiveness of the electric power steering motor are greatly improved.

[0013] Optionally, when both the first bearing and the second bearing are four-point contact ball bearings, that is to say, four-point contact ball bearings are arranged on both axial sides of the rotor core. In this way, the cooperation area and cooperation angle between the first bearing, the second bearing and the rotating shaft are increased, the overall anti-deformation ability of the motor can be further enhanced, the structural stiffness of the electric power steering motor can be further improved, the axial runout amount during the operation of the electric power steering motor can be reduced. In this way, the vibration performance during the operation of the electric power steering motor is further improved, and the vibration and noise of the electric power steering motor can be further reduced.

[0014] After the motor is assembled, the first bearing is located between the first elastic part and the rotor core. The first elastic part abuts between the side of the first bearing facing away from the rotor core and the wall of the first bearing cavity. The first bearing is in interference fit with the rotating shaft. By squeezing the first elastic part, an axial preloading force is applied to the first bearing by the first elastic part to ensure the structural stiffness of the electric power steering motor, which is beneficial to reducing the axial movement amount during the operation of the electric power steering motor.

[0015] Wherein, the second elastic part is arranged around the rotating shaft. The second elastic part abuts against the side of the second bearing facing the rotor core. The second elastic part is used to limit the axial displacement of the second bearing. The second bearing is in interference fit with the rotating shaft.

[0016] The rotating shaft and the second elastic part cooperate to limit the second bearing axially, radially and circumferentially along the rotating shaft. To improve the structural stiffness of the electric power steering motor, the axial movement amount during the operation of the electric power steering motor can be reduced, and the overall anti-deformation ability of the electric power steering motor can be enhanced. In this way, the vibration performance during the operation of the electric power steering motor is further improved, the vibration noise of the electric power steering motor can be further reduced, and the service performance and market competitiveness of the electric power steering motor are greatly improved.

[0017] In addition, the rotating shaft and the second elastic part cooperate. This setting can reduce the influence on the radial clearance of the second bearing by riveting the outer peripheral wall of the second bearing through the convex part, and ensure the radial clearance of the second bearing. In this way, it is beneficial to reduce the frictional torque during the operation of the electric power steering motor. That is to say, this setting takes into account reducing the vibration noise of the electric power steering motor and reducing the frictional torque of the electric power steering motor, and improves the service performance and market competitiveness of the product.

[0018] According to the above-mentioned electric power steering motor of the present application, the following additional technical features may also be provided:

[0019] In some embodiments, optionally, when one of the first bearing and the second bearing is a four-point contact ball bearing, the second bearing is a four-point contact ball bearing.

[0020] In this embodiment, the structures of the first bearing and the second bearing are further defined.

[0021] So that when one of the first bearing and the second bearing is a four-point contact ball bearing, the second bearing is a four-point contact ball bearing and the first bearing is a non-four-point contact ball bearing.

[0022] In some embodiments, optionally, a card slot is further provided in the housing assembly. The card slot is located on the side of the second bearing cavity facing the rotor core, and the card slot communicates with the second bearing cavity; the second elastic part is arranged in the card slot.

[0023] In this embodiment, the matching structure between the second elastic portion and the housing assembly is further defined.

[0024] Specifically, a slot is further provided in the housing assembly, the slot is located on a side of the second bearing cavity facing the rotor core, and the slot is connected to the second bearing cavity.

[0025] The slot is used to install and fix the second elastic part. The second elastic part is arranged in the slot, the second elastic part is arranged around the rotating shaft, and the second elastic part abuts against the second bearing. The second elastic part is used to limit the second bearing along the axial direction of the rotating shaft to ensure the matching size of the second bearing and the rotating shaft. It is beneficial to improve the stability and reliability of the assembly of the rotating shaft and the second bearing, so as to enhance the overall anti-deformation ability of the electric power steering motor and reduce the friction torque of the electric power steering motor.

[0026] In some embodiments, optionally, along the axial direction of the rotating shaft, the width of the slot is smaller than the width of the second elastic portion.

[0027] In this embodiment, the matching structure of the clamping slot and the second elastic portion is further defined.

[0028] Specifically, along the axial direction of the shaft, the width of the slot is smaller than the width of the second elastic part. The second elastic part is interference fit with the slot, the second elastic part is squeezed, and the second elastic part is deformed by its own tightening to effectively limit the displacement of the second bearing in the axial direction of the shaft.

[0029] In some embodiments, optionally, a chamfer is provided on a side of the second elastic portion facing away from the second bearing, a matching bevel is provided on a portion where the slot and the chamfer are arranged opposite to each other, and the chamfer fits with the matching bevel.

[0030] In this embodiment, the matching structure between the second elastic portion and the slot is further defined.

[0031] Specifically, a chamfer is provided on a side of the second elastic portion facing away from the second bearing, a matching inclined surface is provided at a portion where the clamping groove and the chamfer are arranged opposite to each other, and the chamfer is fitted with the matching inclined surface.

[0032] When the second elastic part is assembled in the slot, the chamfer cooperates with the matching inclined surface to play a guiding role, so that the second elastic part can be smoothly interference fit in the slot, which not only meets the use requirements of the second elastic part and the slot interference fit, but also reduces the difficulty of assembling the second elastic part.

[0033] In some embodiments, optionally, along the radial direction of the rotating shaft, the maximum value of the width of the second bearing cavity is recorded as d1, and the maximum value of the width of the slot is recorded as d2; on the cross-section of the electric power steering motor, the angle between the contour line of the matching inclined surface and the outer contour line of the axial end face of the second elastic part is recorded as a, and the cross-section of the motor passes through the axis of the rotating shaft; wherein, 1.02≤d2 / d1≤1.79, 0°<a≤82°.

[0034] In this embodiment, the structure of the housing assembly is further defined.

[0035] Specifically, the second bearing cavity is used to accommodate the second bearing, and the card slot is used to accommodate the second elastic part. Along the radial direction of the rotating shaft, the maximum value of the width of the second bearing cavity is denoted as d1, and the maximum value of the width of the card slot is denoted as d2. On the cross-section of the electric power steering motor, the included angle between the contour line of the mating inclined plane and the outer contour line of the axial end face of the second elastic part is denoted as a.

[0036] Among them, 1.02 ≤ d2 / d1 ≤ 1.79, 0° < a ≤ 82°. This setting can ensure that the second elastic part is effectively installed in the card slot and can ensure that the second elastic part can effectively limit the axial displacement of the second bearing.

[0037] In some embodiments, optionally, along the radial direction of the rotating shaft, the maximum value d1 of the width of the second bearing cavity, the maximum value d2 of the width of the card slot, and the axial clearance δ of the second bearing satisfy: 0 ≤ (2×δ) / (d2 - d1) ≤ 0.5.

[0038] In this embodiment, the mating structure of the housing assembly and the second bearing is further defined.

[0039] Specifically, along the radial direction of the rotating shaft, the maximum value of the width of the second bearing cavity is denoted as d1. Along the radial direction of the rotating shaft, the maximum value of the width of the card slot is denoted as d2. The axial clearance of the second bearing is denoted as δ.

[0040] Among them, d1, d2, and δ satisfy 0 ≤ (2×δ) / (d2 - d1) ≤ 0.5. This setting can reduce the 24th-order noise of the electric power steering motor, which is beneficial to improving the use performance and market competitiveness of the electric power steering motor.

[0041] Optionally, (2×δ) / (d2 - d1) = 0.1, (2×δ) / (d2 - d1) = 0.2, (2×δ) / (d2 - d1) = 0.3, and (2×δ) / (d2 - d1) = 0.4, etc., which are not listed one by one here.

[0042] In some embodiments, optionally, the housing assembly includes: a housing; an end cover, along the axial direction of the rotating shaft, the end cover is connected to one side of the housing, and one of the housing and the end cover is provided with a first bearing cavity, and the other of the housing and the end cover is provided with a second bearing cavity.

[0043] In this embodiment, the housing assembly includes a housing and an end cover. Along the axial direction of the rotating shaft, the end cover is connected to one side of the housing.

[0044] Among them, one of the housing and the end cover is provided with a first bearing cavity, and the other of the housing and the end cover is provided with a second bearing cavity. That is, the housing is provided with a first bearing cavity, the end cover is provided with a second bearing cavity, the first bearing is provided in the housing, and the second bearing is provided in the end cover. The first elastic part is arranged around the rotating shaft, and the first elastic part abuts between the side of the first bearing away from the rotor core and the cavity wall of the first bearing cavity, and the first elastic part is used to apply an axial preload force to the first bearing. The second elastic part is arranged around the rotating shaft, and the second elastic part abuts against the side of the second bearing facing the rotor core, and the second elastic part is used to limit the axial displacement of the second bearing.

[0045] Among them, one of the housing and the end cover is provided with a first bearing cavity, and the other of the housing and the end cover is provided with a second bearing cavity. That is, the housing is provided with a second bearing cavity, the end cover is provided with a first bearing cavity, the first bearing is provided on the end cover, and the second bearing is provided on the housing. The first elastic part is arranged around the rotating shaft, and the first elastic part abuts between the side of the first bearing away from the rotor core and the cavity wall of the first bearing cavity, and the first elastic part is used to apply an axial preload force to the first bearing. The second elastic part is arranged around the rotating shaft, and the second elastic part abuts against the side of the second bearing facing the rotor core, and the second elastic part is used to limit the axial displacement of the second bearing.

[0046] In some embodiments, optionally, the rotor core is also provided with a plurality of magnet slots, which are arranged at intervals along the circumference of the rotating shaft, and the magnet slots are located between the shaft hole and the outer peripheral wall of the rotor core; the electric power steering motor also includes a plurality of permanent magnets, each of which is arranged in a magnet slot.

[0047] In this embodiment, the specific structure of the electric power steering motor is further defined.

[0048] A portion of the rotor core located between the shaft hole and the outer peripheral wall of the rotor core is provided with a plurality of magnet slots, and the plurality of magnet slots are arranged at intervals along the circumferential direction of the rotating shaft.

[0049] The electric power steering motor further comprises a plurality of permanent magnets, each of which is arranged in a magnet slot. That is, the plurality of permanent magnets are arranged in the rotor core, and the plurality of permanent magnets are arranged at intervals along the circumferential direction of the rotating shaft. The permanent magnets are located between the shaft hole and the outer peripheral wall of the rotor core.

[0050] In some embodiments, optionally, along the axial direction of the rotating shaft, the length of the permanent magnet is less than or equal to the length of the core segment.

[0051] In this embodiment, the matching structure of the rotor core and the permanent magnet is further defined.

[0052] Specifically, along the axial direction of the rotating shaft, the length of the permanent magnet is less than or equal to the length of the core segment.

[0053] The iron core segment serves to protect the permanent magnet, thus reducing the probability of squeezing the permanent magnet and consequently damaging the permanent magnet.

[0054] If, along the axial direction of the rotating shaft, the length of the permanent magnet is greater than the length of the iron core segment, then it is likely that a part of the permanent magnet protrudes from the iron core segment. This arrangement is prone to the situation where the permanent magnet is squeezed and damaged, and the service performance of the motor cannot be guaranteed.

[0055] In some embodiments, optionally, the rotor core is further provided with a plurality of weight-reducing holes, which are arranged at intervals along the circumferential direction of the rotating shaft. The weight-reducing holes are located between the rotating shaft and the permanent magnet; the number of weight-reducing holes is greater than or equal to the number of pole pairs of the electric power steering motor.

[0056] In this embodiment, the structure of the rotor core is further defined such that the rotor core is provided with a plurality of weight-reducing holes, which are arranged at intervals around the circumferential direction of the rotating shaft. The weight-reducing holes are located between the rotating shaft and the permanent magnet. The weight-reducing holes serve to reduce the overall weight of the motor.

[0057] In addition, any two adjacent iron core segments are arranged offset in the clockwise or counterclockwise direction, that is, any two adjacent iron core segments are arranged offset in the circumferential direction of the rotor core to form a skewed pole of the rotor. The weight-reducing holes can be used as a positioning basis to assemble the rotor core, providing a reliable structural support for ensuring the formation of the skewed pole of the rotor.

[0058] Furthermore, the number of weight-reducing holes is greater than or equal to the number of pole pairs of the electric power steering motor, and the plurality of weight-reducing holes are arranged at intervals along the circumferential direction of the rotating shaft. In this way, when assembling the rotor core, the plurality of iron core segments can be positioned from multiple directions and angles, and the fitting accuracy of the plurality of iron core segments can be ensured.

[0059] Optionally, the number of weight-reducing holes is equal to the number of pole pairs of the electric power steering motor.

[0060] Optionally, weight-reducing holes are provided on the magnetic pole center line and / or the inter-pole center line of the rotor core. To reduce the moment of inertia and the overall weight of the electric power steering motor while ensuring that the service performance of the electric power steering motor is not affected.

[0061] In some embodiments, optionally, at least a part of the hole wall of the shaft hole is in interference fit with the rotating shaft.

[0062] In this embodiment, the fitting structure of the rotor core and the rotating shaft is defined.

[0063] At least a part of the hole wall of the shaft hole is in interference fit with the rotating shaft. That is, a part of the hole wall of the shaft hole is in interference fit with the rotating shaft. Or the entire hole wall of the shaft hole is in interference fit with the rotating shaft.

[0064] This setting can ensure the mating structure between the rotating shaft and the rotor core, avoiding the separation of the rotating shaft and the rotor core.

[0065] When a part of the hole wall of the shaft hole is in interference fit with the rotating shaft, the contact area between the shaft hole and the rotating shaft can be reduced. That is, while ensuring the service requirement of the interference fit between the rotating shaft and the shaft hole, the radial force formed by the interference fit between the shaft hole and the rotating shaft can also be reduced due to the reduction of the contact area between the shaft hole and the rotating shaft. This can reduce the influence of this radial force on the bonding force between the laminations of the rotor core, which is beneficial to reducing the probability of deformation of the laminations of the rotor core and can further reduce the probability of loosening of multiple laminations of the rotor core.

[0066] Optionally, the hole wall of the shaft hole is a concave-convex wall. The protrusions of the concave-convex wall are in interference fit with the rotating shaft, and the depressions of the concave-convex wall are arranged separately from the rotating shaft. The protrusions and depressions of the concave-convex wall are arranged alternately, and both the protrusions and the depressions extend along the axial direction of the rotating shaft.

[0067] In some embodiments, optionally, the axial clearance of the second bearing is less than or equal to 0.1 mm.

[0068] In this embodiment, the value range of the axial clearance of the second bearing is further limited so that the axial clearance of the second bearing is less than or equal to 0.1 mm. In this way, the axial vibration of the electric power steering motor can be further optimized to further optimize the vibration noise of the electric power steering motor.

[0069] It can be understood that when there is no load, the inner ring of the second bearing is fixed, and the displacement of the outer ring of the second bearing relative to the fixed inner ring from one extreme position to another extreme position along the axial direction of the rotor core is denoted as the axial clearance of the second bearing.

[0070] The second aspect of the present invention provides an electric power steering system, including: the electric power steering motor as in the first aspect.

[0071] The electric power steering system provided by the present invention includes the electric power steering motor as in the first aspect, so it has all the beneficial effects of the above-mentioned electric power steering motor and will not be elaborated one by one here.

[0072] The third aspect of the present invention provides a vehicle, including: the electric power steering motor as in the first aspect; or the electric power steering system as in the second aspect.

[0073] The vehicle provided by the present invention includes the electric power steering motor as in the first aspect or the electric power steering system as in the second aspect, so it has all the beneficial effects of the above-mentioned electric power steering motor or electric power steering system and will not be elaborated one by one here.

[0074] It should be noted that the vehicle can be a new energy vehicle. New energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid electric vehicles, fuel cell electric vehicles, hydrogen engine vehicles, etc.

[0075] The vehicle can also be a fuel vehicle.

[0076] The additional aspects and advantages of the present application will become apparent in the following description section or be learned through the practice of the present application. Description of the Drawings

[0077] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0078] Figure 1 A schematic structural diagram of the first part of an electric power steering motor according to an embodiment of the present application is shown;

[0079] Figure 2 An exploded view of the first part of an electric power steering motor according to an embodiment of the present application is shown;

[0080] Figure 3 An exploded view of the second part of an electric power steering motor according to an embodiment of the present application is shown;

[0081] Figure 4 A schematic structural diagram of a housing, a first bearing, and a first elastic part according to an embodiment of the present application is shown;

[0082] Figure 5 A schematic structural diagram of an end cover, a second bearing, and a second elastic part according to the first embodiment of the present application is shown;

[0083] Figure 6 A schematic structural diagram of an end cover according to the first embodiment of the present application is shown;

[0084] Figure 7 A partial schematic structural diagram of an end cover, a second bearing, and a second elastic part according to the first embodiment of the present application is shown;

[0085] Figure 8 A schematic structural diagram of a second bearing according to an embodiment of the present application is shown;

[0086] Figure 9 A schematic structural diagram of the third part of an electric power steering motor according to an embodiment of the present application is shown;

[0087] Figure 10 A schematic structural diagram of the fourth part of an electric power steering motor according to an embodiment of the present application is shown;

[0088] Figure 11Shows a schematic diagram of the fifth part of the structure of an electric power steering motor according to an embodiment of the present application;

[0089] Figure 12 Shows a schematic diagram of the ratio of the 24th-order noise of the motor of the present application to the motor in the related art.

[0090] Wherein, Figures 1 to 12 The corresponding relationship between the reference numerals and the component names in is:

[0091] 10 Electric power steering motor, 100 Housing assembly, 110 First bearing cavity, 120 Second bearing cavity, 130 Card slot, 132 Matching inclined surface, 140 Housing, 150 End cover, 200 Rotor core, 210 Core segment, 220 Shaft hole, 230 Magnet slot, 240 Weight reduction hole, 300 Rotating shaft, 400 First bearing, 500 Second bearing, 510 Chamfer, 600 First elastic part, 700 Second elastic part, 800 Permanent magnet. Detailed implementation manners

[0092] In order to be able to more clearly understand the above-mentioned objects, features and advantages of the present application, the present application will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0093] In the following description, many specific details are set forth in order to fully understand the present application. However, the present application can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0094] Next, refer to Figures 1 to 12 Describe an electric power steering motor 10, an electric power steering system and a vehicle according to some embodiments of the present application.

[0095] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 7 , Figure 8 , Figure 9 , Figure 10 And Figure 11 As shown, an electric power steering motor 10 according to some embodiments of the present application includes a housing assembly 100, a rotor core 200, a rotating shaft 300, a first bearing 400, a second bearing 500, a first elastic part 600 and a second elastic part 700.

[0096] The housing assembly 100 is provided with a first bearing cavity 110 and a second bearing cavity 120 therein.

[0097] The rotor core 200 is disposed in the housing assembly 100 .

[0098] The rotor core 200 is located between the first bearing cavity 110 and the second bearing cavity 120 .

[0099] The rotor core 200 includes a plurality of core segments 210 .

[0100] A plurality of core segments 210 are stacked.

[0101] Any two adjacent core segments 210 are staggered in a clockwise direction or a counterclockwise direction.

[0102] The rotor core 200 is provided with a shaft hole 220 .

[0103] The shaft hole 220 penetrates the plurality of core segments 210 along the axial direction of the rotor core 200 .

[0104] The rotating shaft 300 passes through the shaft hole 220 .

[0105] The first bearing 400 is disposed in the first bearing cavity 110 .

[0106] The first bearing 400 is sleeved on the rotating shaft 300 .

[0107] The second bearing 500 is disposed in the second bearing cavity 120 .

[0108] The second bearing 500 is sleeved on the rotating shaft 300 .

[0109] The first bearing 400 and the second bearing 500 are both interference fit with the rotating shaft 300 .

[0110] At least one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing.

[0111] The first elastic portion 600 is disposed around the rotating shaft 300 , and the first elastic portion 600 abuts between a side of the first bearing 400 facing away from the rotor core 200 and a cavity wall of the first bearing cavity 110 .

[0112] The first elastic portion 600 is used to apply an axial preload force to the first bearing 400 .

[0113] The second elastic portion 700 is disposed around the rotating shaft 300 , and the second elastic portion 700 abuts against a side of the second bearing 500 facing the rotor core 200 .

[0114] The second elastic portion 700 is used to limit the axial displacement of the second bearing 500 .

[0115] The present application provides an electric power steering motor 10 including a housing assembly 100 , a rotor core 200 , a rotating shaft 300 , a first bearing 400 , a second bearing 500 , a first elastic portion 600 , and a second elastic portion 700 .

[0116] The rotor core 200 includes a plurality of core segments 210 stacked axially along the rotor core 200. Among them, any two adjacent core segments 210 are arranged staggeredly in the clockwise direction, or any two adjacent core segments 210 are arranged staggeredly in the counterclockwise direction. That is to say, any two adjacent core segments 210 are arranged staggeredly in the circumferential direction of the rotor core 200 to form a skewed pole of the rotor. The segmented modular setting of the rotor core 200 has the advantages of being convenient for installation and maintenance, and skewed poles can be formed between the plurality of core segments 210.

[0117] Defining that any two adjacent core segments 210 are arranged staggeredly in the clockwise direction or in the counterclockwise direction can reduce the cogging torque and torque ripple, thereby reducing the electromagnetic vibration. That is to say, by dividing the rotor core 200 into a plurality of core segments 210 and arranging any two adjacent core segments 210 staggeredly in the clockwise direction or in the counterclockwise direction, the specific harmonic content in the electric power steering motor 10 can be effectively suppressed, the torque ripple and cogging torque of the electric power steering motor 10 can be improved, and thus the vibration and noise of the electric power steering motor 10 can be reduced.

[0118] Furthermore, the rotor core 200 is provided with a shaft hole 220. The shaft hole 220 axially penetrates through a plurality of core segments 210 along the rotor core 200. The rotating shaft 300 is inserted into the shaft hole 220. The first bearing 400 is sleeved on the rotating shaft 300. The second bearing 500 is sleeved on the rotating shaft 300. The first bearing 400 is located outside the rotor core 200. The second bearing 500 is located outside the rotor core 200. Among them, at least one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing. That is to say, the first bearing 400 is a four-point contact ball bearing, and / or the second bearing 500 is a four-point contact ball bearing.

[0119] The four-point contact ball bearing can enhance the overall anti-deformation ability of the electric power steering motor 10, is beneficial to improving the structural stiffness of the electric power steering motor 10, and can reduce the axial end play when the electric power steering motor 10 is working. In this way, the vibration performance of the electric power steering motor 10 during operation is further improved, the vibration and noise of the electric power steering motor 10 can be further reduced, and the service performance and market competitiveness of the electric power steering motor 10 are greatly improved.

[0120] Optionally, when both the first bearing 400 and the second bearing 500 are four-point contact ball bearings, that is, four-point contact ball bearings are provided on both axial sides of the rotor core 200. In this way, the mating area and mating angle between the first bearing 400, the second bearing 500 and the rotating shaft 300 are increased, which can further enhance the overall anti-deformation ability of the motor, can further improve the structural stiffness of the electric power steering motor 10, can reduce the axial end play when the electric power steering motor 10 is working. In this way, the vibration performance during the operation of the electric power steering motor 10 is further improved, and the vibration noise of the electric power steering motor 10 can be further reduced.

[0121] Among them, after the motor is assembled, the first bearing 400 is located between the first elastic part 600 and the rotor core 200. The first elastic part 600 abuts between the side of the first bearing 400 facing away from the rotor core 200 and the wall of the first bearing cavity 110. The first bearing 400 is in interference fit with the rotating shaft 300. By squeezing the first elastic part 600, the first elastic part 600 applies an axial pre-tightening force to the first bearing 400 to ensure the structural stiffness of the electric power steering motor 10 and is beneficial to reducing the axial end play when the electric power steering motor 10 is working.

[0122] Among them, the second elastic part 700 is arranged around the rotating shaft 300. The second elastic part 700 abuts on the side of the second bearing 500 facing the rotor core 200. The second elastic part 700 is used to limit the axial displacement of the second bearing 500. The second bearing 500 is in interference fit with the rotating shaft 300.

[0123] The rotating shaft 300 and the second elastic part 700 cooperate to limit the second bearing 500 axially, radially and circumferentially along the rotating shaft 300. To improve the structural stiffness of the electric power steering motor 10, the axial end play when the electric power steering motor 10 is working can be reduced, and the overall anti-deformation ability of the electric power steering motor 10 can be enhanced. In this way, the vibration performance during the operation of the electric power steering motor 10 is further improved, the vibration noise of the electric power steering motor 10 can be further reduced, and the service performance and market competitiveness of the electric power steering motor 10 are greatly improved.

[0124] In addition, the rotating shaft 300 and the second elastic part 700 cooperate. This setting can reduce the influence on the radial clearance of the second bearing 500 by riveting the convex part on the outer peripheral wall of the second bearing 500, and ensure the radial clearance of the second bearing 500. In this way, it is beneficial to reduce the frictional torque when the electric power steering motor 10 is running. That is to say, this setting takes into account reducing the vibration noise of the electric power steering motor 10 and reducing the frictional torque of the electric power steering motor 10, and improves the service performance and market competitiveness of the product.

[0125] Optionally, the first elastic part 600 includes a wave washer, a spring, a torsion spring, a tension spring, etc., which are not listed one by one here.

[0126] Optionally, the second elastic part 700 includes a spring, a torsion spring, a tension spring, etc., which are not listed one by one here.

[0127] It can be understood that when there is no load, the inner ring of the second bearing 500 is fixed, and the displacement of the outer ring of the second bearing 500 relative to the fixed inner ring from one extreme position to another extreme position along the radial direction of the rotor core 200 is denoted as the radial clearance of the second bearing 500.

[0128] It can be understood that when there is no load, the inner ring of the first bearing 400 is fixed, and the displacement of the outer ring of the first bearing 400 relative to the fixed inner ring from one extreme position to another extreme position along the axial direction of the rotor core 200 is denoted as the axial clearance of the first bearing 400. Or, when there is no load, the outer ring of the first bearing 400 is fixed, and the displacement of the inner ring of the first bearing 400 relative to the fixed outer ring from one extreme position to another extreme position along the axial direction of the rotor core 200 is denoted as the axial clearance of the first bearing 400.

[0129] In some embodiments, optionally, when one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing, the second bearing 500 is a four-point contact ball bearing.

[0130] In this embodiment, the structures of the first bearing 400 and the second bearing 500 are further defined.

[0131] So that when one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing, the second bearing 500 is a four-point contact ball bearing and the first bearing 400 is a non-four-point contact ball bearing.

[0132] In some embodiments, optionally, as Figure 5 and Figure 6 shown, a clamping groove 130 is further provided in the housing assembly 100.

[0133] The clamping groove 130 is located on the side of the second bearing cavity 120 facing the rotor core 200.

[0134] The clamping groove 130 communicates with the second bearing cavity 120.

[0135] The second elastic part 700 is arranged in the clamping groove 130.

[0136] In this embodiment, the mating structure of the second elastic part 700 and the housing assembly 100 is further defined.

[0137] Specifically, a clamping groove 130 is further provided inside the housing assembly 100. The clamping groove 130 is located on the side of the second bearing cavity 120 facing the rotor core 200, and the clamping groove 130 communicates with the second bearing cavity 120.

[0138] The clamping groove 130 is used for installing and fixing the second elastic part 700. The second elastic part 700 is arranged in the clamping groove 130, the second elastic part 700 is arranged around the rotating shaft 300, and the second elastic part 700 abuts against the second bearing 500. The second elastic part 700 is used for axially limiting the second bearing 500 along the rotating shaft 300 to ensure the matching dimensions of the second bearing 500 and the rotating shaft 300. It is beneficial to improve the stability and reliability of the assembly of the rotating shaft 300 and the second bearing 500, enhance the overall anti-deformation ability of the electric power steering motor 10, and reduce the frictional torque of the electric power steering motor 10.

[0139] In some embodiments, optionally, along the axial direction of the rotating shaft 300, the width of the clamping groove 130 is smaller than the width of the second elastic part 700.

[0140] In this embodiment, the matching structure of the clamping groove 130 and the second elastic part 700 is further defined.

[0141] Specifically, along the axial direction of the rotating shaft 300, the width of the clamping groove 130 is smaller than the width of the second elastic part 700. The second elastic part 700 is in interference fit with the clamping groove 130, and the second elastic part 700 is extruded. Through the tightening deformation of the second elastic part 700 itself, the displacement of the second bearing 500 in the axial direction of the rotating shaft 300 is effectively restricted.

[0142] In some embodiments, optionally, as Figure 7 shown, a chamfer 510 is provided on the side of the second elastic part 700 facing away from the second bearing 500.

[0143] A mating inclined surface 132 is provided on the part of the clamping groove 130 opposite to the chamfer 510.

[0144] The chamfer 510 is in contact with the mating inclined surface 132.

[0145] In this embodiment, the matching structure of the second elastic part 700 and the clamping groove 130 is further defined.

[0146] Specifically, a chamfer 510 is provided on the side of the second elastic part 700 facing away from the second bearing 500. A mating inclined surface 132 is provided on the part of the clamping groove 130 opposite to the chamfer 510, and the chamfer 510 is in contact with the mating inclined surface 132.

[0147] When the second elastic part 700 is assembled in the card slot 130, the chamfer 510 cooperates with the mating inclined surface 132 to play a guiding role, enabling the second elastic part 700 to be smoothly press-fitted into the card slot 130. This not only meets the use requirement of the interference fit between the second elastic part 700 and the card slot 130 but also reduces the assembly difficulty of the second elastic part 700.

[0148] In some embodiments, optionally, as Figure 6 and Figure 7 shown, along the radial direction of the rotating shaft 300, the maximum value of the width of the second bearing cavity 120 is denoted as d1.

[0149] Along the radial direction of the rotating shaft 300, the maximum value of the width of the card slot 130 is denoted as d2.

[0150] On the cross-section of the electric power steering motor 10, the included angle between the contour line of the mating inclined surface 132 and the outer contour line of the axial end face of the second elastic part 700 is denoted as a, and the cross-section of the motor passes through the axis of the rotating shaft 300.

[0151] Among them, 1.02 ≤ d2 / d1 ≤ 1.79, 0° < a ≤ 82°.

[0152] In this embodiment, the structure of the housing assembly 100 is further defined.

[0153] Specifically, the second bearing cavity 120 is used to accommodate the second bearing 500, and the card slot 130 is used to accommodate the second elastic part 700. Along the radial direction of the rotating shaft 300, the maximum value of the width of the second bearing cavity 120 is denoted as d1, and the maximum value of the width of the card slot 130 is denoted as d2. On the cross-section of the electric power steering motor 10, the included angle between the contour line of the mating inclined surface 132 and the outer contour line of the axial end face of the second elastic part 700 is denoted as a.

[0154] Among them, 1.02 ≤ d2 / d1 ≤ 1.79, 0° < a ≤ 82°. This setting can ensure that the second elastic part 700 is effectively installed in the card slot 130 and can effectively limit the axial displacement of the second bearing 500.

[0155] In some embodiments, optionally, as Figure 6 shown, along the radial direction of the rotating shaft 300, the maximum value d1 of the width of the second bearing cavity 120, the maximum value d2 of the width of the card slot 130, and the axial clearance δ of the second bearing 500 satisfy: 0 ≤ (2×δ) / (d2 - d1) ≤ 0.5.

[0156] In this embodiment, the mating structure of the housing assembly 100 and the second bearing 500 is further defined.

[0157] Specifically, along the radial direction of the rotating shaft 300, the maximum value of the width of the second bearing cavity 120 is recorded as d1. Along the radial direction of the rotating shaft 300, the maximum value of the width of the clamping groove 130 is recorded as d2. The axial clearance of the second bearing 500 is recorded as δ.

[0158] Among them, d1, d2 and δ satisfy 0≤(2×δ) / (d2-d1)≤0.5. This setting can reduce the 24th order noise of the electric power steering motor 10, which is beneficial to improving the performance and market competitiveness of the electric power steering motor 10.

[0159] Optionally, (2×δ) / (d2-d1)=0.1, (2×δ) / (d2-d1)=0.2, (2×δ) / (d2-d1)=0.3 and (2×δ) / (d2-d1)=0.4, etc., which are not listed here one by one.

[0160] In some embodiments, optionally, Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the housing assembly 100 includes a housing 140 and an end cover 150 .

[0161] The end cover 150 is connected to one side of the housing 140 along the axial direction of the rotating shaft 300 .

[0162] One of the housing 140 and the end cover 150 is provided with a first bearing cavity 110 .

[0163] The other of the housing 140 and the end cover 150 is provided with a second bearing cavity 120 .

[0164] In this embodiment, the housing assembly 100 includes a housing 140 and an end cover 150. The end cover 150 is connected to one side of the housing 140 along the axial direction of the rotating shaft 300.

[0165] Among them, one of the housing 140 and the end cover 150 is provided with a first bearing cavity 110, and the other of the housing 140 and the end cover 150 is provided with a second bearing cavity 120. That is, the housing 140 is provided with a first bearing cavity 110, the end cover 150 is provided with a second bearing cavity 120, the first bearing 400 is provided in the housing 140, and the second bearing 500 is provided in the end cover 150. The first elastic part 600 is arranged around the rotating shaft 300, and the first elastic part 600 abuts between the side of the first bearing 400 away from the rotor core 200 and the cavity wall of the first bearing cavity 110, and the first elastic part 600 is used to apply an axial preload force to the first bearing 400. The second elastic part 700 is arranged around the rotating shaft 300, and the second elastic part 700 abuts against the side of the second bearing 500 facing the rotor core 200, and the second elastic part 700 is used to limit the axial displacement of the second bearing 500.

[0166] Among them, one of the housing 140 and the end cover 150 is provided with a first bearing cavity 110, and the other of the housing 140 and the end cover 150 is provided with a second bearing cavity 120. That is, the housing 140 is provided with the second bearing cavity 120, the end cover 150 is provided with the first bearing cavity 110, the first bearing 400 is provided on the end cover 150, and the second bearing 500 is provided on the housing 140. The first elastic part 600 is arranged around the rotating shaft 300, and the first elastic part 600 abuts between the side of the first bearing 400 away from the rotor core 200 and the cavity wall of the first bearing cavity 110, and the first elastic part 600 is used to apply an axial preload force to the first bearing 400. The second elastic part 700 is arranged around the rotating shaft 300, and the second elastic part 700 abuts against the side of the second bearing 500 facing the rotor core 200, and the second elastic part 700 is used to limit the axial displacement of the second bearing 500.

[0167] In some embodiments, optionally, Figure 2 and Figure 3 As shown, the rotor core 200 is further provided with a plurality of magnet slots 230 .

[0168] The plurality of magnet slots 230 are arranged at intervals along the circumferential direction of the rotating shaft 300 .

[0169] The magnet slot 230 is located between the shaft hole 220 and the outer peripheral wall of the rotor core 200 .

[0170] The electric power steering motor 10 further includes a plurality of permanent magnets 800 .

[0171] Each permanent magnet 800 is disposed in a magnet slot 230 .

[0172] In this embodiment, the specific structure of the electric power steering motor 10 is further defined.

[0173] A portion of the rotor core 200 between the shaft hole 220 and the outer peripheral wall of the rotor core 200 is provided with a plurality of magnet slots 230 , and the plurality of magnet slots 230 are arranged at intervals along the circumferential direction of the rotating shaft 300 .

[0174] The electric power steering motor 10 further includes a plurality of permanent magnets 800, each of which is disposed in one magnet slot 230. That is, the plurality of permanent magnets 800 are disposed in the rotor core 200, and the plurality of permanent magnets 800 are arranged at intervals along the circumferential direction of the rotating shaft 300. The permanent magnets 800 are located between the shaft hole 220 and the outer peripheral wall of the rotor core 200.

[0175] In some embodiments, optionally, along the axial direction of the rotating shaft 300 , the length of the permanent magnet 800 is less than or equal to the length of the core segment 210 .

[0176] In this embodiment, the matching structure of the rotor core 200 and the permanent magnet 800 is further defined.

[0177] Specifically, along the axial direction of the rotating shaft 300, the length of the permanent magnet 800 is less than or equal to the length of the iron core segment 210.

[0178] The iron core segment 210 functions to protect the permanent magnet 800, thereby reducing the probability of the permanent magnet 800 being damaged due to extrusion.

[0179] If the length of the permanent magnet 800 is greater than the length of the iron core segment 210 along the axial direction of the rotating shaft 300, then a part of the permanent magnet 800 is likely to protrude from the iron core segment 210. This setting is likely to cause the permanent magnet 800 to be damaged due to extrusion, and the service performance of the motor cannot be guaranteed.

[0180] In some embodiments, optionally, as Figure 2 and Figure 3 shown, the rotor core 200 is further provided with a plurality of weight-reducing holes 240.

[0181] The plurality of weight-reducing holes 240 are arranged at intervals along the circumferential direction of the rotating shaft 300.

[0182] The weight-reducing holes 240 are located between the rotating shaft 300 and the permanent magnet 800.

[0183] The number of the weight-reducing holes 240 is greater than or equal to the number of pole pairs of the electric power steering motor 10.

[0184] In this embodiment, the structure of the rotor core 200 is further defined such that the rotor core 200 is provided with a plurality of weight-reducing holes 240, the plurality of weight-reducing holes 240 are arranged at intervals along the circumferential direction of the rotating shaft 300, and the weight-reducing holes 240 are located between the rotating shaft 300 and the permanent magnet 800. The weight-reducing holes 240 function to reduce the overall weight of the motor.

[0185] In addition, any two adjacent iron core segments 210 are arranged in a staggered manner in the clockwise or counterclockwise direction, that is, any two adjacent iron core segments 210 are arranged in a staggered manner in the circumferential direction of the rotor core 200 to form a skewed pole of the rotor. The weight-reducing holes 240 can be used as a positioning basis to assemble the rotor core 200, providing a reliable structural support for ensuring the formation of the skewed pole of the rotor.

[0186] Furthermore, the number of the weight-reducing holes 240 is greater than or equal to the number of pole pairs of the electric power steering motor 10, and the plurality of weight-reducing holes 240 are arranged at intervals along the circumferential direction of the rotating shaft 300. In this way, when assembling the rotor core 200, the plurality of iron core segments 210 can be positioned from multiple directions and multiple angles, and the matching accuracy of the plurality of iron core segments 210 can be ensured.

[0187] Optionally, the number of the weight-reducing holes 240 is equal to the number of pole pairs of the electric power steering motor 10.

[0188] Optionally, weight-reducing holes 240 are provided on the magnetic pole center line and / or the inter-pole center line of the rotor core 200. This is to reduce the moment of inertia and the overall weight of the electric power steering motor 10 while ensuring that the performance of the electric power steering motor 10 is not affected.

[0189] In some embodiments, optionally, at least a part of the hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300.

[0190] In this embodiment, the fitting structure between the rotor core 200 and the rotating shaft 300 is defined.

[0191] At least a part of the hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300. That is, a part of the hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300. Or the entire hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300.

[0192] This setting can ensure the fitting structure between the rotating shaft 300 and the rotor core 200 and prevent the separation of the rotating shaft 300 and the rotor core 200.

[0193] When a part of the hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300, the contact area between the shaft hole 220 and the rotating shaft 300 can be reduced. That is, while ensuring the use requirement of the interference fit between the rotating shaft 300 and the shaft hole 220, the radial force formed by the interference fit between the shaft hole 220 and the rotating shaft 300 can be reduced due to the reduction of the contact area between the shaft hole 220 and the rotating shaft 300. This can reduce the influence of the radial force on the bonding force between the laminations of the rotor core 200, which is beneficial to reducing the probability of deformation of the laminations of the rotor core 200 and further reducing the probability of loosening of the multiple laminations of the rotor core 200.

[0194] Optionally, the hole wall of the shaft hole 220 is a concave-convex wall. The protrusions of the concave-convex wall are in interference fit with the rotating shaft 300, and the depressions of the concave-convex wall are arranged separately from the rotating shaft 300. The protrusions and depressions of the concave-convex wall are arranged alternately and both the protrusions and depressions extend along the axial direction of the rotating shaft 300.

[0195] In some embodiments, optionally, the axial clearance of the second bearing 500 is less than or equal to 0.1 mm.

[0196] In this embodiment, the value range of the axial clearance of the second bearing 500 is further defined, such that the axial clearance of the second bearing 500 is less than or equal to 0.1 mm. In this way, the axial vibration of the electric power steering motor 10 can be further optimized to further optimize the vibration noise of the electric power steering motor 10.

[0197] It can be understood that when there is no load, the inner ring of the second bearing 500 is fixed, and the displacement of the outer ring of the second bearing 500 relative to the fixed inner ring along the axial direction of the rotor core 200 from one extreme position to another extreme position is denoted as the axial clearance δ of the second bearing 500.

[0198] Optionally, δ = 0.01 mm, δ = 0.02 mm, δ = 0.03 mm, δ = 0.04 mm, δ = 0.05 mm, δ = 0.06 mm, δ = 0.07 mm, δ = 0.08 mm, and δ = 0.09 mm, etc., which are not listed one by one here.

[0199] An electric power steering system according to some other embodiments of the present application includes: an electric power steering motor 10 as in any of the above embodiments.

[0200] An electric power steering system provided by the present application includes the electric power steering motor 10 as in any of the above embodiments, and therefore has all the beneficial effects of the above electric power steering motor 10, which will not be elaborated one by one here.

[0201] A vehicle according to some further embodiments of the present application includes: an electric power steering motor 10 as in any of the above embodiments; or an electric power steering system as in the above embodiments.

[0202] A vehicle provided by the present application includes the electric power steering motor 10 as in any of the above embodiments, or includes an electric power steering system as in the above embodiments, and therefore has all the beneficial effects of the above electric power steering motor 10 or the electric power steering system, which will not be elaborated one by one here.

[0203] It is worth noting that the vehicle can be a new energy vehicle. New energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid electric vehicles, fuel cell electric vehicles, and hydrogen engine vehicles, etc.

[0204] The vehicle can also be a fuel vehicle and a hybrid electric vehicle.

[0205] Optionally, the electric power steering motor 10 includes a rotor core 200, a rotating shaft 300, a first bearing 400, a second bearing 500, a first elastic part 600, and a second elastic part 700. At least one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing, which can enhance the overall anti-deformation ability of the electric power steering motor 10, is beneficial to improving the structural stiffness of the electric power steering motor 10, can reduce the axial runout amount when the electric power steering motor 10 works. In this way, the vibration performance of the electric power steering motor 10 during operation is further improved, the vibration noise of the electric power steering motor 10 can be further reduced, and the service performance and market competitiveness of the electric power steering motor 10 are greatly improved.

[0206] Optionally, the rotor core 200 includes a plurality of core segments 210 which are stacked, and any two adjacent core segments 210 are arranged offset in the clockwise or counterclockwise direction. The rotor core 200 is provided with a shaft hole 220 which axially penetrates through the plurality of core segments 210 along the rotor core 200.

[0207] The electric power steering motor 10 further includes a rotating shaft 300 which is disposed through the shaft hole 220.

[0208] At least one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing. Both the first bearing 400 and the second bearing 500 are sleeved on the rotating shaft 300, and the rotor core 200 is located between the first bearing 400 and the second bearing 500.

[0209] The electric power steering motor 10 further includes a first elastic part 600 and a second elastic part 700. The first elastic part 600 is installed in the first bearing cavity 110, and the second elastic part 700 is installed in the second bearing cavity 120. The first elastic part 600 is sleeved on the rotating shaft 300, and the first bearing 400 is located between the first elastic part 600 and the rotor core 200. After the motor is assembled, the first elastic part 600 is located between the first bearing 400 and the wall of the first bearing cavity 110, and the first elastic part 600 is used to apply an axial pre-tightening force to the first bearing 400. The second elastic part 700 is nested in the clamping groove 130, the second elastic part 700 is located between the second bearing 500 and the clamping groove 130, and the second elastic part 700 is used to limit the axial displacement of the second bearing 500.

[0210] The clamping groove 130 is an annular groove for nesting the second elastic part 700.

[0211] Along the radial direction of the rotating shaft 300, the maximum value of the width of the second bearing cavity 120 is denoted as d1, and the maximum value of the width of the clamping groove 130 is denoted as d2; on the cross-section of the electric power steering motor 10, the included angle between the contour line of the mating inclined surface 132 and the outer contour line of the axial end surface of the second elastic part 700 is denoted as a, and the cross-section of the motor passes through the axis of the rotating shaft 300; wherein, 1.02 ≤ d2 / d1 ≤ 1.79, 0° < a ≤ 82°.

[0212] Along the radial direction of the rotating shaft 300, the maximum value d1 of the width of the second bearing cavity 120, the maximum value d2 of the width of the clamping groove 130 and the axial clearance δ of the second bearing 500 satisfy: 0 ≤ (2×δ) / (d2 - d1) ≤ 0.5.

[0213] The electric power steering motor 10 includes a housing assembly 100, and the housing assembly 100 includes a housing 140 and an end cover 150. One of the housing 140 and the end cover 150 is provided with a first bearing cavity 110, and the other of the housing 140 and the end cover 150 is provided with a second bearing cavity 120. After the electric power steering motor 10 is assembled, the rotor core 200 is located between the first bearing cavity 110 and the second bearing cavity 120. The first bearing cavity 110 is used for assembling with the first bearing 400, and the second bearing cavity 120 is used for assembling with the second bearing 500.

[0214] The electric power steering motor 10 further includes a plurality of permanent magnets 800. The plurality of permanent magnets 800 are arranged on the iron core section 210, and the plurality of permanent magnets 800 are arranged at intervals along the circumferential direction of the shaft hole 220. Along the axial direction of the rotor core 200, the length of the permanent magnet 800 is less than or equal to the length of the iron core section 210.

[0215] The rotor core 200 is provided with a plurality of weight reduction holes 240. The plurality of weight reduction holes 240 are arranged at intervals along the circumferential direction of the rotating shaft 300, and the number of the weight reduction holes 240 is greater than or equal to the number of pole pairs of the motor.

[0216] At least a part of the hole wall of the shaft hole 220 is in interference fit with the rotating shaft 300.

[0217] The first bearing 400 is in interference fit with the rotating shaft 300, and the second bearing 500 is in interference fit with the rotating shaft 300.

[0218] A clamping groove 130 is arranged in the housing assembly 100. The clamping groove 130 is located on the side of the second bearing cavity 120 facing the rotor core 200. The clamping groove 130 is an annular groove. The clamping groove 130 is provided with a mating inclined surface 132, and the clamping groove 130 is used for nesting the second elastic part 700.

[0219] Along the axial direction of the rotating shaft 300, the second elastic part 700 is in interference fit with the second bearing cavity 120. That is, the thickness of the second elastic part 700 is greater than the width of the clamping groove 130. One side of the second elastic part 700 is conical. That is, one side of the second elastic part 700 is provided with a chamfer 510, and the chamfer 510 is matched with the mating inclined surface 132 of the clamping groove 130.

[0220] Optionally, the rotor core 200 includes a plurality of iron core sections 210 stacked along the axial direction of the rotor core 200. Among them, any two adjacent iron core sections 210 are arranged in a stagger along the clockwise direction, or any two adjacent iron core sections 210 are arranged in a stagger along the counterclockwise direction. That is, any two adjacent iron core sections 210 are arranged in a stagger in the circumferential direction of the rotor core 200 to form a rotor skewed pole. The segmented modular setting of the rotor core 200 has the advantages of being convenient for installation and maintenance, and skewed poles can be formed between the plurality of iron core sections 210.

[0221] Defining that any two adjacent iron core segments 210 are arranged in a clockwise or counterclockwise staggered manner can reduce the cogging torque and torque ripple, thereby reducing electromagnetic vibration. That is to say, by dividing the rotor iron core 200 into multiple iron core segments 210 and making any two adjacent iron core segments 210 arranged in a clockwise or counterclockwise staggered manner, the specific harmonic content in the motor can be effectively suppressed, the torque ripple and cogging torque of the motor can be improved, and the vibration and noise of the motor can be reduced.

[0222] Further, along the axial direction of the rotor iron core 200, the length of the permanent magnet 800 is less than or equal to the length of the iron core segment 210. The iron core segment 210 has the function of protecting the permanent magnet 800. In this way, the probability of squeezing the permanent magnet 800 and then causing damage to the permanent magnet 800 can be reduced. If, along the axial direction of the rotor iron core 200, the length of the permanent magnet 800 is greater than the length of the iron core segment 210, then a part of the permanent magnet 800 is likely to protrude from the iron core segment 210. This setting is likely to cause the permanent magnet 800 to be squeezed and damaged, and the service performance of the motor cannot be guaranteed.

[0223] After the motor is assembled, the first elastic part 600 is located between the first bearing 400 and the first bearing cavity 110. By squeezing the first elastic part 600, the first elastic part 600 applies an axial pre-tightening force to the first bearing 400. The second elastic part 700 is located between the second bearing 500 and the clamping groove 130. The second elastic part 700 is nested in the clamping groove 130, and the axial displacement of the second bearing 500 is restricted through its own hoop tightening deformation.

[0224] The four-point contact ball bearing can enhance the overall anti-deformation ability of the motor, is beneficial to improving the structural stiffness of the motor, can reduce the axial end play during the operation of the motor. In this way, the vibration performance during the operation of the motor is further improved, the vibration and noise of the motor can be further reduced, and the service performance and market competitiveness of the motor are greatly improved.

[0225] The rotor iron core 200 is in interference fit with the rotating shaft 300, the first bearing 400 is in interference fit with the rotating shaft 300, and the second bearing 500 is in interference fit with the rotating shaft 300. It is beneficial to improve the overall structural stiffness of the rotor iron core 200, the rotating shaft 300, the first bearing 400 and the second bearing 500, and enhance the overall anti-deformation ability of the rotor iron core 200, multiple permanent magnets 800, the rotating shaft 300, the first bearing 400 and the second bearing 500 to reduce the axial end play during the operation of the motor.

[0226] Both the first bearing 400 and the second bearing 500 are four-point contact ball bearings. The first bearing 400 and the second bearing 500 are both sleeved on the rotating shaft 300. The rotor core 200 is located between the first bearing 400 and the second bearing 500. The axial clearance δ of the second bearing 500 is less than or equal to 0.1 mm, and 0 ≤ (2×δ) / (d2 - d1) ≤ 0.5 is satisfied. Denote (2×δ) / (d2 - d1) = X. Figure 12 The simulation results of the 24th-order noise under different X are shown. Among them, Lp is the per-unit value, and Lp is the ratio of the 24th-order noise under different X to the 24th-order noise of the motor in the related art. In the range of 0 ≤ X ≤ 0.5, the 24th-order noise of the motor is better and the cost performance is the highest.

[0227] The electric power steering motor 10 includes a first elastic part 600 and a second elastic part 700. After the electric power steering motor 10 is assembled, the first elastic part 600 is located between the first bearing 400 and the cavity wall of the first bearing cavity 110. By squeezing the first elastic part 600, the first elastic part 600 applies an axial pre-tightening force to the first bearing 400. The second elastic part 700 is located between the second bearing 500 and the rotor core 200, and the second elastic part 700 is nested in the annular groove (i.e., the clamping groove 130). Through the self-clamping deformation of the second elastic part 700, the second elastic part 700 is used to limit the axial displacement of the second bearing 500.

[0228] In this embodiment, the first bearing cavity 110 is the bearing cavity of the housing 140, and the second bearing cavity 120 is the bearing cavity of the end cover 150.

[0229] As Figure 6 shown, one side of the second elastic part 700 is conical. The second elastic part 700 is nested in the annular groove on one side of the second bearing cavity 120 along the bevel angle of the clamping groove 130. The second elastic part 700 and the annular groove are in axial interference fit. The second elastic part 700 is used to limit the axial displacement of the second bearing 500. Along the radial direction of the rotating shaft 300, the maximum width d2 of the annular groove and the maximum width d1 of the second bearing cavity 120 satisfy 1.02 ≤ d2 / d1 ≤ 1.79.

[0230] As Figure 7 shown, on the cross-section of the electric power steering motor 10, the included angle between the contour line of the mating inclined surface 132 and the outer contour line of the axial end surface of the second elastic part 700 is denoted as a. The cross-section of the motor passes through the axis of the rotating shaft 300, where 0° < a ≤ 82°.

[0231] This setting can ensure that the second elastic part 700 can be effectively installed in the annular groove, and the second elastic part 700 can limit the axial displacement of the outer ring of the second bearing 500.

[0232] Defining that any two adjacent iron core segments 210 are arranged in a staggered manner in the clockwise or counterclockwise direction can reduce the cogging torque and torque ripple, thereby reducing the electromagnetic vibration. That is to say, by dividing the rotor iron core 200 into multiple iron core segments 210 and arranging any two adjacent iron core segments 210 in a staggered manner in the clockwise or counterclockwise direction, the specific harmonic content in the electric power steering motor 10 can be effectively suppressed, the torque ripple and cogging torque of the electric power steering motor 10 can be improved, and thus the vibration and noise of the electric power steering motor 10 can be reduced.

[0233] Furthermore, the rotor iron core 200 is provided with a shaft hole 220. The shaft hole 220 axially penetrates through multiple iron core segments 210 along the rotor iron core 200. A rotating shaft 300 is inserted into the shaft hole 220. A first bearing 400 is sleeved on the rotating shaft 300, and a second bearing 500 is sleeved on the rotating shaft 300. The first bearing 400 is located outside the rotor iron core 200, and the second bearing 500 is located outside the rotor iron core 200. Among them, at least one of the first bearing 400 and the second bearing 500 is a four-point contact ball bearing. That is, the first bearing 400 is a four-point contact ball bearing, and / or the second bearing 500 is a four-point contact ball bearing.

[0234] In this application, the term "multiple" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "joined" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0235] In the description of this specification, the description of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. The above is only the preferred embodiment of this application and is not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. An electric power steering motor, characterized in that: include: A housing assembly, wherein a first bearing cavity and a second bearing cavity are provided in the housing assembly; a rotor core, arranged in the housing assembly, the rotor core being located between the first bearing cavity and the second bearing cavity, the rotor core comprising a plurality of core segments, the plurality of core segments being stacked, any two adjacent core segments being staggered in a clockwise direction or in a counterclockwise direction, the rotor core being provided with an axial hole, the axial hole penetrating the plurality of core segments in the axial direction of the rotor core; A rotating shaft, passing through the shaft hole; A first bearing is disposed in the first bearing cavity, and the first bearing sleeve is disposed on the rotating shaft; A second bearing is disposed in the second bearing cavity, the second bearing sleeve is disposed on the rotating shaft, the first bearing and the second bearing are both interference fit with the rotating shaft, and at least one of the first bearing and the second bearing is a four-point contact ball bearing; a first elastic portion, arranged around the rotating shaft, and abutting between a side of the first bearing away from the rotor core and a cavity wall of the first bearing cavity, the first elastic portion being used to apply an axial preload force to the first bearing; The second elastic portion is arranged around the rotating shaft, the second elastic portion abuts against a side of the second bearing facing the rotor core, and the second elastic portion is used to limit the axial displacement of the second bearing.

2. The electric power steering motor according to claim 1, characterized in that: When one of the first bearing and the second bearing is a four-point contact ball bearing, the second bearing is a four-point contact ball bearing.

3. The electric power steering motor according to claim 1 or 2, characterized in that: A slot is also provided in the housing assembly, the slot is located on a side of the second bearing cavity facing the rotor core, and the slot is connected to the second bearing cavity; The second elastic portion is disposed in the clamping slot.

4. The electric power steering motor according to claim 3, characterized in that: Along the axial direction of the rotating shaft, the width of the clamping groove is smaller than the width of the second elastic portion.

5. The electric power steering motor according to claim 3, characterized in that: A chamfer is provided on a side of the second elastic portion facing away from the second bearing, a matching inclined surface is provided at a portion of the clamping groove opposite to the chamfer, and the chamfer is fitted with the matching inclined surface.

6. The electric power steering motor according to claim 5, characterized in that: Along the radial direction of the rotating shaft, the maximum value of the width of the second bearing cavity is recorded as d1, and the maximum value of the width of the slot is recorded as d2; On the cross section of the electric power steering motor, the angle between the contour line of the matching slope and the outer contour line of the axial end surface of the second elastic portion is denoted as a, and the cross section of the motor passes through the axis of the rotating shaft; Among them, 1.02≤d2 / d1≤1.79, 0°<a≤82°.

7. The electric power steering motor according to claim 3, characterized in that: Along the radial direction of the rotating shaft, the maximum value d1 of the width of the second bearing cavity, the maximum value d2 of the width of the groove and the axial clearance δ of the second bearing satisfy: 0≤(2×δ) / (d2-d1)≤0.

5.

8. The electric power steering motor according to claim 1 or 2, characterized in that: The housing assembly comprises: chassis; An end cover is connected to one side of the casing along the axial direction of the rotating shaft, one of the casing and the end cover is provided with the first bearing cavity, and the other of the casing and the end cover is provided with the second bearing cavity.

9. The electric power steering motor according to claim 1 or 2, characterized in that: The rotor core is further provided with a plurality of magnet slots, which are arranged at intervals along the circumferential direction of the rotating shaft, and the magnet slots are located between the shaft hole and the outer peripheral wall of the rotor core; The electric power steering motor further includes a plurality of permanent magnets, each of which is disposed in one of the magnet slots.

10. The electric power steering motor according to claim 9, characterized in that: Along the axial direction of the rotating shaft, the length of the permanent magnet is less than or equal to the length of the core segment.

11. The electric power steering motor according to claim 9, characterized in that: The rotor core is further provided with a plurality of weight-reducing holes, which are arranged at intervals along the circumference of the rotating shaft, and the weight-reducing holes are located between the rotating shaft and the permanent magnets; The number of the weight-reducing holes is greater than or equal to the number of pole pairs of the electric power steering motor.

12. The electric power steering motor according to claim 1 or 2, characterized in that: At least a portion of the hole wall of the shaft hole is interference fit with the rotating shaft.

13. The electric power steering motor according to claim 1 or 2, characterized in that: The axial clearance of the second bearing is less than or equal to 0.1 mm.

14. An electric power steering system, characterized in that: include: An electric power steering motor as claimed in any one of claims 1 to 13.

15. A vehicle, characterized in that: include: The electric power steering motor according to any one of claims 1 to 13; or The electric power steering system as claimed in claim 14.

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