An electric machine, suspension assembly, and vehicle

Abstract

This invention discloses a motor, a suspension assembly, and a vehicle, relating to the field of vehicle technology. It aims to solve the problem of significant frictional noise during motor startup, leading to poor NVH performance and a subpar driving experience. The motor includes a first assembly, a second assembly, and at least one bearing. The bearing is fixed to the first assembly, and the second assembly is slidably fitted onto the bearing. The static friction coefficient between the second assembly and the bearing is μ1, and the dynamic friction coefficient between the second assembly and the bearing is μ2. μ1 and μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 2.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to an electric motor, a suspension assembly, and a vehicle. Background Technology

[0002] A vehicle includes a body, wheels, and a suspension assembly connecting the body and wheels. The suspension assembly buffers the impact forces transmitted to the body from uneven road surfaces to ensure a smooth ride. Some suspension assemblies also include a motor; adjusting the motor's movement helps maintain a stable vehicle position and improve ride comfort.

[0003] In related technologies, motors are prone to significant frictional noise during startup, resulting in poor NVH performance and a poor driving experience. Summary of the Invention

[0004] The purpose of this invention is to provide a motor, suspension assembly, and vehicle, which aims to solve the problem that the motor is prone to large friction noise during startup, resulting in poor NVH performance of the motor and a poor driving experience of the vehicle.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides an electric motor, comprising: a first component and a second component; and at least one bearing, the bearing being fixed to the first component, the second component being slidably fitted to the bearing; the static friction coefficient between the second component and the bearing is μ1, the dynamic friction coefficient between the second component and the bearing is μ2, and μ1 and μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 2.

[0006] According to the embodiment of the present invention, the static friction coefficient μ1 and dynamic friction coefficient μ2 between the second component and the bearing satisfy: 1≤μ1 / μ2≤1.7. This reduces the force required for the second component to achieve dynamic-static transition relative to the bearing, resulting in less starting resistance experienced by the second component during motor operation. This avoids frictional obstruction between the second component and the bearing due to high starting resistance, and prevents the motor from generating significant frictional noise. Consequently, it helps to avoid noticeable abnormal noise during motor operation and improves the driving experience of the vehicle.

[0007] In some embodiments, μ1 and μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 1.65; or, 1 ≤ μ1 / μ2 ≤ 1.5; μ1 and μ2 satisfy: 0.03 ≤ μ1 - μ2 ≤ 0.07; or, μ1 and μ2 satisfy: 0 < μ1 - μ2 ≤ 0.065; or, μ1 and μ2 satisfy: 0 < μ1 - μ2 ≤ 0.04; or, 0.04 ≤ μ1 - μ2 ≤ 0.05.

[0008] In some embodiments, the static friction coefficient μ1 satisfies: 0.135≤μ1≤0.165; or, 0.14≤μ1≤0.16.

[0009] In some embodiments, the coefficient of kinetic friction μ2 satisfies: 0.08 ≤ μ2 ≤ 0.12; or 0.1 ≤ μ2 < 0.15.

[0010] In some embodiments, the bearing includes a base and a first solid lubricant; The substrate has a first mating surface, which is adapted to mate with the second component. At least a portion of the first solid lubricant is disposed on or exposed on the first mating surface.

[0011] In some embodiments, the substrate is provided with a plurality of receiving holes, one end of which is located on the first mating surface; The first solid lubricant is disposed within the plurality of receiving holes.

[0012] In some embodiments, the material of the first solid lubricant includes at least one of graphite, diamond-like carbon, fluorine-containing compounds, and molybdenum disulfide.

[0013] In some embodiments, the material of the first solid lubricant includes polytetrafluoroethylene and graphite; Wherein, the mass percentage of the polytetrafluoroethylene is greater than or equal to 80% and less than or equal to 95%; and the mass percentage of the graphite is greater than or equal to 5% and less than or equal to 20%.

[0014] In some embodiments, the matrix is ​​a polymer matrix, a copper alloy matrix, a nickel alloy matrix, or a steel matrix.

[0015] In some embodiments, the first solid lubricant is disposed on the first mating surface, and the thickness h of the first solid lubricant satisfies: 1μm≤h≤10μm.

[0016] In some embodiments, the second component includes a body and a wear-resistant component; the body has a second mating surface adapted to mate with the bearing; at least a portion of the wear-resistant component is disposed on or exposed on the second mating surface.

[0017] In some embodiments, the at least one bearing includes a first bearing fixed to the first component, and the second component includes a mandrel slidably disposed within the first bearing.

[0018] In some embodiments, the first component includes a housing, one end of which is provided with a mounting hole along the first direction, and the first bearing is accommodated in the mounting hole and fixed to the housing.

[0019] In some embodiments, the at least one bearing further includes a second bearing, the spindle having a guide hole, the second bearing being fixed within the guide hole, and the second component including a guide member, the guide member being accommodated in the guide hole and slidably passing through the second bearing.

[0020] A second aspect of the present invention provides a suspension assembly including the motor of the first aspect of the present invention.

[0021] According to the embodiments of the present invention, by providing the aforementioned motor, the suspension assembly helps to avoid obvious abnormal noises during operation and improves the driving experience of the vehicle.

[0022] A third aspect of the present invention provides a vehicle including a motor according to the first aspect of the present invention, or a suspension assembly according to the second aspect of the present invention. According to embodiments of the present invention, by providing the aforementioned motor or suspension components, the vehicle can avoid noticeable abnormal noises, thereby improving the driving experience. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the vehicle structure provided in an embodiment of this application; Figure 2 for Figure 1 The diagram shows the connection relationship between the steering knuckle, steering assembly, and suspension assembly in the vehicle shown. Figure 3 A cross-sectional view of the motor provided in an embodiment of this application; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 for Figure 3 Enlarged view of point B in the middle; Figure 6 This is a schematic diagram of the structure of the first bearing in some embodiments of this application; Figure 7 This is a cross-sectional structural schematic diagram of the first bearing in some other embodiments of this application; Figure 8 for Figure 7 Enlarged view of point C in the middle; Figure 9 This is a schematic diagram of the structure of the second bearing in some embodiments of this application; Figure 10 This is a cross-sectional structural schematic diagram of the second bearing according to other embodiments of this application; Figure 11 for Figure 10 Enlarged view of point D in the middle; Figure 12 This is a schematic diagram showing the relationship between the friction coefficient of the second component and the bearing and the material of the first fixed lubricating component; Figure 13 This is one of the simulation images showing the thermal deformation of the first solid lubricant using high-purity graphite. Figure 14 The second simulation image shows the thermal deformation of the first solid lubricant using high-purity graphite. Figure 15 The third simulation image showing the thermal deformation of the first solid lubricant using high-purity graphite; Figure 16 The fourth simulation image showing the thermal deformation of the first solid lubricant using high-purity graphite; Figure 17 The fifth simulation image of the thermal deformation of the first solid lubricant using high-purity graphite; Figure 18 The sixth simulation image of the thermal deformation of the first solid lubricant using high-purity graphite; Figure 19 This is one of the simulation results of the thermal deformation of the first solid lubricant using modified graphite. Figure 20 The second simulation image shows the thermal deformation of the first solid lubricant using modified graphite. Figure 21 The third simulation image shows the thermal deformation of the first solid lubricant using modified graphite. Figure 22 The fourth simulation image shows the thermal deformation of the first solid lubricant using modified graphite. Figure 23 The fifth simulation image showing the thermal deformation of the first solid lubricant using modified graphite; Figure 24 The sixth simulation image showing the thermal deformation of the first solid lubricant using modified graphite; Figure 25 This is a schematic diagram showing the relationship between the friction coefficient of the second component and the bearing and the material of the lubricating medium. Figure 26 This is a schematic diagram of the resistance curve of the motor; Figure 27The NVH test results of a motor using high-purity graphite as the first solid lubricant are shown in the figure. Figure 28 The NVH test results of a motor using diamond-like carbon as the first solid lubricant are shown in the figure. Figure 29 The NVH test results of a motor using modified graphite as the first solid lubricant are shown in the figure. Figure 30 This is a schematic diagram of the assembly structure of the test bench and the motor.

[0025] Figure label: 100. Vehicle; 10. Body; 20. Wheel; 30. Suspension assembly; 1. Motor; 11. First assembly; 111. Housing; 111A. Mounting hole; 112. Magnet assembly; 113. Lower wishbone; 114. Guide; 115. First bearing; 1151. First bearing base; 12. Second component; 121. Mandrel; 121A. Guide hole; 122. Winding structure; 123. Iron core; 124. Second bearing; 1241. Second bearing base; 125. Mandrel sleeve; 2. Tower top assembly; 21. Fixing base; 22. First support; 3. Elastic elements; 6. Receiving hole; 7. First solid lubricant; 350. Stand; 351. Base; 352. Support rod; 353. Top plate; 354. Electric cylinder; 355. Lateral force application mechanism. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or relative positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Unless otherwise specified, the above-described orientation can be flexibly set in practical applications, provided that the relative positional relationship shown in the accompanying drawings is satisfied.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "communication" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a direct connection or an indirect connection through an intermediate medium, or a communication between the internal components of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In embodiments of the invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0031] In embodiments of the present invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in embodiments of the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0032] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0033] This application provides a vehicle 100. The vehicle 100 can be a pure electric vehicle 100, a hybrid electric vehicle 100, a plug-in hybrid electric vehicle 100, a range-extended electric vehicle 100, a gasoline vehicle, etc. The vehicle 100 can also be a sedan, a truck, a bus, a lorry, a trailer, etc. This application does not specifically limit the type of vehicle 100.

[0034] like Figure 1 and Figure 2 As shown, Figure 1 This is a structural schematic diagram of the vehicle 100 provided in an embodiment of this application. Figure 2 for Figure 1 This diagram illustrates the connection relationship between the steering knuckle, steering assembly, and suspension assembly 30 in the vehicle 100. The vehicle 100 may include a wheel 20, a body 10, a steering knuckle, and a steering assembly. The steering knuckle is located on the wheel 20. At least a portion of the steering assembly is located on the body 10, and the steering assembly is connected to the steering knuckle. The position of the steering assembly connected to the steering knuckle is eccentrically positioned relative to the rotation axis of the wheel 20, so that the steering assembly can drive the wheel 20 to steer via the steering knuckle.

[0035] In some embodiments, the steering assembly may include a steering wheel and a steering shaft. The steering wheel is located in the passenger compartment of the vehicle body 10 and is connected to the steering knuckle via the steering shaft. When driving the vehicle 100, the user can turn the steering wheel to rotate the wheels 20 via the steering shaft and steering knuckle, thereby steering the vehicle 100.

[0036] In some embodiments, the vehicle 100 may further include a suspension assembly 30. The suspension assembly 30 is connected between the vehicle body 10 and the wheels 20 to buffer the impact force transmitted to the vehicle body 10 from uneven road surfaces, so as to ensure the smoothness of the vehicle 100 and improve the driving comfort of the vehicle 100.

[0037] In some embodiments, the suspension assembly 30 may be connected between the vehicle body 10 and the steering knuckle on the wheel 20 to prevent the suspension assembly 30 from rotating with the wheel 20. Based on this, as the steering assembly drives the wheel 20 to steer via the steering knuckle, the end of the suspension assembly 30 connected to the steering knuckle will also rotate relative to the end of the suspension assembly 30 connected to the vehicle body 10, so as to ensure the smooth operation of the vehicle 100.

[0038] The structure of the suspension assembly 30 will be further described below. The suspension assembly 30 may include a motor 1, a tower top assembly 2, and an elastic element.

[0039] Optionally, the motor 1 is specifically a linear motor 1. The tower top assembly 2 is connected to the motor 1 and is used to supply current to the motor 1 to drive the motor 1 to actively extend or shorten. An elastic element is sleeved outside the motor 1. During the active extension or shortening process, the motor 1 can release or compress the two ends of the elastic element axially, so that the suspension assembly 30 is in a better vibration damping state under different operating conditions of the vehicle 100.

[0040] Please refer to the reference. Figures 3-5 , Figure 3 This is a cross-sectional view of the motor 1 provided in an embodiment of this application. Figure 4 for Figure 3 Enlarged diagram of point A in the middle. Figure 5 for Figure 3Enlarged schematic diagram at point B. The motor 1 includes a first component 11 and a second component 12. The first component 11 is movable relative to the second component 12 to extend or shorten the motor 1. The direction in which the first component 11 moves relative to the second component 12 is defined as a first direction. The first direction can be consistent with the height direction of the vehicle 100 or inclined relative to the height direction of the vehicle 100. This application does not specifically limit this direction.

[0041] One of the first component 11 and the second component 12 is adapted to connect to the wheel 20. Optionally, one of the first component 11 and the second component 12 is adapted to connect to the wheel 20 via a steering knuckle, and the other of the first component 11 and the second component 12 is adapted to connect to the vehicle body 10. Optionally, the other of the first component 11 and the second component 12 is adapted to connect to the vehicle body 10 via a strut top component 2.

[0042] refer to Figures 3-5 The motor 1 also includes at least one bearing, for example, the motor 1 includes one or more bearings. The bearing is fixed to the first component 11, and the second component 12 is slidably fitted to the bearing. The static friction coefficient between the second component 12 and the bearing is μ1, and the dynamic friction coefficient between the second component 12 and the bearing is μ2.

[0043] For example, the bearing is fixed to the first component 11, and the second component 12 is slidably fitted to the bearing.

[0044] In related technologies, motor 1 generates a large acceleration when starting (i.e., during the transition between dynamic and static states), which in turn produces a large frictional noise, resulting in poor NVH performance of motor 1 and a poor driving experience for vehicle 100.

[0045] During the relative movement of the first component 11 and the second component 12, in the initial stage when the first component 11 and the second component 12 transition from a relatively stationary state to a moving state, there will be starting resistance between the second component 12 and the bearing. The starting resistance of motor 1 refers to the force that resists relative motion generated between the first component 11 and the second component 12 during the acceleration phase when motor 1 starts. This starting resistance comes partly from the no-load resistance of motor 1 and partly from the force required for the second component 12 to achieve the transition from a stationary to a moving state relative to the bearing. Among them, the no-load resistance refers to the force that resists relative motion generated between the first component 11 and the second component 12 during the relative movement when motor 1 is unloaded (i.e., no current is flowing through it).

[0046] Extensive research has revealed that controlling the starting resistance of motor 1 can reduce frictional noise during startup and improve the NVH performance of motor 1.

[0047] In embodiments of the present invention, the coefficient of friction when the relative motion is less than or equal to 1 mm / s is regarded as the static coefficient of friction, and the coefficient of friction when the relative motion is greater than 1 mm / s is regarded as the dynamic coefficient of friction.

[0048] When the ratio of static friction coefficient μ1 to dynamic friction coefficient μ2 is large, the force required for the second component 12 to achieve dynamic-static conversion relative to the bearing is large, resulting in greater starting resistance. Thus, during the operation of motor 1, motor 1 needs to apply a large starting force to the second component 12. The large starting force of motor 1 will cause the second component 12 to generate a large acceleration, resulting in obvious abnormal noise during the operation of motor 1.

[0049] Therefore, to reduce or avoid abnormal noise generated by motor 1 during operation, in some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 2. If the value of μ1 / μ2 is greater than 2, the difference between the static friction coefficient μ1 and the dynamic friction coefficient μ2 is large. This results in a large force required for the second component 12 to achieve dynamic-static transition relative to the bearing, causing the second component 12 to generate a large acceleration during motor 1 startup, thus leading to noticeable abnormal noise from motor 1 during operation. By ensuring that 1 < μ1 / μ2 ≤ 2, the abnormal noise generated by motor 1 can be effectively reduced within this range, thereby improving the driving experience of vehicle 100.

[0050] Optionally, the value of μ1 / μ2 can be 1.08, 1.1, 1.16, 1.2, 1.25, 1.3, 1.33, 1.4, 1.45, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, etc.

[0051] According to the embodiment of the present invention, the motor 1, by ensuring that the static friction coefficient μ1 and dynamic friction coefficient μ2 between the second component 12 and the bearing satisfy: 1 ​​< μ1 / μ2 ≤ 2, requires less force for the second component 12 to achieve dynamic-static transition relative to the bearing. This results in less starting resistance for the second component 12 during the operation of the motor 1, avoiding frictional obstruction between the second component 12 and the bearing due to high starting resistance, and preventing the motor 1 from generating significant frictional noise. This helps to avoid noticeable abnormal noise during the operation of the motor 1 and improves the driving experience of the vehicle 100.

[0052] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 1 < μ1 / μ2 ≤ 1.65. Optionally, the value of μ1 / μ2 can be 1.03, 1.08, 1.1, 1.18, 1.2, 1.25, 1.3, 1.4, 1.5, or 1.65, etc. By ensuring that 1 < μ1 / μ2 ≤ 1.65, within this range, the force required for the second component 12 and the bearing to achieve dynamic-static transition relative to the bearing is further reduced, thereby further reducing the probability and magnitude of abnormal noise generated by the motor 1. This helps to further effectively avoid obvious abnormal noise generated by the motor 1 during operation, thereby further improving the driving experience of the vehicle 100.

[0053] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 1 < μ1 / μ2 ≤ 1.5. Optionally, the value of μ1 / μ2 can be 1.1, 1.18, 1.2, 1.25, 1.3, 1.4, 1.45, or 1.5, etc. By ensuring that 1 < μ1 / μ2 ≤ 1.5, within this range, the force required for the second component 12 and the bearing to achieve dynamic-static transition relative to the bearing is further reduced, thereby further reducing the probability and magnitude of abnormal noise generated by the motor 1. This helps to further effectively avoid obvious abnormal noise generated by the motor 1 during operation, thereby further improving the driving experience of the vehicle 100.

[0054] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 0.03 ≤ μ1 - μ2 ≤ 0.07. Optionally, the values ​​of μ1 - μ2 can be 0.03, 0.04, 0.045, 0.05, 0.06, or 0.07, etc. By ensuring that 0.03 ≤ μ1 - μ2 ≤ 0.07, the values ​​of the static friction coefficient μ1 and the dynamic friction coefficient μ2, as well as the difference between them, are both small. This reduces or avoids abnormal noise from the motor 1 while also reducing frictional wear between the second component 12 and the bearing.

[0055] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 0 < μ1 - μ2 ≤ 0.065. Optionally, the values ​​of μ1 - μ2 can be 0.01, 0.02, 0.03, 0.04, 0.045, 0.05, 0.06, or 0.065, etc. By ensuring that 0 < μ1 - μ2 ≤ 0.065, within this range, the values ​​of the static friction coefficient μ1 and the dynamic friction coefficient μ2 themselves, as well as the difference between them, are further reduced, which is beneficial for further reducing or avoiding abnormal noise and further reducing frictional wear between the second component 12 and the bearing.

[0056] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 0 < μ1 - μ2 ≤ 0.04. Optionally, the values ​​of μ1 - μ2 can be 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, or 0.04, etc. By ensuring that 0 < μ1 - μ2 ≤ 0.065, within this range, the values ​​of the static friction coefficient μ1 and the dynamic friction coefficient μ2 themselves, as well as the difference between them, are further reduced, which is beneficial for further reducing or avoiding abnormal noise and further reducing frictional wear between the second component 12 and the bearing.

[0057] In some embodiments, the static friction coefficient μ1 and the dynamic friction coefficient μ2 satisfy the condition: 0.04 ≤ μ1 - μ2 ≤ 0.05. Optionally, the values ​​of μ1 - μ2 can be 0.04, 0.42, 0.045, 0.048, or 0.05, etc. By ensuring that 0.04 ≤ μ1 - μ2 ≤ 0.05, within this range, the values ​​of the static friction coefficient μ1 and the dynamic friction coefficient μ2 themselves, as well as the difference between them, are further reduced, which is beneficial for further reducing or avoiding abnormal noise and further reducing frictional wear between the second component 12 and the bearing.

[0058] In some embodiments, the static friction coefficient μ1 satisfies: 0.135 ≤ μ1 ≤ 0.165. For example, the value of the friction coefficient μ1 can be 0.135, 0.138, 0.14, 0.145, 0.15, 0.16, or 0.165, etc. A static friction coefficient μ1 in the range of 0.14-0.16 allows the starting resistance to be within a more suitable range, further enabling more stable and smoother relative movement between the first component 11 and the second component 12.

[0059] In some embodiments, the static friction coefficient μ1 satisfies: 0.14 ≤ μ1 ≤ 0.16. For example, the value of the friction coefficient μ1 can be 0.14, 0.145, 0.15, 0.16, etc. A static friction coefficient μ1 in the range of 0.14-0.16 can keep the starting resistance within a more suitable range, thereby further ensuring more stable and smoother relative movement between the first component 11 and the second component 12.

[0060] In some embodiments, the dynamic friction coefficient μ2 satisfies: 0.08 ≤ μ2 ≤ 0.12. For example, the value of the friction coefficient μ1 can be 0.08, 0.09, 0.1, 0.11, 0.12, etc. The larger the dynamic friction coefficient μ2, the greater the starting resistance of the motor 1, and the faster the starting resistance increases with the increase of the dynamic friction coefficient μ2. Within this range, the friction coefficient μ2 keeps the starting resistance within a more suitable range, thereby making the further relative movement of the first component 11 and the second component 12 more stable and smoother.

[0061] In some embodiments, the dynamic friction coefficient μ2 satisfies: 0.1 ≤ μ2 < 0.15. For example, the value of the friction coefficient μ1 can be 0.1, 0.11, 0.015, 0.12, 0.13, 0.14, or 0.145, etc. The larger the dynamic friction coefficient μ2, the greater the starting resistance of the motor 1, and the faster the starting resistance increases with the increase of the dynamic friction coefficient μ2. Within this range, the friction coefficient μ2 keeps the starting resistance within a more suitable range, thereby making the further relative movement of the first component 11 and the second component 12 more stable and smoother.

[0062] In some embodiments, the bearing includes a base and a first solid lubricant 7. The base has a first mating surface adapted to mate with a second component 12. At least a portion of the first solid lubricant 7 is disposed on or exposed on the first mating surface. By providing the first solid lubricant 7, when the second component 12 moves relative to the bearing, the first solid lubricant 7 can provide lubrication, thereby reducing the friction between the second component 12 and the bearing.

[0063] It should be noted that "at least part of the first solid lubricant 7 is exposed above the first mating surface" means that the first solid lubricant 7 can be seen and touched from the first mating surface. The mating surface of the fixed lubricant can be flush with, lower than, or higher than the first mating surface.

[0064] The first mating surface refers to the surface of the substrate facing the second component 12, i.e., the inner wall surface of the substrate. For example, the inner wall surface of the substrate of the first bearing 115 is the first mating surface of the first bearing 115. The inner wall surface of the substrate of the second bearing 124 is the first mating surface of the second bearing 124.

[0065] refer to Figure 6 , Figure 9 In some embodiments, the substrate is provided with a plurality of receiving holes 6, one end of the plurality of receiving holes 6 is located on the first mating surface, and the first solid lubricant 7 is disposed in the plurality of receiving holes 6.

[0066] At this time, during the relative movement of the first component 11 and the second component 12, the material of the first solid lubricant 7 will enter the gap between the base and the second component 12 during the mutual compression between the second component 12 and the bearing, thereby playing a lubricating role.

[0067] By placing the first solid lubricant 7 inside the receiving hole 6, the first solid lubricant 7 can be more firmly attached to the substrate, thereby providing better lubrication and reducing the coefficient of friction between the second component 12 and the bearing.

[0068] The first solid lubricant 7 can be a columnar structure, a block-shaped structure, or the like embedded in the receiving hole 6. The first solid lubricant 7 can also be a powdered or viscous lubricant embedded in the receiving hole 6.

[0069] Optionally, the plurality of receiving holes 6 are divided into multiple groups, each group of receiving holes 6 including at least one receiving hole 6, and the multiple groups of receiving holes 6 are arranged at intervals along the circumference of the bearing.

[0070] In some embodiments, the material of the first solid lubricant 7 includes at least one of graphite, diamond-like carbon (DLC), fluorinated compounds, and molybdenum disulfide (MOS2). That is, the material of the first solid lubricant 7 can be one of graphite, diamond-like carbon, fluorinated compounds, and molybdenum disulfide, or it can be a mixture of at least two of graphite, diamond-like carbon, fluorinated compounds, and molybdenum disulfide.

[0071] The above-mentioned materials have good lubrication properties, and the use of the above-mentioned materials in the first solid lubricant 7 can provide good lubrication for the second component 12 and the bearing.

[0072] When the first solid lubricant 7 is a lubricating coating, the material of the first solid lubricant 7 can be a diamond carbon coating, a polytetrafluoroethylene (PTFE) coating, etc. The thickness of the lubricating coating can be 1μm-10μm. For example, the thickness of the lubricating coating can be 1μm, 3μm, 5μm, 7μm, 9μm, 10μm, etc.

[0073] Lubricating coatings can be applied to the substrate using processes such as electrochemical methods, spraying, vacuum magnetron sputtering, and chemical vapor deposition to ensure strong adhesion to the substrate.

[0074] When the first solid lubricant 7 is embedded in the receiving hole 6, the material of the first solid lubricant 7 can be high-purity graphite, oil-containing graphite, modified lubricant graphite, etc.

[0075] In some embodiments, the material of the first solid lubricant 7 includes polytetrafluoroethylene and graphite, wherein the mass percentage of polytetrafluoroethylene is greater than or equal to 80% and less than or equal to 95%; and the mass percentage of graphite is greater than or equal to 5% and less than or equal to 20%.

[0076] For example, the mass percentage of polytetrafluoroethylene (PTFE) is 80% and the mass percentage of graphite is 20%. Or, the mass percentage of PTFE is 85% and the mass percentage of graphite is 15%. Or, the mass percentage of PTFE is 90% and the mass percentage of graphite is 10%. Or, the mass percentage of PTFE is 95% and the mass percentage of graphite is 5%, etc.

[0077] The first solid lubricant 7, made by mixing polytetrafluoroethylene and graphite in the above-mentioned mass percentages, has better lubrication performance and can play a better lubrication role, so as to more effectively reduce the coefficient of friction between the second component 12 and the bearing.

[0078] refer to Figure 12 , Figure 12 This is a schematic diagram showing the relationship between the coefficient of friction between the second component 12 and the bearing and the material of the first fixed lubricating element. Figure 12 It can be seen that when the first solid lubricant 7 is modified graphite (including polytetrafluoroethylene and graphite) or diamond-like carbon, the static friction coefficient μ1 is reduced by about 50% compared to when the first solid lubricant 7 is made of high-purity graphite. Furthermore, when the material of the first solid lubricant 7 is high-purity graphite, the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 is approximately 2; when the material of the first solid lubricant 7 is modified graphite (including polytetrafluoroethylene and graphite), the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 is approximately 1.5; and when the material of the first solid lubricant 7 is diamond-like carbon, the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 is approximately 1.6. In the embodiments of the present invention, the friction coefficient when the relative motion is less than or equal to 1 mm / s is considered the static friction coefficient, and the friction coefficient when the relative motion is greater than 1 mm / s is considered the dynamic friction coefficient.

[0079] For example, the bearing base is provided with multiple receiving holes 6, and the first solid lubricant 7 is disposed in the receiving holes 6. During the operation of the motor 1, the motor 1 generates a certain amount of heat, which causes the first solid lubricant 7 to be in a high-temperature environment and prone to expansion. When the bearing slides relative to the second component, the bearing is subjected to frictional extrusion loads and high temperature, which can cause the first solid lubricant 7 to form a lubricating film on the relative sliding surface. This lubricating film is continuously carried out by the linear motion during the bearing sliding, but at the same time, the first solid lubricant 7 continuously expands and presses against the second component to replenish the lost lubricating film, thus ensuring a good coefficient of friction, friction reduction and lubrication.

[0080] refer to Figures 13-24 , Figures 13-18 The image shows a simulation of the thermal deformation of the first solid lubricant component 7, which uses high-purity graphite. Figures 19-24 The figure shows the simulation effect of the thermal deformation of the first solid lubricant 7 using modified graphite (including polytetrafluoroethylene and graphite). As can be seen from the figure, under the same conditions, the deformation of the first solid lubricant 7 using high-purity graphite is less than that of the first solid lubricant 7 using modified graphite (including polytetrafluoroethylene and graphite).

[0081] Based on the thermal expansion parameters of the first solid lubricant 7 made of different materials, the coefficients of thermal expansion of modified graphite (including polytetrafluoroethylene and graphite) at 22-78℃ and 95-199℃ are 99.1 μm / (m*K) and 168.6 μm / (m*K), respectively, while the coefficients of thermal expansion of high-purity graphite at 22-78℃ and 95-199℃ are both 4.5 μm / (m*K). Therefore, under the same conditions, the coefficient of thermal expansion of the first solid lubricant 7 made of modified graphite (including polytetrafluoroethylene and graphite) is greater than that of the first solid lubricant 7 made of high-purity graphite. Thus, during the operation of the motor 1, the heat generated by the motor 1 causes the first solid lubricant 7 made of modified graphite (including polytetrafluoroethylene and graphite) to expand and deform to a greater extent than the first solid lubricant 7 made of high-purity graphite.

[0082] Furthermore, at 150°C, the radial extension height of the first solid lubricant 7, made of modified graphite (including polytetrafluoroethylene and graphite), is 0.06 mm. This allows the first solid lubricant 7 to easily extend from the receiving hole 6 during the friction between the bearing and the second component, enabling it to form a lubricating layer in the initial stage and effectively perform its lubricating function. In contrast, the radial contraction height of the first solid lubricant 7, made of high-purity graphite, is 0.06 mm. This makes it difficult for the first solid lubricant 7 to extend from the receiving hole 6 during the friction between the bearing and the second component, resulting in poorer lubrication performance in the initial stage.

[0083] Depend on Figures 13-24 Based on the thermal expansion parameters of the first solid lubricant 7 made of different materials mentioned above, it can be seen that under the same conditions, since the thermal expansion of modified graphite (including polytetrafluoroethylene and graphite) is greater than that of high-purity graphite, the first solid lubricant 7 made of modified graphite (including polytetrafluoroethylene and graphite) is more likely to extend out of the receiving hole 6 to perform a lubricating function. As a result, the lubrication effect of the first solid lubricant 7 made of modified graphite (including polytetrafluoroethylene and graphite) is better than that of the first solid lubricant 7 made of high-purity graphite.

[0084] In some embodiments, the matrix is ​​a polymer matrix, a copper alloy matrix, a nickel alloy matrix, or a steel matrix. Polymer matrices, copper alloy matrices, nickel alloy matrices, and steel matrices all possess good self-lubricating properties, which can improve the lubrication performance between the second component 12 and the bearing, and reduce the coefficient of friction between the second component 12 and the bearing.

[0085] Specifically, when the matrix is ​​a copper alloy matrix, the matrix material can be selected as tin bronze. Steel is an iron-carbon alloy with a carbon content between 0.02% and 2.11% by mass.

[0086] If the matrix is ​​a polymer matrix, its hardness is 50~100HD. For example, the hardness of the matrix can be 50HD, 60HD, 70HD, 80HD, 90HD, 100HD, etc.

[0087] If the substrate is a copper alloy or nickel alloy, its hardness ranges from 100HV to 500HV. For example, the hardness of the substrate can be 100HV, 200HV, 300HV, 400HV, 500HV, etc. For example, if the substrate material is tin bronze, its hardness is 180HV.

[0088] refer to Figures 7-8 , Figures 10-11 In some embodiments, the first solid lubricant 7 is disposed on the first mating surface, and the thickness h of the first solid lubricant 7 satisfies: 1μm≤h≤10μm. For example, the value of h can be 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, etc.

[0089] By placing the first solid lubricant 7 on the first mating surface and setting its thickness within the aforementioned range, the first solid lubricant 7 can fully contact the second component 12 when the second component 12 slides relative to the bearing, and has good support, thereby better lubricating the second component 12 and reducing the coefficient of friction between the second component 12 and the bearing.

[0090] In some embodiments, the first solid lubricant 7 disposed on the first mating surface may be a diamond-like carbon coating or a polytetrafluoroethylene (PTFE) coating. The diamond-like carbon coating or PTFE coating may be formed by processes such as electrochemical methods, spraying, vacuum magnetron sputtering, and chemical vapor deposition.

[0091] In some embodiments, the second component 12 includes a body and a wear-resistant component; the body has a second mating surface adapted to mate with a bearing, and at least a portion of the wear-resistant component is disposed on the first mating surface or exposed on the second mating surface.

[0092] By providing wear-resistant components on the second mating surface of the main body, the hardness of the second component 12 can be increased, for example, by increasing the hardness of the spindle 121 and / or the guide 114, thereby improving the wear resistance of the second component 12 and reducing wear between the second component 12 and the bearing.

[0093] It should be noted that "at least part of the wear-resistant part is exposed on the second mating surface" means that the wear-resistant part can be seen and touched from the second mating surface. The mating surface of the wear-resistant part can be flush with, lower than, or higher than the second mating surface.

[0094] For example, the material of the wear-resistant part can be chromium or diamond-like carbon. For example, the material of the main body can be stainless steel 316L or GCr15.

[0095] For example, the wear-resistant component can be a wear-resistant coating disposed on the second mating surface of the main body. Also for example, the wear-resistant component can be a cylindrical structure fixed to the second mating surface of the main body. Still for example, the wear-resistant component can be a block structure, columnar structure, cylindrical structure, etc., partially embedded in the main body and partially exposed on the second mating surface.

[0096] In some embodiments, the surface roughness Ra of the second mating surface is less than 0.1. For example, the surface roughness Ra of the second mating surface can be made less than 0.1 by polishing or fine grinding processes. This is beneficial for further improving the lubrication effect between the second component 12 and the bearing, effectively reducing the gap between the static friction coefficient μ1 and the dynamic friction coefficient μ2, thereby effectively improving the abnormal noise problem of the motor 1.

[0097] In some embodiments, a lubricating medium may be provided between the second component 12 and the bearing, which can further reduce the friction between the second component 12 and the bearing.

[0098] Optionally, the lubricating medium can be made of polytetrafluoroethylene (PTFE), molybdenum disulfide, etc. Compared with ordinary grease, PTFE, molybdenum disulfide, and other lubricating media have the same viscosity and consistency grade, but the former two contain solid lubricant components, which can effectively reduce adhesive wear. Figure 25 As shown, the coefficients of friction of PTFE and molybdenum disulfide greases are reduced by 57% and 65% respectively compared to ordinary greases. PTFE and molybdenum disulfide are typically composed of μm or nm-sized particles. In the linear sliding layer, these particles primarily function as easily sheared particles with extremely small diameters, reducing the sliding friction of the sliding layer.

[0099] refer to Figure 4 , Figures 6-8 In some embodiments, at least one bearing includes a first bearing 115, which is fixed to a first assembly 11. A second assembly 12 includes a spindle 121, which is slidably disposed within the first bearing 115. The base of the first bearing 115 is a first bearing 115 base. By providing the first bearing 115, the friction between the spindle 121 and the first assembly 11 can be reduced, thereby reducing the starting resistance of the motor 1 and thus helping to solve the problem of abnormal noise.

[0100] refer to Figures 3-4 In some embodiments, the first component 11 includes a housing 111, the housing 111 being aligned along a first direction (e.g., Figure 3A mounting hole 111A is provided at one end of the spindle 121 in the direction W shown in the diagram. The mounting hole 111A can extend along the axial direction of the spindle 121 and communicates with the internal space of the housing 111. The spindle 121 passes through the mounting hole 111A and is slidably connected to the housing 111 along the axial direction of the spindle 121. That is, part of the spindle 121 is located inside the housing 111, and the other part of the spindle 121 is located outside the housing 111.

[0101] The first direction is the direction of movement of the first component 11 relative to the second component 12. The axial direction of the spindle 121 is consistent with the first direction.

[0102] Optionally, the second component 12 further includes a mandrel 121 sleeve, which is sleeved on the outside of the mandrel 121.

[0103] The first bearing 115 is housed in the mounting hole 111A and fixed to the housing 111. The spindle 121 passes through the first bearing 115 and is slidably connected to the first bearing 115 along the axial direction of the spindle 121. The first bearing 115 can be a linear bearing.

[0104] At this time, the main component is the mandrel 121, and the second mating surface can be the outer peripheral surface of the mandrel 121. At least a portion of the wear-resistant component is disposed on or exposed on the outer peripheral surface of the mandrel 121.

[0105] refer to Figure 5 , Figures 9-11 In some embodiments, at least one bearing further includes a second bearing 124. A guide hole 121A is provided within the spindle 121, and the second bearing 124 is fixed within the guide hole 121A. The second assembly 12 includes a guide member 114, which is accommodated in the guide hole 121A and slidably passes through the second bearing 124. Optionally, the second bearing 124 can be a linear bearing. The base of the second bearing 124 is a second bearing 124 base. By providing the second bearing 124, the friction between the guide member 114 and the spindle 121 can be reduced, thereby reducing the starting resistance of the motor 1 and thus helping to solve the problem of abnormal noise.

[0106] In some embodiments, the guide 114 is fixed relative to the housing 111.

[0107] For example, the first component 11 also includes a lower fork 113 connected to the outside of the housing 111. The lower fork 113 and another portion of the spindle 121 are distributed opposite to each other on the outside of the housing 111. The portion of the spindle 121 located outside the housing 111 is used to connect the vehicle body 10, and the lower fork 113 is connected to the wheel 20. By sliding the spindle 121 relative to the housing 111 along the axial direction of the spindle 121, the vehicle body 10 and the wheel 20 can be moved relative to each other, thereby adjusting the distance between the vehicle body 10 and the wheel 20.

[0108] The guide 114 is located inside the housing 111 and connected to the lower fork 113 so as to be fixedly connected to the housing 111 via the lower fork 113.

[0109] The spindle 121 is provided with a guide hole 121A. The guide hole 121A extends along the axial direction of the spindle 121, and the guide member 114 is accommodated in the guide hole 121A. When the first component 11 moves relative to the second component 12, the guide member 114 moves in the guide hole 121A.

[0110] During the relative movement of the spindle 121 and the housing 111, the guide member 114 moves within the guide hole 121A to guide the spindle 121 and the housing 111 through the cooperation of the guide member 114 and the spindle 121, thereby improving the stability and smoothness of the relative movement between the spindle 121 and the housing 111.

[0111] For example, the guide member 114 can be a rod-shaped structure, a plate-shaped structure, an irregular structure, etc., which will not be described in detail here.

[0112] refer to Figure 30 In some embodiments, the starting resistance of the motor 1 is tested using a test bench 350 to verify the effect of the ratio of static friction coefficient μ to dynamic friction coefficient μ on the starting resistance. The test bench 350 includes a base 351, multiple support rods 352, a top plate 353, an electric cylinder 354, and a lateral force application mechanism 355.

[0113] Multiple support rods 352 are connected between the base 351 and the top plate 353 to support the top plate 353. An electric cylinder 354 is connected to the top plate 353. A lateral force applicator 355 is mounted on the base 351. Exemplarily, the lateral force applicator 355 can be a pneumatic pressurizing device such as a cylinder, a hydraulic pressurizing device such as a hydraulic push rod, an electric pressurizing device such as an electric push rod, etc.

[0114] When testing the starting resistance of motor 1, one of the first component 11 and the second component 12 can be fixedly connected to the base 351, and the other of the first component 11 and the second component 12 can be connected to the electric cylinder 354. The electric cylinder 354 is used to drag the first component 11 and the second component 12 to move relative to each other. Furthermore, while the electric cylinder 354 is dragging the first component 11 and the second component 12 to move relative to each other, the lateral force application mechanism 355 is used to apply a lateral force to one of the first component 11 and the second component 12.

[0115] The first component 11 and the second component 12 include a lower fork arm 113. The lower fork arm 113 is provided with two bolt holes for fixing the fork arm to the base 351 with bolts, thereby fixing the first component 11 and the second component 12 to the base 351.

[0116] The direction of relative movement between the first component 11 and the second component 12 is the same as the vertical direction, and the direction of the lateral force is perpendicular to the direction of relative movement between the first component 11 and the second component 12, and also perpendicular to the line connecting the two bolt holes on the fork arm. Specifically, while applying a vertical force to the other of the first component 11 and the second component 12, an additional lateral force (i.e., radial force) is also applied to the other of the first component 11 and the second component 12.

[0117] It should be noted that the direction of gravity is fixed, while the direction of the force applied by the test bench 350 may be the same as or opposite to the direction of gravity. Therefore, the direction of gravity can be defined as the negative direction.

[0118] The test bench 350 also includes a tension sensor and a pressure sensor. The tension sensor is used to detect the magnitude of the force output by the electric cylinder 354. The pressure sensor is used to detect the magnitude of the force output by the lateral force application mechanism 355.

[0119] It should be noted that before testing motor 1, the values ​​detected by the tension sensor and pressure sensor need to be zeroed to ensure the accuracy of the test results.

[0120] The test bench 350 may also include a position sensor for detecting the relative displacement of the first component 11 and the second component 12, and combining this position sensor with data detected by a tension sensor and a pressure sensor to obtain a resistance curve of the starting resistance of the motor 1. In some other examples, the relative displacement of the first component 11 and the second component 12 may also be detected using a displacement sensor of the motor 1.

[0121] For example, during the starting resistance test of motor 1, the second component 12 can move relative to the first component 11 along a first direction and move between a compression limit position and a tensile limit position. The process of the second component 12 moving from a position close to the tensile limit to a position close to the compression limit, and the process of the second component 12 moving from a position close to the compression limit to a position close to the tensile limit, both require three stages: an acceleration stage, a constant speed stage, and a deceleration stage.

[0122] The two endpoints of the second component 12 during the acceleration phase are designated as the first position and the second position, respectively. The force that prevents the second component 12 from moving from the first position to the second position is the starting resistance of the motor 1.

[0123] For details, please refer to Figure 26 , Figure 26 This is a graph showing the resistance of the second component 12 of motor 1 during its movement relative to the first component 11. The curve segment a5 in the graph (i.e., the curve segment between the 0 point and the displacement L) is the curve of the starting resistance of motor 1, and the displacement L is the displacement of the second component 12 of motor 1 during the acceleration phase.

[0124] In order to reduce friction noise during motor 1 startup and improve the NVH performance of motor 1, the distance L that motor 1 moves from the first position to the second position and the starting resistance of motor 1 need to be controlled within a suitable range.

[0125] If the distance L that the first component 11 moves from the first position to the second position is too short, the acceleration required for the first component 11 during the acceleration phase will be greater, which can easily lead to severe frictional resistance between the first component 11 and the second component 12, thus easily generating frictional noise. Conversely, if the distance L is too long, it will result in a slower response speed of the motor 1, affecting its performance. Therefore, the distance L that the first component 11 moves from the first position to the second position needs to be appropriate to reduce frictional noise.

[0126] Furthermore, if the starting resistance f4 is too large, i.e., the force preventing the first component 11 from moving is too large, it will lead to significant frictional resistance between the first component 11 and the second component 12. This would require a large acceleration when the motor 1 starts, easily generating frictional noise. Conversely, if the starting resistance f is too small, less than the weight G of the first component 11, the first component 11 cannot move relative to the second component 12 during the extension process of the motor 1. Therefore, the starting resistance f acting on the first component 11 needs to be appropriate to reduce frictional noise and ensure that the motor 1 can move normally.

[0127] Extensive research has revealed that the distance L that the first component 11 moves from the first position to the second position is related to the lateral force A applied to the second component 12, the maximum velocity B of the first component 11, and the acceleration C of the first component 11. Therefore, the length of the distance L that the first component 11 moves from the first position to the second position can be reasonably set based on the lateral force A applied to the second component 12, the maximum velocity B of the first component 11, and the acceleration C of the first component 11.

[0128] Furthermore, the starting resistance f experienced by the first component 11 is related to the lateral force A applied to the second component 12, the maximum speed B of the first component 11, the acceleration C of the first component 11, and the gravity G of the first component 11. Therefore, the magnitude of the starting resistance f experienced by the first component 11 can be reasonably set based on the lateral force A applied to the second component 12, the maximum speed B of the first component 11, the acceleration C of the first component 11, and the gravity G of the first component 11.

[0129] Specifically, in some embodiments, the first component 11 can move relative to the second component 12 along a first direction. After the first component 11 is stationary relative to the second component 12 at a first position, the first component 11 is controlled to move relative to the second component 12 to a second position. The length of the motor 1 when the first component 11 is in the second position is less than the length of the motor 1 when the first component 11 is in the first position.

[0130] The distance L that the first component 11 moves from the first position to the second position satisfies: L = 3.00289 - 0.000344 × A - 0.030683 × B - 0.002967 × C - 0.000011 × A × B - 2.35042 × 10⁻⁷ × A × C + 0.000355 × B × C.

[0131] Furthermore, during the process of controlling the first component 11 to move from the first position to the second position, the force F applied to the first component 11 satisfies: F = -f4 - G.

[0132] Where f4 is the starting resistance of the first component 11, and the starting resistance f4 satisfies: 0<|f4|≤(1.50801-7.98184×10-6×A-0.000424×B-0.000251×C+4.11618×10-7×A×B+8.73602×10-8×A×C+0.000014×B×C)×|G|, where “||” indicates taking the absolute value, G is the gravity of the first component 11; A is the lateral force applied to the second component 12; B is the maximum speed of the first component 11; and C is the acceleration of the first component 11.

[0133] It should be noted that A, B, and C are just numerical values, representing the influence of different factors on the distance L and starting resistance f4 of the first component 11 of motor 1. Different values ​​of A, B, and C can be selected according to different test requirements.

[0134] In some embodiments, the first solid lubricant 7 is made of different materials, and the vibration frequency and abnormal noise of the motor 1 are different. Using a material with a smaller ratio of static friction coefficient μ1 to dynamic friction coefficient μ2 is beneficial to reduce the abnormal noise of the motor 1 during operation and improve the NVH performance of the motor 1.

[0135] like Figures 27-29 As shown, Figure 27 The NVH test results of the motor 1, which uses high-purity graphite for the first solid lubricant 7, are shown in the figure. Figure 28 The NVH test results of motor 1 using diamond-like carbon for the first solid lubricant 7 are shown in the figure. Figure 29 The figure shows the NVH test results of the motor 1 using modified graphite as the first solid lubricant 7. Through vehicle NVH testing of motors 1 using high-purity graphite and modified graphite, it can be seen from the figure that the motor 1 using high-purity graphite as the first solid lubricant 7 exhibits significant vibration in the 120-100Hz frequency range, resulting in a drumming noise. The motor 1 using diamond-like carbon as the first solid lubricant 7 vibrates in the 20-100Hz frequency range, but the vibration frequency is significantly lower than that of the motor 1 using high-purity graphite as the first solid lubricant 7, reducing the drumming noise. The motor 1 using modified graphite (including polytetrafluoroethylene and graphite) as the first solid lubricant 7 shows no significant vibration in the 20-100Hz frequency range, and the vehicle exhibits no drumming noise, improving the overall quietness of the vehicle.

[0136] from Figures 27-29 The comparison shows that the frequency range in which friction noise occurs is 30-200Hz. Figure 27 The vibration was most severe in the middle. Figure 28 The vibration was significantly reduced. Figure 27 and Figure 28 The vibration situation in it is significantly better than Figure 29 The vibration is severe. Figure 29 There is virtually no noticeable vibration. In other words, Figure 29 The situation of friction noise is more than Figure 27 and Figure 28 The problem of friction noise has been significantly improved. Furthermore, when... Figure 27 Corresponding motor 1 and Figure 29 When the corresponding motor 1 is installed on the vehicle for testing... Figure 9 A noticeable frictional noise can be heard from motor 1, while Figure 15 The corresponding motor 1 has almost no friction noise.

[0137] Combination Figure 12 It can be seen that the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 of the first solid lubricant 7 made of different materials is as follows: the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 of modified graphite (including polytetrafluoroethylene and graphite) is smaller than that of diamond-like carbon, and the ratio of the static friction coefficient μ1 to the dynamic friction coefficient μ2 of diamond-like carbon is smaller than that of high-purity graphite. Figures 27-29The test results shown indicate that the NVH test results of motor 1 using modified graphite (including polytetrafluoroethylene and graphite) are significantly better than those of motor 1 using diamond-like carbon and high-purity graphite. This suggests that using materials with a smaller ratio of static friction coefficient μ1 to dynamic friction coefficient μ2 can reduce abnormal noise during operation and improve the NVH performance of motor 1.

[0138] Furthermore, it can be seen that the smaller the ratio of static friction coefficient μ1 to dynamic friction coefficient μ2, the smaller the starting resistance f4 of motor 1 during operation, the less abnormal noise generated by motor 1, and the better NVH performance.

[0139] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electric motor (1), characterized in that, include: First component (11) and second component (12); as well as At least one bearing, the bearing being fixed to the first component (11), and the second component (12) being slidably fitted to the bearing; The static friction coefficient between the second component (12) and the bearing is μ1, and the dynamic friction coefficient between the second component (12) and the bearing is μ2. μ1 and μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 2.

2. The motor (1) according to claim 1, characterized in that, μ1 and μ2 satisfy: 1 ​​< μ1 / μ2 ≤ 1.65; Alternatively, 1 < μ1 / μ2 ≤ 1.5; Alternatively, μ1 and μ2 satisfy: 0.03 ≤ μ1 - μ2 ≤ 0.07; Alternatively, μ1 and μ2 satisfy: 0 < μ1 - μ2 ≤ 0.065; Alternatively, μ1 and μ2 satisfy: 0 < μ1 - μ2 ≤ 0.04; Alternatively, μ1 and μ2 satisfy: 0.04≤μ1-μ2≤0.

05.

3. The motor (1) according to claim 1, characterized in that, The static friction coefficient μ1 satisfies: 0.135≤μ1≤0.165; or 0.14≤μ1≤0.

16.

4. The motor (1) according to claim 1, characterized in that, The coefficient of kinetic friction μ2 satisfies: 0.08≤μ2≤0.12; or 0.1≤μ2<0.

15.

5. The motor (1) according to claim 1, characterized in that, The bearing includes a base and a first solid lubricant (7); The substrate has a first mating surface, which is adapted to mate with the second component (12); At least a portion of the first solid lubricant (7) is disposed on or exposed on the first mating surface.

6. The motor (1) according to claim 5, characterized in that, The substrate is provided with a plurality of receiving holes (6), and one end of the plurality of receiving holes (6) is located on the first mating surface; The first solid lubricant (7) is disposed within the plurality of receiving holes (6).

7. The motor (1) according to claim 5, characterized in that, The material of the first solid lubricant (7) includes at least one of graphite, diamond-like carbon, fluorine-containing compounds, and molybdenum disulfide.

8. The motor (1) according to claim 7, characterized in that, The materials of the first solid lubricant (7) include polytetrafluoroethylene and graphite; The polytetrafluoroethylene comprises 80% or more by mass and 95% or less by mass; the graphite comprises 5% or more by mass and 20% or less by mass.

9. The motor (1) according to claim 5, characterized in that, The matrix is ​​a polymer matrix, a copper alloy matrix, a nickel alloy matrix, or a steel matrix.

10. The motor (1) according to claim 5, characterized in that, The first solid lubricant (7) is disposed on the first mating surface, and the thickness h of the first solid lubricant (7) satisfies: 1μm≤h≤10μm.

11. The motor (1) according to claim 5, characterized in that, The second component (12) includes a main body and a wear-resistant component; The main body has a second mating surface, which is adapted to mate with the bearing. At least a portion of the wear-resistant component is disposed on or exposed on the second mating surface.

12. The motor (1) according to any one of claims 1-11, characterized in that, The at least one bearing includes a first bearing (115) fixed to the first component (11), and the second component (12) includes a mandrel (121) slidably inserted into the first bearing (115).

13. The motor (1) according to claim 12, characterized in that, The first component (11) includes a housing (111), and the housing (111) has a mounting hole (111A) at one end along the first direction. The first bearing (115) is housed in the mounting hole (111A) and fixed to the housing (111).

14. The motor (1) according to claim 12, characterized in that, The at least one bearing further includes a second bearing (124), the spindle (121) is provided with a guide hole (121A), the second bearing (124) is fixed in the guide hole (121A), and the second component (12) includes a guide member (114), the guide member (114) is accommodated in the guide hole (121A) and slidably passes through the second bearing (124).

15. A suspension assembly (30), characterized in that, Includes the motor (1) as described in any one of claims 1-14.

16. A vehicle (100), characterized in that, Includes the motor (1) as described in any one of claims 1-14, or the suspension assembly (30) as described in claim 15.

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