A differential damper and a hub motor containing the same

Abstract

The present invention belongs to the technical field of in-wheel hub motors and provides a differential damper and an in-wheel hub motor incorporating the differential damper. The differential damper comprises a damping chamber cover plate and a damping chamber planetary carrier. Multiple oil-gas compression variable damping closed chambers are provided on one side of the damping chamber cover plate. A damping piston is disposed between the damping chamber cover plate and the damping chamber base. The damping piston comprises a piston base, a shaft sleeve, and a compression block that matches the oil-gas compression variable damping closed chambers. The damping chamber planetary carrier is provided with multiple evenly distributed planetary ports, each containing a planetary gear. The transmission ends of the planetary gears are configured to mesh with the sun gear and ring gear. The present invention ensures the matching of the in-wheel hub motor's speed and torque, improving the stability of the output torque. Furthermore, the present invention is lightweight, eliminating the need for thicker wire, and facilitates better heat dissipation, thereby improving the operating performance of vehicles equipped with the in-wheel hub motor.

Description

Technical Field

[0001] The present invention belongs to the technical field of hub motors, and in particular relates to a differential damper and a hub motor containing the differential damper. Background Art

[0002] For traditional vehicles, clutches, transmissions, drive shafts, differentials, and even transfer cases are essential. These components are generally heavy and complicate the vehicle's structure, requiring regular maintenance and leading to high failure rates. In-wheel motors integrate the power, transmission, and braking systems into the wheel hub, significantly simplifying the mechanical components of the electric vehicle. This drive method shortens the power transmission path and improves the vehicle's transmission efficiency. Because in-wheel motors can independently drive a single wheel, they can accommodate multiple drive modes, including front-wheel drive, rear-wheel drive, and four-wheel drive. By achieving differential steering similar to tracked vehicles through different left and right wheel speeds, or even reverse rotation, the in-wheel motor can reduce the vehicle's turning radius.

[0003] Existing in-wheel motors include a housing, a rotor assembly, a stator armature assembly, a stator support, and a wheel hub bearing assembly. Vehicles using in-wheel motors are equipped with in-wheel motors in their paired wheel hubs. However, because the in-wheel motors are directly mounted on the tires, they come into indirect contact with the ground and are subject to complex forces fed back from the ground. This can lead to problems such as motor shaft movement, vibration, and rotation, affecting the motor's output torque. Furthermore, if the in-wheel motors of front-wheel drive, rear-wheel drive, or four-wheel drive vehicles are out of sync, this can cause driving friction and impact within one or more of the in-wheel motors. These friction and impacts can directly affect the motor's speed and torque, negatively impacting the vehicle's driving performance. Summary of the Invention

[0004] In response to the technical problems existing in the above-mentioned vehicle hub motor, the present invention proposes a differential damper and a hub motor containing the differential damper, which have a reasonable design and a simple structure, are beneficial to extending the service life of the hub motor and improving the vehicle's operating performance.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is as follows: the present invention provides a differential damper and a hub motor containing the differential damper, wherein a differential damper includes a damping chamber cover plate and a damping chamber planetary carrier arranged opposite to each other, the damping chamber cover plate is provided with an axial connecting piece connecting it to the damping chamber planetary carrier, a plurality of oil-gas compression variable damping closed chambers distributed at intervals are provided on one side of the damping chamber cover plate, the oil-gas compression variable damping closed chamber is used to store pressurized oil and air, and the supply end and the breathing end of the oil-gas compression variable damping closed chamber are respectively provided with a pressure regulating element. Oil hole and breathing valve, a damping piston is arranged between the damping chamber cover and the damping chamber base, the damping piston includes a piston base, a shaft sleeve is arranged at the center of the piston base, the shaft sleeve is used to be connected to the motor shaft transmission and to seal with the inner wall of the damping chamber cover and the inner wall of the damping chamber planetary carrier, the edge of the piston base is provided with a plurality of compression blocks that match the oil and gas compression variable damping closed cavity one by one, the damping chamber planetary carrier is provided with a plurality of evenly distributed planetary ports, planetary gears are arranged in the planetary ports, and the transmission end of the planetary gear is used to engage with the sun gear and the ring gear.

[0006] Preferably, the compression variable block includes a radial portion, an arc-shaped portion is provided at one end of the radial portion away from the center of the sleeve, and the oil-gas compression variable damping closed chamber includes a radial opening cooperating with the radial portion and an arc-shaped opening cooperating with the arc-shaped portion, and the arc-shaped trajectory length of the arc-shaped opening is greater than the arc-shaped trajectory length of the arc-shaped portion.

[0007] Preferably, the axial connecting member includes a shaft portion, a countersunk portion is provided at the end of the shaft portion, a pin is provided on the side of the shaft portion, and a pin hole cooperating with the pin is provided on the damping chamber planetary carrier near the damping chamber cover.

[0008] A hub motor comprises a shell, a rotor assembly is arranged inside the shell, a stator-armature assembly and a resolver are arranged inside the rotor assembly, a stator support is arranged inside the stator-armature assembly, a hub bearing assembly is arranged inside the stator support, the hub bearing assembly comprises a motor shaft, the above-mentioned differential damper is arranged inside the hub bearing assembly, the hub bearing assembly comprises a sun gear matched with a planetary gear, the sun gear is arranged on the motor shaft, an axial tube body is provided on the rotor assembly and is sleeved on the motor shaft, the axial tube body is connected to the sun gear by a key, and a gear ring matched with the planetary gear is provided on the inside of the stator support.

[0009] Preferably, a hub motor further includes a hybrid cooling structure, wherein the hybrid cooling structure includes a water cooling component and an air cooling component.

[0010] Preferably, the water cooling assembly includes a water inlet and a water outlet arranged on the outer shell, and a serpentine pipeline distributed around the stator support is provided between the water inlet and the water outlet, and the serpentine pipeline is formed by connecting a plurality of U-shaped pipes in sequence.

[0011] Preferably, the stator support is provided with a plurality of circulating air channels, the circulating air channels are communicated with the outer shell front to back, and the outer shell is provided with an air inlet and an air outlet connected with the circulating air channels.

[0012] Preferably, the resolver is arranged on the stator support and away from the differential damper, and the rotor assembly is provided with a plurality of adjustment ports opposite to the differential damper.

[0013] Compared with the prior art, the advantages and positive effects of the present invention are:

[0014] 1. The present invention provides a differential damper in which the oil-gas compression variable damping closed chamber can provide buffering resistance to the damping piston after being filled with pressurized oil and air. The oil-gas compression variable damping closed chamber and the damping piston will maintain the same speed as much as possible under the drive of the hub motor, effectively reducing or even avoiding the problems of friction, movement and vibration inside the hub motor, ensuring the matching degree of the hub motor speed and torque, improving the stability of the output torque, and thus protecting the vehicle's operating performance and the actual service life of the present invention.

[0015] 2. The in-wheel motor provided by the present invention can not only ensure the running performance of the vehicle by adding a differential damper, but also play a decelerating role by designing the planetary gears, gears and ring gears, and can also enable the in-wheel motor to obtain the required speed acceleration ratio with a smaller mass, avoid the use of thicker wires, and also facilitate obtaining better heat dissipation performance, thereby improving the running performance of the vehicle using the in-wheel motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 An exploded diagram of a differential damper provided in an embodiment;

[0018] Figure 2 A front view of a differential damper provided in an embodiment;

[0019] Figure 3 A cross-sectional view of a differential damper provided in an embodiment along the BB direction;

[0020] Figure 4 An axonometric view of the internal structure of a differential damper provided in an embodiment;

[0021] Figure 5 An exploded view of a hub motor provided in an embodiment;

[0022] Figure 6 A side view of a hub motor provided in an embodiment;

[0023] Figure 7 A front view of a hub motor provided in an embodiment;

[0024] Figure 8 A cross-sectional view of a hub motor taken along the AA direction provided in an embodiment;

[0025] In the above figures, 1. housing; 2. rotor assembly; 21. regulating port; 3. stator armature assembly; 4. resolver; 5. hub bearing assembly; 51. sun gear; 52. motor shaft; 53. ring gear; 6. differential damper; 61. damping chamber cover plate; 62. damping chamber planet carrier; 63. axial connector; 631. shaft portion; 632. countersunk head; 633. pin; 64. oil-gas compression variable damping closed chamber; 641. radial port; 642. arcuate port; 65. oil filling port; 66. breathing valve; 67. damping piston; 671. piston base; 672. compression block; 672a. radial portion; 672b. arcuate portion; 673. sleeve; 68. Planetary gear; 7. Hybrid cooling structure; 71. Water cooling assembly; 711. Water inlet; 712. Water outlet; 713. Serpentine pipe; 72. Air cooling assembly; 721. Circulating air duct; 722. Air inlet; 723. Air outlet; 8. Stator support. DETAILED DESCRIPTION

[0026] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other unless they conflict. For the convenience of description, the words "upper", "lower", "left", and "right" appearing below only indicate the upper, lower, left, and right directions consistent with the drawings themselves and do not limit the structure.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Examples, such as Figure 1-4As shown, the present invention provides a differential damper, a differential damper, comprising a damping chamber cover plate 61 and a damping chamber planetary carrier 62 arranged opposite to each other, the damping chamber cover plate 61 is provided with an axial connecting member 63 connecting it to the damping chamber planetary carrier 62, a plurality of oil-gas compression variable damping closed chambers 64 spaced apart are provided on one side of the damping chamber cover plate 61, the oil-gas compression variable damping closed chamber 64 is used to store pressurized oil and air, the supply end and the breathing end of the oil-gas compression variable damping closed chamber 64 are respectively provided with a refueling hole 65 and a breathing valve 66, a damping piston 67 is provided between the damping chamber cover plate 61 and the damping chamber base, the damping piston 67 comprises a piston base 671, a shaft sleeve 673 is provided at the center of the piston base 671, and the shaft sleeve 673 The piston base 671 is designed to provide a driving connection with the motor shaft 52 and seal against the inner wall of the damping chamber cover plate 61 and the inner wall of the damping chamber planet carrier 62. The edge of the piston base 671 is equipped with multiple compression blocks 672 that mate with the oil-gas compression variable damping sealed chamber 64. The damping chamber planet carrier 62 is provided with multiple evenly distributed planetary ports, each of which houses planetary gears 68. The transmission ends of the planetary gears 68 mesh with the sun gear 51 and the ring gear 53. The damping piston 67 is rotatable about the axis of the motor shaft 52, and the extensions of its sleeve 673 at both ends seal against the inner walls of the damping chamber cover plate 61 and the inner walls of the damping chamber planet carrier 62. In this way, the oil-gas compression variable damping closed chamber 64 maintains a relatively sealed environment with the damping chamber cover 61, damping chamber planetary carrier 62, and damping piston 67 assembled. Furthermore, the volume of the oil-gas compression variable damping closed chamber 64 is larger than that of the damping piston 67, allowing the damping piston 67 to maintain a certain cushioning angle within the oil-gas compression variable damping closed chamber 64. The oil filling hole 65 is used to fill the oil-gas compression variable damping closed chamber 64 with pressurized oil, while the breather valve 66 allows some air under pressure to enter or be discharged from the oil-gas compression variable damping closed chamber 64. The pressurized oil can be lubricating oil, which, as a liquid, is incompressible.

[0029] Furthermore, each oil-gas compression variable damping closed chamber 64 is relatively independent and sealed. During the process of filling the components in the oil-gas compression variable damping closed chamber 64 with pressurized oil, the resistance experienced by the compression block 672 of the damping piston 67 increases nonlinearly. After filling to a certain amount, because all oil-gas compression variable damping closed chambers 64 contain uneven volumes of air and pressurized oil, the resistance experienced by the damping piston 67 increases rapidly and nonlinearly until the differential damper 6, driven by the hub motor, reaches equilibrium with its oil-gas compression variable damping closed chamber 64 and the damping piston 67 and rotates at the same speed. In this way, the piston will never form a mechanical impact on the bottom of the cavity, and the problems of friction, movement, and vibration inside the hub motor are effectively reduced or even avoided, ensuring the matching degree of the hub motor speed and torque, improving the stability of the output torque, and thus guaranteeing the vehicle's operating performance and the actual service life of the present invention.

[0030] To improve the cushioning performance of the differential damper 6, the present invention provides a compression block 672 comprising a radial portion 672a. An arcuate portion 672b is provided at one end of the radial portion 672a, distal from the center of the sleeve 673. The oil-gas compression variable damping sealed chamber 64 comprises a radial opening 641, which cooperates with the radial portion 672a, and an arcuate opening 642, which cooperates with the arcuate portion 672b. The arcuate path length of the arcuate opening 642 is greater than that of the arcuate portion 672b. The edge of the arcuate opening 642 is sealed against the outer wall of the sleeve 673, preventing the medium in the entire oil-gas compression variable sealed chamber from overflowing from the sidewalls of the damping piston 67. Immediately after being driven by the sun gear 51, the damping piston 67 generates a force equilibrium with the medium in the oil-gas compression variable damping closed chamber 64. Its radial portion 672a rotates around the center along the length of the radial opening 641, while the arcuate portion 672b rotates along the length of the arcuate opening 642 until equilibrium is restored and the oil-gas compression variable damping closed chamber 64 rotates synchronously with the damping piston 67. The end of the arcuate portion 672b of the variable pressure block 672 provides an effective buffering surface, which not only achieves a relatively sensitive response but also ensures smooth operation, contributing to noise reduction and extended component life.

[0031] In order to improve the rapid assembly performance of the differential damper 6, the axial connector 63 provided by the present invention includes a shaft portion 631, a countersunk head 632 provided at the end of the shaft portion 631, a pin 633 provided on the side of the shaft portion 631, and a pin hole that cooperates with the pin 633 provided near the damping cavity cover on the damping cavity planetary carrier 62. In this way, after the shaft portion 631 is inserted into the damping cavity cover plate 61 and the damping cavity planetary carrier 62 and reaches the depth limit, the pin 633 is driven into the pin hole from a radial position to achieve the rapid connection of the differential damper 6. It should be noted that the number of axial connectors 63 connecting the damping cavity cover plate 61 and the damping cavity planetary carrier 62 on the differential damper 6 is at least 3 and is evenly distributed.

[0032] like Figure 4-8 As shown, the present invention provides a hub motor comprising a housing 1, within which is disposed a rotor assembly 2. Inside the housing 1 are disposed a stator-armature assembly 3 and a resolver 4. Inside the stator-armature assembly 3 are disposed a stator support 8. Inside the stator support 8 are disposed a hub bearing assembly 5, which includes a motor shaft 52. Resolver 4 is an electromagnetic sensor and the most critical sensor in a motor controller, used to measure the angular displacement and angular velocity of a rotating object. Resolver 4, along with the rotor assembly 2, stator-armature assembly 3, stator support 8, and hub bearing assembly 5, are all based on existing mature technologies and will not be further described in this embodiment. On this basis, the present invention provides a differential damper 6 within the wheel hub bearing assembly 5. The wheel hub bearing assembly 5 includes a sun gear 51 that cooperates with planetary gears 68. The sun gear 51 is disposed on a motor shaft 52. The rotor assembly 2 is provided with an axial tube that sleeves on the motor shaft 52. The axial tube is keyed to the sun gear 51. The stator support is provided with a ring gear 53 that cooperates with the planetary gears 68. In this way, after the magnetic induction portion of the rotor assembly 2 interacts with the current-generating stator armature assembly 3 to generate movement, the rotor assembly 2 transmits rotational power to the sun gear 51. The sun gear 51 drives the entire differential damper 6 through the planetary gears 68. The differential damper 6 gradually achieves balance during rotation, and its shaft sleeve 673 directly drives the motor shaft 52 to output rotational power, thereby achieving the wheel hub motor driving the wheel hub. The in-wheel motor can not only ensure the running performance of the vehicle by adding a differential damper 6, but also play a decelerating role by designing the planetary gear 68, the gear and the ring gear 53, and can also enable the in-wheel motor to obtain the required speed acceleration ratio with a smaller mass, avoid the use of thicker wire, and thus improve the driving control performance and running performance of the vehicle using the in-wheel motor.

[0033] Considering the added heat dissipation challenges inherent in the integrated design of the in-wheel motor, the present invention incorporates a hybrid cooling structure 7 within the in-wheel motor, comprising a water-cooling assembly 71 and an air-cooling assembly 72. By employing these two cooling methods, the in-wheel motor is simultaneously cooled, effectively preventing the inefficient dissipation of heat generated by friction after prolonged operation.

[0034] To improve the performance of the hub motor provided by the present invention, the water-cooling assembly 71 includes a water inlet 711 and a water outlet 712 provided on the housing 1. A serpentine pipe 713 is disposed between the water inlet 711 and the water outlet 712, surrounding the stator support 8. The serpentine pipe 713 is formed by connecting multiple U-shaped tubes in sequence, with both sides of each U-shaped tube mating or nesting with assembly channels machined in the stator armature assembly 3. For air cooling, the present invention provides multiple circulating air ducts 721 on the stator support 8. These circulating air ducts 721 communicate with the housing 1 front to back, and the housing 1 is provided with an air inlet and an air outlet 722 connected to the circulating air ducts 721. The hub motor's housing and its internal components form two cavities, located at opposite ends. Compressed gas enters the closed cavity within the hub motor through the air inlet, flows through the gap between the rotor assembly 2 and the stator-armature assembly 3, and then to the opposite side. This opposite side is connected to the circulating air channel 721. Therefore, the gas flows from the circulating air channel 721 toward the air outlet 722 until it is discharged from the hub motor. During this flow, the gas exchanges heat with the hot air in the closed cavity and the heat-generating components within the hub motor. The heat-carrying gas is discharged through the air outlet 722, thus achieving air cooling. The cooling principle of the water cooling link is that the serpentine pipe 713 itself contacts the stator-armature assembly 3. Water enters the serpentine track from the water inlet 711 and flows through all the assembly channels along the water cooling pipe trajectory. After multiple in-and-out cycles, it is discharged from the water outlet 712. This achieves water cooling of the stator-armature assembly 3, thereby enhancing the cooling effect together with the air cooling function. The air cooling structure and water cooling structure of the hub motor are well combined and the different paths do not interfere with each other. The mixed cooling effect is better, which can better meet certain heat dissipation requirements and provide a good guarantee for improving the operating performance of the hub motor.

[0035] To facilitate adjustment and assembly of the resolver 4, the present invention provides a resolver 4 mounted on the stator support 8, away from the differential damper 6. The rotor assembly 2 is provided with a plurality of adjustment ports 21, facing the differential damper 6. This allows for quick and accurate adjustment of the resolver 4's position directly through the adjustment ports 21 during assembly of the in-wheel motor, before the housing is installed.

[0036] The above description is merely a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any person skilled in the art may utilize the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change, and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A differential damper, characterized in that: The invention comprises a damping chamber cover plate and a damping chamber planetary carrier which are arranged opposite to each other, an axial connecting piece connecting the damping chamber cover plate and the damping chamber planetary carrier is provided, a plurality of oil-gas compression variable damping closed chambers which are distributed at intervals are provided on one side of the damping chamber cover plate, the oil-gas compression variable damping closed chamber is used to store pressurized oil and air, the supply end and the breathing end of the oil-gas compression variable damping closed chamber are respectively provided with a refueling hole and a breathing valve, a damping piston is provided between the damping chamber cover plate and the damping chamber base, the damping piston comprises a piston base, a shaft sleeve is provided at the center of the piston base, the shaft sleeve is used to be connected to the motor shaft for transmission and to be connected to the inner of the damping chamber cover plate The wall and the inner wall of the damping chamber planetary carrier are sealed together, the edge of the piston base is provided with a plurality of compression blocks that match the oil and gas compression variable damping closed cavity one by one, the damping chamber planetary carrier is provided with a plurality of evenly distributed planetary ports, the planetary ports are provided with planetary gears, and the transmission end of the planetary gear is used to engage with the sun gear and the ring gear; the axial connecting member includes a shaft portion, the end of the shaft portion is provided with a countersunk head, the side of the shaft portion is provided with a pin, and the damping chamber planetary carrier is provided with a pin hole that matches the pin near the damping chamber cover. The number of axial connecting members connecting the damping chamber cover plate and the damping chamber planetary carrier is at least 3 and is evenly distributed.

2. A differential damper according to claim 1, characterized in that: The compression block includes a radial portion, an arc-shaped portion is provided at one end of the radial portion away from the center of the sleeve, and the oil-gas compression variable damping closed chamber includes a radial opening cooperating with the radial portion and an arc-shaped opening cooperating with the arc-shaped portion, and the arc-shaped trajectory length of the arc-shaped opening is greater than the arc-shaped trajectory length of the arc-shaped portion.

3. A hub motor, comprising a housing, a rotor assembly disposed inside the housing, a stator-armature assembly and a resolver disposed inside the rotor assembly, a stator support disposed inside the stator-armature assembly, a hub bearing assembly disposed inside the stator support, the hub bearing assembly comprising a motor shaft, characterized in that: A differential damper according to any one of claims 1 to 2 is arranged inside the hub bearing assembly, the hub bearing assembly includes a sun gear that cooperates with the planetary gear, the sun gear is arranged on the motor shaft, the rotor assembly is provided with an axial tube body that is sleeved on the motor shaft, the axial tube body is connected to the sun gear by a key, and a gear ring that cooperates with the planetary gear is arranged on the inner side of the stator support.

4. The hub motor according to claim 3, characterized in that: It also includes a hybrid cooling structure, which includes a water cooling component and an air cooling component.

5. The hub motor according to claim 4, characterized in that: The water cooling assembly includes a water inlet and a water outlet arranged on the shell, and a serpentine pipeline distributed around the stator support is arranged between the water inlet and the water outlet. The serpentine pipeline is formed by connecting a plurality of U-shaped pipes in sequence.

6. The hub motor according to claim 5, characterized in that: The stator support is provided with a plurality of circulating air channels, the circulating air channels are communicated with the housing front to back, and the housing is provided with an air inlet and an air outlet communicated with the circulating air channels.

7. The hub motor according to claim 6, characterized in that: The resolver is arranged on the stator support and is far away from the differential damper. The rotor assembly is provided with a plurality of adjustment ports opposite to the differential damper.

Images