Wheel driving system and electric automobile

Abstract

The embodiment of the utility model provides a wheel driving system and an electric vehicle. The wheel driving system comprises a gear ring, a sun gear and a chain transmission system. The gear ring is used for being coaxially connected to a wheel, and the sun gear is used for being connected to a power source. The chain transmission system comprises a first planetary gear, a first chain wheel, a connecting rod, a chain, a second chain wheel and a second planetary gear, the first planetary gear is meshed with the sun gear, the first chain wheel is in coaxial transmission connection with the first planetary gear, the first chain wheel is connected to the second chain wheel through the chain, and the second planetary gear is in coaxial transmission connection with the second chain wheel; the second planetary gear is meshed with the gear ring, and the rotating center of the first chain wheel and the rotating center of the second chain wheel are rotationally connected to the connecting rod. The first planetary gear is configured to have a fixed distance from the sun gear in the radial direction, and the second planetary gear is configured to have a fixed distance from the ring gear in the radial direction. The electric automobile comprises the wheel driving system.

Description

Technical Field

[0001] This application relates to the automotive field, and more particularly to wheel drive systems and electric vehicles. Background Technology

[0002] US Patent No. 20230311646A1 discloses a wheel drive system comprising a motor, a sun gear, a ring gear, wheels, gears, and connecting rods. Its advantages include: allowing radial relative movement between the wheels and the motor; eliminating the universal joints and half-shafts found in traditional automobiles, saving axial space; and supporting both the motor and sun gear on the subframe, reducing unsprung mass and improving driving stability compared to existing technologies that mount the motor on the wheels.

[0003] However, it still has some problems, such as:

[0004] (1) There are many gear pairs that need to mesh, and the power transmission path is long, resulting in meshing loss and low transmission efficiency.

[0005] (2) All gears must mesh with at least two gears, which makes the gears prone to damage and reduces their service life.

[0006] (3) When the wheel and the motor move radially relative to each other, the gears and connecting rods in the transmission system will also move. The rigidity of the connecting rod transmission system is poor, requiring an axial support structure, which is prone to wear.

[0007] (4) Apart from the motor and sun gear, other transmission system components are still connected to the suspension system, and the unsprung mass is still relatively large, leaving room for further reduction.

[0008] (5) The sun gear is connected to multiple (e.g., three) connecting rods, which need to be axially offset. As the number of connecting rods increases, the axial space required by the drive system also increases. Utility Model Content

[0009] To address or mitigate at least one of the problems mentioned in the background art, this application provides a wheel drive system and an electric vehicle.

[0010] The wheel drive system provided in this application includes:

[0011] A toothed ring for coaxial connection to a wheel;

[0012] Sun gear, which is used to connect to a power source;

[0013] A chain drive system includes a first planetary gear, a first sprocket, a connecting rod, a chain, a second sprocket, and a second planetary gear. The first planetary gear meshes with the sun gear. The first sprocket is coaxially connected to the first planetary gear. The first sprocket is connected to the second sprocket via the chain. The second planetary gear is coaxially connected to the second sprocket and meshes with a gear ring. The rotation centers of the first sprocket and the second sprocket are rotatably connected to the connecting rod.

[0014] The first planetary gear is configured to be at a fixed radial distance from the sun gear, and the second planetary gear is configured to be at a fixed radial distance from the ring gear.

[0015] In at least one embodiment, the wheel drive system includes a power source and a suspension system, the power source being connected to the vehicle body, and the gear ring being connected to the suspension system.

[0016] In at least one embodiment, the wheel drive system includes a planetary carrier, a first planetary gear rotatably connected to the planetary carrier, the planetary carrier rotatably connected to the output shaft of the power source, or rotatably connected to the housing of the power source, or rotatably connected to the vehicle body, such that the radial distance between the first planetary gear and the sun gear remains unchanged, and the first planetary gear is always meshed with the sun gear.

[0017] In at least one embodiment, the wheel drive system includes a plurality of chain drive systems, wherein a plurality of the first planetary gears in the plurality of chain drive systems are rotatably connected to the planet carrier.

[0018] In at least one embodiment, the wheel drive system includes the wheel, the wheel includes a hub, the gear ring is fixedly connected to the hub, and the second planetary gear is rotatably connected to the hub about the axis of the hub, such that the radial distance between the second planetary gear and the gear ring remains unchanged, and the second planetary gear is always meshed with the gear ring.

[0019] In at least one embodiment, the hub includes an annular groove into which the shaft of the second planetary gear extends, the shaft of the second planetary gear being able to rotate relative to the sun gear in addition to rotating on its own axis.

[0020] In at least one embodiment, the gear ring is formed as an internal gear ring, and the second planetary gear meshes with the internal teeth of the gear ring.

[0021] In at least one embodiment, the power source is an electric motor.

[0022] In at least one embodiment, the first planetary gear and the second planetary gear have the same number of teeth.

[0023] The electric vehicle provided in this application includes the wheel drive system as described above.

[0024] While achieving radial relative motion between the sun gear and the ring gear, the chain drive system of this application eliminates three gear pairs compared to the prior art, shortening the power transmission path, reducing meshing losses, and resulting in higher transmission efficiency. Furthermore, each planetary gear meshes only with another gear, instead of two gears as required in the prior art, making the gears in this application less prone to wear and extending their service life. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of a wheel drive system according to an embodiment of this application is shown.

[0026] Figure 2 A side view schematic diagram of a wheel drive system according to an embodiment of this application is shown.

[0027] Figure 3 The diagram illustrates a wheel drive system according to an embodiment of this application, with the sun gear and ring gear coaxial on different road surfaces, the axis of the sun gear being lower than the axis of the ring gear, and the axis of the sun gear being higher than the axis of the ring gear.

[0028] Explanation of reference numerals in the attached figures

[0029] 100 gear ring

[0030] 200 wheels

[0031] 210 wheels

[0032] 220 tires

[0033] 300 Sun Gear

[0034] 400 Power Source

[0035] 510 First Planetary Gear

[0036] 520 First Sprocket

[0037] 530 linkage

[0038] 540 chain

[0039] 550 Second Sprocket

[0040] 560 Second Planetary Gear

[0041] 600 suspension system

[0042] 700 body

[0043] 800 planetary carriers Detailed Implementation

[0044] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0045] This application provides a wheel drive system and an electric vehicle.

[0046] See Figure 1 , Figure 2 The wheel drive system may include a ring gear 100, a sun gear 300, and a chain drive.

[0047] The gear ring 100 is coaxially connected to the wheel 200 and can drive the wheel 200 to rotate.

[0048] The sun gear 300 is used to connect to the power source 400. The power source 400 can be an electric motor. Furthermore, the sun gear 300 can be connected to the output shaft of the electric motor.

[0049] The chain drive system may include a first planetary gear 510, a first sprocket 520, a connecting rod 530, a chain 540, a second sprocket 550, and a second planetary gear 560. The first planetary gear 510 meshes with the sun gear 300. The first sprocket 520 is coaxially connected to the first planetary gear 510 (e.g., it can be integrally formed or connected by a key, hereinafter the same). The first sprocket 520 is connected to the second sprocket 550 via the chain 540. The second planetary gear 560 is coaxially connected to the second sprocket 550 and meshes with the gear ring 100. This allows the power source 400 to transmit power to the gear ring 100 sequentially through the sun gear 300 and the chain drive system, thereby driving the wheel 200 to rotate.

[0050] The rotation centers of the first sprocket 520 and the second sprocket 550 are rotatably connected to the connecting rod 530, for example, to both ends of the connecting rod 530, thereby maintaining the distance between the two sprockets via the connecting rod 530. The first planetary gear 510 is configured to have a fixed radial distance from the sun gear 300, and the second planetary gear 560 is configured to have a fixed radial distance from the ring gear 100. Therefore, when the first planetary gear 510 revolves around the sun gear 300, the second planetary gear 560 can be pulled by the connecting rod 530 to revolve around the sun gear 300.

[0051] For the motion process, see Figure 3(1) When the gear ring 100 and the sun gear 300 are coaxial, the sun gear 300 rotates, and the first planetary gear 510 revolves and rotates with the sun gear 300. The second planetary gear 560 also revolves and rotates relative to the sun gear 300, and the angle C formed by the line connecting the first planetary gear 510 and the sun gear 300 and the connecting rod 530 remains unchanged. See also Figure 3 (2) and (3) After the gear ring 100 and the sun gear 300 move relative to each other in the radial direction, the angle C formed by the line connecting the first planetary gear 510 and the sun gear 300 and the connecting rod 530 will continue to change as the first planetary gear 510 revolves.

[0052] Compared to the prior art, the chain drive system of this application eliminates three gears (when the coaxially arranged sprocket and planetary gear are considered as one gear), or eliminates three gear pairs. This shortens the power transmission path, reduces meshing losses, and results in higher transmission efficiency. Each planetary gear meshes with only one other gear, instead of two gears as required in the prior art, making the gears in this application less prone to wear and extending their service life.

[0053] The chain drive system in this application has a relatively simple structure. A chain drive system only requires one connecting rod 530. In addition to revolution, only the second planetary gear 560 and the second sprocket 550 will move radially relative to the sun gear 300. Compared with the prior art, the support structure has less wear.

[0054] Furthermore, the wheel drive system may include a power source 400 and a suspension system 600. The power source 400 is connected to the vehicle body 700 (e.g., subframe), and the gear ring 100 is connected to the suspension system 600. For example, the gear ring 100 may be connected to the wheel hub 210, which is connected to the suspension system 600. It is understood that the wheel hub 210 is rotatable relative to the suspension system 600, and the suspension system 600 provides axial and radial support to the wheel hub 210.

[0055] Furthermore, the wheel drive system includes a planetary carrier 800, a first planetary gear 510 rotatably connected to the planetary carrier 800, the planetary carrier 800 rotatably connected to the output shaft of the power source 400, or rotatably connected to the housing of the power source 400, or rotatably connected to the vehicle body 700, such that the radial distance between the first planetary gear 510 and the sun gear 300 remains unchanged, and the first planetary gear 510 is always meshed with the sun gear 300.

[0056] In this application, the first planetary gear 510 is supported on the vehicle body 700 by the planetary carrier 800, reducing unsprung mass and improving vehicle handling stability. This application controls the first planetary gear 510 to mesh with the sun gear 300 via the planetary carrier 800, eliminating the need for a direct rotatable connection between the connecting rod end and the shaft of the sun gear 300, as in the prior art. Furthermore, the connecting rods 530 in this application do not need to be connected to the sun gear 300 and can be coplanar, resulting in a relatively smaller axial dimension required for the chain drive system.

[0057] Furthermore, the wheel drive system may include multiple chain drive systems (e.g., three), with multiple first planetary gears 510 in the multiple chain drive systems rotatably connected to the planet carrier 800. Of course, the number of chain drive systems in this application may be one, two, three or more.

[0058] Furthermore, the wheel drive system may include a wheel 200, which includes a hub 210. A gear ring 100 is fixedly connected to the hub 210, and a second planetary gear 560 is rotatably connected to the hub 210 around the axis of the hub 210, such that the radial distance between the second planetary gear 560 and the gear ring 100 remains unchanged, and the second planetary gear 560 is always meshed with the gear ring 100.

[0059] For example, an annular groove may be provided on the hub 210, into which the shaft of the second planetary gear 560 can extend, thereby controlling the radial distance between the second planetary gear 560 and the gear ring 100. In addition to rotating on its own axis, the shaft of the second planetary gear 560 can also revolve relative to the sun gear 300 within the groove.

[0060] Furthermore, the gear ring 100 can be formed as an internal gear ring, and the second planetary gear 560 can mesh with the inner side (internal teeth) of the gear ring 100.

[0061] Furthermore, the first planetary gear 510 and the second planetary gear 560 can have the same number of teeth, so that the gears run smoothly.

[0062] See Figure 1 , Figure 2 Wheel 200 may include tire 220.

[0063] The electric vehicle provided in this application embodiment may include the aforementioned wheel drive system.

[0064] The above description is the preferred embodiment of this application. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A wheel drive system, characterized by, Comprising: a ring gear for coaxially connecting to a wheel; a sun gear for connecting to a power source; a chain transmission system comprising a first planetary gear, a first sprocket, a connecting rod, a chain, a second sprocket, a second planetary gear, the first planetary gear engaging with the sun gear, the first sprocket coaxially drivingly connecting to the first planetary gear, the first sprocket connecting to the second sprocket through the chain, the second planetary gear coaxially drivingly connecting to the second sprocket, the second planetary gear engaging with the ring gear, the rotation center of the first sprocket and the rotation center of the second sprocket rotatingly connecting to the connecting rod, the first planetary gear is configured to have a fixed distance from the sun gear in a radial direction, and the second planetary gear is configured to have a fixed distance from the ring gear in a radial direction.

2. The wheel drive system according to claim 1, characterized by The wheel drive system comprises a power source for connecting to a vehicle body and a suspension system, and the ring gear is connected to the suspension system.

3. A wheel drive system according to claim 2, characterised in that, The wheel drive system comprises a carrier, the first planetary gear rotatingly connecting to the carrier, the carrier rotatingly connecting to an output shaft of the power source, or rotatingly connecting to a housing of the power source, or rotatingly connecting to the vehicle body, so that the distance between the first planetary gear and the sun gear in a radial direction is constant, and the first planetary gear is always engaging with the sun gear.

4. A wheel drive system according to claim 3, characterised in that, The wheel drive system comprises a plurality of the chain transmission systems, and a plurality of the first planetary gears in the plurality of the chain transmission systems respectively rotatingly connecting to the carrier.

5. The wheel drive system of claim 1, wherein, The wheel drive system comprises the wheel, the wheel comprising a hub, the ring gear fixedly connecting to the hub, and the second planetary gear rotatingly connecting to the hub around an axis of the hub, so that the distance between the second planetary gear and the ring gear in a radial direction is constant, and the second planetary gear is always engaging with the ring gear.

6. A wheel drive system according to claim 5, characterised in that, The hub comprises an annular groove, and the shaft of the second planetary gear extends into the groove, and the shaft of the second planetary gear can revolve around the sun gear in the groove in addition to rotating on its own axis.

7. The wheel drive system of claim 1, wherein, The ring gear is formed as an internal ring gear, and the second planetary gear engages with the internal teeth of the ring gear.

8. The wheel drive system of claim 1, wherein, The power source is an electric motor.

9. The wheel drive system of claim 1, wherein, The first planetary gear and the second planetary gear have the same number of teeth.

10. An electric vehicle, characterized by The wheel drive system according to any one of claims 1 to 9. The wheel drive system according to any one of claims 1 to 9.

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