A four-motor and WW wheel system combined hub motor device

Abstract

A four-motor hub motor device with a WW wheel train is disclosed, comprising four motor units, each including a motor drive unit and a motor body unit. The motor shaft of the motor body unit is connected to the input end of a reduction system via an input gear. The output end of the reduction system is connected to the wheel hub, and the wheel hub is connected to the tire, realizing power output and transmission. The reduction system includes an internal gear ring meshing with the input gear. The internal gear ring is connected to a double planetary gear shaft via a double planetary gear shaft. One side of the double planetary gear meshes with a fixed-end sun gear, which is connected to the wheel hub shaft. The other side of the double planetary gear meshes with an output-end sun gear, which is connected to the wheel hub and supported on the wheel hub shaft by a bearing system, transmitting the motor power to the wheel hub. This invention, through the four-motor hub motor device with a WW wheel train, achieves multi-motor power distribution, offering advantages such as safety, reliability, high energy utilization, convenient heat dissipation, and compact structure.

Description

Technical Field

[0001] This invention belongs to the field of new energy vehicle hub motor technology, specifically relating to a four-motor and WW wheel system combined hub motor device. Background Technology

[0002] Traditional hub motor drive systems typically employ a single motor drive for ease of control, then use a clutch and complex transmission system to achieve different speed and torque requirements for electric vehicles. For example, a patent application titled "An Automatic Transmission Hub Motor" (publication number: CN 113715954A) discloses a single-motor driven dual-stage planetary reduction hub system. Its structural principle consists of a main shaft, hub, power input components, and a core assembly and automatic transmission mechanism housed within the hub. It primarily uses a clutch to achieve single-motor drive of the hub motor, meeting the vehicle's output torque and speed requirements. However, the transmission system is complex, has low transmission efficiency, high cost, and a long development cycle.

[0003] Currently, there are also multi-motor driven hub motors. The core of these motors is to achieve speed and torque coupling between the two motors through the transmission of multiple motors and a reduction mechanism. For example, a patent application entitled "A Hub Motor" (publication number: CN113824284A) discloses a dual-motor driven hub system. It forms a dual-motor coupled transmission system by coupling the rotor of the second motor after the first motor drives it. This requires controlling the second motor when it is not powered on and the second rotor is already rotating, which is difficult to control.

[0004] The reduction system of hub motors widely uses planetary gear reducers, which requires the machining of an internal gear ring, resulting in a large radial dimension and high machining difficulty. In addition, the reduction ratio of a single-stage planetary reducer is usually 3-5, so multiple stages of gear reduction are required to achieve the required torque. The motor is usually designed inside the reducer, which leads to obstructed heat dissipation. For example, the patent application entitled "A Split-Shaft Hub Motor" (publication number: CN 111327155 A) discloses a hub system driven by a single motor. Its structural principle is that the hub motor system is composed of a hub motor, a sun gear, a double planetary gear, and an internal gear ring. The double planetary gear drives the internal gear ring to rotate and ultimately drive the wheel forward. Its disadvantages are large radial dimension, small transmission ratio, low efficiency of hub motor and unreliability.

[0005] In summary, current in-wheel motor devices for electric vehicles have the following shortcomings:

[0006] 1) Achieving torque coupling of a single motor through a complex transmission system results in a complex structure; 2) The widespread use of single-motor drive means that the motor cannot meet optimal efficiency output under different operating conditions of the vehicle, leading to low energy utilization. Furthermore, failures can directly paralyze the vehicle, resulting in low fault tolerance and poor reliability; 3) The widely used reduction gear outputs to the wheel hub through an internal gear ring, resulting in a large radial dimension and a transmission ratio of only 3-5, requiring a large multi-stage reduction gear; In addition, the motor is located in the middle of the wheel hub, and the heat generated by the motor stator winding needs to be transferred to the outside through the casing and reduction gear, requiring forced air cooling and water cooling, making the system complex, difficult to maintain, and expensive. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention aims to provide a four-motor and WW planetary gear system combined hub motor device, which combines four motors with the WW planetary gear system to form a hub system structure in which the motor and reducer are highly integrated; the four motors can be connected according to the power requirements of the vehicle to ensure that each motor operates in the optimal efficiency range; water cooling, oil cooling and forced air cooling are omitted, and the system is simple; the four identical motors have the advantages of modularity and low cost; the large gear ring of the planetary reducer is omitted, and the size is small.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A four-motor and WW wheel system combined hub motor device includes four identical first motor devices 35, second motor devices 36, third motor devices 37 and fourth motor devices 39. Each motor device includes a motor drive device and a motor body device. The motor shaft 24 of the motor body device is connected to the input end of the reduction system via an input gear 1. The output end of the reduction system is connected to the wheel hub 7. The wheel hub 7 is connected to the tire 34 to realize the output and transmission of power.

[0010] The first motor drive device 17, second motor drive device 18, third motor drive device 19, and fourth motor drive device 23 of the first motor device 35, second motor device 36, third motor device 37, and fourth motor device 39 include a motor drive control circuit 21. The motor drive control circuit 21 is fixed to the right motor frame 22 and the left circuit board frame 16 of the motor body device by tie rods 25 distributed along the circumference. The left circuit board frame 16 is connected to the right motor frame 22.

[0011] The motor body assembly includes a right motor frame 22, which is connected to a left motor frame 29 via a motor frame tie rod 28. A motor stator 27 is provided inside the right motor frame 22 and the left motor frame 29. The motor stator 27 is fitted with a motor rotor 26, which is connected to a motor shaft 24. The motor shaft 24 is supported on the right motor frame 22 and the left motor frame 29 via a bearing system.

[0012] The reduction system includes an internal gear ring 2 that meshes with the input gear 1. The internal gear ring 2 is positioned on the hub shaft via a ball bearing system 12 and a bearing retainer ring. The internal gear ring 2 is connected to a planetary gear shaft 3. A double planetary gear is supported on the planetary gear shaft 3 by a roller bearing system 5. The axial position of the double planetary gear is positioned by a hole elastic retainer ring 14 and a bearing system. The bearing system is positioned with the planetary gear shaft 3 by a shaft elastic retainer ring 15. The right planetary gear of the double planetary gear meshes with a right fixed-end sun gear 10, which is connected to the hub shaft 20. The left planetary gear of the double planetary gear meshes with an output-end sun gear 9, which is connected to the hub 7 and supported on the hub shaft 20 by a hub bearing 11. A left pressure plate 6 for the planetary gear is connected to the left side of the planetary gear shaft 3. The left pressure plate 6 is fixed to the internal gear ring 2 via a shaft identical to that of the planetary gear shaft 3.

[0013] There are three double planetary gears, which are distributed circumferentially along the right fixed end sun gear 10 and the output end sun gear 9, namely the first double planetary gear 4, the second double planetary gear 30 and the third double planetary gear 31.

[0014] The outer side of the wheel hub is fixed by two locking nuts 32.

[0015] A steering system 38 is connected to the hub axle 20.

[0016] The first motor device 35, the second motor device 36, the third motor device 37, and the fourth motor device 39 are AC permanent magnet synchronous motors.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) Since the present invention uses four motors and WW wheel system combined hub motors, the four motors can be connected one, two, three or three according to the power requirements of the vehicle, which enables the hub motor system to have more flexible power distribution and realize the torque coupling of multiple motors through the switching of different modes.

[0019] (2) Since the multi-motor power splitting of the present invention allows the motor to work more in the optimal working range, the overall efficiency will be higher and the energy utilization rate can be improved. In addition, due to the dispersion of multiple motors, the solution is safer and more reliable than the traditional single-motor drive motor failure causing the loss of vehicle power, and has a higher fault tolerance rate.

[0020] (3) Since the present invention adopts the WW gear train, its double planetary gears avoid the traditional internal gear ring machining by fixing the sun gear, which reduces the cost and reduces the radial dimension of the reducer, making the overall structure more compact; in addition, since the four motor devices of the present invention are placed on the left side of the hub and the stator is exposed, the ventilation and heat dissipation are excellent. Attached Figure Description

[0021] Figure 1 This is a front sectional view of an embodiment of the present invention.

[0022] Figure 2 This is a left view of the hub motor combining four motors and WW wheel system of the present invention.

[0023] Figure 3 This is a left view of the flange connecting the four motors and their drive system of the present invention.

[0024] Figure 4 This is a right view of the hub motor combining four motors and WW wheel system of the present invention. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.

[0026] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 A four-motor and WW wheel system combined hub motor device includes four identical first motor devices 35, second motor devices 36, third motor devices 37 and fourth motor devices 39. Each motor device includes a motor drive device and a motor body device. The motor shaft 24 of the motor body device is connected to the input gear 1 via a flat key or spline. The input gear 1 is connected to the input end of the reduction system, transmitting power from the input gear 1 to the reduction system. The output end of the reduction system is connected to the wheel hub 7, and the wheel hub 7 is connected to the tire 34 to realize the output and transmission of power.

[0027] Reference Figure 1 , Figure 3The first motor drive device 17, the second motor drive device 18, the third motor drive device 19, and the fourth motor drive device 23 of the first motor device 35, the second motor device 36, the third motor device 37, and the fourth motor device 39 are connected to the motor drive control circuit 21. The motor drive control circuit 21 is fixed to the right motor frame 22 and the left circuit board frame 16 of the motor body device by six tie rods 25 distributed circumferentially. The left circuit board frame 16 is connected to the right motor frame 22 by circuit board fixing bolts 33.

[0028] Reference Figure 1 The motor body assembly includes a right motor frame 22, which is connected to a left motor frame 29 via a motor frame tie rod 28. The motor frame tie rod 28 is fixed by nuts on both sides. A motor stator 27 is provided inside the right motor frame 22 and the left motor frame 29. The motor stator 27 mates with the motor rotor 26. The motor rotor 26 is connected to the motor shaft 24 via a flat key or spline. The motor shaft 24 is supported on the right motor frame 22 and the left motor frame 29 by a bearing system. The motor rotor 26 is positioned by sleeves on both sides and by the right motor frame 22 and the left motor frame 29.

[0029] Reference Figure 1 , Figure 2 The reduction system includes an internal gear ring 2 that meshes with the input gear 1. The internal gear ring 2 is positioned on the hub shaft via a ball bearing system 12 and an elastic retaining ring. The internal gear ring 2 is positioned on the planetary gear shaft 3 by the shoulder and end elastic retaining ring 8 of the planetary gear shaft 3. The internal gear ring 2 is connected to the planetary gear shaft 3 by a flat key or spline. A double planetary gear is supported on the planetary gear shaft 3 by a roller bearing system 5. The axial position of the double planetary gear is positioned by a hole elastic retaining ring 14 and a bearing system. In addition, the bearing system is positioned on the planetary gear shaft 3 by a shaft elastic retaining ring 15. The right side of the double planetary gear... The planetary gear meshes with the right fixed-end sun gear 10, which is connected to the hub shaft 20 via a flat key or spline. The left planetary gear of the double planetary gear meshes with the output sun gear 9, which is connected to the hub 7 via hub bolts 13 and supported on the hub shaft 20 via hub bearings 11. The left side of the planetary gear shaft 3 is connected to the left side pressure plate 6 of the planetary gear, which is fixed to the outside of the left side pressure plate 6 via elastic retaining rings 8. The left side pressure plate 6 of the planetary gear is fixed to the internal gear ring 2 via a shaft identical to that of the planetary gear shaft 3, and the two sides of the shaft are positioned by elastic retaining rings.

[0030] like Figure 2As shown, there are three double planetary gears, which are distributed circumferentially along the right fixed end sun gear 10 and the output end sun gear 9, namely the first double planetary gear 4, the second double planetary gear 30 and the third double planetary gear 31; the outer side of the hub is fixed by two locking nuts 32.

[0031] like Figure 4 As shown, the output ends of the first motor device 35, the second motor device 36, the third motor device 37, and the fourth motor device 39 are driven by the internal gear ring 2 through four input gears 1; the hub shaft 20 is connected to the steering system 38.

[0032] The first motor device 35, the second motor device 36, the third motor device 37, and the fourth motor device 39 are AC permanent magnet synchronous motors.

[0033] The working principle of this invention is as follows:

[0034] Four independent first motor units 35, second motor units 36, third motor units 37, and fourth motor units 39 are controlled by four independent first motor drive units 17, second motor drive units 18, third motor drive units 19, and fourth motor drive units 23, respectively. The output shafts of the motors transmit power to the corresponding input gears 1, and the four input gears 1 jointly drive the internal gear ring 2. The internal gear ring 2 is supported on the wheel hub shaft 20, and a double planetary gear is supported on the internal gear ring 2 via the planetary gear shaft 3. The left planetary gear of the double planetary gear meshes with the output sun gear 9, so the power is transmitted to the output sun gear 9 via the internal gear ring 2, and the power is finally transmitted to the wheel hub 7 and the tire 34. The right planetary gear of the double planetary gear meshes with the fixed sun gear 10, which is connected to the wheel hub shaft 20. The wheel hub shaft 20 is also connected to the reversing system 38 to realize the vehicle steering control.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention are all within the scope of protection of the present invention.

Claims

1. A four-motor and WW wheel train combined hub motor device, comprising four identical first motor devices (35), second motor devices (36), third motor devices (37) and fourth motor devices (39), characterized in that: Each motor device includes a motor drive device and a motor body device; the motor shaft (24) of the motor body device is connected through the input gear (1) and the input end of the reduction system, the output end of the reduction system is connected with the wheel hub (7), and the wheel hub (7) is connected with the tire (34) to realize the output and transmission of power; The reduction system comprises an inner ring gear (2) in gear engagement with the input gear (1), the inner ring gear (2) is positioned on the wheel hub shaft (20) through a ball bearing system (12) and a bearing retainer, the inner ring gear (2) is connected on a planetary gear shaft (3), the planetary gear shaft (3) supports a double planetary gear through a roller bearing system (5), the double planetary gear is positioned in the axial direction through a hole elastic retainer (14) and a bearing system, and the bearing system is positioned on the planetary gear shaft (3) through an elastic retainer (15) for the shaft; the right planetary gear of the double planetary gear is in engagement with a right fixed end sun gear (10), the right fixed end sun gear (10) is connected to the wheel hub shaft (20); the left planetary gear of the double planetary gear is in engagement with an output end sun gear (9), the output end sun gear (9) is connected to the wheel hub (7), and the output end sun gear (9) is supported on the wheel hub shaft (20) through a wheel hub bearing (11); the left planetary gear is connected to a planetary gear left side pressing plate (6) on the left side of the planetary gear shaft (3), and the planetary gear left side pressing plate (6) is fixed on the inner ring gear (2) through the same shaft as the planetary gear shaft (3). The double planetary gears are three in total and are distributed along the circumferences of the right fixed end sun gear (10) and the output end sun gear (9), and are respectively a first double planetary gear (4), a second double planetary gear (30) and a third double planetary gear (31).

2. A four-motor with WW train combined in-wheel motor device according to claim 1, characterized by: The first motor drive device (17), the second motor drive device (18), the third motor drive device (19) and the fourth motor drive device (23) of the first motor device (35), the second motor device (36), the third motor device (37) and the fourth motor device (39) comprise a motor drive control circuit (21), the motor drive control circuit (21) is fixed on a motor right rack (22) and a circuit board left rack (16) of the motor body device through a circumferentially distributed pull rod (25), and the circuit board left rack (16) is connected to the motor right rack (22).

3. A four-motor with WW train combined in-wheel motor device according to claim 1, characterized in that: The motor body device comprises the motor right rack (22), the motor right rack (22) is connected with a motor left rack (29) through a motor rack pull rod (28), and the motor right rack (22) and the motor left rack (29) are internally provided with a motor stator (27), the motor stator (27) is internally matched with a motor rotor (26), the motor rotor (26) is connected to a motor shaft (24), and the motor shaft (24) is supported on the motor right rack (22) and the motor left rack (29) through a bearing system.

4. A four-motor with WW train combined in-wheel motor device according to claim 1, characterized by: The outer side of the wheel hub is fixed through two locking nuts (32).

5. A four-motor with WW train combined in-wheel motor device according to claim 1, characterized by: The wheel hub shaft (20) is connected with a steering system (38).

6. A four-motor with WW train combined in-wheel motor device according to claim 1, characterized by: The first motor device (35), the second motor device (36), the third motor device (37) and the fourth motor device (39) are AC permanent magnet synchronous motors.

Images