Symmetrical wheel edge dual-motor planetary gear train driving and transmission device for electric commercial vehicle

Abstract

A symmetrical wheel edge dual-motor planetary gear train driving and transmission device for an electric commercial vehicle comprises a left half shaft and a right half shaft which are the same, each half shaft comprises a permanent magnet synchronous motor MG, the output of each permanent magnet synchronous motor MG is connected with one end of a synchronizer gear shifting mechanism through a first planetary gear train, and the other end of each synchronizer gear shifting mechanism is connected to one end of an output shaft; the other end of the output shaft is connected with a wheel-side planetary gear train, a disc type motor MG is installed on the output shaft, and the output of the disc type motor MG is connected with the input of a wheel through the wheel-side planetary gear train. A motor driver of the permanent magnet synchronous motor MG and a motor driver of the disc type motor MG are connected with the battery; the driving device is simple in structure, small in size and light in weight, larger torque can be output under the smaller size due to the application of the disc type motor, and the driving device can have better power performance, energy-saving performance and control performance due to the fact that two rows of planetary gear trains are adopted to achieve two working modes; the device has the advantages of good economic dynamic property, high transmission efficiency and simplicity in operation.

Description

Technical Field

[0001] The present invention relates to the technical field of electric commercial vehicles, and in particular to a symmetrical wheel-side dual-motor planetary gear train driving and transmission device for an electric commercial vehicle. Background Art

[0002] In recent years, with the advancement of battery technology and the development of related industries, pure electric commercial vehicles have become the best choice to meet the future demand for cargo transportation while complying with energy-saving and environmental protection policies. In the field of new energy commercial vehicles, the current mainstream power systems are mostly composed of a central motor with a simple transmission. The need for multi-axis drive is combined with the transmission and rear axle of traditional fuel vehicles to form the vehicle drive system, which greatly increases the space occupied by the drive system in commercial vehicles, compresses the cargo capacity of commercial vehicles, and increases the overall weight of the vehicle, aggravating the energy loss of the vehicle, and poor energy economy. Therefore, it is of great significance to seek to design a distributed wheel-side drive system with high transmission efficiency and good power economy.

[0003] The power density of traditional radial flux motors is relatively low and the rotor and stator are arranged in a concentric cylindrical shape, which will cause the axial size of the drive system to be too large, making the axial space layout not compact enough. The disc motor is an axial flux motor with a relatively high power density and the rotor and stator of the motor are arranged in a parallel disc shape, which can greatly reduce the axial size and overall weight of the drive and transmission system. In addition, traditional electric commercial vehicles often need to operate under low-speed and high-torque operating conditions. High-torque radial flux motors are often oversized, while disc motors are particularly suitable for operating under low-speed and high-torque conditions.

[0004] The working environment of commercial electric vehicles is complex. Common operating conditions include low-speed high-torque climbing, high-speed low-torque operation on flat roads, and complex urban conditions. Therefore, there are high requirements for the performance of the drive and transmission system. The patent application named "A dual-drive source and double-row planetary gear system multi-mode coupling drive system and automobile" (CN112895883A) discloses that the transmission system directly driven by a single motor has problems such as low motor efficiency, lack of power and insufficient energy saving, which cannot meet the requirements of commercial electric vehicles under complex conditions. The dual-motor coupling drive system can realize multiple working modes. During the vehicle driving process, it can select the appropriate working mode according to the road conditions and reasonably allocate the power of the two motors, so that the two motors work in a higher efficiency range under different operating conditions, which can improve the efficiency of the entire drive and transmission system and extend the vehicle's driving range.

[0005] In summary, the existing electric commercial vehicle drive and transmission have the following deficiencies: 1) Existing electric commercial vehicles often work in low-speed and high-torque situations, which are particularly suitable for using disc motors as power sources. However, existing electric commercial vehicles still use traditional high-speed radial flux motors, resulting in problems such as complex transmission system structure and large axial dimensions; 2) The wheel-side motors of existing electric commercial vehicles are often driven by a single motor, which causes problems such as low motor efficiency when meeting different working modes such as low-speed and high-torque climbing, high-speed and low-torque operation on flat roads, and complex urban working conditions. Summary of the invention

[0006] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle, which has a simple structure, small size and light weight. The application of a disc motor enables a larger torque to be output in a smaller volume. The use of two rows of planetary gear trains to realize two working modes can enable the drive device to have better power performance, energy-saving performance and controllability; it has the advantages of good economic power, high transmission efficiency and simple operation.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle includes two identical left and right half-axles, the half-axles include a permanent magnet synchronous motor MG1, the output of the permanent magnet synchronous motor MG1 is connected to one end of a synchronizer shift mechanism 6 via a first planetary gear train 3, the other end of the synchronizer shift mechanism 6 is connected to one end of an output shaft 12, the other end of the output shaft 12 is connected to a wheel-side planetary gear train 4, a disc motor MG2 is mounted on the output shaft 12, the output of the disc motor MG2 is connected to the input of a wheel 5 via the wheel-side planetary gear train 4; the motor drivers 8 of the permanent magnet synchronous motor MG1 and the disc motor MG2 are connected to a battery 7.

[0009] The first planetary gear train 3 includes a first sun gear 3-1, the first sun gear 3-1 input is connected to the permanent magnet synchronous motor MG1 output, the first sun gear 3-1 is meshed with the first planetary gear 3-2, the first planetary gear 3-2 is connected to the first planet carrier 3-3, the first planet carrier 3-3 is connected to the first ring gear 3-4, and the first ring gear 3-4 is connected to the frame; the power of the permanent magnet synchronous motor MG1 is decelerated through the first planetary gear train 3 and output from the first planet carrier 3-3; the first planet carrier 3-3 is connected to the synchronizer shift mechanism 6.

[0010] The wheel-side planetary gear train 4 includes a second sun gear 4-1, the second sun gear 4-1 is connected to the input and output shaft 14, the second sun gear 4-1 is meshed with the second planetary gear 4-2, the second planetary gear 4-2 is connected to the second planet carrier 4-3, the second planet carrier 4-3 is connected to the second ring gear 4-4, and the second ring gear 4-4 is connected to the frame; the power of the wheel-side planetary gear train 4 is input by the second sun gear 4-1 and output by the second planet carrier 4-3.

[0011] The second ring gear 4 - 4 is connected to the wheel ring gear bracket 11 , the wheel ring gear bracket 11 is connected to the disc motor stator fixing flange 14 , and the disc motor MG2 is connected to the other side of the disc motor stator fixing flange 14 .

[0012] The fixing plate of the disc motor MG2 cooperates with the center hole of the drum brake 10 , and the brake shoe of the drum brake 10 rubs against the brake drum 13 to brake the wheel 5 .

[0013] The synchronizer shift mechanism 6 realizes the separation and engagement of the first planetary gear train 3 and the output shaft 12, and is powered by a thin small hydraulic cylinder 9 fixed on the first ring gear 3-4. The hydraulic cylinder is fixed, and the piston is connected to the fork bolt of the synchronizer shift mechanism 6. The separation and engagement of the synchronizer shift mechanism 6 are realized by the piston movement of the thin small hydraulic cylinder 9.

[0014] An operating mode of a symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle, including a single drive mode of a disc motor MG2 and a torque coupling mode of a permanent magnet synchronous motor MG1 and a disc motor MG2:

[0015] Disc motor MG2 driving mode: The commercial vehicle is driven by disc motor MG2 alone. The piston of thin small hydraulic cylinder 9 extends to drive the shift fork to move, so that the engagement sleeve of synchronizer shift mechanism 6 is disengaged from the first planetary gear train 3. The permanent magnet synchronous motor MG1 does not work, and the disc motor MG2 drives the wheel 5 through the wheel side planetary gear train 4.

[0016] Torque coupling mode of permanent magnet synchronous motor MG1 and disc motor MG2: The commercial vehicle is driven by permanent magnet synchronous motor MG1 and disc motor MG2. The piston of thin small hydraulic cylinder 9 retreats, driving the shift fork to move, so that the engagement sleeve of synchronizer shift mechanism 6 engages with the first planetary gear train 3. The rotation speed of the first planetary carrier 3-3 of the first planetary gear train 3 driven by permanent magnet synchronous motor MG1 is synchronized with the output shaft 12 driven by disc motor MG2, and the torque coupling of permanent magnet synchronous motor MG1 and disc motor MG2 is realized at the output shaft 12. The coupled torque is finally further reduced and increased through the wheel-side planetary gear train 4 to realize the driving of wheel 5.

[0017] The disk motor MG2 has a rated speed of 1500 rpm, a rated power of 30 kW, and a peak torque of 381.96 N·m. The motor has a diameter of 280 mm and an axial dimension of only 81 mm.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] (1) The present invention integrates the drive motor (permanent magnet synchronous motor MG1, disc motor MG2) and the reducer (first planetary gear train 3, wheel-side planetary gear train 4) on the wheel side, which reduces the weight of the vehicle drive system, facilitates the spatial layout of commercial vehicles, and shortens the transmission chain of the drive system, thereby improving the transmission efficiency and the energy consumption economy of the vehicle. The present invention adopts a wheel-side distributed drive system of the left and right half-axles, which does not require the differential and main reducer of the traditional vehicle drive shaft, further reducing the weight of the vehicle and improving the vehicle's operating economy. The left and right half-axles of the present invention can achieve complete decoupling of the left and right half-axles by controlling the permanent magnet synchronous motor MG1 and the disc motor MG2, that is, the function of the electronic differential lock can be realized, thereby improving the vehicle's passability and safety. The present invention adopts a wheel-side planetary gear train 4, which reduces the load and size of the reducer and the half-axles under the same transmission ratio, and further obtains a larger ground clearance of the vehicle, thereby improving the vehicle's passability.

[0020] (2) The present invention adopts a disk-type motor MG2 with axial magnetic flux, which has a relatively large power density and the motor rotor and stator are arranged in a parallel disk shape, which can greatly reduce the axial size and overall weight of the drive and transmission system. The disk-type motor MG2 used in the present invention has a rated speed of 1500rpm, a rated power of 30kW, and can achieve a peak torque of 381.96N·m. The motor diameter is 280mm and the axial dimension is only 81mm.

[0021] (3) The torque coupling mode of the permanent magnet synchronous motor MG1 and the disc motor MG2 of the present invention can realize a variety of working modes. During the driving process of the vehicle, the appropriate working mode can be selected according to the road conditions and the power of the two motors can be reasonably allocated, so that the two motors can work in a higher efficiency range under different operating conditions, which can improve the efficiency of the entire drive and transmission system and extend the vehicle's cruising range. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of a semi-axle according to an embodiment of the present invention.

[0024] Figure 3 It is a semi-axial cross-sectional view of an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the embodiments and drawings.

[0026] Reference Figure 1 A symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle includes two identical left and right half-axles, which together constitute the drive shaft of the vehicle; the half-axle includes a permanent magnet synchronous motor MG1, the output of the permanent magnet synchronous motor MG1 is connected through the first planetary gear train 3 and one end of a synchronizer shift mechanism 6, and the other end of the synchronizer shift mechanism 6 is connected to one end of an output shaft 12, and the first planetary gear train 3 and the output shaft 12 can be torque-coupled through the friction synchronization of the synchronizer shift mechanism 6; the other end of the output shaft 12 is connected to a wheel-side planetary gear train 4, and a disc motor MG2 is installed on the output shaft 12, and the output of the disc motor MG2 is connected through the wheel-side planetary gear train 4 and the input of the wheel 5; the motor driver 8 of the permanent magnet synchronous motor MG1 and the disc motor MG2 is connected to a battery 7, and the power output of the battery 7 is supplied to the permanent magnet synchronous motor MG1 and the disc motor MG2 through the motor driver 8, and at the same time, the disc motor MG2 can also realize regenerative braking energy recovery and transmit power to the battery 7 through the inverter.

[0027] The disk motor MG2 is connected to the output shaft 12 via a key, and the power is directly transmitted to the output shaft 12 .

[0028] Reference Figure 2 The first planetary gear train 3 includes a first sun gear 3-1, the first sun gear 3-1 input is connected to the permanent magnet synchronous motor MG1 output, the first sun gear 3-1 is meshed with the first planetary gear 3-2, the first planetary gear 3-2 is connected to the first planet carrier 3-3, the first planet carrier 3-3 is connected to the first ring gear 3-4, and the first ring gear 3-4 is connected to the frame; the power of the permanent magnet synchronous motor MG1 is output from the first planet carrier 3-3 through the first planetary gear train deceleration; the first planet carrier 3-3 is connected to the synchronizer shift mechanism 6 through an involute spline.

[0029] Reference Figure 2 The wheel-side planetary gear system 4 includes a second sun gear 4-1, the second sun gear 4-1 is connected to the input and output shaft 14, the second sun gear 4-1 is meshed with the second planetary gear 4-2, the second planetary gear 4-2 is connected to the second planetary carrier 4-3, the second planetary carrier 4-3 is connected to the second ring gear 4-4, and the second ring gear 4-4 is connected to the frame; the power of the wheel-side planetary gear system 4 is input by the second sun gear 4-1 and output by the second planetary carrier 4-3; the power of the drive system is finally output by the second planetary carrier 4-3 to transmit the power to the wheel 5.

[0030] Reference Figure 3The second gear ring 4 - 4 is fixedly connected to the wheel gear ring bracket 11 and remains stationary. The wheel gear ring bracket 11 is connected to the disc motor stator fixing flange 14 , and the disc motor MG2 is connected to the other side of the disc motor stator fixing flange 14 .

[0031] Reference Figure 3 The disc motor MG2 fixing plate cooperates with the center hole of the drum brake 10 to achieve centering, and the brake shoe of the drum brake 10 rubs against the brake drum 13 to achieve braking of the wheel 5.

[0032] The disk motor MG2 has a rated speed of 1500 rpm, a rated power of 30 kW, and can achieve a peak torque of 381.96 N·m. The motor has a diameter of 280 mm and an axial dimension of only 81 mm.

[0033] Reference Figure 3 The synchronizer shift mechanism 6 realizes the separation and engagement of the first planetary gear train 3 driven by the permanent magnet synchronous motor MG1 and the output shaft 12. The power is provided by a thin small hydraulic cylinder 9 fixed on the first ring gear 3-4. The hydraulic cylinder is fixed, and the piston is connected to the fork bolt of the synchronizer shift mechanism 6. The separation and engagement of the synchronizer shift mechanism 6 are realized by the piston movement of the thin small hydraulic cylinder 9.

[0034] A symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle has two operating modes: a single drive mode of the disc motor MG2 and a torque coupling mode of the permanent magnet synchronous motor MG1 and the disc motor MG2:

[0035] Disc motor MG2 driving mode: The commercial vehicle is driven by disc motor MG2 alone. The piston of thin small hydraulic cylinder 9 extends to the right, driving the shift fork to move to the right, so that the engagement sleeve of synchronizer shift mechanism 6 is disengaged from the first planetary gear train 3. The permanent magnet synchronous motor MG1 does not work, and the disc motor MG2 drives the wheel 5 through the wheel side planetary gear train 4.

[0036] Torque coupling mode of permanent magnet synchronous motor MG1 and disc motor MG2: The movement of the commercial vehicle is driven by permanent magnet synchronous motor MG1 and disc motor MG2. The piston of thin small hydraulic cylinder 9 retreats to the left, driving the shift fork to move to the left, so that the engagement sleeve of synchronizer shift mechanism 6 engages with the first planetary gear train 3, so that the rotation speed of the first planetary carrier 3-3 of the first planetary gear train 3 driven by permanent magnet synchronous motor MG1 is synchronized with the output shaft 12 driven by disc motor MG2, and the torque coupling of permanent magnet synchronous motor MG1 and disc motor MG2 is realized at the output shaft 12. The coupled torque is finally further reduced and increased through the wheel-side planetary gear train 4 to realize the driving of wheel 5.

Claims

1. A symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle, characterized in that: The invention comprises two identical left and right half shafts, wherein the half shafts comprise a permanent magnet synchronous motor MG (1), wherein the output of the permanent magnet synchronous motor MG (1) is connected to one end of a synchronizer shift mechanism (6) via a first planetary gear train (3), wherein the other end of the synchronizer shift mechanism (6) is connected to one end of an output shaft (12), wherein the other end of the output shaft (12) is connected to a wheel-side planetary gear train (4), wherein a disk motor MG (2) is mounted on the output shaft (12), wherein the output of the disk motor MG (2) is connected to the input of a wheel (5) via the wheel-side planetary gear train (4); and the motor drivers (8) of the permanent magnet synchronous motor MG (1) and the disk motor MG (2) are connected to a battery (7).

2. The device according to claim 1, characterized in that: The first planetary gear train (3) comprises a first sun gear (3-1), the first sun gear (3-1) input is connected to the output of the permanent magnet synchronous motor MG (1), the first sun gear (3-1) is meshed with the first planetary gear (3-2), the first planetary gear (3-2) is connected to the first planet carrier (3-3), the first planet carrier (3-3) is connected to the first ring gear (3-4), and the first ring gear (3-4) is connected to the frame; the power of the permanent magnet synchronous motor MG (1) is decelerated through the first planetary gear train (3) and output from the first planet carrier (3-3); the first planet carrier (3-3) is connected to the synchronizer shift mechanism (6).

3. The device according to claim 1, characterized in that: The wheel-side planetary gear train (4) comprises a second sun gear (4-1), the second sun gear (4-1) is connected to an input and output shaft (14), the second sun gear (4-1) is meshed with a second planetary gear (4-2), the second planetary gear (4-2) is connected to a second planet carrier (4-3), the second planet carrier (4-3) is connected to a second ring gear (4-4), and the second ring gear (4-4) is connected to a frame; the power of the wheel-side planetary gear train (4) is input by the second sun gear (4-1) and output by the second planet carrier (4-3).

4. The device according to claim 3, characterized in that: The second gear ring (4-4) is connected to the wheel gear ring bracket (11), the wheel gear ring bracket (11) is connected to the disc motor stator fixing flange (14), and the disc motor MG (2) is connected to the other side of the disc motor stator fixing flange (14).

5. The device according to claim 1, characterized in that: The fixing plate of the disc motor MG (2) cooperates with the center hole of the drum brake (10), and the brake shoe of the drum brake (10) rubs against the brake drum (13) to brake the wheel (5).

6. The device according to claim 1, characterized in that: The synchronizer shift mechanism (6) realizes the separation and engagement of the first planetary gear train (3) and the output shaft (12), and is powered by a thin small hydraulic cylinder (9) fixed on the first gear ring (3-4). The hydraulic cylinder is fixed, and the piston is connected to the shift fork bolt of the synchronizer shift mechanism (6). The separation and engagement of the synchronizer shift mechanism (6) are realized by the movement of the piston of the thin small hydraulic cylinder (9).

7. The device according to claim 1, characterized in that: The disk motor MG (2) has a rated speed of 1500 rpm, a rated power of 30 kW, and a peak torque of 381.96 N·m. The motor has a diameter of 280 mm and an axial dimension of only 81 mm.

8. The operating mode of the symmetrical wheel-side dual-motor planetary gear train drive and transmission device for an electric commercial vehicle according to claim 1, characterized in that: The present invention comprises a single drive mode of the disk motor MG (2) and a torque coupling mode of the permanent magnet synchronous motor MG (1) and the disk motor MG (2): The disc motor MG (2) drives the commercial vehicle alone. The disc motor MG (2) drives the commercial vehicle alone. The piston of the thin small hydraulic cylinder (9) extends to drive the shift fork to move, so that the engagement sleeve of the synchronizer shift mechanism (6) is disengaged from the first planetary gear train (3). The permanent magnet synchronous motor MG (1) does not work, and the disc motor MG (2) drives the wheels (5) through the wheel side planetary gear train (4). The permanent magnet synchronous motor MG (1) and the disk motor MG (2) torque coupling mode: the commercial vehicle is driven by the permanent magnet synchronous motor MG (1) and the disk motor MG (2). The piston of the thin small hydraulic cylinder (9) retracts, driving the shift fork to move, so that the engagement sleeve of the synchronizer shift mechanism (6) engages with the first planetary gear train (3). The rotation speed of the first planet carrier (3-3) of the first planetary gear train (3) driven by the permanent magnet synchronous motor MG (1) is synchronized with the output shaft (12) driven by the disk motor MG (2). The torque coupling of the permanent magnet synchronous motor MG (1) and the disk motor MG (2) is realized at the output shaft (12). The coupled torque is finally further reduced and increased in distance through the wheel side planetary gear train (4), thereby driving the wheel (5).

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