An electric vehicle transmission active damping coupling

Abstract

A damping coupling used in a multi-gear transmission of an electric vehicle, which is composed of a group of rigid transmission units capable of bearing the maximum torque of the system and a group of damping transmission units not required to bear the maximum torque of the system; during gear shifting, the damping capacity of the damping transmission units is increased by actively adjusting the gap between the two semi-coupling rigid contact surfaces of the rigid transmission units, or by actively adjusting the thickness of the rigid material in the damping transmission units.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle transmission technology, specifically, to a coupling used in multi-speed transmissions of electric vehicles for connecting an electric motor to the multi-speed transmission. Background Technology

[0002] Traditional electric vehicles use a single-speed reducer. Because they do not require gear shifting, there is no impact or vibration caused by gear shifting. Therefore, the connection between the motor and the transmission system is generally a rigid coupling. As the market demands higher performance and lower costs for electric vehicles, multi-speed transmissions are gradually being adopted in large numbers. However, multi-speed transmissions generate huge impacts when shifting gears. Using couplings with low damping performance can damage the transmission system. The high torque and high speed that traditional vibration couplings can withstand are contradictory to their damping performance. Under certain size constraints, traditional vibration couplings cannot meet the requirements of high torque, high speed and high damping performance of the transmission system when the electric vehicle transmission is working. However, based on the characteristics of electric vehicle transmission shifting, the above problems can be solved.

[0003] Most existing multi-speed transmissions for electric vehicles do not use clutches. Taking the AMT (Automated Manual Transmission) as an example, they mainly use active synchronization to achieve synchronization between the gear to be engaged and the splined shaft, thereby reducing the huge impact generated during gear shifting. During normal driving, the coupling of an electric vehicle experiences high torque and high speed. However, during gear shifting, the operating torque of the electric motor decreases significantly, especially at the moment the gear to be engaged with the splined shaft, when the electric motor's operating torque drops to zero. At the same time, the inertial torque on the coupling also decreases significantly. This solution designs a new type of coupling based on the characteristics of electric vehicle transmission shifting. During normal driving, the coupling can withstand high torque and high speed with relatively low vibration damping performance. During gear shifting, when the torque on the coupling decreases, the vibration damping performance is greatly improved, thus achieving a balance between high torque and high speed and high vibration damping performance, significantly reducing the huge impact generated during gear shifting. Summary of the Invention

[0004] A coupling consists of two half-couplings. A torque transmission system that can independently transmit power system torque between the two half-couplings is defined as a transmission unit. Most flexible couplings have a set of flanges or protrusions on the driving shaft half-coupling and a set of grooves or flange holes on the driven shaft half-coupling. There are elastic devices between the protrusions and grooves, or between the flanges and flange holes. The torque of the power system is transmitted through the contact between the flanges / protrusions, grooves / flange holes, and the elastic devices therein. These elastic devices are the main damping components of the coupling. This solution defines this torque transmission system as a damping transmission unit. Its characteristic is that it has damping function, but its load-bearing capacity is limited under certain size constraints and cannot withstand the high-power torque of the drive motor. If the torque of the coupling transmission system is transmitted only through the rigid contact surface of the flanges / protrusions and grooves / flange holes, without any elastic devices playing a major damping role, this solution defines this torque transmission system as a rigid transmission unit. Its characteristic is that it has no damping function but its load-bearing capacity is limited. This solution integrates a damping transmission unit and a rigid transmission unit into a coupling system. The two transmission units are connected in parallel along the torque transmission path. This coupling system has at least one rigid transmission unit that can withstand the maximum limit torque of the transmission system and one damping transmission unit that does not need to withstand the maximum limit torque of the transmission system but has excellent elasticity and damping performance. When the electric vehicle is driving normally, the torque of the motor mainly drives the transmission through the rigid transmission unit that can withstand high torque and high speed, while the damping transmission unit that can withstand high torque and high speed but has excellent damping performance bears less torque. When the transmission shifts gears, the output power of the motor is zero at the moment the gear to be engaged by the transmission meshes with the spline shaft. Since the rigid transmission unit and the damping transmission unit are connected in parallel, the damping transmission unit can withstand the main transmission torque between the motor and the transmission, while the contact torque of the rigid transmission unit can be disconnected by the damping transmission unit, so that the main contact torque between the motor and the transmission is separated from the rigid transmission unit.For the torque borne by the rigid transmission unit to be disconnected by the damping transmission unit, there must be a gap between the rigid contact surfaces of the two half-couplings of the rigid transmission unit. This gap cannot be too large when the motor outputs high torque; otherwise, the maximum load-bearing capacity of the elastic device in the damping transmission unit needs to be increased. Since the load-bearing capacity and damping capacity of the elastic device in the damping transmission unit are irreconcilable within a certain size range, increasing the maximum load-bearing capacity of the elastic device will inevitably decrease the damping capacity. Taking the damping device of a tire structure as an example, under impact, a high-pressure tire is more prone to bursting than a low-pressure tire, meaning a high-pressure tire has a low load-bearing capacity. However, for the same amount of deformation, a high-pressure tire has a stronger damping capacity than a low-pressure tire. During gear shifting, the drive motor can output zero torque, and the elastic device does not need a large load-bearing capacity, only a strong damping capacity. This solution addresses this by actively adjusting the two half-couplings of the rigid transmission unit at the moment of gear shifting. The above problem can be solved by dynamically adjusting the maximum deformation of the elastic element of the damping transmission unit by adjusting the maximum gap of the rigid contact surface. Specifically, a gap adjustment block is added between the rigid contact surfaces of the two half-couplings of the rigid transmission unit. This adjustment block is made of rigid material capable of withstanding the maximum torque of the drive motor. When the drive motor is working normally, the gap between the rigid contact surfaces of the two half-couplings is reduced. During gear shifting, when the motor output power is zero at the instant the gear to be engaged with the spline shaft, the gap between the rigid contact surfaces of the two half-couplings of the rigid transmission unit is actively increased, thereby increasing the maximum deformation of the elastic element of the damping transmission unit and improving the damping capacity. A second solution is to keep the gap of the rigid transmission unit constant and instead adjust the thickness of the rigid material in the damping transmission unit. Both solutions operate on the same principle, and the final effect is to actively increase the maximum deformation of the elastic element of the damping transmission unit during vibration to improve the damping capacity.

[0005] This solution can be achieved by modifying a traditional flexible pin coupling. A traditional flexible pin coupling consists of a drive shaft half-coupling and a driven shaft half-coupling. The drive shaft half-coupling has a disc-shaped body with pins and elastic elements on the pins, while the driven shaft half-coupling has a flange hole, referred to as a pin hole. After the pin is inserted into the pin hole, the torque between the drive and driven shafts is transmitted through the pin, the elastic elements on the pin, and the inner wall of the pin hole. The pin, the elastic elements on the pin, and the pin hole constitute a vibration damping transmission mechanism. The traditional elastic sleeve pin coupling has a poor load-bearing capacity because the elastic element on the coupling needs to withstand the maximum torque of the transmission system. To solve this problem, this invention adds a rigid transmission unit with variable clearance to the traditional elastic sleeve pin coupling. The two transmission units are connected in parallel to transmit the torque of the power system. The rigid transmission unit can withstand the maximum torque of the transmission system with a smaller size. When shifting gears, the vibration damping capacity of the coupling can be improved by adjusting the clearance between the rigid contact surfaces of the two half-coupling flanges and flange holes of the rigid transmission unit. Attached Figure Description

[0006] Figure 1 This is an axial plan view of the coupling.

[0007] Figure 2 yes Figure 1 Side view sectional view.

[0008] In the diagram: 1 is the disc-shaped body of the drive shaft half coupling, 2 is the disc-shaped body of the driven shaft half coupling, 3 is the fixed disc of the clearance adjusting block, 4 is the movable bearing, 5 is the output shaft, 6 is the clearance adjusting block, 7 is the flange of the rigid transmission unit, 8 is the flange of the damping transmission unit, 9 is the elastic element, 10 is the flange hole of the damping transmission unit, 11 is the flange hole of the rigid transmission unit, and 12 is the input shaft. Detailed Implementation

[0009] The present invention will be further described below with reference to the accompanying drawings and embodiments: like Figure 1 , 2The high-damping coupling shown consists of a driving half-coupling, a driven half-coupling, and a clearance adjusting block fixing plate (3). The driving half-coupling consists of a driving half-coupling disc body (1), a set of rigid transmission unit flanges (7), a set of damping transmission unit flanges (8), and a coupling input shaft (12). The coupling input shaft (12) is located at the center of the left side of the driving half-coupling disc body (1). A movable bearing (4) is mounted on the coupling input shaft (12), and a clearance adjusting block fixing plate (3) is mounted on the movable bearing (4). A set of clearance adjusting blocks is mounted on the clearance adjusting block fixing plate (3). (6) The gap adjusting block (6) is a long strip that is thin at one end and thick at the other, with a sloping transition in the middle. The damping transmission unit flange (8) is wrapped with a ring of elastic elements (9). The driven shaft half coupling consists of a driven shaft half coupling disc body (2) and an output shaft (5). The driven shaft half coupling disc body (2) has a set of rigid transmission unit flange holes (11) and a set of damping transmission unit flange holes (10). When the gap adjusting block fixing disc, the driving half coupling, and the driven shaft half coupling are engaged: each damping transmission unit flange (8) and the wrapped elastic element (9) on the driving shaft half coupling can be smoothly inserted into the corresponding position. The flange hole (10) of the middle damping transmission unit allows each rigid transmission unit flange (7) on the drive shaft half coupling to be smoothly inserted into the corresponding rigid transmission unit flange hole (11). A sufficiently large gap is left between the inner walls of each rigid transmission unit flange (7) and the corresponding rigid transmission unit flange hole (11) so that two gap adjustment blocks (6) can be smoothly inserted. The gap adjustment block (6) installed on the gap adjustment block fixing plate (3) passes through the opening on the disc-shaped body (1) of the drive shaft half coupling and is inserted into the gap between the inner walls of the flange (7) and the corresponding rigid transmission unit flange hole (11). The drive motor works normally. The thick end of the time gap adjusting block (6) and the inner wall of the flange (7) and flange hole (11) form a transmission unit. At this time, the gap between the rigid transmission surfaces of the rigid transmission unit is small, and the maximum deformation of the elastic element (9) is also small. When shifting gears, when the output power of the drive motor is zero, the fixed plate (3) of the time gap adjusting block moves to the left through the moving bearing (4) so ​​that the thin end of the time gap adjusting block (6) and the inner wall of the flange (7) and flange hole (11) form a transmission unit. At this time, the gap between the rigid transmission surfaces of the rigid transmission unit becomes larger, which increases the maximum deformation of the elastic element (9) and thus improves the shock absorption capacity of the coupling.

[0010] The beneficial effects of this invention are: This solution increases the vibration damping capacity of the coupling by actively adjusting the gap between the rigid transmission surfaces of the rigid transmission unit during gear shifting. Compared with the traditional fixed gap design, it can significantly improve the vibration damping capacity of the coupling without changing the maximum load capacity of the elastic element.

Claims

1. A method for improving vibration damping capacity when subjected to vibration using a vibration-damping coupling consisting of a set of rigid transmission units capable of bearing the system's maximum torque and a set of vibration-damping transmission units that do not need to bear the system's maximum torque, characterized by: When subjected to vibration, the maximum deformation of the elastic element of the damping transmission unit is actively increased to improve the damping capacity.

2. A shock-absorbing coupling used in a multi-speed transmission of an electric vehicle, and a shock-absorbing method during gear shifting, characterized in that: The coupling consists of a set of rigid transmission units that can bear the maximum torque of the system and a set of damping transmission units that do not need to bear the maximum torque of the system. When shifting gears, the maximum deformation of the elastic element of the damping transmission unit is actively increased to improve the damping capacity.

3. A method for actively increasing the maximum deformation of the elastic element of the shock-absorbing transmission unit during gear shifting, according to claim 2, in a multi-speed transmission of an electric vehicle, characterized in that: The coupling has at least one rigid transmission unit that can bear the maximum torque of the system and one damping transmission unit that does not need to bear the maximum torque of the system. When shifting gears, the maximum clearance of the rigid contact surfaces of the two half-couplings of the rigid transmission unit is actively changed, which increases the maximum deformation of the elastic device of the damping transmission unit.

4. A method for actively changing the maximum clearance between the rigid contact surfaces of the two half-couplings of a rigid transmission unit during gear shifting, according to claim 3, of a shock-absorbing coupling on a multi-speed transmission of an electric vehicle, characterized in that: A set of clearance adjustment blocks is added between the rigid contact surfaces of the two half-couplings of the rigid transmission unit.

5. A method for using the clearance adjusting block of the rigid transmission unit during gear shifting in a shock-absorbing coupling for a multi-speed transmission of an electric vehicle according to claim 4, characterized in that: The gap adjustment block is a long strip that is thin at one end and thick at the other, with a sloping transition in the middle. When the drive motor is working normally, the thick end of the gap adjustment block is inserted between the rigid contact surfaces of the two half-couplings of the rigid transmission unit. When shifting gears, the thin end moves to the rigid contact surfaces of the two half-couplings of the rigid transmission unit.

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