A wet clutch

Abstract

The present invention discloses a wet clutch, which includes a main hub, a housing assembly fixedly connected to the main hub, a steel plate group fixedly connected to the housing assembly, a friction plate group sleeved on the main hub, an inner housing fixedly connected to the friction plate group, and an acting piston sleeved on the main hub and capable of axially moving along the main hub to press or release the friction plate group against the steel plate group; a first input portion for inputting torque is provided at the front end of the main hub, a second input portion for inputting torque is provided at the rear end of the main hub, a first output portion for outputting torque is provided on the housing assembly, and a second output portion for outputting torque is provided on the inner housing.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive clutches, and particularly to a wet clutch. Background Art

[0002] At present, some hybrid transmissions with electromechanical coupling systems have achieved the coupling of the first power source and the second power source, but there is only one power output end. There is a wet clutch in the transmission system, but it can only be disconnected from one power output end by separating the clutch, so as to realize the range-extending power generation function. Or, by combining and closing the clutch, the power outputs of the first power source and the second power source are transmitted to the power output end. Among them, the wet clutch is splined to the input shaft for coupling the first power source and the second power source, and the input shaft is directly splined to the generator or has a structure with gear transmission for speed increase. The layout structure of this type of wet clutch is not compact, the layout space is long, and the cost is high.

[0003] In the pure electric dual-motor drive scheme, generally, two drive motors are coaxially arranged to directly achieve power coupling, or two drive motors transmit power coupling to the intermediate shaft through different gear meshes. There is no wet clutch structure in the transmission system, and the fixed gear ratio is not conducive to optimizing the matching of power performance and the highest efficiency. Both layout schemes can achieve power coupling, but they cannot directly achieve power splitting. If power splitting is to be achieved, an additional clutch and planetary gear set need to be added.

[0004] The foregoing description is for the purpose of providing general background information and does not necessarily constitute prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a clutch that can achieve both power coupling and power separation.

[0006] The present invention provides a wet clutch, which includes a main hub, a housing assembly fixedly connected to the main hub, a steel sheet group fixedly connected to the housing assembly, a friction plate group sleeved on the main hub, an inner housing fixedly connected to the friction plate group, and an actuating piston sleeved on the main hub and axially movable along the main hub to press or release the friction plate group against the steel sheet group.

[0007] A first input portion for inputting torque is provided at the front end of the main hub, a second input portion for inputting torque is provided at the rear end of the main hub, a first output portion for outputting torque is provided on the housing assembly, and a second output portion for outputting torque is provided on the inner housing.

[0008] Further, the main hub is integrally formed.

[0009] Further, a first bearing hole is provided at the center of the front end face of the main hub, and a second bearing hole is provided at the center of the rear end face of the main hub; the first input part is an input gear, and the second input part is an input spline sleeve.

[0010] Further, the main hub is integrally formed by hobbing, finish turning, and gear grinding processes with the centers of the first bearing hole and the second bearing hole as the positioning references.

[0011] Further, the housing assembly includes a piston support skeleton and a housing that are fixedly connected. The piston support skeleton is fixedly connected to the main hub. The housing is a ring-shaped hollow structure. An external spline is provided on the outer surface of the housing, and an internal spline is provided on the inner surface of the housing. The external spline of the housing forms the first output part, and an external spline is provided on the outside of the steel sheet group to mesh with the internal spline of the housing.

[0012] Further, a piston chamber is formed between the housing assembly and the acting piston. The piston chamber is connected to the pressure oil circuit. The acting piston can be driven by the oil pressure in the piston chamber to move along the axial direction of the main hub away from the piston support skeleton.

[0013] Further, it further includes a balance chamber cover plate fixedly connected to the main hub. The balance chamber cover plate and the piston support skeleton are located on different sides of the acting piston along the axial direction of the main hub. A balance chamber is formed between the balance chamber cover plate and the acting piston.

[0014] Further, balance chamber oil is filled in the balance chamber to counteract the centrifugal force generated by the oil in the piston chamber.

[0015] Further, it further includes a return spring located in the balance chamber to drive the acting piston to move along the axial direction of the main hub away from the balance chamber cover plate. One end of the return spring abuts against the balance chamber cover plate, and the other end of the return spring abuts against the acting piston.

[0016] Further, the steel sheet group and the acting piston are located on different sides of the friction plate group along the axial direction of the main hub. When the oil pressure in the piston chamber is greater than the elastic force of the return spring, the acting piston can press the friction plate group towards the steel sheet group.

[0017] The wet clutch provided by the present invention has two power input ends at both ends of the main hub, and takes the housing assembly fixedly connected to the main hub and the inner housing that is clutch-connected to the housing assembly as two power output ends, realizing that one clutch body has two power input ends and two power output ends, improving the reliability of the vehicle's power output, enriching the flexibility of the vehicle's selection of power output ends, enabling different working modes, and can be combined with a planetary gear set and a brake to form a transmission system with two gear ratios or a transmission structure with two power outputs. By integrally designing the clutch hub and the input shaft gear into the main hub, the layout space and the manufacturing cost of parts are saved, and the transmission process is reduced; the main hub is integrally formed, the gear shaft and the two bearing holes can be machined in one clamping on a machine tool, and the gear grinding can be processed with the two bearing holes as the reference, with high production and processing accuracy, avoiding multiple clampings and switching of processing references, shortening the processing time and saving costs. By setting a balance cavity, it is used to offset the centrifugal force generated by the oil in the piston cavity as the clutch rotates, resulting in the pressure in the piston cavity fluctuating with the change of speed, thereby reducing the control difficulty of the clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic cross-sectional structure diagram of the wet clutch according to the first embodiment of the present invention;

[0019] Figure 2 is Figure 1 a schematic cross-sectional structure diagram of the main hub in the wet clutch;

[0020] Figure 3 is Figure 1 a schematic exploded view of the wet clutch after hiding the inner housing;

[0021] Figure 4 is Figure 1 a schematic connection diagram of the wet clutch in the transmission system;

[0022] Figure 5 is a schematic connection diagram of the wet clutch according to the second embodiment of the present invention in the transmission system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following will further describe in detail the specific embodiments of the present invention with reference to the drawings and embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0024] First Embodiment

[0025] Please refer to Figures 1 to 4, the first embodiment of the present invention provides a wet clutch for a hybrid vehicle, which includes a main hub 10, a housing assembly 20, a steel sheet group 30, an adjusting steel sheet 31, an outer snap ring 32, a friction plate group 40, an inner housing 50, an acting piston 60, a balance chamber cover plate 70, an inner snap ring 71, and a return spring 80.

[0026] Please refer to Figure 2 , the main hub 10 is a composite structure of a gear - shaft - spline sleeve. Along the axial direction, the front end is an input gear, and the rear end is an input spline sleeve. The input gear forms a first input part 11, and the first input part 11 is connected to a GCU (Generator Control Unit) through gear transmission to input the torque of the motor. The input spline sleeve forms a second input part 12, and the second input part 12 is connected to an ICE (Internal Combustion Engine) through splines or end face dog teeth to input the torque of the engine. The main hub 10 is provided with a first bearing hole 13 at the center of the end face of the input gear, and a second bearing hole 14 at the center of the end face of the input spline sleeve.

[0027] The main hub 10 is integrally formed. During processing, the two bearing holes are precisely turned as the reference for hobbing the gear. After heat treatment, the inner circles of the bearing holes are ground, and then the gear teeth are ground with the two bearing holes as the reference. In this embodiment, by integrally designing the clutch hub and the input shaft gear as the main hub 10, the layout space and the manufacturing cost of parts are saved, and the transmission process is reduced; the main hub 10 is integrally formed, and the gear shaft and the two bearing holes can be machined in one clamping on one machine tool. The gear grinding can be processed with the two bearing holes as the reference, with high production and processing accuracy, avoiding multiple clamps and switching of processing references, shortening the processing time and saving costs.

[0028] Please refer to Figure 1 and Figure 3 , the housing assembly 20 includes a piston support skeleton 21 and a housing 22. The two components are connected together by laser welding or electron beam welding to reduce the difficulty of stamping dies. After the housing assembly 20 is welded integrally, the piston support skeleton 21 is welded to the main hub 10. The housing 22 is a ring - shaped hollow structure, with an external spline on the outer surface and an internal spline on the inner surface. The external spline of the housing 22 forms a first output part 221, and the internal spline of the housing 22 meshes with the external spline of the steel sheet group 30 to transmit torque. The adjusting steel sheet 31 and the outer snap ring 32 are used to limit the axial position of the steel sheet group 30 on the housing 22.

[0029] The acting piston 60 is sleeved on the main hub 10 and can move axially along the main hub 10. An interference-fitted O-ring seal 61 is provided between the acting piston 60 and the main hub 10, and an interference-fitted D-ring seal 62 is provided between the acting piston 60 and the outer housing assembly 20. The outer housing assembly 20, the main hub 10, and the acting piston 60 form a piston chamber (not labeled) by the sealing action of the O-ring seal 61 and the D-ring seal 62. The piston chamber is connected to the external pressure oil circuit, and the pressure oil circuit can inject oil into the piston chamber, and the oil in the piston chamber can also flow out through the pressure oil circuit. When the oil pressure in the piston chamber increases, the acting piston 60 is driven by the oil pressure to move axially along the main hub 10 in a direction away from the piston support skeleton 21.

[0030] The balance chamber cover plate 70 is fixedly connected to the main hub 10, and the inner snap ring 71 is used to limit the axial position of the balance chamber cover plate 70. The balance chamber cover plate 70, the acting piston 60, and the piston support skeleton 21 are arranged in sequence along the axial direction of the main hub 10. A lip seal (not shown) for sealing is also provided on the side of the acting piston 60 facing the balance chamber cover plate 70. A balance chamber (not labeled) is formed between the balance chamber cover plate 70 and the acting piston 60. The balance chamber is filled with balance chamber oil, which is used to offset the centrifugal force generated by the piston chamber oil as the clutch rotates, resulting in the fluctuation of the piston chamber pressure with the change of speed, thereby reducing the control difficulty of the clutch. The return spring 80 is located in the balance chamber, with one end abutted against the balance chamber cover plate 70 and the other end abutted against the acting piston. The balance chamber oil in the balance chamber can prevent the spring force of the return spring disk 80 from increasing, resulting in an increase in the oil pressure at the Kisspoint of the clutch, and the control oil pressure of the clutch will change with the speed, making it impossible to accurately control the clutch. The cross-sectional area of the balance chamber can be basically equal to the cross-sectional area of the piston chamber, so that most of the centrifugal forces generated by the oil in the two chambers during rotation can be offset, making the oil pressure at the Kisspoint of the clutch basically the same at different speeds, simplifying the self-learning of the Kisspoint oil pressure of the clutch and facilitating the control of the clutch.

[0031] The friction plate group 40 is sleeved on the main hub 10. The inner housing 50 is splined to the friction plate group 40, and the inner housing 50 forms the second output part 51. The friction plate group 40 can slide axially along the main hub 10 and can be pressed against the steel plate group 30 to form a friction pair. The acting piston 60, the friction plate group 40, and the steel plate group 30 are arranged in sequence along the axial direction of the main hub 10.

[0032] When the clutch is under the action of a certain oil pressure in the piston chamber, the friction pair is pressed to generate a frictional torque, so that the clutch is closed and torque can be transmitted. The magnitude of the transmitted torque can be adjusted according to requirements by the number and size of the friction pairs, as well as the oil pressure controlling the piston chamber. When the oil in the piston chamber is depressurized, the return spring 80 can squeeze out the oil in the piston chamber to make the piston 60 return, separating the originally pressed friction plate group 40 and steel plate group 30. At this time, the clutch is in the open state, and it is ensured that the piston can move under a certain oil pressure to prevent the clutch from being accidentally engaged.

[0033] Please refer to Figure 4 , in this embodiment, the first input part 11 and the second input part 12 are respectively connected to the GCU and the ICE, and the first input part 11 and the second input part 12 are coaxial. On the one hand, when the vehicle needs to start the engine during driving, the GCU can be used as a starter to tow-start the engine, and then the engine can charge the GCU in the high-efficiency speed range to realize the range-extending power generation mode. On the other hand, when the vehicle needs a sufficient power source when the battery state of charge (SOC) is sufficient, both the ICE and the GCU can transmit the power power flow to the power output end of the product through the two power input sources of the product. At the same time, in the engine direct drive mode, if the power of the ICE is greater than the power demand of the whole vehicle, the ICE can use the excess power to drive the GCU to generate electricity, thereby increasing the SOC of the whole vehicle.

[0034] At the power output end, when the clutch remains in the disengaged state, all power is output through the first output part 221 of the housing 22. If the TCU (Transmission Control Unit) inputs a clutch engagement signal to the hydraulic system, the hydraulic system fills the piston chamber with oil, and a certain oil pressure is maintained in the piston chamber to press the friction plate group 40 and the steel plate group 30. If the TCU monitors that the rotational speed difference between the two ends of the clutch meets the engagement condition, the hydraulic system increases the clutch engagement pressure to ensure that the clutch is in a fully engaged state, thereby realizing the lossless transmission of power from the steel plate group 30 to the friction plate group 40, and at this time, the output of the second output part 51 of the product is realized. If the whole vehicle does not need to transmit torque through the clutch engagement, the clutch control valve on the hydraulic module receives the TCU clutch disengagement command, opens the valve core to unload the oil pressure in the piston chamber, and the return spring 80 of the clutch releases the elastic potential energy to compress the oil in the piston chamber and squeeze out the oil from the piston chamber. Thus, the pressed friction plate group 40 and the steel plate group 30 are separated, realizing the opening of the clutch, and at this time, the characteristics of one power output port of the product are restored.

[0035] In other embodiments, the connection relationship between the two input parts and the two output parts can be swapped for input and output, and it still does not affect the function of the clutch to couple and decouple power. The transmission method between each transmission part can also be changed according to actual needs.

[0036] The wet clutch provided in this embodiment realizes that one clutch body has two power input ends and two power output ends by using the two ends of the main hub 10 as two power input ends respectively, and using the outer housing assembly 20 fixedly connected to the main hub 10 and the inner housing 50 that is clutch-connected to the outer housing assembly 20 as two power output ends. This improves the reliability of the vehicle's power output, enriches the flexibility of the vehicle's selection of power output ends, can achieve different working modes, and can be combined with a planetary gear set and a brake to form a transmission system with a two-speed ratio.

[0037] By integrally designing the clutch hub and the input shaft gear as the main hub 10, the layout space and the manufacturing cost of parts are saved, and the transmission process is reduced; the main hub 10 is integrally formed, the gear shaft and the two bearing holes can be machined in one clamping on one machine tool, and the gear grinding can be processed with the two bearing holes as the reference, with high production and processing accuracy, avoiding multiple clamps and switching of processing references, shortening the processing time and saving costs. By setting a balance chamber, it is used to offset the centrifugal force generated by the oil in the piston chamber as the clutch rotates, resulting in the fluctuation of the piston chamber pressure with the change of speed, thereby reducing the control difficulty of the clutch.

[0038] Second Embodiment

[0039] Reference Figure 5 , the difference between the wet clutch provided in the second embodiment of the present invention and the first embodiment is that the wet clutch is used in a new energy vehicle, and the vehicle has two motors EM1 and EM2. EM1 is connected to the first input part 11, and EM2 is connected to the second input part 12. The first output part 221 is connected to the vehicle's rear wheels, and the second output part 51 is connected to the vehicle's front wheels. When the steel sheet group 30 and the friction plate group 40 are separated, the vehicle is a rear-wheel drive vehicle. When the steel sheet group 30 and the friction plate group 40 are pressed tightly, the vehicle is a four-wheel drive vehicle. The two-wheel and four-wheel drive modes can be quickly switched according to the owner's selection and application conditions, enriching the flexibility of the vehicle's selection of power output ends.

[0040] In the drawings, for clarity, the dimensions and relative dimensions of layers and regions are exaggerated. It should be understood that when an element such as a layer, region, or substrate is referred to as being "formed on", "disposed on", or "located on" another element, the element can be directly disposed on the other element, or there can also be an intermediate element. In contrast, when an element is referred to as being "directly formed on" or "directly disposed on" another element, there is no intermediate element.

[0041] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0042] In this text, unless otherwise clearly defined and limited, the terms "install", "connect", and "couple" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0043] In this text, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the sake of clear expression of the technical solution and convenient description. Therefore, it cannot be understood as a limitation to the present invention.

[0044] In this text, the sequential adjectives "first", "second", etc. used to describe elements are only for differentiating elements with similar attributes, and do not mean that the elements described in this way must follow a given order, or time, space, rank, or other limitations.

[0045] In this text, unless otherwise specified, the meanings of "a plurality of" and "several" are two or more.

[0046] In this text, the term "comprise", "include" or any other variant thereof is intended to cover a non-exclusive inclusion. In addition to the listed elements, it may also include other elements not specifically listed.

[0047] As described above, it is only the specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A wet clutch, characterized in that, it includes a main hub, a housing assembly fixedly connected to the main hub, a steel sheet group fixedly connected to the housing assembly, a friction plate group sleeved on the main hub, an inner housing fixedly connected to the friction plate group, and an acting piston sleeved on the main hub that can move axially along the main hub to press or release the friction plate group against the steel sheet group; a first input part for inputting torque is provided at the front end of the main hub, a second input part for inputting torque is provided at the rear end of the main hub, the axes of the first input part and the second input part are the same, a first output part for outputting torque is provided on the housing assembly, and a second output part for outputting torque is provided on the inner housing.

2. The wet clutch according to claim 1, characterized in that, the main hub is integrally formed by machining.

3. The wet clutch according to claim 2, characterized in that, a first bearing hole is provided at the center of the front end face of the main hub, and a second bearing hole is provided at the center of the rear end face of the main hub; the first input part is an input gear, and the second input part is an input spline sleeve.

4. The wet clutch according to claim 3, characterized in that, the main hub is integrally formed by hobbing, precision turning, and gear grinding processes with the centers of the first bearing hole and the second bearing hole as the positioning reference.

5. The wet clutch according to claim 1, characterized in that, the housing assembly includes a piston support skeleton and a housing fixedly connected, the piston support skeleton is fixedly connected to the main hub, the housing is a ring-shaped hollow structure, an external spline is provided on the outer surface of the housing, an internal spline is provided on the inner surface of the housing, the external spline of the housing forms the first output part, and an external spline is provided on the outside of the steel sheet group to mesh with the internal spline of the housing.

6. The wet clutch according to claim 5, characterized in that, a piston cavity is formed between the housing assembly and the acting piston, the piston cavity is connected to a pressure oil circuit, and the acting piston can be driven by the oil pressure in the piston cavity to move axially along the main hub in a direction away from the piston support skeleton.

7. The wet clutch according to claim 6, characterized in that, it further includes a balance cavity cover plate fixedly connected to the main hub, the balance cavity cover plate and the piston support skeleton are located on different sides of the acting piston along the axial direction of the main hub, and a balance cavity is formed between the balance cavity cover plate and the acting piston.

8. The wet clutch according to claim 7, characterized in that, balance cavity oil for offsetting the centrifugal force generated by the oil in the piston cavity is filled in the balance cavity.

9. The wet clutch according to claim 7, characterized in that, it further includes a return spring located in the balance cavity for driving the acting piston to move axially along the main hub in a direction away from the balance cavity cover plate, one end of the return spring abuts against the balance cavity cover plate, and the other end of the return spring abuts against the acting piston.

10. The wet clutch according to claim 9, characterized in that, The steel sheet group and the acting piston are located on different sides of the friction plate group along the axial direction of the main hub. When the hydraulic pressure in the piston cavity is greater than the elastic force of the return spring, the acting piston can press the friction plate group towards the steel sheet group.

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