High-torque wet clutch applied to pure electric multi-gear gearbox

Abstract

The high-torque wet clutch applied to the pure electric multi-gear gearbox comprises an input shaft, an outer shell, an inner shell, a main hub, a friction clutch assembly and a piston assembly, the main hub is arranged on the periphery of the input shaft in a sleeved mode, the piston assembly is arranged on the outer edge of the main hub in a sleeved mode, and the piston assembly comprises an acting piston and a balance piston which are mutually nested. A spring reset mechanism is arranged between the acting piston and the balance piston, an axial limiting structure is arranged between the balance piston and the main hub, and when the acting piston and the balance piston approach to a preset distance, the outer edge end face of the acting piston abuts against and pushes the end face of the friction clutch assembly, so that adjacent friction structures in the friction clutch assembly are attached to each other; the inner shell and the main hub rotate synchronously to transmit torque, oil flowing through the friction assembly guarantees good heat dissipation performance, good heat capacity guarantees stability of the system, high-torque transmission under low oil pressure can be achieved, and the electric drive high-rotating-speed working condition can be fully adapted.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicle clutches, and in particular to a high-torque wet clutch applied to a pure electric multi-speed gearbox. Background Art

[0002] Existing pure electric vehicle models all use a single-speed reduction gearbox, which has high requirements on motor performance such as speed and torque. In order to extend the driving range, a larger capacity battery is often required, and the system speed is too high, affecting the NVH performance of the entire vehicle.

[0003] Therefore, there is an actual demand for developing two-speed or multi-speed electric drive gearboxes. The core component of general gearbox design is the clutch. The electric drive gearbox has extremely high requirements for the clutch design. It needs to withstand extremely high speeds and transmit extremely large torques. It also requires a compact space, with the axial length and radial dimensions limited to a very small space. The clutch also requires a fast response, quickly interrupting and connecting the torque at the millisecond level. However, the two-speed or multi-speed clutch designs commonly used in the market cannot meet this requirement.

[0004] In summary, the existing gearboxes used in pure electric vehicles have technical problems that make it difficult to meet the high speed and high torque requirements of electric vehicles, as well as compact space and rapid response. Utility Model Content

[0005] The technical problem to be solved by the utility model is that the existing gearboxes for pure electric vehicles are difficult to meet the working requirements of electric vehicles with high speed and high torque, compact space and rapid response.

[0006] To solve the above problems, the utility model provides a high-torque wet clutch applied to a pure electric multi-speed transmission, comprising an input shaft, an outer shell, a main wheel hub, a friction clutch assembly and a piston assembly, wherein the main wheel hub is sleeved on the outer periphery of the input shaft, and the piston assembly is a hollow annular shell sleeved on the outer edge of the main wheel hub, the piston assembly comprises an acting piston and a balancing piston nested in each other, a spring reset mechanism is arranged between the acting piston and the balancing piston, an axial limiting structure for positioning the axial position of the balancing piston relative to the main wheel hub is arranged between the balancing piston and the main wheel hub, the outer edge end face of the acting piston and the end of the friction clutch assembly are located at a radial position that can cooperate with each other, when the acting piston and the balancing piston are close to a preset distance, the outer edge end face of the acting piston presses against the end face of the friction clutch assembly, so that the adjacent friction structures in the friction clutch assembly fit together, so that the outer shell and the inner shell rotate synchronously to transmit torque.

[0007] The utility model provides a novel wet clutch design, wherein a friction clutch assembly and a piston assembly are arranged between an outer shell and a main wheel hub, and the axial feed of the piston assembly is pushed by hydraulic input oil. The piston assembly comprises an elastic reset action piston, wherein a sealed oil chamber is formed between the outer side of the action piston and the main wheel hub and the outer shell. When the oil pressure input into the oil chamber reaches a threshold value, the oil pressure pushes the action piston to move axially, and the friction structure of the friction clutch assembly assembled alternately is pushed by the action piston, so that the two parts of the friction clutch assembly that cooperate with each other are mutually abutted, and the two parts that originally can rotate relative to each other in the circumferential direction are circumferentially fixed, so as to synchronize the rotational motion of the gear at the output end with the input shaft, and achieve the on-off control of the rotational motion, i.e., power transmission. The design is controlled by hydraulic pressure, and the oil flowing through the friction assembly ensures good heat dissipation, and the good heat capacity ensures the stability of the system. The clutch design realizes the transmission of low pressure and high torque through the design of the oil pressure driving piston, fully adapts to the working conditions of high speed of electric drive, and effectively solves the technical problems that the existing gearbox for pure electric vehicles is difficult to meet the high speed and high torque of electric vehicles, and the working requirements of compact space and rapid response.

[0008] As a preferred solution, a sealing lip is provided between the inner edge surface of the working piston and the main wheel hub to form a seal therebetween, and a sealed pressure chamber is formed between the working piston, the inner edge side of the outer shell, and the inner edge of the main wheel hub, which is used to push the working piston to move relative to the outer shell, the main wheel hub, and the balancing piston when the hydraulic pressure in the pressure chamber exceeds a threshold. The sealing design between the piston assembly and the main wheel hub is optimized to ensure the driving effect of the oil pressure pushing the piston.

[0009] As a preferred solution, the inner edge of the main hub is provided with a first oil passage at a position close to the working piston, for inputting hydraulic oil into the pressure cavity; the inner edge of the main hub is provided with a second oil passage at a position between the working piston and the balancing piston, for inputting lubricating oil into the balancing cavity between the working piston and the balancing piston. The oil in the piston can fully ensure the stability of the piston action.

[0010] As a preferred solution, the outer peripheral surface of the main hub is sleeved with an oil guide cover, and the axial position of the oil guide cover is adjacent to the balance piston. The oil conduction design is optimized, and the lubricating oil is collected and transported to the end of the inner shell through the structure of the oil guide cover.

[0011] As a preferred solution, the axial limiting structure is an axial retaining spring clamped to the outer peripheral surface of the main hub, and one end surface of the axial retaining spring abuts against the end surface of the oil guide cover, and the axial position of the balancing piston is limited by the abutment between the end surface of the oil guide cover and the end surface of the balancing piston. The design of the axial limiting structure is optimized, and the structure of the axial retaining spring can not only assist in fixing the oil guide cover but also limit the range of motion of the balancing piston.

[0012] As a preferred solution, the oil guide cover is conical, and the main hub is further provided with a third oil passage at the inner edge, and the third oil passage communicates with the space between the oil guide cover and the main hub. The design of the lubricating oil passage in the main hub is optimized, and the third oil passage connection position is set in the oil guide cover to guide the flow of the lubricating oil.

[0013] As a preferred solution, the input shaft is provided with input oil passages respectively connected to the first oil passage, the second oil passage and the third oil passage at positions corresponding to the first oil passage, the second oil passage and the third oil passage, respectively. The oil input design at the input shaft position is optimized to ensure the connectivity of the oil passages.

[0014] As a preferred solution, the outer peripheral surface of the input shaft is provided with three annular grooves on the axial surface between the input oil passages, and sealing rings are embedded in the annular grooves to seal and separate adjacent input oil passages, thereby optimizing the separation of the oil space, especially sealing and separating the oil space inside and outside the balance oil chamber.

[0015] As a preferred solution, the friction clutch assembly includes a plurality of friction plates and partition plates spaced apart from each other, the partition plates are all circumferentially positioned and connected to the inner shell, the friction plates are all circumferentially positioned and connected to the inner side surface of the outer shell, and the outer side surface of the inner shell is fixedly connected to a gearbox gear, thereby optimizing the structural design of the friction clutch. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the partial cross-sectional structure of a high-torque wet clutch applied to a pure electric multi-speed transmission provided by the utility model.

[0017] in, Figure 1 middle:

[0018] 1. Main wheel hub; 2. Input shaft; 3. Outer shell; 4. Action piston; 5. Balance piston; 6. Transmission gear; 7. Inner shell; 8. Oil guide cover; 9. Sealing lip; 10. Sealing ring; 13. First oil channel; 14. Second oil channel; 15. Third oil channel; 16. Spring return mechanism; 16-1. Spring end plate; 16-2. Compression spring; 17. Shaft retaining spring; 18. Friction clutch assembly; 18-1. Single-sided friction plate; 18-2. Partition plate; 18-3. Friction plate; 19. Retaining ring; 20. Optional hole retaining spring; 21. Optional back plate. DETAILED DESCRIPTION

[0019] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0020] Before explaining the working principle of the present invention in detail, the description of the present invention needs to be further explained: In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, an indirect connection through an intermediate medium, or a welding connection between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] refer to Figure 1 The following embodiments are described, Figure 1 A schematic diagram of the partial cross-sectional structure of a high-torque wet clutch applied to a pure electric multi-speed transmission provided by the utility model.

[0023] The utility model provided in this embodiment provides a high-torque wet clutch applied to a pure electric multi-speed transmission, comprising an input shaft 2, an outer shell 3, a main hub 1, a friction clutch assembly 18 and a piston assembly, wherein the main hub 1 is sleeved on the outer periphery of the input shaft 2, and the piston assembly is a hollow annular shell sleeved on the outer edge of the main hub 1, and the piston assembly comprises an action piston 4 and a balance piston 5 which are nested with each other, a spring reset mechanism 16 is arranged between the action piston 4 and the balance piston 5, and an axial limiting structure for positioning the axial position of the balance piston 5 relative to the main hub 1 is arranged between the balance piston 5 and the main hub 1, the outer edge end face of the action piston 4 and the end of the friction clutch assembly 18 are located at radial positions that can cooperate with each other, and when the action piston 4 and the balance piston 5 are close to a preset distance, the outer edge end face of the action piston 4 pushes the end face of the friction clutch assembly 18 tightly, so that the adjacent friction structures in the friction clutch assembly 18 fit together, so that the outer shell 3 and the inner shell 7 rotate in steps to transmit torque.

[0024] The utility model provides a novel wet clutch design, wherein a friction clutch assembly 18 and a piston assembly are arranged between an outer shell 3 and a main wheel hub 1, and the piston assembly is driven to advance axially by hydraulic input oil, and the piston assembly comprises an elastic reset action piston, wherein a sealed oil chamber is formed between the outer side of the action piston and the main wheel hub 1 and the outer shell 3, and when the oil pressure input into the oil chamber reaches a threshold value, the oil pressure drives the action piston 4 to move axially, and the friction structure of the friction clutch assembly 18 that matches the position is pushed by the action piston 4, so that the two parts of the friction clutch assembly 18 that match each other are abutted against each other, so that the original The two parts that can rotate relative to each other in the circumferential direction are fixed in the circumferential direction, so as to synchronize the rotational motion of the gear at the output end with the input shaft, and achieve the on-off control of the rotational motion, i.e., power transmission. The design uses hydraulic control, and the oil flowing through the friction component ensures good heat dissipation. The good heat capacity ensures the stability of the system. The clutch design realizes the transmission of low pressure and high torque through the design of the oil pressure drive piston, which fully adapts to the working conditions of high speed of electric drive, and effectively solves the technical problems that the existing gearboxes for pure electric vehicles are difficult to meet the high speed and high torque of electric vehicles, and the space is compact and the response is fast. The preferred design of the spring reset mechanism 16 includes a compression spring 16-2 and spring end plates 16-1 at both ends of the compression spring 16-2. The two spring end plates 16-1 are respectively against the inner side surfaces of the working piston 4 and the balance piston 5, which are used to limit the compression spring 16-2 to prevent the spring from falling out of the predetermined position.

[0025] In the technical solution provided by this embodiment, a sealing lip 9 is provided between the inner edge surface of the working piston 4 and the main wheel hub 1 to form a seal therebetween, and a sealed pressure chamber is formed between the working piston 4, the inner edge side of the outer shell 3 and the inner edge of the main wheel hub 1, which is used to push the working piston 4 to move relative to the outer shell, the main wheel hub and the balance piston 5 when the hydraulic pressure in the pressure chamber exceeds the threshold. That is, when the liquid pressure in the pressure chamber is large enough, the spring return mechanism 16 will be compressed, and when the liquid pressure in the pressure chamber decreases, the spring return mechanism 16 will push the working piston 4 to move in the direction close to the end surface of the outer shell 3, and the adjacent friction structures in the friction clutch assembly 18 are separated, and the clutch is opened at this time, interrupting the torque transmission.

[0026] It should be noted that the pressure chamber is connected to the pressure oil input, and the sealing lip 9 is installed on the outer circumference of the main hub 1. A groove for installation can be set at a corresponding position on the outer circumference of the main hub 1, and the sealing lip 9 is set in the groove. This design optimizes the sealing design between the piston assembly and the main hub 1, and the sealing effect is ensured by the structure of the sealing lip 9, which ensures the driving effect of the oil pressure pushing the piston.

[0027] The inner edge of the center hole of the outer shell 3 is preferably fixedly connected to the outer edge of the end face of the main hub 1 by welding; the outer shell 3 is preferably provided with an oil hole to ensure that the lubricating oil flows out of the clutch smoothly; a retaining ring 19 is provided on the outer edge of the outer shell 3, and a protrusion is provided on the outer periphery of the outer shell 3 to provide axial positioning of the retaining ring 19. This structure limits the radial expansion of the outer shell 3 at high speed to ensure structural stability; another optional design of the outer shell 3 is to omit the retaining ring 19 by adopting various structural forms with high-speed stability, such as a cylindrical outer shape without splines or a basin-like flange at the tail of the spline.

[0028] In the technical solution provided in this embodiment, a first oil channel 13 is provided on the inner edge of the main hub 1 at a position close to the working piston 4, which is used to input hydraulic oil into the pressure chamber; a second oil channel 14 is provided on the inner edge of the main hub 1 at a position between the working piston 4 and the balancing piston 5, which is used to input lubricating oil into the balancing chamber between the working piston 4 and the balancing piston 5.

[0029] This design optimizes the oil pressure output structure on both sides of the piston assembly, so that the oil pressure inside and outside the piston can be controlled separately, and the oil connected inside the piston can fully ensure the stability of the piston movement; in addition, the lubricating oil liquid in the balance cavity of the piston assembly connected to the second oil channel 14 generates centrifugal force with the rotation speed, which can offset part of the centrifugal force in the pressure chamber. Combined with the spring return mechanism 16 to offset the centrifugal force of the pressure chamber, it can ensure that the clutch has good controllability and stability.

[0030] In the technical solution provided in this embodiment, an oil guide cover 8 is sleeved on the outer circumference of the main hub 1, and the axial position of the oil guide cover 8 is adjacent to the balance piston 5. The oil conduction design is optimized, and the lubricating oil is collected and transported to the root of the inner shell through the structure of the oil guide cover 8.

[0031] In the technical solution provided in this embodiment, the axial limiting structure is a shaft retaining spring 17 clamped on the outer peripheral surface of the main hub 1, and one end surface of the shaft retaining spring 17 abuts against the end surface of the oil guide cover 8, and the axial position of the balancing piston 5 is limited by the abutment between the end surface of the oil guide cover 8 and the end surface of the balancing piston 5. The design of the axial limiting structure is optimized, and the structure of the shaft retaining spring 17 can not only assist in fixing the oil guide cover 8 but also limit the range of motion of the balancing piston 5.

[0032] In the technical solution provided by this embodiment, the oil guide cover 8 is in a conical shape, and the main hub 1 is further provided with a third oil passage 15 at the inner edge, and the third oil passage 15 connects the space between the oil guide cover 8 and the main hub 1. The design of the lubricating oil passage in the main hub 1 is optimized, and the connecting position of the third oil passage 15 is set in the oil guide cover 8 to guide the flow direction of the lubricating oil.

[0033] In the technical solution provided in this embodiment, the input shaft 2 is provided with input oil passages respectively connected to the first oil passage 13, the second oil passage 14 and the third oil passage 15. The oil input design at the position of the input shaft 2 is optimized to ensure the connectivity of the oil passages.

[0034] In the technical solution provided in this embodiment, the outer peripheral surface of the input shaft 2 is provided with three annular grooves on the axial surface between the input oil passages, and sealing rings 10 are embedded in the annular grooves to seal and separate adjacent input oil passages. Through the three annular grooves and the matching sealing rings 10, the oil of the gearbox housing is statically sealed and introduced into the pressure, balance and cooling oil passages, optimizing the separation of the oil space, especially the oil space inside and outside the balance piston is sealed and separated.

[0035] In the technical solution provided in this embodiment, the friction clutch assembly 18 includes a plurality of friction plates 18-3 and partition plates 18-2 that are spaced apart from each other. The partition plates 18-2 are all circumferentially positioned and connected to the inner shell 7, and the friction plates 18-3 are all circumferentially positioned and connected to the inner side surface of the outer shell 3. The outer side surface of the inner shell 7 is fixedly connected to the transmission gear 6.

[0036] This design optimizes the structural design of the friction clutch, wherein the preferred design is to use a phase or spline connection as the above-mentioned circumferential positioning structure, the gearbox gear 6 can be a parallel shaft gear, a planetary gear, or other forms of gears or other elements; the inner housing 7 is preferably connected to the gearbox gear 6 by a fixed connection method such as welding or riveting, and the side edge of the inner housing 7 has an external spline for circumferentially fixedly connecting the partition plate 18-2, and the partition plate 18-2 can slide axially along the inner housing 7; in addition, oil holes are preferably arranged on the inner housing 7 to allow the lubricating oil to evenly enter the friction pair and take away the heat generated by friction, thereby ensuring good clutch thermal capacity and high system stability.

[0037] In addition, the preferred configuration is that the friction clutch assembly 18 also includes a single-sided friction plate 18-1 and an optional back plate 21 located at both axial ends of each friction plate 18-3 and the partition plate 18-2, the optional back plate 21 is fixedly mounted on the inner edge surface of the outer shell 3 through an optional hole retaining ring 20, and the single-sided friction plate 18-1 is also fixedly mounted on the inner edge surface of the outer shell 3. The advantages of this clutch are that no axial external force acts on parts other than the clutch, which greatly improves the stability and reliability of the gearbox.

[0038] Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the utility model.

Claims

1. A high torque wet clutch for a pure electric multi-speed transmission, characterized in that: The invention comprises an input shaft (2), an outer shell (3), an inner shell (7), a main wheel hub (1), a friction clutch assembly (18) and a piston assembly, wherein the main wheel hub (1) is sleeved on the outer periphery of the input shaft (2), the piston assembly is a hollow annular shell sleeved on the outer edge of the main wheel hub (1), the piston assembly comprises an action piston (4) and a balance piston (5) which are nested with each other, a spring return mechanism (16) is arranged between the action piston (4) and the balance piston (5), and a spring return mechanism (16) is arranged between the balance piston (5) and the main wheel hub (1). An axial limiting structure is provided for locating the axial position of the balancing piston (5) relative to the main wheel hub (1); the outer edge end face of the acting piston (4) and the end of the friction clutch assembly (18) are located at radial positions that can cooperate with each other; when the acting piston (4) and the balancing piston (5) are close to a preset distance, the outer edge end face of the acting piston (4) pushes the end face of the friction clutch assembly (18) tightly, so that adjacent friction structures in the friction clutch assembly (18) fit together, so that the outer shell (3) and the inner shell (7) rotate synchronously to transmit torque.

2. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 1, characterized in that: A sealing lip (9) is provided between the inner edge surface of the acting piston (4) and the main wheel hub (1) to form a seal therebetween. A sealed pressure chamber is formed between the acting piston (4), the inner edge side of the outer shell (3) and the inner edge of the main wheel hub (1), and is used to push the acting piston (4) to move relative to the outer shell, the main wheel hub and the balance piston (5) when the hydraulic pressure in the pressure chamber exceeds a threshold value.

3. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 2, characterized in that: A first oil passage (13) is provided on the inner edge of the main wheel hub (1) at a position abutting against the working piston (4) for inputting hydraulic oil into the pressure chamber; a second oil passage (14) is provided on the inner edge of the main wheel hub (1) at a position between the working piston (4) and the balancing piston (5) for inputting lubricating oil into the balancing chamber between the working piston (4) and the balancing piston (5).

4. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 3, characterized in that: An oil guide cover (8) is sleeved on the outer peripheral surface of the main wheel hub (1), and the axial position of the oil guide cover (8) is adjacent to the balance piston (5).

5. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 4, characterized in that: The axial limiting structure is an axial retaining spring (17) clamped on the outer peripheral surface of the main wheel hub (1), and the end surface of one side of the axial retaining spring (17) abuts against the end surface of the oil guide cover (8), and the axial position of the balancing piston (5) is limited by the abutment between the end surface of the oil guide cover (8) and the end surface of the balancing piston (5).

6. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 5, characterized in that: The oil guide cover (8) is in the shape of a cone, and the main wheel hub (1) is also provided with a third oil passage (15) at the inner edge, wherein the third oil passage (15) communicates with the space between the oil guide cover (8) and the main wheel hub (1).

7. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 6, characterized in that: The input shaft (2) is provided with input oil passages respectively connected to the three oil passages at positions corresponding to the first oil passage (13), the second oil passage (14) and the third oil passage (15).

8. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 7, characterized in that: The outer peripheral surface of the input shaft (2) is provided with three annular grooves on the axial surface between the input oil passages, and sealing rings (10) are embedded in each of the annular grooves for sealing and separating adjacent input oil passages.

9. The high torque wet clutch applied to a pure electric multi-speed transmission according to claim 1, characterized in that: The friction clutch assembly (18) comprises a plurality of friction plates (18-3) and partition plates (18-2) which are spaced apart from each other, wherein the partition plates (18-2) are all circumferentially positioned and connected to the inner shell (7), and the friction plates (18-3) are all circumferentially positioned and connected to the inner side surface of the outer shell (3), and the outer side surface of the inner shell (7) is fixedly connected to a gearbox gear (6).

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