Pressure relief device of wet clutch, wet clutch and transmission system

Abstract

A pressure relief device of a wet clutch comprises a first pressure relief oil hole, a second pressure relief oil hole, a blocking piece and a pressure relief elastic piece, the first pressure relief oil hole is used for being communicated with a working oil cavity of the wet clutch, and the blocking piece is movably arranged between the first pressure relief oil hole and the second pressure relief oil hole; the pressure relief elastic piece is used for providing elastic force for driving the blocking piece to move, so that when the wet clutch is engaged, the blocking piece is located at the position where the first pressure relief oil hole and the second pressure relief oil hole are mutually blocked, and when the wet clutch is disengaged, the blocking piece is located at the position where the first pressure relief oil hole and the second pressure relief oil hole are mutually communicated or blocked. The pressure relief device of the wet clutch is communicated with the working oil cavity, working oil in the working oil cavity is prevented from leaking when the wet clutch is in a joint state, and the working oil can be completely discharged when the wet clutch is in a separation state. The utility model further provides a wet clutch and a transmission system.

Description

Technical Field

[0001] The utility model relates to the technical field of the structure of wet clutches, in particular to a pressure relief device for a wet clutch, a wet clutch and a transmission system. Background Art

[0002] A clutch is a very important component in a mechanical transmission system, used to transmit and cut off the power from the engine to the gearbox and the power output device, and prevent parts from being damaged when the transmission system and the power output device are overloaded. It is widely used in agricultural machinery, construction machinery, hybrid vehicles and other fields. A wet clutch is a clutch that cools the friction surface with oil. During the engagement process, the heat generated due to slip friction can be taken away by the cooling oil at any time, thus effectively controlling the temperature of the friction surface and significantly reducing the wear of the friction surface. It is mostly used in agricultural machinery, construction machinery and hybrid vehicles.

[0003] When a wet clutch is engaged, working oil enters the piston cavity. The working oil rotates in the piston cavity to generate centrifugal force, and the centrifugal force of the working oil will generate dynamic pressure on the piston. When the wet clutch is disengaged, most of the working oil is discharged from the piston cavity, but there is still a small part of the working oil that is not discharged. The dynamic pressure generated by this part of the working oil will push the piston to move, making the gap between the clutch steel sheet and the clutch friction sheet in the wet clutch smaller or even close, which will undoubtedly affect the disengagement effect and cause poor operation.

[0004] Initially, the high-pressure oil in the piston cavity of the wet clutch was unloaded through the piston damping hole, but the damping hole was blocked by the clutch steel sheet, which was not conducive to the rapid separation of the friction element and was prone to damping hole jamming, resulting in clutch ablation caused by incomplete separation of the friction element.

[0005] In the prior art, Chinese Patent CN 117605771 A discloses a lightweight self-lubricating and rapid pressure-relieving clutch. By opening a pressure relief oil hole on the cylinder liner, the overall weight of the cylinder liner is reduced without changing the overall shape of the cylinder liner; during the clutch engagement process, the high-pressure oil pushes the piston to move, and the piston squeezes the friction element, so that the power of the driving gear is transmitted to the cylinder liner, and then drives the driven shaft to rotate. The piston movement no longer blocks the inlet end of the pressure relief oil hole. At this time, part of the high-pressure oil flows through the pressure relief oil hole to the outer edge of the friction element to dissipate heat and cool the friction element; during the clutch disengagement process, the piston moves toward the side close to the cylinder liner under the action of the reset assembly. At this time, the oil between the piston and the cylinder liner is accelerated through the pressure relief oil hole under the action of the piston, accelerating the pressure relief process during the clutch disengagement stage, realizing the self-pressure relief of the oil, and quickly separating the friction element. However, the pressure relief oil hole structure in this patent has the problem of working oil leakage during the clutch engagement process, which affects the clutch engagement effect. Summary of the Utility Model

[0006] In view of this, the present utility model provides a pressure relief device for a wet clutch, a wet clutch, and a transmission system. By connecting the working oil chamber of the wet clutch, when the wet clutch is in the engaged state, it can prevent the working oil in the working oil chamber from leaking to avoid affecting the engagement effect of the clutch. When the wet clutch is in the disengaged state, it can completely discharge the working oil from the working oil chamber, eliminate the dynamic pressure generated by the centrifugal force of the working oil on the piston, make the wet clutch disengage completely, prevent the occurrence of bad operations, and thus greatly improve the performance of agricultural machinery, construction machinery, and hybrid vehicles.

[0007] To achieve the above object:

[0008] The present application provides a pressure relief device for a wet clutch, including a first pressure relief oil hole, a second pressure relief oil hole, a plug, and a pressure relief elastic member. Among them, the first pressure relief oil hole is used to connect the working oil chamber of the wet clutch, and the plug is movably arranged between the first pressure relief oil hole and the second pressure relief oil hole; the pressure relief elastic member is used to provide an elastic force to drive the movement of the plug, so that when the wet clutch is engaged, the plug is in a position where the first pressure relief oil hole and the second pressure relief oil hole are blocked from each other, and when the wet clutch is disengaged, the plug is in a position where the first pressure relief oil hole and the second pressure relief oil hole are connected or blocked from each other.

[0009] In one embodiment, the wet clutch includes an outer hub and a piston. An accommodation cavity is formed in the outer hub, a positioning post is arranged in the accommodation cavity, the plug is movably arranged in the accommodation cavity, and two ends of the pressure relief elastic member respectively abut against the plug and the positioning post; the second pressure relief oil hole is formed in the positioning post, and the first pressure relief oil hole is arranged inside the outer hub near the outside of the piston, and the second pressure relief oil hole is coaxially arranged with the first pressure relief oil hole.

[0010] In one embodiment, the elastic acting force of the pressure relief elastic member when the plug blocks the first pressure relief oil hole is less than the pressure relief working oil acting force, and the elastic acting force of the pressure relief elastic member when the plug blocks the second pressure relief oil hole is greater than the pressure relief working oil acting force.

[0011] In one embodiment, the plug is of a spherical structure, and a conical surface structure matching the spherical structure is arranged at the end of the second pressure relief oil hole.

[0012] In one embodiment, the pressure relief elastic member is a pressure relief spring.

[0013] In one embodiment, the wet clutch includes an inner hub, an outer hub, a clutch assembly, a piston, and an elastic assembly. The elastic assembly is disposed between the piston and the inner hub and is configured to provide a force for separating the clutch assembly. A sliding member slidably connected to the outer hub is provided on the outer side of the piston, and the blocking member is a sealing ring disposed on the sliding member. A first pressure relief oil hole and a second pressure relief oil hole are respectively disposed on both sides of the sliding member. The first pressure relief oil hole and the second pressure relief oil hole are located inside the outer hub near the outer side of the piston. A transition oil drain groove is provided on the sliding member. When the clutch assembly is separated, the elastic assembly replaces the pressure relief elastic member to drive the piston to drive the sealing ring on the sliding member to move so that the transition oil drain groove communicates with the first pressure relief oil hole and the second pressure relief oil hole respectively. When the clutch assembly is engaged, the piston drives the sealing ring on the sliding member to move so that the first pressure relief oil hole and the second pressure relief oil hole are blocked from each other.

[0014] In one embodiment, the wet clutch includes an inner hub, an outer hub, a clutch assembly, a piston, and an elastic assembly disposed between the piston and the inner hub and configured to provide a force for separating the clutch assembly. A sliding member slidably connected to the outer hub is provided on the outer side of the piston, and the blocking member is a sealing ring disposed on the sliding member. The first pressure relief oil hole is located inside the outer hub near the outer side of the piston, and the second pressure relief oil hole is disposed inside the sliding member. A transition oil drain groove is provided on the sliding member, and the second pressure relief oil hole communicates with the transition oil drain groove. When the clutch assembly is separated, the elastic assembly replaces the pressure relief elastic member to drive the piston to drive the sealing ring on the sliding member to move so that the transition oil drain groove communicates with the first pressure relief oil hole. When the clutch assembly is engaged, the piston drives the sealing ring on the sliding member to move so that the first pressure relief oil hole and the second pressure relief oil hole are blocked from each other.

[0015] In one embodiment, the cross-sectional areas of the first pressure relief oil hole and the second pressure relief oil hole are equal. The width of the transition oil drain groove along the axial direction of the sliding member is equal to the width of the first pressure relief oil hole along the axial direction of the sliding member. The length of the sealing ring on the sliding member is equal to or greater than the sum of the stroke of the piston and the maximum wear amount of the clutch assembly.

[0016] In one embodiment, the piston is provided with a piston sleeve. The elastic assembly includes a return elastic member, an elastic member baffle, and a second elastic retaining ring. Among them, the return elastic member is sleeved on the piston sleeve to abut against the inner side of the piston, and the elastic member baffle and the second elastic retaining ring are fixedly sleeved on the outer hub from the inside to the outside in sequence.

[0017] Based on the same concept as the foregoing utility model, the present application further provides a wet clutch, and the wet clutch can be provided with a pressure relief device such as the foregoing wet clutch.

[0018] Based on the same concept as the foregoing utility model, the present application further provides a transmission system, and the transmission system can be provided with a wet clutch such as the foregoing.

[0019] The pressure relief device, wet clutch and transmission system of the wet clutch provided by the present utility model connect the working oil cavity of the wet clutch. When the wet clutch is in the engaged state, the blocking member moves under the action of the working oil to block the first pressure relief oil hole and the second pressure relief oil hole from each other, preventing the working oil in the working oil cavity from leaking and avoiding affecting the engagement effect of the clutch. When the wet clutch is in the disengaged state, the blocking member moves under the elastic action of the pressure relief elastic member to connect the first pressure relief oil hole and the second pressure relief oil hole to each other, so that when the wet clutch is disengaged, the working oil can be completely discharged. Then the blocking member can move to the initial position to block the first pressure relief oil hole and the second pressure relief oil hole from each other, eliminating the dynamic pressure generated by the centrifugal force of the working oil on the piston, making the wet clutch disengage completely, preventing the occurrence of bad operations, and thus greatly improving the performance of agricultural machinery, construction machinery and hybrid vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 and Figure 2 respectively schematically show the overall structures of the wet clutch of the embodiments of the present utility model from different perspectives.

[0022] Figure 3 Schematically shows the overall sectional structure of the wet clutch of the embodiments of the present utility model.

[0023] Figure 4 Schematically shows the first pressure relief device in the embodiments of the present utility model.

[0024] Figure 5 Schematically shows the second pressure relief device in the embodiments of the present utility model.

[0025] Figure 6 Schematically shows the second structure of the sliding member in the embodiments of the present utility model.

[0026] Figure 7 Schematically shows Figure 11 the sectional structure of

[0027] Figure 8 Schematically shows the influence of the piston movement on the second pressure relief device in the embodiments of the present utility model.

[0028] Figure 9Schematically shows the third pressure relief device in the embodiment of the present utility model.

[0029] Figure 10 Schematically shows the third structure of the sliding member in the embodiment of the present utility model.

[0030] Figure 11 Schematically shows Figure 10 the sectional structure of

[0031] Figure 12 Schematically shows the influence of the piston movement on the third pressure relief device in the embodiment of the present utility model.

[0032] Figure 13 Schematically shows the oil circuit distribution structure of the wet clutch in the embodiment of the present utility model.

[0033] Figure 14 Schematically shows the influence of the piston movement on the first piston lubricating oil outlet hole and the second piston lubricating oil outlet hole in the embodiment of the present utility model.

[0034] Figure 15 Schematically shows the structure of the clutch assembly in the embodiment of the present utility model.

[0035] Figure 16 Schematically shows the structure of the elastic component in the embodiment of the present utility model.

[0036] Figure 17 Schematically shows the structure of the brake assembly in the embodiment of the present utility model. Detailed implementation manners

[0037] Next, specific embodiments of the present utility model will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the description of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0038] In the description of the present utility model, unless otherwise clearly defined and limited, terms such as "arranged", "provided with", "installed", "connected", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0039] The terms "upper", "inner", "one side", "both sides", "inner side", "side part", "outer side", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of description and simplification of the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0040] The terms "first", "second", "third", "fourth", etc. are only used to distinguish elements with similar attributes, rather than indicating or implying relative importance or a specific order.

[0041] The term "comprising" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to including the listed elements, it may also include other elements not specifically listed.

[0042] As Figures 1 to 5 and Figure 9 As shown, the wet clutch of the embodiment of the present application includes an input transmission member 10, an output transmission member 20, a clutch assembly 50, a piston 60, and a working oil circuit 101. Among them, the input transmission member 10 and the output transmission member 20 are coaxially arranged. The clutch assembly 50 includes a first part and a second part. The input transmission member 10 is fixedly connected to the first part, and the output transmission member 20 is fixedly connected to the second part. The piston 60 is movably arranged outside the second part to push the second part to be in close contact with or separated from the first part, so that the clutch assembly 50 is engaged or separated. A working oil cavity 901 is formed between the clutch assembly 50 and the piston 60, and the working oil circuit 101 communicates with the working oil cavity 901. The wet clutch of the embodiment of the present application further includes a pressure relief device 100 for the wet clutch. The pressure relief device 100 for the wet clutch includes a first pressure relief oil hole 110, a second pressure relief oil hole 120, a plug 130, and a pressure relief elastic member 140. Among them, the first pressure relief oil hole 110 communicates with the working oil cavity 901, and the plug 130 is movably arranged between the first pressure relief oil hole 110 and the second pressure relief oil hole 120. The pressure relief elastic member 140 is used to provide an elastic force to drive the movement of the plug 130, so that when the clutch assembly 50 is engaged, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are blocked from each other, and when the clutch assembly 50 is separated, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are either communicated with each other or blocked from each other.

[0043] As Figure 3As shown, in one embodiment, the clutch assembly 50 further includes an inner hub 30 and an outer hub 40. The inner hub 30 is fixedly connected to the input transmission member 10, and the outer hub 40 is fixedly connected to the output transmission member 20. The clutch assembly 50 is axially movably connected to the inner hub 30. The first part is fixedly connected to the inner hub 30 in the circumferential direction, and the second part is fixedly connected to the outer hub 40 in the circumferential direction. The piston 60 includes a piston sleeve 65 sleeved on the outer hub 40. The wet clutch further includes an elastic assembly 70. One end of the elastic assembly 70 is sleeved on the piston sleeve 65. The elastic assembly 70 is arranged between the piston 60 and the inner hub 30 and is used to provide a force for separating the first part and the second part of the clutch assembly 50.

[0044] As Figure 3 shown, the wet clutch further includes a brake assembly 80. The brake assembly 80 is sleeved on one end of the outer hub 40 away from the inner hub 30. The sliding member 61 is used to abut against the side of the brake assembly 80. A brake return elastic member 64 is sleeved on the free end of the sliding member 61, and the brake return elastic member 64 is a spring structure.

[0045] As Figure 4 shown, in one embodiment, a receiving cavity 150 is formed in the outer hub 40. A positioning post 160 is arranged in the receiving cavity 150. The plug 130 is movably arranged in the receiving cavity 150. Two ends of the pressure relief elastic member 140 respectively abut against the plug 130 and the positioning post 160. The second pressure relief oil hole 120 is formed in the positioning post 160. The first pressure relief oil hole 110 is arranged in the outer hub 40 at a position close to the outside of the piston 60. The second pressure relief oil hole 120 and the first pressure relief oil hole 110 are coaxially arranged. In one embodiment, the plug 130 is a spherical structure, and a conical surface structure 121 matching the spherical structure is arranged at the end of the second pressure relief oil hole 120 to ensure the blocking effect. Specifically, the pressure relief elastic member 140 is a pressure relief spring, with a simple and compact structure and easy installation and arrangement.

[0046] In an embodiment, the elastic force of the pressure relief elastic member 140 when the blocking member 130 blocks the first pressure relief oil hole 110 is less than the pressure relief working oil force, and the elastic force of the pressure relief elastic member 140 when the blocking member 130 blocks the second pressure relief oil hole 120 is greater than the pressure relief working oil force. Specifically, when the working oil cavity 901 is filled with oil, the working oil enters from the first pressure relief oil hole 110. At this time, the force F1 of the working oil is much greater than the resilience F2 of the pressure relief elastic member 140. Therefore, the spherical blocking member 130 is pushed to squeeze the pressure relief elastic member 140 and fit with the conical surface structure 121 inside the second pressure relief oil hole 120. In this way, the blocking member 130 blocks the second pressure relief oil hole 120 and prevents the working oil in the working oil cavity 901 from leaking. When the working oil cavity 901 discharges oil, a small part of the working oil generates dynamic pressure to push the blocking member 130 close to the second pressure relief oil hole 120. At this time, the blocking member 130 cannot fit with the conical surface structure 121, otherwise the excess working oil cannot be discharged. To meet the above requirements, let the force of the pressure relief elastic member 140 when the blocking member 130 blocks the first pressure relief oil hole 110 be F21, the force of the pressure relief elastic member 140 when the pressure relief ball blocks the second pressure relief oil hole 120 be F22, and the pressure relief working oil force be F1'. Then, F21 < F1' < F22 should be satisfied. In this way, the pressure relief ball neither blocks the first pressure relief oil hole 110 nor blocks the second pressure relief oil hole 120, and the excess working oil will flow outwards from the second pressure relief oil hole 120. Therefore, when the wet clutch is separated, the working oil can be completely discharged, the dynamic pressure generated by the centrifugal force of the working oil on the piston 60 can be eliminated, the clutch assembly 50 can be separated completely, and the generation of bad operations can be prevented. It can be understood that in some embodiments not shown, the above pressure relief assembly can also be arranged at other positions of the outer hub 40 to achieve discharging the excess working oil in the working oil cavity 901 when the working oil cavity 901 discharges oil. The axis of the installation cavity 150 can be arranged in a manner that intersects the axis of the output transmission member 20 at various angles.

[0047] As Figures 5 to 7 shown, in an embodiment, a sliding member 61 slidably connected to the outer hub 40 is provided on the outside of the piston 60. The blocking member 130 is a sealing ring provided on the sliding member 61. The first pressure relief oil hole 110 and the second pressure relief oil hole 120 are respectively provided on both sides of the sliding member 61. An annular transitional oil discharge groove 63 is provided on the sliding member 61. When the clutch assembly 50 is separated, the elastic assembly 70 replaces the pressure relief elastic member 140 to drive the piston 60 to drive the sealing ring on the sliding member 61 to move so that the annular transitional oil discharge groove 63 communicates with the first pressure relief oil hole 110 and the second pressure relief oil hole 120 respectively. When the clutch assembly 50 is engaged, the piston 60 drives the sealing ring on the sliding member 61 to move to block the first pressure relief oil hole 110 and the second pressure relief oil hole 120.

[0048] As Figure 8As shown, when the clutch assembly 50 is disengaged, i.e., when the piston stroke △ is 0, the working oil in the working oil chamber 901 flows out through the first pressure relief oil hole 110, the annular transition oil drain groove 63 on the sliding member 61, and the second pressure relief oil hole 120, which can avoid the dynamic pressure from affecting the disengagement effect of the wet clutch. When the clutch assembly 50 is engaged, i.e., when the piston stroke is △ = α, the braking return elastic member 64 pushes the sliding member 61 to axially move along with the piston 60. At this time, the first pressure relief oil hole 110 is blocked by the blocking ring on the sliding member 61 to ensure that there is a sufficiently large pressure in the working oil chamber 901. Considering the wear of the clutch assembly 50, i.e., when the piston stroke is △ = α + δ, the position of the sliding member 61 is offset, but the first pressure relief oil hole 110 is still blocked by the sliding member 61 to ensure that there is a sufficiently large pressure in the working oil chamber 901. The cross-sectional areas of the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are equal. Let the width of the first pressure relief oil hole 110 along the axial direction of the sliding member 61 be d4, then the width z of the annular transition oil drain groove 63 along the axial direction of the sliding member 61 should satisfy z = d4, and the length y of the blocking ring should satisfy: y ≥ α + [δ], where [δ] is the maximum wear amount of the clutch assembly 50.

[0049] As Figures 9 to 11 shown, in an embodiment, a sliding member 61 slidably connected to the outer hub 40 is provided outside the piston 60. The blocking member 130 is a blocking ring provided on the sliding member 61. The first pressure relief oil hole 110 is provided in the outer hub 40 near the outside of the piston 60. The second pressure relief oil hole 120 is provided in the sliding member 61. The sliding member 61 is provided with an annular transition oil drain groove 63. The second pressure relief oil hole 120 communicates with the annular transition oil drain groove 63. When the clutch assembly 50 is disengaged, the elastic assembly 70 replaces the pressure relief elastic member 140 to drive the piston 60 to drive the blocking ring on the sliding member 61 to move so that the transition oil drain groove 63 communicates with the first pressure relief oil hole 110. When the clutch assembly 50 is engaged, the piston 60 drives the blocking ring on the sliding member 61 to move to block the first pressure relief oil hole 110 and the second pressure relief oil hole 120. Specifically, the second oil drain hole 120 axially penetrates through the sliding member 61 to communicate with the annular transition oil drain groove 63.

[0050] As Figure 12As shown, when the clutch assembly 50 is disengaged, i.e., the piston stroke △ is 0, the working oil in the working oil chamber 901 flows out through the first oil drain hole 110, the annular transition oil drain groove 63, and the second oil drain hole 120, which can avoid the dynamic pressure from affecting the disengagement effect of the wet clutch. When the clutch assembly 50 is engaged, i.e., the piston stroke is △ = α, the braking return elastic member 64 pushes the sliding member 61 to axially move along with the piston 60. At this time, the first oil drain hole 110 is blocked by the blocking ring on the sliding member 61 to ensure that there is a sufficiently large pressure in the working oil chamber 901. Considering the wear of the clutch assembly 50, i.e., the piston stroke is △ = α + [δ], the position of the sliding member 61 is offset, but the first oil drain hole 110 is still blocked by the sliding member 61 to ensure that there is a sufficiently large pressure in the working oil chamber 901. Let the width of the first oil drain hole 110 along the axis of the sliding member 61 be d4, then the width z of the annular groove on the sliding member 61 along the axis of the sliding member 61 should satisfy z = d4. The cross-sectional area of the second oil drain hole 120 is equal to the cross-sectional area of the first oil drain hole 110. The blocking member 130 is a blocking ring provided on the sliding member 61, and the length y of the blocking ring should satisfy the condition: y ≥ α + [δ], where [δ] is the maximum wear amount.

[0051] As Figure 3 and Figure 13 shown, in an embodiment, the working oil path 101 enters the output transmission member 20 along the end of the output transmission member 20 and sequentially passes through the output transmission member 20 and the outer hub 40 in directions parallel and perpendicular to the axis of the output transmission member 20 and is communicated with the working oil chamber 901, i.e., the position near the inner side of the outer hub 40. Specifically, the above setting manner of the working oil path 101 has a simple and compact structure, is easy to process and manufacture, and can improve the flow efficiency of each oil path respectively.

[0052] As Figure 15As shown, in one embodiment, the first part is the clutch disc 51, the second part is the clutch friction disc 52, and the clutch assembly further includes a first elastic member 53, a positioning member 54, and a separating elastic member 55. Among them, the clutch disc 51, the clutch friction disc 52, and the first elastic member 53 are alternately movably sleeved on the inner hub 30. The outer periphery of the clutch disc 51 is circumferentially fitted into the outer hub 40, and the inner periphery of the clutch friction disc 52 is circumferentially fitted into the inner hub 30. The positioning member 54 is disposed through the clutch disc 51 along the direction parallel to the axis of the input transmission member 10. The two ends of the positioning member 54 are respectively fixedly connected to the side portions of the inner hub 30 and the outer hub 40. The two ends of the positioning member 54 are sleeved with first elastic support members 56, and the first elastic support members 56 are used to pre-tighten the ends of the positioning member 54 so that the positioning member 54 is always fixedly connected to the inner hub 30 and the outer hub 40 respectively. The separating elastic members 55 are spaced between adjacent clutch discs 51. On the side of the clutch assembly 50 close to the inner hub 30, an adjusting piece 57 and a first elastic retaining ring 58 are sequentially arranged from the inside to the outside. Specifically, the clutch disc 51 and the adjusting piece 57 are steel sheets, the first elastic member 53 is a corrugated spring, the positioning member 54 is a positioning rubber rod, the separating elastic member 55 is a separating spring, and the first elastic support member 56 is a pre-tightening spring. Specifically, corrugated springs are arranged between the clutch disc 51 and the clutch friction disc 52. When the wet clutch is separated, the clutch disc 51 and the clutch friction disc 52 are separated completely and evenly, and the output transmission member 20 can be quickly stopped, improving the stability and reliability of the separation process. The positioning rubber rods and separating springs are arranged circumferentially on the clutch disc 51. The positioning rubber rods can improve the coaxiality between the clutch discs 51 and improve the stability of the engagement and separation processes of the clutch assembly 50. The separating springs can make the separation process more uniform and thorough and improve the separation response speed. It is easy to understand that in some embodiments not shown, the type and position of the first elastic member 53 between the clutch disc 51 and the clutch friction disc 52 can be adjusted according to actual situations, and the positioning member 54 and the separating elastic member 55 on the clutch disc 51 can also be arranged on the clutch friction disc 52 or other positions of the clutch disc 51.

[0053] Specifically, let the thickness of the clutch disc 51 be h1, the thickness of the clutch friction disc 52 be h2, and the average gap between the clutch disc 51 and the clutch friction disc 36 in the separated state of the clutch assembly 50 be λ. Then the thickness H of the adjusting piece 57 is H = h1 + h2 + λ. The adjusting piece 57 can be replaced with a pair of the clutch disc 51 and the clutch friction disc 52, and the thickness of the adjusting piece 57 can also be set as the sum of the thicknesses and the average gap of multiple pairs of the clutch disc 51 and the clutch friction disc 52. In this way, the output torque of the entire wet clutch can be increased to adapt to higher-power vehicles or construction machinery.

[0054] As Figure 16As shown, in one embodiment, the elastic component 70 includes a return elastic member 71, an elastic member baffle 72, and a second elastic retaining ring 73. Among them, the return elastic member 71 is sleeved on the piston sleeve 65 of the piston 60 to abut against the inner side of the piston 60, and the elastic member baffle 72 and the second elastic retaining ring 73 are fixedly sleeved on the outer hub 40 in sequence from the inside to the outside. Specifically, the return elastic member 71 is a spring structure. The elastic component with the above structural form is easy to arrange and install, has a simple and compact structure, and is convenient to apply an elastic force to the piston 60 to stably and reliably realize the reset of the piston 60.

[0055] As Figure 17 shown, in one embodiment, the braking component 80 includes a brake pad 81, a brake friction plate 82, and a second elastic member 83. Among them, the brake pad 81, the brake friction plate 82, and the second elastic member 83 are alternately movably sleeved on the outer hub 40, and a third elastic retaining ring 84 fixedly sleeved on the outer hub 40 is provided on the outer side of the braking component 80. Specifically, the brake pad 81 is a steel sheet, and the second elastic member 83 is a corrugated spring. Specifically, corrugated springs are provided between the brake pad 81 and the brake friction plate 82. When the wet clutch is engaged, the brake pad 81 and the brake friction plate 82 are separated completely and evenly, reducing the energy loss of the braking component 80 and improving the transmission efficiency during the engagement process.

[0056] As Figure 3 shown, specifically, the outer hub 40 includes a first outer hub 41 and a second outer hub 42 that are fixedly connected to each other.

[0057] As Figure 3 shown, in one embodiment, the inner hub 30 is provided with an installation sleeve 31, the clutch component 50 is sleeved on the installation sleeve 31, and lubrication holes 32 are provided at intervals on the installation sleeve 31. Through the lubrication holes 32 provided at intervals on the installation sleeve 31, uniform lubrication and cooling of the clutch component 50 can be further realized.

[0058] As Figure 3 shown, in one embodiment, the sliding member 61 is arranged along the axis direction parallel to the output transmission member 20, the sliding member 61 is symmetrically arranged relative to the axis of the output transmission member 20, a second elastic support member 62 is sleeved on the sliding member 61, the second elastic support member 62 is a pre-tightening spring, and the pre-tightening spring is used to pre-tighten the sliding member 61, so that the sliding member 61 is always connected to the outer hub 40. Specifically, the sliding member 61 can also be used as a positioning member between the piston 60 and the braking component 80. The piston 60 and the first outer hub 41 are positioned and connected through the sliding member 61. The sliding member 61 is equipped with a pre-tightening spring to pre-tighten the sliding member 61, so that the sliding member 61 is always connected to the piston 60 and the first outer hub 41, which can improve the coaxiality between the piston 60 and the first outer hub 41 and make the reciprocating movement of the piston 60 stable, reliable, and without inclination.

[0059] AsFigure 3 As shown, in one embodiment, a first bearing 11 is sleeved on the input transmission member 10. The first bearing 11 is embedded in the bearing seat 12, and the bearing seat 12 is fixedly connected to the first part of the housing. A second bearing 43 is sleeved on the outer hub 40, and the second bearing 43 is fixedly connected to the second part of the housing. A third bearing 21 is sleeved on the output transmission member 20, and the third bearing 21 is fixedly connected to the third part of the housing. The first part of the housing, the second part of the housing, and the third part of the housing are fixedly connected in sequence.

[0060] To assemble the wet clutch: (1) Weld the first outer hub 41 and the second outer hub 42 together by an electronic speed welder. Install sealing rings on the piston 60 and the second outer hub 42. Install a preloading spring that mates with the sliding member 61 on the second outer hub 42. Install the sliding member 61 into the piston 60 to achieve positioning through the sliding member 61; (2) Use a tooling to compress the return elastic member 71, install the elastic member baffle 72, and then install the second snap ring 73 for axial limit; (3) Install the fourth bearing 13, i.e., a thrust needle roller bearing, on the inner hub 30. Mate the inner hub 30 with the second outer hub 42. Alternately install the clutch discs 51, the first elastic member 53, and the clutch friction discs 52. Install the positioning member 54 and the mating separating elastic member 55. Install the adjusting piece 57 and use a tooling to compress it. Then install the first snap ring 58 for axial limit; (4) Alternately install the brake pads 81, the second elastic member 83, and the brake friction discs 82 on the second outer hub 42. Use a tooling to compress them. Then install the third snap ring 84 for axial limit; (5) Embed the first bearing 11 into the bearing seat 12. The first bearing 11 is a deep groove ball bearing. The input transmission member 11 (i.e., the input shaft) mates with the first bearing 11, and the bearing seat 12 is connected to the first part of the housing; (6) Install the second bearing 43 on the second part of the housing. The second bearing 43 is a first cylindrical roller bearing. The second outer hub 42 mates with the second bearing 43. When the second part of the housing is connected to the first part of the housing, the input transmission member 10 and the inner hub 30 are connected by a spline; (7) Install the third bearing 21 on the third part of the housing. The third bearing 21 is a second cylindrical roller bearing. Install the inner ring of the second cylindrical roller bearing into the output transmission member 20 (i.e., the output shaft). When the third part of the housing is connected to the second part of the housing, the output transmission member 20 and the second outer hub 42 are connected by a spline. Therefore, by fixing the three parts of the wet clutch on the housing and then connecting the housing parts in sequence, the assembly of the wet clutch is indirectly achieved, reducing the assembly difficulty of the wet clutch and improving the assembly accuracy and reliability of the wet clutch.

[0061] As Figure 3 and Figure 13As shown, in one embodiment, a lubrication cavity 902 is formed between the clutch assembly 50 and the piston 60. The piston 60 is provided with a first piston lubricating oil outlet hole i and a second piston lubricating oil outlet hole j. The first piston lubricating oil outlet hole i and the second piston lubricating oil outlet hole j can be selectively or simultaneously communicated with the lubricating oil path 102. When the clutch assembly 50 is disengaged, the lubricating oil path 102 is communicated with the lubrication cavity 902 through the first piston lubricating oil outlet hole i or the second piston lubricating oil outlet hole j. When the clutch assembly 50 is engaged, the lubricating oil path 102 is communicated with the lubrication cavity 902 through the second piston oil outlet hole j or through the first piston lubricating oil outlet hole i and the second piston lubricating oil outlet hole j.

[0062] As Figure 3 and Figure 13 As shown, in one embodiment, the cross-sectional area of the first piston lubricating oil outlet hole i is smaller than that of the second piston lubricating oil outlet hole j. When the first part and the second part of the clutch assembly 50 are separated, the lubricating oil path 102 is communicated with the lubrication cavity 902 through the first piston lubricating oil outlet hole i. When the first part and the second part are in close contact, the lubricating oil path 102 is communicated with the lubrication cavity 902 through the second piston oil outlet hole j.

[0063] As Figure 14 As shown, in one embodiment, when the lubricating oil path 102 is communicated with the lubrication cavity through the second piston oil outlet hole j, a part of the second piston lubricating oil outlet hole j is offset from the lubricating oil path 102, and the part offset from the lubricating oil path 102 and the first piston lubricating oil outlet hole i are respectively located on both sides of the lubricating oil path 102. The cross-sectional area of the part of the second piston lubricating oil outlet hole j aligned with the lubricating oil path 102 is larger than that of the first piston lubricating oil outlet hole i. Or, when the lubricating oil path 102 is communicated with the lubrication cavity 902 through the second piston oil outlet hole j, the second piston lubricating oil outlet hole j is aligned with the lubricating oil path 102. Or, when the lubricating oil path 102 is communicated with the lubrication cavity 902 through the second piston oil outlet hole j, a part of the second piston lubricating oil outlet hole j is offset from the lubricating oil path 102, and the part offset from the lubricating oil path 102 and the first piston lubricating oil outlet hole i are respectively located on the same side of the lubricating oil path 102. The cross-sectional area of the part of the second piston lubricating oil outlet hole j aligned with the lubricating oil path 102 is larger than that of the first piston lubricating oil outlet hole i.

[0064] As Figure 3 and Figure 13 As shown, in one embodiment, the lubricating oil path 102 enters the output transmission member 20 along the side part of the output end of the output transmission member 20, and sequentially passes through the output transmission member 20 and the outer hub 40 in directions parallel to and perpendicular to the axis of the output transmission member 20, and is respectively communicated with the inner cavity 90 and the brake assembly 80. Specifically, the above-mentioned setting manner of the lubricating oil path 102 has a simple and compact structure, is easy to process and manufacture, and can respectively improve the flow efficiency of each oil path.

[0065] In one embodiment, let the cross-sectional area of the first piston lubricating oil outlet hole i be A1, and the flow rate passing through it be Q1; the cross-sectional area of the second piston lubricating oil outlet hole j be A2, and the flow rate passing through it be Q2; the cross-sectional area of the first lubricating oil outlet hole f of the lubricating oil path 102 be A3, and the flow rate passing through it be Q3; the flow rate passing through the lubricating oil inlet hole b of the lubricating oil path 102 be Q. Then when the clutch assembly 50 is disengaged:

[0066] ;

[0067] ;

[0068] Then there is

[0069] ;

[0070] ;

[0071] Q3≥Q 3min , where Q 3min is the minimum lubricating flow rate required for the heat dissipation of the brake assembly 80;

[0072] When the clutch assembly (50) is engaged:

[0073] ;

[0074] ;

[0075] Then there is

[0076] ;

[0077] ;

[0078] Q2≥Q 2min , where Q 2min is the minimum lubricating flow rate required for the heat dissipation of the clutch assembly 50.

[0079] For example: Let Q = 20 L / min, A1 = 2 mm 2 , A2 = 20 mm 2 , A3 = 3 mm 2 , Q 2min = 17.14 L / min,

[0080] Q 3min = 2.56 L / min. Then when the clutch is disengaged: Q1 = 12.48 L / min, Q3 = 7.52 L / min > 2.56 L / min. Then when the clutch is engaged: Q2 = 18.29 L / min > 17.14 L / min, Q3 = 1.71 L / min.

[0081] As Figure 3 , Figures 13 to 15 shown, specifically, the working principle of the wet clutch according to the embodiment of the present application is as follows: The input transmission member 10 is always provided with an input speed and an input torque by the engine. The input transmission member 10 is connected to the inner hub 30 through a spline and drives the inner hub 30 to rotate. The inner hub 30 is circumferentially connected to the clutch friction plate 52 through a spline groove and spline mating structure and drives the clutch friction plate 52 to rotate. When the working oil chamber 901 is filled with oil, the piston 60 presses the clutch assembly 50. At this time, the clutch friction plate 52 and the clutch plate 51 are axially pressed against each other and drive the clutch plate 51 to rotate. The clutch plate 51 is circumferentially connected to the first outer hub 41 in the outer hub 40 through a spline and spline groove mating structure and drives the first outer hub 41 to rotate. The first outer hub 41 and the second outer hub 42 are connected together by electron beam welding. The second outer hub 42 is connected to the output transmission member 20 through a spline and spline groove mating structure and drives the output transmission member 20 to rotate and output speed and torque. When the working oil chamber 901 is drained of oil, under the action of the return elastic member 71, the piston 60 returns to the initial position. Under the action of the first elastic member 53, the clutch friction plate 52 and the clutch plate 51 will disengage, and the clutch friction plate 52 cannot transmit the speed and torque to the clutch plate 51. The sliding member 61 presses the brake assembly 80 under the action of the piston 60 returning. At this time, the brake plate 81 and the brake friction plate 82 are axially pressed against each other. Since the brake friction plate 82 has been circumferentially limited by the housing, the brake plate 81 is braked by the brake friction plate 82. The brake plate 81 is connected to the second outer hub 42 through a spline and spline groove mating structure and brakes the second outer hub 42. The second outer hub 42 is connected to the output transmission member 20 through a spline and spline groove mating structure and brakes the output transmission member 20. In this way, braking can be synchronously implemented when the wet clutch is disengaged, so that the output transmission member 20 stops rotating and prevents the occurrence of bad operations. When the working oil chamber 901 is filled with oil, the sliding member 61 moves with the piston 60 and separates from the brake plate 81. The brake plate 81 and the brake friction plate 82 also separate under the action of the second elastic member 83, and no braking effect is generated, which has no influence on the transmission efficiency of the wet clutch.

[0082] To achieve the engagement of the wet clutch, it is necessary to introduce working oil into the working oil chamber 901 to make the piston 60 move. At this time, the clutch plate 51 and the clutch friction plate 52 will be pressed against each other. When the wet clutch is disengaged, the piston 60 returns to the initial position, and the brake plate 81 and the brake friction plate 82 will be pressed against each other. A large amount of heat will inevitably be generated during the engagement process of the clutch plate 51 and the clutch friction plate 52, and a part of heat will also be generated when the brake plate 81 and the brake friction plate 82 are braking. At this time, sufficient lubricating and cooling oil is required to improve the friction environment and dissipate heat. To achieve the movement of the piston 60, the lubrication and cooling of the clutch plate 51 and the clutch friction plate 52, and the brake plate 81 and the brake friction plate 82, working oil holes and lubricating and cooling oil holes need to be provided respectively.

[0083] Please refer to the setting of the working oil hole and the lubricating and cooling oil hole Figure 4 To realize the movement of the piston 60, the working oil enters from the working oil inlet hole a of the output shaft, flows into the working oil cavity 901 through the working oil outlet hole c of the output shaft and the working oil inlet hole d of the outer hub, and then the movement of the piston 60 can be promoted. To lubricate and cool the clutch disc 51, the clutch friction disc 52, the brake disc 81 and the brake friction disc 82, a part of the lubricating and cooling oil enters from the lubricating oil inlet hole b, flows into the first piston lubricating oil outlet hole i or the second piston lubricating oil outlet hole j through the second output shaft lubricating oil outlet hole g and the second lubricating oil outlet hole h to lubricate and cool the clutch assembly 50; another part of the lubricating and cooling oil flows in through the first output shaft lubricating oil outlet hole e and the first lubricating oil outlet hole f to lubricate and cool the brake assembly 80.

[0084] Please refer to the influence of the movement of the piston 60 on the piston lubricating oil outlet hole Figure 5 The cross-sectional area of the first piston lubricating oil outlet hole i is much smaller than that of the second piston lubricating oil outlet hole j. When the wet clutch is disengaged, the clutch disc 51 and the clutch friction disc 52 are not engaged, and less heat is generated, so the required lubricating and cooling oil flow rate is less, while the brake disc 81 and the brake friction disc 82 are engaged, and more heat is generated, so the required lubricating and cooling oil flow rate is more.

[0085] Assume the piston stroke is △. When the working oil is not introduced into the working oil cavity 901, the piston stroke is 0. A part of the lubricating and cooling oil flows into the lubricating cavity 902 after flowing into the first piston lubricating oil outlet hole i through the second lubricating oil outlet hole h. At this time, a larger part of the lubricating and cooling oil flows to the brake assembly 80, and a smaller part of the lubricating and cooling oil flows to the clutch assembly 50. In this way, a large amount of heat generated when the brake disc 81 and the brake friction disc 82 are engaged can be taken away, and it can also prevent the increase of the drag torque caused by too much oil between the clutch disc 51 and the clutch friction disc 52, affecting the braking effect of the wet clutch on the output shaft. When the wet clutch is engaged, the clutch disc 51 and the clutch friction disc 52 are engaged, and more heat is generated, so the required lubricating and cooling oil flow rate is more, while the brake disc 81 and the brake friction disc 82 are not engaged, and less heat is generated, so the required lubricating and cooling oil flow rate is less. When the wet clutch is engaged, the working oil cavity 901 is already filled with working oil. Assume the total clearance between the clutch disc 51 and the clutch friction disc 52 is α, then the piston stroke at this time is △ = α. A part of the lubricating and cooling oil flows into the lubricating cavity 902 after flowing into the second piston lubricating oil outlet hole j through the second lubricating oil outlet hole h. At this time, a larger part of the lubricating and cooling oil flows to the clutch assembly 50, and a smaller part of the lubricating and cooling oil flows to the brake assembly 80. In this way, a large amount of heat generated when the clutch disc 51 and the clutch friction disc 52 are engaged can be taken away, and it can also prevent the increase of the drag torque caused by too much oil between the brake disc 81 and the brake friction disc 82, affecting the power transmission efficiency of the wet clutch.

[0086] When the clutch plate 51 and the clutch friction plate 52 wear each other during engagement, the total gap between the clutch plate 51 and the clutch friction plate 52 will increase, and the piston stroke will also increase. Assuming the wear amount is δ, the piston stroke at this time is △=α+δ. Since when the wear amount δ is 0, the second piston lubricating oil outlet hole j does not shift to completely overlap with the second lubricating oil outlet hole h, but a certain stroke is reserved. Therefore, after the clutch plate 51 and the clutch friction plate 52 wear each other, the piston stroke △ will gradually increase, and the second piston lubricating oil outlet hole j will gradually shift to a position that completely overlaps with the second lubricating oil outlet hole h. And as the wear amount δ increases, the piston stroke △ further increases, and the second piston lubricating oil outlet hole j will shift to the other side of the second lubricating oil outlet hole h. During the entire process of the clutch plate 51 and the clutch friction plate 52 wearing each other during engagement, the second piston lubricating oil outlet hole j always overlaps with the second lubricating oil outlet hole h, that is, there is always an oil passage for transmitting lubricating and cooling oil, and the cross-sectional area of ​​this oil passage is always larger than the cross-sectional area of ​​the first piston lubricating oil outlet hole i. In this way, when the clutch plate 51 and the clutch friction plate 52 engage and wear each other, there is always enough flow to take away a large amount of heat generated by the engagement, thereby ensuring the working stability of the wet clutch.

[0087] In an embodiment not shown, when the wet clutch is disengaged, the lubricating oil path 102 is connected to the lubricating chamber 902 through the first piston lubricating oil outlet hole i. At this time, a larger portion of the lubricating cooling oil flows to the brake assembly 80, and a smaller portion of the lubricating cooling oil flows to the clutch assembly 50. This can take away a large amount of heat generated when the brake plate 81 and the brake friction plate 82 are engaged, and can also prevent the increase of the displacement torque caused by excessive oil between the clutch plate 51 and the clutch friction plate 52, thereby affecting the braking effect of the wet clutch on the output shaft; when the wet clutch is engaged, the lubricating oil path 102 is connected to the lubricating chamber 902 through the first piston lubricating oil outlet hole i and the second piston lubricating oil outlet hole j. At this time, a larger portion of the lubricating cooling oil flows to the clutch assembly 50, and a smaller portion of the lubricating cooling oil flows to the brake assembly 80. This can take away a large amount of heat generated when the clutch plate 51 and the clutch friction plate 52 are engaged, and can also prevent the increase of the displacement torque caused by excessive oil between the brake plate 81 and the brake friction plate 82, thereby affecting the power transmission efficiency of the wet clutch.

[0088] Therefore, two piston lubricating oil outlet holes are provided on the piston 60. When the wet clutch is engaged, the piston lubricating oil outlet hole with a larger cross-sectional area is used for oil passage. When the wet clutch is disengaged, the piston lubricating oil outlet hole with a smaller cross-sectional area is used for oil passage. Alternatively, when the wet clutch is engaged, both lubricating oil outlet holes are used for oil passage at the same time. When the wet clutch is disengaged, one lubricating oil outlet hole is used for oil passage. In this way, the flow rate can be reasonably distributed according to the frictional heat generation of the clutch assembly 50 and the brake assembly 80, improving the reliability of the electro-hydraulic wet multi-disc clutch. The lubricating oil outlet hole with a larger internal dimension on the piston 60 can always maintain a large enough oil passage with the second lubricating oil hole h throughout the whole process of mutual wear between the clutch disc 51 and the clutch friction disc 52, ensuring that there is always enough oil supply flow during the engagement process of the wet clutch and improving the stability of the wet clutch.

[0089] Specifically, when the wet clutch is engaged, the working oil enters the working oil chamber 901. The working oil rotates in the working oil chamber 901 to generate centrifugal force, and the centrifugal force of the working oil will generate a dynamic pressure on the piston 60. When the wet clutch is disengaged, most of the working oil is discharged from the working oil chamber 901, but there is still a small part of the working oil that is not discharged. The dynamic pressure generated by this part of the working oil will push the piston 60 to move, reducing the gap between the clutch disc 51 and the clutch friction disc 52 or even making them stick together, which will undoubtedly affect the disengagement effect and cause poor operation. To eliminate the influence of this part of the working oil, a pressure relief assembly 100 is provided: The pressure relief assembly 100 includes a first pressure relief oil hole 110, a second pressure relief oil hole 120, a plug 130, and a pressure relief elastic member 140. Among them, the first pressure relief oil hole 110 is communicated with the working oil chamber 901, and the plug 130 is movably arranged between the first pressure relief oil hole 110 and the second pressure relief oil hole 120; the pressure relief elastic member 140 is used to provide an elastic force to drive the plug 130 to move, so that when the clutch assembly 50 is engaged, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are blocked from each other. When the clutch assembly 50 is disengaged, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are either communicated with each other or blocked from each other, so that when the clutch assembly 50 is engaged, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are blocked from each other, preventing the working oil in the working oil chamber from leaking and avoiding affecting the engagement effect of the clutch. When the clutch assembly 50 is disengaged, the plug 130 is in a position where the first pressure relief oil hole 110 and the second pressure relief oil hole 120 are communicated with each other, so that all the working oil can be completely discharged when the clutch assembly is disengaged.

[0090] Based on the same concept as the foregoing embodiments, the embodiment of the present application further provides a transmission system, and the transmission system can be provided with a wet clutch as in the foregoing embodiments.

[0091] According to the above embodiments, it can be seen that the pressure relief device, wet clutch and transmission system of the wet clutch involved in the present utility model, by setting a pressure relief communicating with the working oil cavity, when the clutch assembly is engaged, the blocking member moves under the action of the working oil so that the first pressure relief oil hole and the second pressure relief oil hole are blocked from each other, preventing the working oil in the working oil cavity from leaking to avoid affecting the engagement effect of the clutch. When the clutch assembly is disengaged, the blocking member moves under the elastic force of the pressure relief elastic member so that the first pressure relief oil hole and the second pressure relief oil hole communicate with each other, so that the working oil can be completely discharged when the clutch assembly is disengaged. Then the blocking member can move to the initial position so that the first pressure relief oil hole and the second pressure relief oil hole are blocked from each other, eliminating the dynamic pressure generated by the centrifugal force of the working oil on the piston, making the clutch assembly disengage completely, preventing the occurrence of bad operations, and thus greatly improving the performance of agricultural machinery, construction machinery and hybrid vehicles.

[0092] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the appended claims.

Claims

1. A pressure relief device for a wet clutch, characterized in that: The invention comprises a first pressure relief oil hole (110), a second pressure relief oil hole (120), a blocking member (130) and a pressure relief elastic member (140), wherein the first pressure relief oil hole (110) is used to communicate with the working oil chamber (901) of the wet clutch, and the blocking member (130) is movably arranged between the first pressure relief oil hole (110) and the second pressure relief oil hole (120); The pressure relief elastic member (140) is used to provide an elastic force for driving the blocking member (130) to move, so that when the wet clutch is engaged, the blocking member (130) is in a position where the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are blocked from each other, and when the wet clutch is disengaged, the blocking member (130) is in a position where the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are connected to or blocked from each other.

2. The pressure relief device of a wet clutch according to claim 1, wherein the wet clutch comprises an outer hub (40) and a piston (60), characterized in that: An accommodating cavity (150) is provided in the outer hub (40), a positioning column (160) is provided in the accommodating cavity (150), the blocking member (130) is movably disposed in the accommodating cavity (150), and two ends of the pressure relief elastic member (140) respectively abut against the blocking member (130) and the positioning column (160); The second pressure relief oil hole (120) is opened on the positioning column (160), the first pressure relief oil hole (110) is arranged in the outer hub (40) at a position close to the outside of the piston (60), and the second pressure relief oil hole (120) and the first pressure relief oil hole (110) are arranged coaxially.

3. The pressure relief device for a wet clutch according to claim 2, characterized in that: When the blocking member (130) blocks the first pressure relief oil hole (110), the elastic force of the pressure relief elastic member (140) is smaller than the pressure relief working oil force, and when the blocking member (130) blocks the second pressure relief oil hole (120), the elastic force of the pressure relief elastic member (140) is larger than the pressure relief working oil force.

4. The pressure relief device for a wet clutch according to claim 2 or 3, characterized in that: The blocking member (130) is a spherical structure, and the end of the second pressure relief oil hole (120) is provided with a conical surface structure (121) that matches the spherical structure.

5. The pressure relief device of a wet clutch according to claim 1, wherein the wet clutch comprises an inner hub (30), an outer hub (40), a clutch assembly (50), a piston (60) and an elastic assembly (70), wherein the elastic assembly (70) is arranged between the piston (60) and the inner hub (30) and is used to provide a force to separate the clutch assembly (50), characterized in that: A sliding member (61) slidably connected to the outer hub (40) is provided on the outer side of the piston (60); the blocking member (130) is a sealing ring provided on the sliding member (61); The first pressure relief oil hole (110) and the second pressure relief oil hole (120) are respectively arranged on both sides of the sliding member (61); the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are located in the outer hub (40) close to the outer side of the piston (60); and a transition oil relief groove (63) is provided on the sliding member (61); When the clutch assembly (50) is separated, the elastic assembly (70) replaces the pressure relief elastic member (140) to drive the piston (60) to drive the sealing ring on the sliding member (61) to move so that the transition oil relief groove (63) is connected to the first pressure relief oil hole (110) and the second pressure relief oil hole (120) respectively; When the clutch assembly (50) is engaged, the piston (60) drives the blocking ring on the sliding member (61) to move so that the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are blocked from each other.

6. The pressure relief device of a wet clutch according to claim 1, wherein the wet clutch comprises an inner hub (30), an outer hub (40), a clutch assembly (50), a piston (60) and an elastic assembly (70), wherein the elastic assembly (70) is arranged between the piston (60) and the inner hub (30) and is used to provide a force to separate the clutch assembly (50), characterized in that: A sliding member (61) slidably connected to the outer hub (40) is provided on the outer side of the piston (60); the blocking member (130) is a sealing ring provided on the sliding member (61); The first pressure relief oil hole (110) is arranged in the outer hub (40) at a position close to the outer side of the piston (60), the second pressure relief oil hole (120) is arranged in the sliding member (61), a transition oil relief groove (63) is arranged on the sliding member (61), and the second pressure relief oil hole (120) is connected to the transition oil relief groove (63); When the clutch assembly (50) is separated, the elastic assembly (70) replaces the pressure relief elastic member (140) to drive the piston (60) to drive the sealing ring on the sliding member (61) to move so that the transition oil relief groove (63) is connected to the first pressure relief oil hole (110); When the clutch assembly (50) is engaged, the piston (60) drives the blocking ring on the sliding member (61) to move so that the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are blocked from each other.

7. The pressure relief device for a wet clutch according to claim 5 or 6, characterized in that: The cross-sectional areas of the first pressure relief oil hole (110) and the second pressure relief oil hole (120) are equal, the width of the transition oil relief groove (63) along the axial direction of the sliding member (61) is equal to the width of the first pressure relief oil hole (110) along the axial direction of the sliding member (61), and the length of the sealing ring on the sliding member (61) is equal to or greater than the sum of the stroke of the piston (60) and the maximum wear of the clutch assembly (50).

8. The pressure relief device for a wet clutch according to claim 5 or 6, characterized in that: The piston (60) is provided with a piston sleeve (65), and the elastic component (70) comprises a return elastic member (71), an elastic member baffle (72) and a second elastic retaining ring (73); wherein the return elastic member (71) is sleeved on the piston sleeve (65) to abut against the inner side of the piston (60), and the elastic member baffle (72) and the second elastic retaining ring (73) are fixedly sleeved on the outer hub (40) in sequence from the inside to the outside.

9. A wet clutch, characterized in that: The wet clutch is provided with a pressure relief device for a wet clutch as claimed in any one of claims 1 to 8.

10. A transmission system, characterized in that: The transmission system is provided with the wet clutch as claimed in claim 9.

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