A friction power take-off with built-in brake structure

Abstract

In order to solve the problems of output port rotation after the power take-off is disengaged and the oil chamber sharing and sequence of the friction gear-engaging structure and the brake locking structure, the present invention provides a friction power take-off with a built-in brake structure, comprising a housing, an output end cover, an output shaft, an output gear sequentially sleeved on the output shaft from the inside to the outside, a gear-engaging piston, a brake piston and a brake locking assembly, a clutch friction plate group is also arranged between the output gear and the output shaft, the brake locking assembly comprises a first brake shoe for abutting against the inner wall of the output end cover, a closed cavity is arranged between the gear-engaging piston and the brake piston, the gear-engaging piston drives the clutch friction plate group to fix and separate the output gear and the output shaft, drives the brake piston to drive the brake locking assembly to lock and separate with the output end cover, thereby realizing the disengagement and engagement of the power take-off during vehicle driving, and the brake locking device avoids the rotation of the output port and the influence on the rear connection mechanism after the power take-off is disengaged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a friction power take-off with a built-in braking structure. Background Art

[0002] With the development of society, the demand for special vehicles continues to increase, and there are more and more types of vehicles. Special vehicles generally use power take-offs to output power from the engine or gearbox, so that the vehicle can operate under special applications. For some special applications, the vehicle uses a power take-off during driving, and the power take-off needs to be able to engage and disengage during driving. This generally adopts a friction plate structure, but after the power take-off is disengaged, due to the existence of friction, the power take-off output port rotates slightly, which affects the rear connection mechanism. Summary of the invention

[0003] In order to solve the problem of output port rotation after the power take-off is disengaged and the oil chamber sharing and sequence of the friction gear-engaging structure and the brake locking structure, the present invention provides a friction power take-off with a built-in brake structure, and the technical solution adopted is as follows:

[0004] A friction power take-off with a built-in brake structure, comprising a housing, an output shaft and an output end cover, characterized in that:

[0005] The inner and outer ends of the output shaft are rotatably connected to the box body and the output end cover respectively, and the output shaft is coaxially sleeved with an output gear, a gear-engaging piston, a brake piston and a brake locking assembly in sequence from the inside to the outside in the axial direction, and a torque transmission gear is coaxially fixedly connected to the output shaft, and the first shaft shoulder and the second shaft shoulder are respectively arranged on the inner and outer sides of the axial direction of the torque transmission gear;

[0006] The output gear is coaxially connected to the axial inner side of the first shoulder of the output shaft, and the output gear is coaxially fixedly connected to a gear ring located radially outside the torque transmission gear on the axial outer side, and a clutch friction plate group is provided between the gear ring and the torque transmission gear;

[0007] The gear engaging piston and the brake piston are both located axially outside the second shaft shoulder and are both slidably connected to the output shaft along the length direction of the output shaft. A closed cavity is provided between the gear engaging piston and the brake piston, and a conical ring with an inner bevel is provided axially outside the brake piston.

[0008] The brake locking assembly is composed of an inner ring and a first brake shoe. The inner ring is coaxially fixedly connected to the radial outer side of the output shaft. The first brake shoe is hinged to the radial outer side of the inner ring. A first push plate is fixedly connected to the axial inner side wall of the first brake shoe. An inclined surface is provided on the axial inner end surface of the first push plate to cooperate with the cone ring for axial sliding.

[0009] In addition, a limiting member for axially limiting the above-mentioned components is arranged on the output shaft located axially outside the gear-engaging piston, axially inside the brake piston, axially outside the brake locking assembly and axially inside the output gear, and a reset member is arranged between the gear-engaging piston and the second shaft shoulder, and between the brake piston and the brake locking assembly, and the reset member stiffness between the brake piston and the brake locking assembly is smaller than the reset member stiffness between the gear-engaging piston and the second shaft shoulder;

[0010] The output shaft is provided with a first oil channel, the oil inlet of the first oil channel is located at the inner end of the output shaft, and the outlet of the first oil channel is connected to the closed cavity between the gear engaging piston and the brake piston.

[0011] Preferably, a second brake shoe is further provided on the radially outer side of the inner ring, the second brake shoe is hingedly connected to the radially outer side wall of the inner ring, and the second brake shoe and the first brake shoe are at different positions in the circumferential direction of the radially outer side wall of the inner ring, a second push plate is fixedly connected to the axially outer side wall of the second brake shoe, an inclined surface is provided on the axial inner side surface of the second push plate, and the inner end surface of the second push plate is located on the inner side of the inner end surface of the first push plate in the axial direction.

[0012] Preferably, a brake ring is provided on the inner side of the output end cover, a brake slot is provided on the brake ring, and a brake boss which is engaged with the brake slot is fixedly connected to the radial outer side surface of the second brake shoe.

[0013] Preferably, the limit member includes a first retaining spring located axially outside the gear shift piston, a second retaining spring located axially inside the brake piston, a third retaining spring located axially outside the brake locking assembly, and a fourth retaining spring located axially inside the output gear.

[0014] Preferably, the reset member includes a first diaphragm spring connected between the gear engaging piston and the second shaft shoulder, and a second diaphragm spring connected between the inner ring and the brake piston.

[0015] Preferably, a second oil passage is further provided on the output shaft, and an oil outlet of the second oil passage is connected to the cavity between the torque transmission gear and the gear ring.

[0016] The beneficial effects of the present invention are:

[0017] 1. This device can realize the disengagement and engagement of the power take-off during vehicle driving. By setting a brake structure, it avoids the slight rotation of the output port after the power take-off is disengaged and the influence on the rear connection mechanism;

[0018] 2. The brake locking assembly provided in the present invention can take into account the advantages of friction braking and rigid braking, thereby greatly improving the braking torque.

[0019] 3. The present invention uses a shared oil chamber for the gear-engaging piston and the brake piston, and can simultaneously control the clutch friction plate group and the brake lock assembly during gear-engaging and gear-disengaging operations. In addition, the stiffness of the reset member between the brake piston and the brake lock assembly is smaller than the stiffness of the reset member between the gear-engaging piston and the second shaft shoulder, which can ensure that when the pressure in the gear-disengaging oil chamber increases, the brake piston acts first to release the brake, and when the pressure in the gear-disengaging oil chamber decreases, the brake piston acts later to start the brake, thereby solving the problem of the sequential action sequence of the clutch friction plate group and the brake lock assembly during gear-engaging and gear-disengaging operations and avoiding wear of the transmission structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the present invention

[0021] Figure 2 Schematic diagram of the output end cover structure

[0022] Figure 3 Schematic diagram of the output gear structure

[0023] Figure 4 Schematic diagram of the output shaft structure

[0024] Figure 5 Schematic diagram of the brake lock assembly structure

[0025] Figure 6 Schematic diagram of the structure of the first brake shoe and the second brake shoe

[0026] Figure 7 Schematic diagram of the connection structure between the output shaft and the brake lock assembly

[0027] Among them, 1-box, 2-output end cover, 21-brake ring, 22-brake slot;

[0028] 3-output gear, 31-ring gear;

[0029] 4-output shaft, 41-first shaft shoulder, 42-torque transmission gear, 43-second shaft shoulder, 44-first oil passage, 441-first oil passage outlet, 45-second oil passage;

[0030] 5-clutch friction plate group;

[0031] 6-gear engaging piston, 61-first diaphragm spring, 62-circular ring;

[0032] 7-brake piston, 71-cone ring, 72-second diaphragm spring;

[0033] 8-brake locking assembly, 81-inner ring, 82-first brake shoe, 821-first push plate, 83-spring, 84-connecting pin, 85-key, 86-second brake shoe, 861-second push plate, 862-brake boss;

[0034] 9-third retaining spring, 10-first bearing, 11-fourth retaining spring, 12-retaining ring, 13-first retaining spring, 14-second retaining spring, 15-second bearing, 16-third bearing. DETAILED DESCRIPTION

[0035] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0036] In the description of the invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the viewing direction or positional relationships and are only for the convenience of describing the invention, rather than indicating or implying 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 invention.

[0037] like Figure 1-7 The friction power take-off with built-in brake structure shown in the figure comprises a housing 1, an output end cover 2, an output gear 3, an output shaft 4, a clutch friction plate group 5, a gear-engaging piston 6, a brake piston 7 and a brake locking assembly 8. The left end of the output shaft 4 is rotatably connected to the housing 1 through a second bearing 15, and the right end is rotatably connected to the output end cover 2 through a third bearing 16. The output gear 3, the gear-engaging piston 6, the brake piston 7 and the brake locking assembly 8 are coaxially sleeved on the output shaft 4 in sequence from left to right.

[0038] Specifically, the output end cover 2 is as follows Figure 2 As shown, a brake ring 21 is coaxially fixedly connected to the left side, and two groups of brake grooves 211 are provided on the brake ring 21.

[0039] Output shaft 4 Figure 4 As shown, a coaxially distributed torque transmission tooth 42 is provided in the middle, the diameter of the torque transmission tooth 42 is larger than the output shaft 4, and a first shaft shoulder 41 and a second shaft shoulder 43 are fixedly connected to the output shaft 4 on the left and right sides of the torque transmission tooth 42 respectively.

[0040] The output gear 3 is coaxially connected to the output shaft 4 through the first bearing 10, and the output gear 3 is located on the left side of the first shaft shoulder 41. The output shaft 4 is also fixedly connected with a retaining ring 12 located on the left side of the output gear 3. The output shaft 4 outside the retaining ring 12 is fixedly connected with a fourth retaining spring 11. The retaining ring 12 and the fourth retaining spring 11 axially limit the left side position of the output gear 3, and the first shaft shoulder 41 limits the right side position of the output gear 3. The output gear 3 is as shown in FIG. Figure 3As shown, a gear ring 31 is coaxially fixedly connected to the right side, gear teeth are arranged on the inner wall of the gear ring 31 , and a clutch friction plate group 5 is arranged between the gear ring 31 and the torque transmission gear 42 .

[0041] The gear engaging piston 6 is located on the right side of the second shoulder 43. The gear engaging piston 6 and the output shaft 4 have a clearance fit and a first O-ring 63 is provided between the two for sealing. The gear engaging piston 6 can slide left and right along the length direction of the output shaft 4. A first retaining spring 13 located axially outside the sliding piston 6 is fixedly connected to the radial outer wall of the output shaft 4. A circular ring 62 is coaxially fixedly connected to the right end of the gear engaging piston 6. The second shoulder 43 and the first retaining spring 13 are used to limit the left and right directions of the gear engaging piston 6. A first diaphragm spring 61 is also connected between the gear engaging piston 6 and the second shoulder 43. In the disengaged gear state, the first diaphragm spring 61 pushes the gear engaging piston 6 to move to the right and contact the first retaining spring 13.

[0042] The brake piston 7 is located on the right side of the gear-engaging piston 6. The brake piston 7 is slidably connected between the radial outer wall of the output shaft 4 and the inner wall of the ring 62. A second O-ring 64 and a third O-ring 73 are respectively arranged between the radial outer wall of the brake piston 7 and the inner wall of the ring 62, and between the radial inner wall of the brake piston 7 and the output shaft 4 for sealing. A closed cavity is formed between the brake piston 7 and the ring 62. A second retaining spring 14 located on the left side of the brake piston 7 is fixedly connected to the output shaft 4. A second diaphragm spring 72 is connected between the brake piston 7 and the inner ring 81 of the brake locking assembly 8. The brake piston 7 is limited in the left and right directions by the second retaining spring 14 and the inner ring 81 of the brake locking assembly 8. In addition, a cone ring 71 is also fixedly connected to the right side surface of the brake piston 7. The outer side surface of the cone ring 71 is provided with an inner inclined surface. In the gear-disengaging state, the second diaphragm spring 72 pushes the brake piston 7 to the left and contacts the second retaining spring 14. In addition, in this embodiment, the stiffness of the second diaphragm spring 72 is less than the stiffness of the first diaphragm spring 61.

[0043] Brake lock assembly 8 Figure 1 , Figure 5 , Figure 6 as well as Figure 7As shown, it includes an inner ring 81, a first brake shoe 82, a spring 83, and a second brake shoe 86. A keyway is provided on the inner wall of the inner ring 81. The inner ring 81 is coaxially fixedly connected to the output shaft 4 through a key 85. Two groups of first brake shoes 82 are respectively hinged to the upper and lower ends of the radial outer wall of the inner ring 81 through connecting pins 84, and two groups of second brake shoes 86 are respectively hinged to the front and rear ends of the radial outer wall of the inner ring through connecting pins 84. The first brake shoe 82 and the second brake shoe 86 are both arc-shaped rod-shaped structures, and their movable ends are distributed along the same circumferential direction. The first brake shoe 82 and the second brake shoe 86 are both connected to the radial outer wall of the inner ring 81 with a spring 83. In addition, the first brake shoe 82 is fixedly connected to the first push plate 821 on the axial inner wall, that is, the left end face, and the second brake shoe 86 is fixedly connected to the axial inner wall, that is, the left end face. A second push plate 861 is fixedly connected to the surface, and the inner end surfaces of the first push plate 821 and the second push plate 861 are both provided with inclined surfaces that are slidably connected to the inner inclined surface of the cone ring 71. The left end surface of the second push plate 861 is located on the left side of the left end surface of the first push plate 821, that is, the second push plate 861 extends to the left side by a greater length than the first push plate 821, and a brake boss 862 that protrudes outward by a certain length is fixedly connected to the radial outer side wall of the second brake shoe 86, and the brake boss 862 can be snap-fitted with the brake slot 211. In the disengaged state, the first brake shoe 82 is driven by the spring 83 to press radially outward on the brake ring 21 to complete braking, and the second brake shoe 86 is driven by the spring 83 to push the brake boss 862 radially outward to embed into the brake slot 211 to complete locking.

[0044] In addition, a first oil passage 44 and a second oil passage 45 distributed along the axial direction are provided inside the output shaft 4. The oil inlets of the two oil passages are both located at the left end of the output shaft 4. The first oil passage outlet 441 is connected to the cavity between the gear shift piston 6 and the brake piston 7. The gear shift piston 6 and the brake piston 7 are driven by oil pressure to slide axially along the output shaft 4. The oil outlet of the second oil passage 45 is connected to the cavity between the ring gear 31 and the torque transmission tooth 42. Lubricating oil is often passed through the second oil passage 45 for lubricating the clutch friction plate group 5 and the first bearing 10.

[0045] The working principle of this device is as follows:

[0046] In the disengaged gear state, no oil flows in the first oil channel 44. At this time, the gear engaging piston 6 is pressed to the right against the first retaining spring 13 under the action of the first diaphragm spring 61, and the brake piston 7 is pressed to the left against the second retaining spring 14 under the action of the second diaphragm spring 72. The first brake shoe 82 is pressed against the inner wall of the brake ring 21 under the action of the spring 83 to prevent the output shaft 4 from rotating. The clutch friction plate group 5 is separated from the ring gear 31 and the torque transmission tooth 42, and the output gear 3 can rotate freely around the output shaft 4 through the first bearing 10, and power cannot be transmitted to the output shaft 4.

[0047] When the gear is engaged, the high-pressure oil enters the cavity between the gear engaging piston 6 and the brake piston 7 through the first oil passage 44. At this time, since the gear engaging piston 6 and the brake piston 7 have the same oil cavity diameter, and the second diaphragm spring 72 has a smaller stiffness than the first diaphragm spring 61, the oil will first push the brake piston 7 to overcome the pressure of the second diaphragm spring 72 and move right. Moreover, since the left end face of the second push plate 861 is located axially inside the left end face of the first push plate 821, the inner inclined surface of the cone ring 71 first contacts the inclined surface of the second push plate 861, and compresses the second push plate 861 radially inward along the inclined surface, so that the brake boss 862 is disengaged. The brake slot 211 is released, the locked state is released, the brake piston 7 continues to move to the right, the inner inclined surface of the cone ring 71 contacts the inclined surface of the first push plate 821, and the first push plate 821 is compressed radially inward along the inclined surface, so that the first brake shoe 82 is out of contact with the brake ring 21, and the braking state is released; when the oil pressure continues to increase, the oil pushes the gear-engaging piston 6 to overcome the pressure of the first diaphragm spring 61 and move left, and the left end of the gear-engaging piston 6 presses the clutch friction plate group 5, and the upper and lower ends of the clutch friction plate group 5 are respectively pressed against the ring gear 31 and the torque transmission tooth 42, thereby transmitting the power of the output gear 3 to the output shaft 4 through the clutch friction plate group 5.

[0048] When the gear is disengaged, the oil flow in the first oil channel 44 is cut off, the pressure drops, and the gear engaging piston 6 moves to the right and resets under the action of the first diaphragm spring 61. The gear engaging piston 6 is limited to the right by the first retaining spring 13. At this time, the left end of the gear engaging piston 6 is separated from the clutch friction plate group 5, and the power transmission between the output gear 3 and the output shaft 4 is interrupted, and the brake piston 7 moves to the left. The inner inclined surface of the cone ring 71 first disengages from the inclined surface of the first push plate 821, and the first brake shoe 82 contacts the brake ring 21 under the action of the spring 83. Under the action of the friction force, the speed of the output shaft 4 is reduced and the brake is applied. When the brake piston 7 continues to move to the left, the inclined surface of the cone ring 71 disengages from the inclined surface of the second push plate 861, and the second push plate 861 rotates radially outward under the action of the spring 83 until the brake boss 862 is embedded in the brake groove 211, completing the locking and resetting.

[0049] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A friction power take-off with a built-in brake structure, comprising a housing (1), an output shaft (4) and an output end cover (2), characterized in that: The output shaft (4) is rotatably connected to the housing (1) and the output end cover (2) at its inner and outer ends respectively, and the output shaft (4) is coaxially sleeved with an output gear (3), a gear-engaging piston (6), a brake piston (7) and a brake locking assembly (8) in sequence from the inside to the outside in the axial direction, and a torque transmission tooth (42) is coaxially fixedly connected to the output shaft (4), and the torque transmission tooth (42) is provided with a first shaft shoulder (41) and a second shaft shoulder (43) at its inner and outer axial sides respectively; The output gear (3) is coaxially rotatably connected to the axial inner side of the first shoulder (41) of the output shaft (4); the axial outer side of the output gear (3) is coaxially fixedly connected to a gear ring (31) located radially outside the torque transmission gear (42); a clutch friction plate group (5) is provided between the gear ring (31) and the torque transmission gear (42); The gear engaging piston (6) and the brake piston (7) are both located axially outside the second shaft shoulder (43) and are both slidably connected to the output shaft (4) along the length direction of the output shaft. A sealed cavity is provided between the gear engaging piston (6) and the brake piston (7). A conical ring (71) with an inner bevel is provided axially outside the brake piston (7). The brake locking assembly (8) is composed of an inner ring (81) and a first brake shoe (82), wherein the inner ring (81) is coaxially fixedly connected to the radial outer side of the output shaft (4), the first brake shoe (82) is hinged to the radial outer side of the inner ring (81), a first push plate (821) is fixedly connected to the axial inner side wall of the first brake shoe (82), and an inclined surface is provided on the axial inner end surface of the first push plate (821) for axial sliding with the cone ring (71); In addition, a limiting member for axially limiting the above-mentioned components is arranged on the output shaft (4) located axially outside the gear-engaging piston (6), axially inside the brake piston (7), axially outside the brake locking assembly (8), and axially inside the output gear (3); a reset member is arranged between the gear-engaging piston (6) and the second shaft shoulder (43), and between the brake piston (7) and the brake locking assembly (8); and the reset member between the brake piston (7) and the brake locking assembly (8) has a stiffness smaller than the reset member between the gear-engaging piston (6) and the second shaft shoulder (43); The output shaft (4) is provided with a first oil passage (44), the oil inlet of the first oil passage (44) is located at the inner end of the output shaft (4), and the first oil passage outlet (441) is connected to the closed cavity between the gear engaging piston (6) and the brake piston (7).

2. The friction power take-off with built-in brake structure according to claim 1, characterized in that: A second brake shoe (86) is also provided on the radial outer side of the inner ring (81), the second brake shoe (86) is hingedly connected to the radial outer side wall of the inner ring (81), and the second brake shoe (86) and the first brake shoe (82) are located at different positions in the circumferential direction of the radial outer side wall of the inner ring (81), a second push plate (861) is fixedly connected to the axial outer side wall of the second brake shoe (86), an inclined surface that cooperates and slides with the inner inclined surface of the cone ring (71) is provided on the axial inner side surface of the second push plate (861), and the inner end surface of the second push plate (861) is located on the inner side of the inner end surface of the first push plate (821) in the axial direction.

3. The friction power take-off with built-in brake structure according to claim 2, characterized in that: A brake ring (21) is provided on the inner side of the output end cover (2), a brake slot (211) is provided on the brake ring (21), and a brake boss (862) which is engaged with the brake slot (211) is fixedly connected to the radial outer side surface of the second brake shoe (86).

4. The friction power take-off with built-in brake structure according to claim 1, characterized in that: The limiting member comprises a first retaining spring (13) located axially outside the gear engaging piston (6), a second retaining spring (14) located axially inside the brake piston (7), a third retaining spring (9) located axially outside the brake locking assembly (8), and a fourth retaining spring (11) located axially inside the output gear (3).

5. The friction power take-off with built-in brake structure according to claim 1, characterized in that: The reset member comprises a first diaphragm spring (61) connected between the gear-engaging piston (6) and the second shaft shoulder (43), and a second diaphragm spring (72) connected between the inner ring (81) and the brake piston (7).

6. The friction power take-off with built-in brake structure according to claim 1, characterized in that: The output shaft (4) is also provided with a second oil passage (45), and an oil outlet of the second oil passage (45) is connected to a cavity between the torque transmission gear (42) and the gear ring (31).

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