A brake mechanism

Abstract

The present invention relates to the technical field of agricultural machinery, and in particular to a brake mechanism, including a brake fork shaft, a fork, a fixed shaft and a wet clutch assembly; the fork is fixed on the brake fork shaft, and the brake fork shaft is fixed on the gearbox; the wet clutch assembly includes a clutch housing, an inner hub located inside the clutch housing, a push plate, a friction plate with outer teeth and a metal plate with inner teeth, and the fork is located outside the push plate; the push plate is slidably mounted on the inner hub through a pin, and a spring is sleeved on the pin; the rotation of the fork can push the push plate to slide axially and push the metal plate to have friction contact with the friction plate. This structure solves the braking problem in the field of tractor / rotavator gearboxes. At the same time, the structure uses a wet clutch in the gearbox, does not require sealing, and can be connected to any high-speed and low-torque shaft in the gearbox, thereby realizing the characteristics of a "small" clutch solving a "large" braking problem.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, and in particular to a braking mechanism. Background Technology

[0002] Currently, there are several design options for tractor braking mechanisms. One common approach is to use a dry clutch at the drive wheel end of the output shaft. Dry clutches are air-cooled, and during operation, they lack lubrication, resulting in poor cooling and lubrication of the friction plates. Consequently, they wear out relatively quickly and have a short lifespan. Furthermore, this location bears significant torque and stress, making the friction plates prone to breakage, often necessitating larger brake discs and increasing manufacturing costs. Another approach involves extending the braking mechanism from the front of the gearbox, employing a drum brake system. This includes brake shoes mounted on a fixed backplate base and a brake drum connected to the wheel axle. High-density brake pads are fitted onto the brake shoes. During braking, friction between the inner wall of the brake drum and the brake pads generates frictional resistance, forcing the brake drum to decelerate and stop rotating, thus achieving braking. This approach requires extending the output shaft, increasing the overall structural complexity of the vehicle and placing higher demands on its layout and manufacturing processes. Additionally, sealing issues must be addressed. When used in paddy field operations, if the seal fails, water can enter the braking system, preventing proper operation and severely impacting driving safety.

[0003] How to reduce manufacturing costs and simplify the structure while ensuring braking performance has become an important issue in brake mechanism design. Summary of the Invention

[0004] To address the problems of existing tractor braking mechanisms, such as the wear and short lifespan of dry clutch structures, the need for an output shaft leading to complex structures, and the requirement for separate sealing, this invention provides a braking mechanism that requires no sealing, can be installed using the available space inside the gearbox, and features a simple structure and stable operation.

[0005] A braking mechanism includes a brake shift fork shaft, a shift fork, a fixed shaft, and a wet clutch assembly. The shift fork is fixed to the brake shift fork shaft, which is fixed to a gearbox. The wet clutch assembly includes a clutch housing, an inner hub located inside the clutch housing, a push plate, a friction plate with external teeth, and a metal plate with internal teeth. The clutch housing is rigidly connected to a drive shaft. The friction plate is slidably disposed on the clutch housing and can rotate synchronously with the clutch housing. The metal plate is slidably disposed on the outer side of the inner hub. The positions of the friction plate and the metal plate are alternately arranged. One end of the fixed shaft is fixed to the gearbox, and the other end is rotatably connected to the clutch housing. The fixed shaft is rigidly connected to the inner hub inside the clutch housing. The push plate is located inside the clutch near one end of the shift fork and is slidably connected to the fixed shaft. The shift fork is located on the outer side of the push plate. The push plate is slidably mounted on the inner hub via a pin, and a spring is sleeved on the pin. Rotation of the shift fork can push the push plate to slide axially and push the metal plate to make frictional contact with the friction plate.

[0006] Furthermore, the clutch housing is rigidly connected to the drive shaft via a keyway.

[0007] Furthermore, the fixed shaft and the clutch housing are rotatably connected by bearings, and a shaft end cap is provided between the inside of the clutch housing and the inner hub.

[0008] Furthermore, it also includes a brake pedal and a brake rocker arm; the rotating end of the brake pedal and one end of the brake rocker arm are fixed on the brake clutch shaft, and the other end of one end of the brake shift rocker arm is fixedly connected to the brake shift fork shaft.

[0009] Furthermore, the brake rocker arm is connected to the brake clutch shaft via a brake conversion rocker arm and a brake stroke adjusting screw; one end of the brake conversion rocker arm is fixed to the brake clutch shaft, and the other end is slidably mounted on the brake stroke adjusting screw; one end of the brake stroke adjusting screw is connected to one end of the brake rocker arm.

[0010] Furthermore, the drive shaft is either the travel shaft or the output main shaft of the gearbox.

[0011] The beneficial effects of this invention are as follows: This structure solves the braking problem in the field of tractor / rotary tiller gearboxes. This structure has advantages such as low cost, simple structure, stable quality, and easy assembly. Furthermore, this structure uses a wet clutch within the gearbox, eliminating the need for sealing. A spline can be installed at one end of any shaft within the gearbox 4 to connect to the wet clutch assembly, eliminating the need for an additional output shaft. Its small size and simple structure allow it to achieve the characteristic of a 'small' clutch solving 'large' braking. Attached Figure Description

[0012] Figure 1 This is a structural diagram showing one arrangement of the braking mechanism of the present invention on a tractor gearbox;

[0013] Figure 2 for Figure 1 Side view;

[0014] Figure 3 This is a diagram showing the transmission structure of the braking mechanism of the present invention within the tractor gearbox;

[0015] Figure 4 This is a schematic diagram of a braking mechanism of the present invention;

[0016] Figure 5 for Figure 4 Cross-sectional view;

[0017] In the diagram: 1. Brake shift fork shaft; 2. Shift fork; 3. Fixed shaft; 4. Gearbox; 5. Clutch housing; 6. Inner hub; 7. Push plate; 8. Friction plate; 9. Metal plate; 10. Pin; 11. Spring; 12. Keypad; 13. Output spindle; 14. Bearing; 15. Shaft end cap; 16. Brake pedal; 17. Brake rocker arm; 18. Brake clutch shaft; 19. Brake conversion rocker arm; 20. Brake travel adjusting screw; 21. Travel shaft; 22. Main clutch shift fork shaft; 23. Push block. Detailed Implementation

[0018] The braking mechanism of the present invention will be described in detail below with reference to the embodiments.

[0019] like Figure 3 , Figure 4 , Figure 5 As shown, a braking mechanism includes a brake shift fork shaft 1, a shift fork 2, a fixed shaft 3, and a wet clutch assembly. The shift fork 2 is fixed to the brake shift fork shaft 1, and the brake shift fork shaft 1 is fixed to the gearbox 4. The wet clutch assembly includes a clutch housing 5, an inner hub 6 located inside the clutch housing 5, a push plate 7, a friction plate 8 with external teeth, and a metal plate 9 with internal teeth. The clutch housing 5 is rigidly connected to the drive shaft. The friction plate 8 is slidably disposed on the clutch housing 5 and can rotate synchronously with the clutch housing 5. The metal plate 9 is slidably disposed on the outer side of the inner hub 6. The positions of friction plate 8 and metal plate 9 are alternately arranged; one end of fixed shaft 3 is fixed to gearbox 4; the other end is rotatably connected to clutch housing 5; fixed shaft 3 is rigidly connected to inner hub 6 inside clutch housing 5; push plate 7 is located inside clutch near shift fork 2 and is slidably connected to fixed shaft 3; shift fork 2 is located outside push plate 7; push plate 7 is slidably mounted on inner hub 6 via pin 10, and spring 11 is sleeved on pin 10; rotation of shift fork 2 can push push plate 7 to slide axially and push metal plate 9 to friction contact with friction plate 8.

[0020] like Figure 2As shown, one end of the fixed shaft 3 is bolted to the gearbox body 4 and does not rotate, while the other end is connected to the inner hub 6 via a spline to keep the inner hub 6 and metal plate 9 from rotating. When the clutch is open, the clutch housing 5 is rigidly connected to the drive shaft via a spline, and can rotate with the drive shaft in a free state. When the clutch is engaged, the friction between the friction plates 8 and metal plate 9 prevents the clutch housing 5 from rotating, thereby preventing the drive shaft from rotating and achieving a braking effect. The gearbox has an oil bath environment, making the wet clutch assembly an oil bath gearbox, eliminating the need for a separate sealing structure. Furthermore, it can be connected to any shaft with high speed and low torque, thus enabling a small clutch to handle large braking situations.

[0021] In this embodiment, a push block 23 is installed on the outer side of the drive wheel end push plate. The push block 23 is slidably installed on the fixed shaft 3. The shift fork 2 pushes the push plate 7 into the clutch housing 5 by moving the push block 23.

[0022] like Figure 5 As shown, the clutch housing 5 is rigidly connected to the drive shaft via the keypad 12. A connecting block is located at the rear of the clutch housing 5, and a corresponding connecting hole is located on the side of the keypad 12. The connecting block engages with the connecting hole, thus achieving a fixed connection between the clutch housing 5 and the keypad 12. A buffer pad is installed between the clutch housing 5 and the keypad 12 to absorb and disperse vibrations and impacts, protecting both the clutch housing 5 and the keypad 12 from damage, while also improving transmission stability. An integrally formed sleeve is located on the other side of the keypad 12, and the sleeve is rigidly connected to the drive shaft.

[0023] like Figure 1 , Figure 2 As shown, the fixed shaft 3 and the clutch housing 5 are rotatably connected by the bearing 14. The drive shaft drives the clutch housing 5 to rotate, while the fixed shaft 3 remains stationary. A shaft end cap 15 is provided between the inside of the clutch housing 5 and the inner hub 6 to reduce friction.

[0024] like Figure 1 , Figure 3As shown, it also includes a brake pedal 16 and a brake rocker arm 17; the rotating end of the brake pedal 16 and one end of the brake rocker arm 17 are fixed to the brake clutch shaft 18, and the other end of one end of the brake shift rocker arm 19 is fixedly connected to the brake shift fork shaft 1. Both ends of the brake clutch shaft 18 are fixed to the gearbox, and are adapted to the installation position of the wet clutch assembly. When the user presses the brake pedal 16, it drives the brake clutch shaft 18 to rotate, which in turn drives the brake rocker arm 17 and the brake shift fork shaft 1 to rotate. The brake shift fork shaft 1 drives the shift fork 2 to rotate, and the rotation of the shift fork 2 pushes the push plate 7 to move into the clutch housing 5, thereby pushing the friction plate 8 to engage with the metal plate 9. The friction force is used to prevent the clutch housing 5 from rotating and to prevent the drive shaft from rotating, thus achieving the braking effect. When the brake pedal 16 is stopped, the push plate returns to its original position under the action of spring stress, and the friction plate 8 separates from the metal plate 9, allowing the clutch housing and drive shaft to continue to rotate.

[0025] The brake rocker arm 17 is connected to the brake clutch shaft 18 via the brake conversion rocker arm 19 and the brake stroke adjusting screw 20; one end of the brake conversion rocker arm 19 is fixed on the brake clutch shaft 18, and the other end is slidably mounted on the brake stroke adjusting screw 20; one end of the brake stroke adjusting screw 20 is connected to one end of the brake rocker arm 17.

[0026] The drive shaft can be the travel shaft 21 or the output main shaft 13 of the gearbox 4, etc., and can be connected to any high-speed, low-torque shaft within the gearbox 4. The structure is conveniently laid out, utilizing the available space within the gearbox 4, resulting in a small footprint, simple structure, low cost, and stable quality. A spline can be installed at one end of any shaft within the gearbox 4 to connect to the wet clutch assembly. Then, the rotation of the brake rocker arm 17 and the shift fork 2 shaft causes the friction plate 8 to engage with the metal plate 9. The friction between the friction plate 8 and the metal plate 9 prevents the shaft from rotating, thus achieving braking. In this embodiment, the drive shaft is the travel shaft 21.

[0027] This braking mechanism is also applicable to the gearbox 4 of harvesters and rotary tillers, and has the characteristics of wide applicability.

Claims

1. A brake mechanism, characterized in that: The invention comprises a brake fork shaft (1), a fork (2), a fixed shaft (3) and a wet clutch assembly; the fork (2) is fixed on the brake fork shaft (1), and the brake fork shaft (1) is fixed on the gearbox (4); the wet clutch assembly comprises a clutch housing (5), an inner hub (6) located inside the clutch housing (5), a push plate (7), a friction plate (8) with external teeth and a metal plate (9) with internal teeth; the clutch housing (5) is rigidly connected to the transmission shaft; the friction plate (8) is slidably arranged on the clutch housing (5) and can rotate synchronously with the clutch housing (5); the metal plate (9) is slidably arranged on the outer side of the inner hub (6); the friction plate (8) and The positions of the metal sheets (9) are arranged alternately; one end of the fixed shaft (3) is fixed on the gearbox (4); the other end is rotatably connected to the clutch housing (5); the fixed shaft (3) is rigidly connected to the inner hub (6) inside the clutch housing (5); the push plate (7) is located inside the clutch near one end of the shift fork (2) and is slidably connected to the fixed shaft (3); the shift fork (2) is located outside the push plate (7); the push plate (7) is slidably mounted on the inner hub (6) through a pin (10), and a spring (11) is sleeved on the pin (10); the rotation of the shift fork (2) can push the push plate (7) to slide axially and push the metal sheet (9) to have friction contact with the friction plate (8).

2. The brake mechanism according to claim 1, characterized in that: The clutch housing (5) is rigidly connected to the transmission shaft via a spline (12).

3. The brake mechanism according to claim 1 or 2, characterized in that: It also includes a brake pedal (16) and a brake rocker arm (17); the rotating end of the brake pedal (16) and one end of the brake rocker arm (17) are fixed on the brake clutch shaft (18), and the other end of one end of the brake conversion rocker arm (19) is fixedly connected to the brake fork shaft (1).

4. The brake mechanism according to claim 3, characterized in that: The brake rocker arm (17) is connected to the brake clutch shaft (18) through the brake conversion rocker arm (19) and the brake stroke adjustment screw rod (20); one end of the brake conversion rocker arm (19) is fixed on the brake clutch shaft (18), and the other end is slidably mounted on the brake stroke adjustment screw rod (20); one end of the brake stroke adjustment screw rod (20) is connected to one end of the brake rocker arm (17).

5. The brake mechanism according to claim 1, 2 or 4, characterized in that: The fixed shaft (3) and the clutch housing (5) are rotatably connected via a bearing (14), and a shaft end pressure cover (15) is provided between the interior of the clutch housing (5) and the inner wheel hub (6).

6. The brake mechanism according to claim 3, characterized in that: The fixed shaft (3) and the clutch housing (5) are rotatably connected via a bearing (14), and a shaft end pressure cover (15) is provided between the interior of the clutch housing (5) and the inner wheel hub (6).

7. The brake mechanism according to claim 1, 2, 4 or 6, characterized in that: The transmission shaft is a travel shaft (21) or an output main shaft (13) of the gearbox (4).

8. The brake mechanism according to claim 3, characterized in that: The transmission shaft is a travel shaft (21) or an output main shaft (13) of the gearbox (4).

9. The brake mechanism according to claim 5, characterized in that: The transmission shaft is a travel shaft (21) or an output main shaft (13) of the gearbox (4).

Images