Gearbox four-wheel drive / two-wheel drive switching structure and vehicle

Abstract

The utility model relates to the technical field of gearbox, disclose a kind of gearbox four-wheel drive two-wheel drive switching structure and vehicle, by adding front box and wet clutch in gearbox, when vehicle is extinguished, hydraulic oil is returned to oil sump from piston cavity, so that disc spring promotes piston, so that driving piece and driven piece are pasted together, realize gearbox four-wheel drive function and parking brake function under the premise of no hydraulic input, the power of above-mentioned function is derived from the mechanical energy stored when compression of disc spring itself. Brake torque is transmitted to front and rear output shafts by the friction between driving piece and driven piece.

Description

Technical Field

[0001] This utility model relates to the field of transmission technology, and in particular to a transmission four-wheel drive and two-wheel drive switching structure and vehicle. Background Technology

[0002] Four-wheel drive / two-wheel drive switching is a common feature in off-road vehicles. Four-wheel drive provides better adaptability to complex terrain, while two-wheel drive offers higher efficiency and thus better fuel economy. In excavators and loaders, four-wheel drive is often used for heavy loads and harsh working conditions, while two-wheel drive (rear-wheel drive) is often used for low-load conditions and vehicle relocation.

[0003] Current technology has the following drawbacks: The four-wheel drive and two-wheel drive functions of current excavator loaders are achieved through a separate hydraulic switch. In the absence of pressure, the four-wheel drive function switches to two-wheel drive. In the two-wheel drive state, when parked, the front axle braking torque is naturally lost, resulting in lower overall vehicle braking torque and a tendency for the vehicle to roll away on steep inclines. Utility Model Content

[0004] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a transmission four-wheel drive / two-wheel drive switching structure and vehicle, enabling the transmission to perform four-wheel drive and parking brake functions without hydraulic input.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0006] In a first aspect, a four-wheel drive / two-wheel drive switching structure for a transmission includes a transmission housing. A front housing is located at the front end of the housing. One end of a rear output shaft extends into the transmission housing and is connected to an input gear via a spline. A first piston cylinder is provided within the housing. A first driven plate and a first driving plate are alternately arranged on the rear side of the first piston cylinder. A four-wheel drive / two-wheel drive piston capable of pressing the first driven plate is provided inside the first piston cylinder. A disc spring is provided between the rear side of the front housing and the four-wheel drive / two-wheel drive piston. The disc spring pushes the four-wheel drive / two-wheel drive piston so that the first driven plate and the first driving plate are pressed together. The first driving plate is also connected to the input gear via a spline. The transmission also includes a front output shaft. One end of the front output shaft passes through the front housing and is inserted into the rear output shaft. The first piston cylinder is connected to the front output shaft via a spline. A wet clutch is provided in the front housing around the front output shaft. The wet clutch includes a parking disc spring, a second driving plate, and a second driven plate. In the off state, the parking disc spring pushes the second driven plate and the second driving plate together.

[0007] As a further implementation, the other end of the rear output shaft is connected to a rear output flange.

[0008] As a further implementation, the front housing is provided with a first oil passage, which extends through the front housing and the front output shaft to the first piston chamber of the first piston cylinder. Hydraulic oil enters the first piston chamber through the first oil passage to push the four-wheel drive and two-wheel drive pistons, thereby compressing the disc springs, which is the two-wheel drive state.

[0009] As a further implementation, the second driving plate is connected to the front output shaft via a spline. A second piston cylinder is provided in the front housing. The second driven plate and the second driving plate are alternately arranged in the front housing at the rear side of the second piston cylinder. The second piston cylinder has a second piston chamber. A parking piston that can press the second driven plate is provided in the second piston chamber. The parking piston is located in the second piston chamber. A parking disc spring is located on the side of the parking piston away from the second driven plate.

[0010] As a further implementation, a retaining ring with a hole is provided on the side of the parking disc spring in the front housing away from the parking piston to abut against the parking disc spring, and an oil seal seat is provided on the side of the retaining ring away from the parking disc spring.

[0011] As a further implementation, the front housing is provided with a second oil passage that extends into the second piston chamber. Hydraulic oil enters the second piston chamber and pushes the parking piston to press against the parking disc spring.

[0012] As a further implementation, the first oil passage is connected to the first solenoid valve via a first oil circuit, and the first solenoid valve is connected to the transmission oil pump.

[0013] As a further implementation, the second oil passage is connected to the second solenoid valve via a second oil circuit, and the second solenoid valve is connected to the transmission oil pump and is connected in parallel with the first solenoid valve.

[0014] As a further implementation, the first solenoid valve is connected to the power supply via a circuit with a four-wheel drive switch to achieve drive state switching; the second solenoid valve is connected to the power supply via a circuit with a parking switch.

[0015] Secondly, a vehicle, which is a non-road vehicle, includes a transmission four-wheel drive / two-wheel drive switching structure as described above.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention adds a front housing and a wet clutch to the transmission. When the vehicle is turned off, hydraulic oil returns from the piston chamber to the oil pan, causing the disc spring to push the piston, bringing the driving and driven discs together. This enables the transmission to perform four-wheel drive and parking brake functions without hydraulic input. The power for these functions comes from the mechanical energy stored during the compression of the disc spring. The braking torque is transmitted to the front and rear output shafts through the friction between the driving and driven discs. Attached Figure Description

[0018] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0019] Figure 1 This is a schematic diagram of the overall structure of the gearbox four-wheel drive and two-wheel drive switching structure in this utility model embodiment;

[0020] Figure 2 This is a schematic diagram of the overall structure of the gearbox four-wheel drive and two-wheel drive switching structure in this utility model embodiment;

[0021] Figure 3 This is a partial structural diagram of the gearbox four-wheel drive and two-wheel drive switching structure in an embodiment of this utility model;

[0022] Figure 4 This is a schematic diagram of the oil circuit arrangement in an embodiment of this utility model.

[0023] The diagram exaggerates the spacing or dimensions between parts to show their positions; the diagram is for illustrative purposes only.

[0024] The components are: 1. Oil seal, 2. Oil seal seat, 3. Hole retaining ring, 4. Disc spring, 5. Four-wheel drive and two-wheel drive pistons, 6. Input gear, 7. Housing, 8. Rear output flange, 9. Locking nut, 10. Rear output shaft, 12. Piston base, 13. First piston cylinder, 14. First driven plate, 15. First driving plate, 16. Front output shaft, 17. Front output flange, 18. Spacer sleeve, 19. Dust cover, 20. Hole retaining ring; 22. Parking disc spring, 23. Parking piston, 24. Second driven plate, 25. Second driving plate; 26. Second oil passage, 11. First oil passage; 110. Front housing;

[0025] 31. Second solenoid valve, 32. First solenoid valve, 33. Safety valve, 34. Oil pump, 35. Oil pan, 36. Second oil circuit, 37. First oil circuit, 38. Four-wheel drive switch, 39. Parking switch, 40. Power supply. Detailed Implementation

[0026] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] Example 1

[0028] In a typical embodiment of this utility model, refer to Figures 1-4As shown, a four-wheel drive and two-wheel drive switching structure for a transmission includes a transmission housing, a front housing located at the front end of the housing, and a set of wet clutches located within the front housing.

[0029] like Figure 1 As shown, one end of the rear output shaft 10 extends into the gearbox housing and is connected to the input gear 6 via a spline. The power output by the engine can be transmitted to the input gear 6, and the rotation of the input gear 6 can drive the rear output shaft 10 to rotate.

[0030] The end of the rear output shaft that extends out of the housing 7 is connected to the rear output flange 8. The locking nut 9 at the output flange 8 is used to prevent the output flange 8 from falling off.

[0031] like Figure 1 As shown in the view direction, the right end represents the rear end and the left end represents the front end. The housing 7 is equipped with a first piston cylinder 13. The rear side of the first piston cylinder 13 is provided with a first driven plate and a first driving plate. The cross-section of the first piston cylinder 13 is cylindrical. The first driven plate and the first driving plate are specifically located on the inner side of the rear end of the first piston cylinder 13.

[0032] The first piston chamber inside the first piston cylinder is equipped with a four-wheel drive or two-wheel drive piston 5 that can press the leftmost first driven plate. Specifically, the first piston chamber is formed between the bottom of the first piston cylinder and the four-wheel drive or two-wheel drive piston 5, where hydraulic oil can enter.

[0033] like Figure 1 As shown, the bottom of the first piston cylinder is located near the left end of the first piston cylinder, and the rear end (right end) of the first piston cylinder is open. The first driving plate and the first driven plate are alternately arranged on the right side of the bottom of the first piston cylinder. The cross section of the four-wheel drive and two-wheel drive piston 5 is a U-shaped structure, which can pass through the bottom of the cylinder to press the first driving plate and the first driven plate. The through part is set with sliding seal.

[0034] A piston base 12 is provided on the inner side of the right end of the first piston cylinder, which serves as a support and can be used in conjunction with the four-wheel drive and two-wheel drive pistons 5 to clamp the first driving plate 15 and the first driven plate 14.

[0035] When installing the piston base 12, it is advisable to weld the piston base 12 to one side of the input gear 6, as long as it can support the first driving plate 15.

[0036] The first driving plate 15 is also connected to the input gear via a spline; the input gear 6 can drive the rear output shaft 10 and the first driving plate 15 to rotate. The first driven plate 14 is engaged with the inner side of the first piston cylinder 13. When the disc spring 4 releases its compression force, causing the four-wheel drive and two-wheel drive pistons 5 to move to the right, the piston base 12 can clamp the first driving plate 15 and the first driven plate 14 together. Under the action of friction, the first piston cylinder 13 can rotate.

[0037] like Figure 1 and Figure 2 , Figure 3 As shown, a front housing 110 is located at the front end of the housing 7. One end of the front output shaft passes through the front housing 110 and is inserted into the front end of the rear output shaft 10. A disc spring 4 is located between the rear side of the front housing and the four-wheel drive and two-wheel drive pistons. The disc spring 4 is sleeved around the front output shaft 16. A retaining ring 20 is located around the front output shaft 16, near the rear side of the front housing. The retaining ring 20 limits the left end of the disc spring 4, and the right end of the disc spring 4 abuts against the four-wheel drive and two-wheel drive pistons.

[0038] Under the action of the disc spring 4, the disc spring 4 pushes the four-wheel drive and two-wheel drive piston 5 so that the first driven plate 14 and the first driving plate 15 are pressed together. When the vehicle is moving, the four-wheel drive and two-wheel drive piston 5 presses the first driven plate under the action of the disc spring 4, which is the four-wheel drive state. Only when it is necessary to switch to the two-wheel drive state can the hydraulic oil enter the first piston chamber through the four-wheel drive switch 38 to compress the disc spring 4 and actively switch to the two-wheel drive state.

[0039] like Figure 1 As shown, the center of the bottom of the first piston cylinder 13 is fitted onto the front output shaft and connected to the front output shaft via a spline. Rotation of the first piston cylinder causes the front output shaft 16 to rotate, thus achieving four-wheel drive functionality.

[0040] A wet clutch is provided in the front housing 110 around the front output shaft 16. The wet clutch includes a parking disc spring, a second driving plate 25 and a second driven plate 24. When the engine is off, the parking disc spring 22 releases its elastic force, pushing the second driven plate 24 and the second driving plate 25 to stick together. At this time, the four-wheel drive parking function can be realized when the engine is off.

[0041] like Figures 1-4 As shown, the front housing 110 is provided with a first oil passage 11. The extension path of the first oil passage 11 extends through the front housing 110 and the front output shaft 16 to the first piston chamber of the first piston cylinder 13, allowing hydraulic oil to enter between the four-wheel drive / two-wheel drive piston 5 and the bottom of the first piston cylinder. Specifically, the first oil passage 37 can enter the first piston chamber through the first oil passage 11 provided on the front housing, pushing the four-wheel drive / two-wheel drive piston to the left with hydraulic oil, causing the disc spring 4 to be compressed. At this time, the first driving plate 15 and the first driven plate 14 separate, and it is in two-wheel drive mode.

[0042] The second driving plate 25 inside the front housing is connected to the front output shaft 16 via a spline. The front output shaft 16 is connected to the front output flange 17. The second driving plate is located near the bottom of the front housing (at the rear end of the front housing). The front housing contains a second piston cylinder structure, meaning the front housing structure can be used as the outer wall of the second piston cylinder. The second piston cylinder has a second piston chamber, and the second piston chamber also contains a parking piston that can press against the second driven plate. The second piston cylinder also has the same cylinder bottom as the first piston cylinder. The cylinder bottom is fixedly connected to the inner side of the front housing, forming the main piston cylinder structure. A parking piston is located on the left side of the cylinder bottom, and the parking piston has a similar structure to the four-wheel drive and two-wheel drive pistons. The parking piston, the cylinder bottom, and the inner wall of the front housing form a second piston chamber, which serves as an oil inlet space.

[0043] The second driven plate 24 and the second driven plate 25 are alternately arranged in the front housing body behind the second piston cylinder, specifically between the right end of the parking piston and the bottom of the front housing body.

[0044] The parking disc spring is located on the side of the parking piston away from the second driven plate, and a retaining ring 3 is provided inside the front housing. The retaining ring 3 abuts against the parking disc spring 22, and the right end of the parking disc spring 22 abuts against the parking piston 23. The parking piston 23 can pass through the bottom of the cylinder to press against the second driven plate 24. The second driven plate 24 is engaged with the inside of the front housing.

[0045] The front housing 110 has an opening at the left end, and an oil seal seat 2 is provided on the side of the hole away from the parking disc spring 22 using a retaining ring 3. A spacer sleeve 18 is fitted around the front output shaft 16, and the oil seal seat 2 with an oil seal 1 is located around the spacer sleeve 18, which is existing technology and is intended for sealing. A dust cover 19 is provided on the outside of the oil seal seat 2 and is integrated with the front output flange 17.

[0046] like Figure 3 As shown, the front housing 110 is provided with a second oil passage 26, which extends into the second piston chamber, that is, between the bottom of the second piston cylinder and the parking piston 23. When hydraulic oil comes in, it can push the parking piston 23 to the left to press the parking disc spring 22.

[0047] like Figure 4 As shown, the first oil passage 11 is connected to the first solenoid valve 32 via the first oil circuit 37, and the first solenoid valve 32 is connected to the transmission oil pump 34. The second oil passage 26 is connected to the second solenoid valve 31 via the second oil circuit 36, and the second solenoid valve 31 is connected to the transmission oil pump 34. The second solenoid valve 31 and the first solenoid valve 32 are connected in parallel and are both connected to the same transmission oil pump 34 via oil circuits. The transmission oil pump 34 is connected to the oil pan 35. The solenoid valves are also connected to the oil pan via an oil circuit with a safety valve 33 to ensure safety.

[0048] The first solenoid valve 32 is connected to the power supply 40 via a circuit with a four-wheel drive switch 38 to achieve drive state switching, and can actively switch the original four-wheel drive state to two-wheel drive state; the second solenoid valve 31 is connected to the power supply 40 via a circuit with a parking switch 39.

[0049] like Figure 1 and Figure 2 As shown, in the absence of hydraulic pressure, the disc spring 4 of this embodiment presses the first driving plate and the first driven plate together to achieve the four-wheel drive function in the normal state, and the power can be transmitted to the front output shaft and the rear output shaft at the same time.

[0050] The state can be switched by the four-wheel drive switch 38. When the four-wheel drive switch 38 is pressed, the hydraulic oil in the oil pan enters the first piston chamber through the transmission oil pump 34, oil circuit, first solenoid valve 32, first oil circuit, and first oil passage 11, thereby pushing the four-wheel drive and two-wheel drive piston 5 to the left. At this time, the first driving plate separates and the four-wheel drive becomes two-wheel drive.

[0051] After the vehicle is turned off, the disc spring 4 pushes the right-hand four-wheel drive and two-wheel drive piston 5, causing the first driving plates to clamp together, thus providing a parking brake function; or in four-wheel drive mode, it also provides a parking brake function.

[0052] When the vehicle is moving, the hydraulic oil in the oil pan can enter the second piston chamber through the transmission oil pump 34, oil circuit, second solenoid valve 31, second oil circuit, and second oil passage 26 by opening the second solenoid valve 31. The second piston chamber contains hydraulic oil, which can push the parking piston to the left to compress the parking disc spring 22. At this time, the second driving plate and the second driven plate separate, and there is no braking.

[0053] When the vehicle is turned off, the parking disc spring 22 releases its compression force, and the hydraulic oil in the second piston chamber is forced back into the oil pan. At this time, the second driving plate and the second driven plate are pressed together, and their contact with the first driving plate and the first driven plate works in conjunction to realize the four-wheel drive automatic parking function after the vehicle is turned off. This function ensures that the front axle has braking torque at the same time, resulting in a large overall braking torque. Therefore, the four-wheel drive automatic parking function solves the problem that in two-wheel drive mode, the front axle braking torque is naturally lost when parking, resulting in low overall vehicle braking torque and the vehicle being prone to rolling on steep slopes. It achieves automatic parking function when the vehicle is turned off. When the vehicle is started, the hydraulic oil re-enters the second piston chamber, releasing the front axle braking.

[0054] Example 2

[0055] A vehicle, which is a non-road vehicle, includes the gearbox four-wheel drive and two-wheel drive switching structure described in Embodiment 1. After the vehicle is parked and the engine is turned off, the hydraulic oil in the piston chamber returns to the oil pan, which can realize the four-wheel drive automatic parking function. The automatic parking and four-wheel drive functions are realized by mechanical device, and the combination of the two realizes a highly reliable engine-off parking function.

[0056] By adding a front housing and a wet clutch to the transmission, four-wheel drive and parking brake functions are achieved without hydraulic input. The power for these functions comes from the mechanical energy stored during the compression of the disc springs. The braking torque is transmitted to the front and rear output shafts through the friction between the driving and driven discs.

[0057] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A transmission structure for switching between four-wheel drive and two-wheel drive, characterized in that, The system includes a gearbox housing with a front housing at its front end. One end of the rear output shaft extends into the gearbox housing and is connected to the input gear via a spline. The housing contains a first piston cylinder, with a first driven plate and a first driving plate alternately arranged on the rear side of the first piston cylinder. A four-wheel drive / two-wheel drive piston is located within the first piston cylinder, capable of pressing the first driven plate. A disc spring is located between the rear side of the front housing and the four-wheel drive / two-wheel drive piston, pushing the piston to bring the first driven plate and the first driving plate into close contact. The first driving plate is also connected to the input gear via a spline. The system also includes a front output shaft, one end of which passes through the front housing and engages with the rear output shaft. The first piston cylinder is connected to the front output shaft via a spline. A wet clutch is located within the front housing surrounding the front output shaft. The wet clutch includes a parking disc spring, a second driving plate, and a second driven plate. In the off-state state, the parking disc spring pushes the second driven plate and the second driving plate into close contact.

2. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 1, characterized in that, The other end of the rear output shaft is connected to the rear output flange.

3. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 2, characterized in that, The front housing is provided with a first oil passage. The first oil passage extends from the front housing and the front output shaft to the first piston chamber of the first piston cylinder. Hydraulic oil enters the first piston chamber through the first oil passage to push the four-wheel drive and two-wheel drive pistons, thereby compressing the disc springs. At this time, it is in the two-wheel drive state.

4. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 3, characterized in that, The second driving plate is connected to the front output shaft via a spline. A second piston cylinder is provided in the front housing. The second driven plate and the second driving plate are alternately arranged in the front housing at the rear side of the second piston cylinder. The second piston cylinder has a second piston chamber. A parking piston that can press the second driven plate is provided in the second piston chamber. The parking piston is located in the second piston chamber. A parking disc spring is located on the side of the parking piston away from the second driven plate.

5. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 4, characterized in that, The parking disc spring inside the front housing is provided with a retaining ring on the side away from the parking piston to abut against the parking disc spring, and an oil seal seat is provided on the side of the retaining ring away from the parking disc spring.

6. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 5, characterized in that, The front housing is provided with a second oil passage that extends into the second piston chamber. Hydraulic oil enters the second piston chamber and pushes the parking piston to press against the parking disc spring.

7. A gearbox four-wheel drive / two-wheel drive switching structure according to claim 6, characterized in that, The first oil passage is connected to the first solenoid valve via the first oil circuit, and the first solenoid valve is connected to the transmission oil pump.

8. The gearbox four-wheel drive / two-wheel drive switching structure according to claim 7, characterized in that, The second oil passage is connected to the second solenoid valve via the second oil circuit. The second solenoid valve is connected to the transmission oil pump and is connected in parallel with the first solenoid valve.

9. A gearbox four-wheel drive / two-wheel drive switching structure according to claim 8, characterized in that, The first solenoid valve is connected to the power supply via a circuit with a four-wheel drive switch to achieve drive state switching; the second solenoid valve is connected to the power supply via a circuit with a parking switch.

10. A vehicle, characterized in that, The vehicle is a non-road vehicle, including the gearbox four-wheel drive and two-wheel drive switching structure as described in any one of claims 1-9.

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