Off-road vehicle drive axle
By adopting integrated parking structure and self-adjustment mechanism in non-highway vehicle drive axles, the problem of lack of emergency braking and parking brake machinery for wet drive axles is solved, and quantitative return and emergency braking are achieved, improving Vehicle safety and friction plate life reduce maintenance costs.
Patent Information
- Application Number
- CN202420756199.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-12
- Publication Date
- 2024-12-13
- Estimated Expiration
- 2034-04-12
AI Technical Summary
The existing wet drive axles lack emergency braking function, parking brake machinery can relieve difficulties, and the brake clearance return method has problems such as difficulty or irrelevance return, which affects the safety and maintenance costs of the vehicle.
A non-highway vehicle drive axle is designed, adopting an integrated structure of road parking, including driving brake and parking brake components, and quantitative return and emergency braking are achieved through self-adjustment mechanism and mechanical release mechanism to reduce the braking system. Complexity and cost.
The demand for driving, parking and emergency braking is achieved, the system reliability and friction plate service life is improved, the damage to gear oil by high braking temperature is reduced, and maintenance costs are reduced.
Smart Images
Figure CN222157184U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of vehicles, and more specifically, to a wet brake for an off-highway vehicle drive axle. Background Art
[0002] In the driving mechanism of off-road vehicles, the drive axle is used to transmit the driving force of the engine or motor to the wheels, so that the wheels can achieve the effect of reducing speed and increasing torque. It includes several main components such as the main reducer assembly, differential assembly, wet brake assembly, wheel reducer assembly, and wheel hub assembly. Since off-road vehicles are used in high-intensity working environments such as engineering, the brake assembly, as a key component related to vehicle driving safety, must have high reliability.
[0003] At present, the wet drive axle adopts a built-in wet driving brake and an external dry caliper disc parking brake. Compared with the integrated driving and parking brake, the disadvantage is that it lacks the emergency braking function and requires space to arrange the external caliper disc brake. The existing integrated driving and parking brake is not suitable for the compact wet drive axle, and it lacks the mechanical release function of the parking brake. Once the parking brake hydraulic system fails, it is difficult to release the parking brake.
[0004] When the wet brake is not braking, a certain amount of brake clearance needs to be left for the friction plate to avoid friction plate drag. To this end, when the brake is released, the piston must be able to return automatically, and it is best to achieve quantitative return. At present, there are two commonly used piston return methods. One is to use the elastic shear deformation of the sealing ring to achieve piston return. The advantage is that quantitative return can be achieved, but the disadvantage is that the return amount is very small, generally within 0.5mm, and the return amount cannot be adjusted. There will be a certain amount of drag on multiple friction plates, generating high temperature. The second is to force the piston to return by a spring. The advantage is that the return amount is large, but the disadvantage is that quantitative return cannot be achieved. As the friction plate wears, the brake clearance will become larger and larger, and the brake response time will increase accordingly.
[0005] Therefore, there is an urgent need for an off-highway vehicle drive axle that can solve the above problems. Utility Model Content
[0006] One object of the utility model is to provide a new technical solution for an off-highway vehicle drive axle, which can solve the above-mentioned problems.
[0007] According to the first aspect of the utility model, an off-road vehicle drive axle is provided, comprising a main reducer assembly and a differential assembly connected to each other, the two sides of the differential assembly are respectively connected with brake assemblies, the brake assembly is connected with a bridge housing and a wheel hub assembly, the wheel hub assembly is installed with a wheel-side reducer assembly, the brake assembly comprises an outer shell, a bottom shell and a brake assembly, the brake assembly is installed between the outer shell and the bottom shell, a service brake chamber close to the brake assembly and a parking brake chamber away from the brake assembly are arranged in the outer shell, the service brake chamber and the parking brake chamber are distinguished by an isolation portion of the shell, a service brake assembly is arranged in the service brake chamber, a parking brake assembly is arranged in the parking brake chamber, a parking top rod on the parking brake assembly passes through the outer shell to drive the brake assembly; a parking brake mechanical release mechanism is arranged on the outer shell, and the parking brake mechanical release mechanism is used to manually drive the parking brake assembly to release the brake.
[0008] Preferably, the service brake assembly includes a service brake piston, a service brake sealing area is arranged between the service brake piston and the isolation portion, and the service brake sealing area is connected to the service brake pedal through a first high-pressure oil pipe; a self-adjusting mechanism is arranged on the side of the service brake piston away from the brake assembly, and the self-adjusting mechanism is connected to the isolation portion.
[0009] Preferably, the self-adjusting mechanism includes a return spring, a baffle, a return pin and a coil spring, the coil spring is fixed to the service brake piston, the return pin is inserted into the coil spring and has an interference fit therewith, the baffle is fixed to the isolation portion, the return spring is located between the baffle and the isolation portion, and one end of the return pin passes through the baffle and is connected to the return spring.
[0010] Preferably, the return spring is a claw spring, a limit retaining ring is provided at the end of the return pin, the limit retaining ring is connected to the return spring, and the return spring always applies a pulling force toward the isolation portion to the limit retaining ring.
[0011] Preferably, the parking brake assembly comprises a parking brake piston, wherein the parking brake piston is provided with a parking brake sealing area between the isolation parts, and the parking brake sealing area is connected to the parking brake pedal through a second high-pressure oil pipe; the parking brake piston is connected with the parking top rod, and the parking top rod passes through the isolation part and abuts against the service brake piston; an elastic mechanism is provided on the side of the parking brake piston away from the isolation part, and the elastic mechanism always presses the parking brake
[0012] The vehicle brake piston applies a thrust toward the isolation portion.
[0013] Preferably, the elastic mechanism is a plurality of disc springs arranged in a stacked manner, and a disc spring retaining ring is provided on the inner wall of the outer shell, and the disc spring retaining ring is used to retain the disc spring.
[0014] Preferably, the parking brake release mechanism comprises a drive rod and a drive block, the drive block is arranged in the parking brake sealing area, the drive slope of the drive block abuts against the parking brake piston, and the drive rod is used to push the drive block to move toward the parking brake piston.
[0015] Preferably, the driving rod comprises a rod body and a stud, the rod body is arranged between the driving block and the stud, and the stud is threadedly connected to the housing.
[0016] Preferably, three parking top rods are provided and evenly arranged, and the parking top rods are fixedly connected to the parking brake piston via a retaining spring.
[0017] Preferably, the brake assembly includes a dynamic friction plate and a static friction plate, the dynamic friction plate is connected to the spline of the rotating shaft and can slide along the axial direction of the rotating shaft, the outer edge of the static friction plate is connected to the spline on the inner wall of the outer shell and can slide along the axial direction of the rotating shaft, and the static friction plate and the dynamic friction plate are alternately stacked.
[0018] According to an embodiment of the present disclosure, the driving and parking integrated structure is used to realize the three requirements of driving braking, parking braking and emergency braking on one brake. Compared with the existing wet drive axle which needs to be equipped with an additional bridge-outboard brake to realize the parking and emergency braking functions, the complexity of the braking system is reduced, and the manufacturing cost can also be reduced.
[0019] The parking brake is released by a mechanical device, which improves the reliability of the system.
[0020] By adding a quantitative return mechanism for the brake clearance to the service brake, the brake clearance Δ value can be accurately set and always kept constant without changing with the wear of the friction plate, which can ensure complete release of the brake, reduce drag, increase the service life of the friction plate, and ensure a constant brake response time, thereby improving the safety of vehicle operation;
[0021] Because the friction plate has less drag, the damage to the gear oil caused by high braking temperature is reduced, and the gear oil replacement period can be extended; under normal use, the friction plate can be maintenance-free, reducing the cost of axle maintenance for customers.
[0022] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.
[0024] Figure 1 is a schematic structural diagram of an off-highway vehicle drive axle in one embodiment of the present application;
[0025] Figure 2 yes Figure 1 A schematic diagram of the structure of the middle brake assembly;
[0026] Figure 3 yes Figure 2 Schematic diagram of the position structure of the middle housing and the brake assembly;
[0027] Figure 4 yes Figure 2 A schematic diagram of the structure of the middle brake assembly;
[0028] Figure 5 yes Figure 4 The structural diagram at A in the middle;
[0029] Figure 6 yes Figure 4 The structural diagram at B in the middle;
[0030] Figure 7 yes Figure 2 Schematic diagram of the structure of the mechanical release mechanism of the parking brake. DETAILED DESCRIPTION
[0031] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention.
[0032] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses.
[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.
[0034] In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.
[0035] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.
[0036] like Figures 1 to 7 As shown, an off-road vehicle drive axle in an embodiment of the present application includes a main reducer assembly 21 and a differential assembly 22 connected to each other, the two sides of the differential assembly 22 are respectively connected with a brake assembly 10, the brake assembly 10 is connected with a bridge housing 11 and a wheel hub assembly 31, the wheel hub assembly 31 is installed with a wheel-side reducer assembly 32, the brake assembly 10 includes a housing 100, a bottom housing 120 and a brake assembly 140, the brake assembly 140 is installed between the housing 100 and the bottom housing 120, and the housing 100 is provided with a service brake cavity close to the brake assembly 140 111 and a parking brake chamber 112 away from the brake assembly 140, the service brake chamber 111 and the parking brake chamber 112 are distinguished by the isolation portion 110 of the shell, the service brake chamber 111 is provided with a service brake assembly, the parking brake chamber 112 is provided with a parking brake assembly, the parking top rod 330 on the parking brake assembly passes through the isolation portion 110 to drive the brake assembly 140; the shell 100 is provided with a parking brake mechanical release mechanism 400, and the parking brake mechanical release mechanism 400 is used to manually drive the parking brake assembly to release the brake.
[0037] In one embodiment of the present application, the brake assembly 140 includes a dynamic friction plate 142 and a static friction plate 141. The inner edge of the dynamic friction plate 142 rotates together with the transmission shaft 130 through a spline sleeve and can move left and right along the axial direction. The outer edge of the static friction plate 141 is connected to the housing 100 through a spline and cannot rotate but can move left and right along the axial direction. The static friction plate 141 and the dynamic friction plate 142 are alternately stacked.
[0038] The brake assembly 140 is immersed in a lubricating oil environment, and grooves are provided on the dynamic friction plate 142. Most of the heat generated by the friction of the friction plate when the vehicle brakes is dissipated through the lubricating oil circulation and the housing 100, so that the brake components will not be damaged due to excessive internal temperature.
[0039] In one embodiment of the present application, the service brake assembly includes a service brake piston 210, a service brake sealing area 220 is arranged between the service brake piston 210 and the isolation portion 110, and the service brake sealing area 220 is connected to the service brake pedal through a first high-pressure oil pipe; a self-adjusting mechanism 240 is arranged on the side of the service brake piston 210 away from the brake assembly 140, and the self-adjusting mechanism 240 is connected to the isolation portion 110.
[0040] Two annular grooves are machined on the service brake piston 210, and two rubber sealing rings are installed therein to form a service brake sealing area 220. Three axial step holes are machined on the service brake piston 210, and correspondingly, the isolation part 110 is also machined with countersunk holes, and three self-adjusting mechanisms 240 are installed between the two.
[0041] The working principle of the service brake: after the service brake pedal is stepped on, the high-pressure oil enters the service brake sealing area 220, which can push the service brake piston 210 to move leftward to press the brake assembly 140. At this time, the parking brake sealing area 340 is also connected with high-pressure oil to release the parking brake.
[0042] After the service brake pedal is released, the high-pressure oil cannot enter the service brake sealing area 220. Driven by the service brake clearance self-adjusting mechanism 240, the service brake piston 210 moves rightward by a rated distance Δ (i.e., the distance between the return spring 243 and the baffle plate 244), the pressure on the brake assembly 140 disappears, and the service brake is released.
[0043] In one embodiment of the present application, the self-adjusting mechanism 240 includes a return spring 243, a baffle plate 244, a return pin 241 and a coil spring 242. The coil spring 242 is fixed to the service brake piston 210. The return pin 241 is inserted into the coil spring 242 and has an interference fit therewith. The baffle plate 244 is fixed to the isolation portion 110. The return spring 243 is located between the baffle plate 244 and the isolation portion 110. One end of the return pin 241 passes through the baffle plate 244 and is connected to the return spring 243.
[0044] In one embodiment of the present application, the return spring 243 is a claw spring, and a limiting retaining ring 245 is provided at the end of the return pin 241. The limiting retaining ring 245 is connected to the return spring 243, and the return spring 243 always applies a pulling force toward the isolation portion 110 to the limiting retaining ring 245.
[0045] The working principle of the self-adjusting mechanism 240 is as follows: there is a gap Δ between the return spring 243 and the baffle plate 244. The size of this gap is the preset gap size at the friction surface. A coil spring 242 is mounted on the return pin 241. Its inner diameter is smaller than the return pin 241, so there is a certain friction between the two. When the pedal is released, this friction can drive the service brake piston 210 to move right. If the friction plate is worn due to use, the gap between the friction surfaces increases. When the service brake piston 210 moves left during braking, the return spring 243 and the baffle plate 244 are in contact, and the dynamic friction plate 142 and the static friction plate 141 are still not compressed, the hydraulic pressure will push the service brake piston 210 to continue to move left, while the return pin 241 can no longer move, and the coil spring 242 and the return pin 241 slide until the friction plate is compressed.
[0046] When the pedal is released, the return spring 243 drives the service brake piston 210 to retreat a distance of Δ through the return pin 241 and the coil spring 242. Thus, the brake can maintain a fixed brake clearance Δ, where Δ can be set to 0.8-1.0 mm, and the brake will not have a problem of excessive brake clearance due to friction plate wear.
[0047] In one embodiment of the present application, the parking brake assembly includes a parking brake piston 310, and a parking brake sealing area 340 is provided between the parking brake piston 310 and the isolation portion 110, and the parking brake sealing area 340 is connected to the parking brake pedal through a second high-pressure oil pipe; a parking top rod 330 is connected to the parking brake piston 310, and the parking top rod 330 passes through the isolation portion 110 and abuts against the service brake piston 210; an elastic mechanism 320 is provided on the side of the parking brake piston 310 away from the isolation portion 110, and the elastic mechanism 320 always applies a thrust to the parking brake piston 310 toward the isolation portion 110.
[0048] In one embodiment of the present application, two annular grooves are machined on the parking brake piston 310, and two O-shaped rubber sealing rings are respectively installed therein, forming a parking brake sealing area 340. Two disc springs 321 and disc spring 321 retaining rings are placed back to back on the right side of the parking brake piston 310 in sequence. At the right end of the parking brake chamber 112, an annular groove with a half arc cross section is machined, and a steel wire retaining ring is placed. The steel wire retaining ring restricts the disc spring 321 retaining ring from axially escaping. During assembly, the disc spring 321 should be compressed with an instrument before the steel wire retaining ring can be inserted. The two disc springs 321 generate axial thrust due to compression, pressing the parking brake piston 310 against the left end face of the parking brake chamber 112.
[0049] Three evenly spaced φ20H7 through holes are processed on the isolation part 110. Three φ12H7 through holes are processed on the parking brake piston 310. The two sections of the three parking top rods 330 are respectively inserted into the φ20H7 through hole and the φ12H7 through hole of the parking brake piston 310, and O-rings are installed at the matching positions to ensure that the parking brake sealing area 340 does not leak oil. The rightmost end of the three parking top rods 330 is equipped with a retaining spring to ensure that the parking top rods 330 follow the movement of the parking brake piston 310.
[0050] Working principle of parking brake: When the vehicle needs to be parked, the parking brake pedal is pressed, and the high-pressure oil leading to the parking brake is cut off. Under the pressure of the two disc springs 321, the parking brake piston 310 moves left, and the oil in the parking brake sealing area 340 is squeezed back into the oil tank. The three parking rams 330 are pushed by the parking brake piston 310, which in turn pushes the service brake piston 210 to move leftward, pressing the brake assembly 140, and the vehicle is parked.
[0051] When the parking state needs to be released, the parking pedal is released, and the high-pressure oil enters the parking brake sealing area 340. Under the action of the oil pressure, the parking brake piston 310 moves rightward, and the disc spring 321 is compressed. The parking top rod 330 moves rightward with the parking brake piston 310 and is separated from the service brake piston 210. The brake assembly 140 loses axial pressure, thereby releasing the parking state, and the vehicle can drive normally.
[0052] In one embodiment of the present application, there are three parking brake release mechanisms, including a driving rod and a driving block 410. The driving block 410 is arranged in the parking brake sealing area 340. The driving inclined surface 411 of the driving block 410 is against the parking brake piston 310. The driving rod is used to push the driving block 410 to move toward the parking brake piston 310.
[0053] In one embodiment of the present application, the driving rod includes a rod body 420 and a stud 430 . The rod body 420 is disposed between the driving block 410 and the stud 430 . The stud 430 is threadedly connected to the housing 100 .
[0054] Parking brake mechanical release mechanism 400 Principle: When the parking brake system cannot release the parking brake due to a hydraulic failure, the parking brake can be released by the parking brake release mechanism.
[0055] The three studs 430 are screwed into three evenly distributed radial threaded holes on the outer circumference of the housing 100 through their external threads, and the rod body 420 is pressed tightly, and the arc surface at the front end of the rod body 420 contacts the driving block 410. The driving block 410 is a cylindrical body with a driving inclined surface 411 processed thereon, and the driving inclined surface 411 contacts the parking brake piston 310 with a chamfer.
[0056] When the mechanical release of the brake is not required, the drive block 410 can move axially along the hole without hindering the movement of the parking brake piston 310. When the parking brake needs to be released mechanically, we can insert an Allen wrench into the Allen countersunk hole of the stud 430, screw the stud 430, contact the drive block 410, and the drive bevel 411 contacts the chamfer of the parking brake piston 310. Apply tightening force evenly to the three studs 430, and the drive block 410 can push the parking brake piston 310 to move right through the contact of the drive bevel 411. The parking jack 330 no longer transmits the axial force generated by the disc spring 321. The service brake piston 210 moves right under the drive of the return mechanism, and the brake assembly 140 can be disengaged, and the parking brake can be released eventually.
[0057] According to an embodiment of the present application, the driving and parking integrated structure is used to realize the three requirements of driving braking, parking braking and emergency braking on one brake. Compared with the existing wet drive axle which needs to be equipped with an additional bridge-outboard brake to realize the parking and emergency braking functions, the complexity of the braking system is reduced, and the manufacturing cost can also be reduced.
[0058] The parking brake is released by a mechanical device, which improves the reliability of the system.
[0059] By adding a quantitative return mechanism for the brake clearance to the service brake, the brake clearance Δ value can be accurately set and always kept constant without changing with the wear of the friction plate, which can ensure complete release of the brake, reduce drag, increase the service life of the friction plate, and ensure a constant brake response time, thereby improving the safety of vehicle operation;
[0060] Because the friction plate has less drag, the damage to the gear oil caused by high braking temperature is reduced, and the gear oil replacement period can be extended; under normal use, the friction plate can be maintenance-free, reducing the cost of axle maintenance for customers.
[0061] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.
Claims
1. An off-highway vehicle drive axle, characterized in that: It includes a main reducer assembly and a differential assembly connected to each other, the two sides of the differential assembly are respectively connected with a brake assembly, the brake assembly is connected with a bridge housing and a wheel hub assembly, the wheel hub assembly is installed with a wheel-side reducer assembly, the brake assembly includes an outer shell, a bottom shell and a brake assembly, the outer shell is provided with a service brake chamber close to the brake assembly and a parking brake chamber away from the brake assembly, the service brake chamber and the parking brake chamber are distinguished by an isolation portion of the outer shell, the service brake chamber is provided with a service brake assembly, the parking brake chamber is provided with a parking brake assembly, the parking top rod on the parking brake assembly passes through the outer shell to drive the brake assembly; the outer shell is provided with a parking brake mechanical release mechanism, the parking brake mechanical release mechanism is used to manually drive the parking brake assembly to release the brake.
2. The off-highway vehicle drive axle according to claim 1, characterized in that: The service brake assembly includes a service brake piston, a service brake sealing area is arranged between the service brake piston and the isolation part, and the service brake sealing area is connected to the service brake pedal through a first high-pressure oil pipe; a self-adjusting mechanism is arranged on the side of the service brake piston away from the brake assembly, and the self-adjusting mechanism is connected to the isolation part.
3. The off-highway vehicle drive axle according to claim 2, characterized in that: The self-adjusting mechanism includes a return spring, a baffle, a return pin and a coil spring, the coil spring is fixed to the service brake piston, the return pin is inserted into the coil spring and has an interference fit therewith, the baffle is fixed to the isolation portion, the return spring is located between the baffle and the isolation portion, and one end of the return pin passes through the baffle and is connected to the return spring.
4. The off-highway vehicle drive axle according to claim 3, characterized in that: The return spring is a claw-shaped spring, a limit retaining ring is arranged at the end of the return pin, the limit retaining ring is connected to the return spring, and the return spring always applies a pulling force toward the isolation portion to the limit retaining ring.
5. The off-highway vehicle drive axle according to claim 2, characterized in that: The parking brake assembly includes a parking brake piston, wherein a parking brake sealing area is provided between the parking brake piston and the isolation part, and the parking brake sealing area is connected to the parking brake pedal through a second high-pressure oil pipe; the parking brake piston is connected to the parking top rod, and the parking top rod passes through the isolation part and abuts against the service brake piston; an elastic mechanism is provided on the side of the parking brake piston away from the isolation part, and the elastic mechanism always applies a thrust to the parking brake piston toward the isolation part.
6. The off-highway vehicle drive axle according to claim 5, characterized in that: The elastic mechanism is a plurality of disc springs arranged in layers, and a disc spring retaining ring is provided on the inner wall of the shell, and the disc spring retaining ring is used to retain the disc spring.
7. The off-highway vehicle drive axle according to claim 6, characterized in that: The parking brake release mechanism includes a driving rod and a driving block, wherein the driving block is arranged in the parking brake sealing area, the driving inclined surface of the driving block abuts against the parking brake piston, and the driving rod is used to push the driving block to move toward the parking brake piston.
8. The off-highway vehicle drive axle according to claim 7, characterized in that: The driving rod comprises a rod body and a stud, wherein the rod body is arranged between the driving block and the stud, and the stud is threadedly connected to the housing.
9. The off-highway vehicle drive axle according to claim 5, characterized in that: The parking top rods are provided with three and are evenly arranged. The parking top rods are fixedly connected to the parking brake piston via a retaining spring.
10. The off-highway vehicle drive axle according to claim 1, characterized in that: The brake assembly includes a dynamic friction plate and a static friction plate. The dynamic friction plate is connected to the spline of the rotating shaft and can slide along the axial direction of the rotating shaft. The outer edge of the static friction plate is connected to the spline on the inner wall of the outer shell and can slide along the axial direction of the rotating shaft. The static friction plate and the dynamic friction plate are alternately stacked.