Locking differential mechanism structure for loader drive axle

Abstract

The invention relates to the technical field of limited slip differentials, and discloses a locking differential structure for a loader drive axle, which comprises a differential shell, the left side of the differential shell is fixedly connected with a differential shell cover, and a planet wheel shaft is fixedly connected with the differential shell; the lock-up clutch assembly comprises a piston, a driving friction plate and a driven friction plate, wherein the piston is arranged in the differential shell and close to a differential shell cover, and the driving friction plate and the driven friction plate are arranged in a staggered mode. A wave spring is arranged between every two adjacent driving friction plates, hydraulic oil enters a differential shell through a lock-up clutch oil duct to push a piston, the piston pushes the friction plates to enable the wave springs to be compressed, the driving friction plates make contact with the driven friction plates to achieve lock-up slip limiting, and lock-up slip limiting is achieved through a hydraulic lock-up clutch structure. The locking coefficient is obviously improved, the driving capability of the engine is furthest exerted, and the problem of road slip is effectively solved; in addition, by arranging the wave spring, the sliding friction time of the friction plate can be effectively shortened, and the defect that a limited-slip differential friction plate is prone to abrasion is overcome.

Description

Technical Field

[0001] The invention relates to the technical field of limited slip differentials, in particular to a locking differential structure for a loader drive axle. Background Art

[0002] The differential is an important part of the power transmission system of vehicles such as loaders. Its function is to achieve differential effect when the wheel speeds on both sides of the drive shaft are inconsistent (such as when the vehicle turns), to prevent the wheels from slipping, and to reduce driving resistance and tire wear. The disadvantage of ordinary planetary gear differentials is that when the vehicle is driving on muddy and slippery roads, it is easy to slip and lose traction due to insufficient wheel adhesion. Therefore, some loaders are equipped with limited slip differentials to effectively improve the slip phenomenon.

[0003] Existing limited slip differentials, such as Figure 7 As shown, when slipping, the rotational torque of the left and right half-shaft gears is different, and the axial force generated is also different. The axial force on the non-slipping side is large, and the planetary bevel gear shaft moves the planetary bevel gear slightly toward the slipping side, and pushes the pressure plate on the slipping side through the V-shaped inclined surface of the pressure plate to press the friction plate. When there is a speed difference between the half-shaft gears on both sides (slipping or turning), the master and slave friction plates generate friction torque while slipping. The direction of the torque is opposite to the direction of the fast-rotating side (slipping side) and consistent with the direction of the slow-rotating side, thereby achieving limited slip. However, the existing limited slip differential has the following disadvantages: 1. The maximum locking coefficient is about 5, that is, the driving torque on the non-slip side is 5 times that on the slip side, and the locking coefficient is relatively small; 2. The planetary bevel gears move left and right, affecting the meshing performance of the differential gears and reducing the reliability of the gears; 3. When turning, because there is a speed difference between the left and right half-shaft gears, the axial forces of the half-shaft gears on both sides are not completely equal, and the friction plate on the side with a higher speed is pressed tightly. The limited slip differential will increase the steering force, and the slippage of the master and slave friction plates will accelerate their wear, reducing reliability. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a locking differential structure for a loader drive axle, which utilizes a hydraulic locking clutch structure to achieve locking and limited slip, and the locking coefficient is significantly improved, thereby maximizing the driving ability of the engine and effectively solving the problem of road slippage; in addition, by providing a wave spring, the sliding time of the friction plate can be effectively reduced, thereby overcoming the disadvantage that the limited slip differential friction plate is easy to wear.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A locking differential structure for a loader drive axle, comprising a differential housing, a left half-shaft gear, a right half-shaft gear, a planetary bevel gear and a locking clutch assembly arranged in the differential housing, wherein the left side of the differential housing is fixedly connected to a differential housing cover, the planetary bevel gear is mounted on a planetary gear shaft, and the planetary gear shaft is fixedly connected to the differential housing; the locking clutch assembly comprises a piston arranged inside the differential housing near the differential housing cover, an active friction plate and a driven friction plate arranged in a staggered manner;

[0007] The piston is connected to the reset structure, and a wave spring is arranged between two adjacent active friction plates. The active friction plate is fixedly connected to the differential housing, and the driven friction plate is fixedly connected to the left half-shaft gear. A locking clutch oil passage is arranged on the differential housing cover, and the hydraulic oil enters the differential housing through the locking clutch oil passage to push the piston. The piston pushes the friction plate to compress the wave spring, and the active friction plate and the driven friction plate come into contact to realize locking and limited slip.

[0008] As a further implementation, an oil chamber is formed between the piston inside the differential housing and the differential cover, and the locking clutch oil passage extends to the oil chamber.

[0009] As a further implementation method, a step structure is provided on the inner side of the differential housing near one end of the differential housing cover, the piston cross-section is convex and adapted to the step structure, and the reset structure is a disc spring, one end of the disc spring is sleeved on the piston, and the other end abuts the step structure.

[0010] As a further implementation, the differential housing is fixedly connected to the active friction plate via an internal spline, the active friction plate is sleeved on the left half-shaft gear, and the left half-shaft gear is fixedly connected to the driven friction plate via an external spline.

[0011] As a further implementation, the outer diameter of the driven friction plate is smaller than the outer diameter of the driving friction plate, and the wave spring is sleeved on the peripheral side of the driven friction plate.

[0012] As a further implementation method, the planetary gear axle includes a long shaft, a positioning sleeve and a short shaft. The positioning sleeve is arranged in the middle position of the long shaft, the two sides of the positioning sleeve cooperate with one end of the short shaft, the other end of the short shaft is fixedly connected to the differential housing, and the two ends of the long shaft are fixedly connected to the differential housing.

[0013] As a further implementation, a pressure plate is provided inside the differential housing, and the pressure plate is located against the right side of the friction plate away from the piston.

[0014] As a further implementation method, the half-shaft gear is installed on the half-shaft, and speed sensors are provided on the left and right half-shafts. The speeds of the left and right speed sensors are compared to determine the degree of slippage.

[0015] As a further implementation method, it also includes a bracket, which is located on the peripheral side of the differential housing cover. The bracket is provided with a clutch oil channel. An oil sleeve is provided between the bracket and the differential housing cover. The clutch oil channel is connected to the locking clutch oil channel through the oil sleeve.

[0016] As a further implementation, the clutch oil channel is used to connect to an oil pump assembly through an oil circuit, and the oil pump assembly is controlled by a solenoid valve, and the solenoid valve is equipped with a manual switch.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. The present invention utilizes a hydraulic locking clutch structure to achieve locking and limited slip, and the locking coefficient is significantly improved, which maximizes the driving ability of the engine and effectively solves the problem of road slip. In addition, by setting a wave spring, the sliding time of the friction plate can be effectively reduced, the disadvantage of easy wear of the limited slip differential friction plate can be overcome, and the problem that the limited slip differential in the prior art will increase the steering force when turning can be solved, thereby improving the traction performance and working efficiency of the loader.

[0019] 2. The cross shaft assembly of the present invention is fixedly connected to the differential housing, which will not affect the meshing performance of the differential gears and ensure reliability.

[0020] 3. The present invention can detect the rotational speeds of the left and right half shafts by setting a rotational speed sensor, and compare them through a control system. When the difference between the two rotational speed values ​​exceeds a set range, the control system can automatically control the solenoid valve to lock and limit slip. The solenoid valve is also equipped with a manual switch, which can enable the driver to manually open the differential lock as needed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] Figure 1 1 is a schematic diagram of the internal structure of a locking differential for a loader drive axle in an embodiment of the present invention;

[0023] Figure 2 It is a partial structural schematic diagram of a locking differential for a loader drive axle in an embodiment of the present invention;

[0024] Figure 3 1 is a schematic diagram of the overall structure of a locking differential for a loader drive axle in an embodiment of the present invention;

[0025] Figure 4 It is a partial structural schematic diagram of a locking differential for a loader drive axle in an embodiment of the present invention;

[0026] Figure 51 is a schematic diagram of the overall structure of a locking differential for a loader drive axle in an embodiment of the present invention;

[0027] Figure 6 is a schematic diagram of the overall structure of a cross-axis assembly in an embodiment of the present invention;

[0028] Figure 7 It is a structural schematic diagram of an existing limited slip differential.

[0029] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for reference only.

[0030] Among them: 1. differential cover, 2. differential housing, 3. main reducer and driven wheel, 4. piston, 5. disc spring, 6. master and slave friction plates, 7. wave spring, 8. pressure plate, 9. left half shaft gear, 10. planetary bevel gear, 11. cross shaft assembly, 12. right half shaft gear, 13. locking clutch oil channel, 13-1. oil channel inlet, 14. oil chamber, 16. input gear, 17. bracket, 18. plug, 19. sealing ring, 20. oil sleeve, 21. adjusting round nut; 11-1. long shaft, 11-2. positioning sleeve, 11-3. short shaft, 12-1. right half shaft, 12-2. speed sensor. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] Embodiment 1

[0033] In a typical embodiment of the present invention, reference is made to Figure 1-Figure 6 As shown, a locking differential structure for a loader drive axle comprises a differential case 2, a left half-shaft gear 9, a right half-shaft gear 12, a planetary bevel gear 10 and a locking clutch assembly arranged in the differential case 2, wherein the left side of the differential case 2 is fixedly connected to the differential case cover 1, the planetary bevel gear 10 is mounted on the planetary gear shaft, and the planetary gear shaft is fixedly connected to the differential case 2; the locking clutch assembly comprises a piston 4 arranged inside the differential case 2 near the differential case cover 1, and an active friction plate and a driven friction plate arranged alternately; the piston 4 is connected to a reset structure, a wave spring 7 is arranged between two adjacent active friction plates, the active friction plate is fixedly connected to the differential case 2, and the driven friction plate is fixedly connected to the left half-shaft gear 9; a locking clutch oil passage 13 is provided on the differential case cover 1, and hydraulic oil enters the differential case 2 through the locking clutch oil passage 13 to push the piston 4, and the piston 4 pushes the friction plate to compress the wave spring 7, and the active friction plate and the driven friction plate contact to realize locking and limited slip.

[0034] This embodiment realizes locking by hydraulic means, which can effectively improve the locking coefficient. By providing the wave spring 7, the disadvantage of easy wear of the limited slip differential friction plate can be overcome, thereby improving the traction performance and working efficiency of the loader.

[0035] like Figure 1-Figure 2 As shown, the differential cover 1 is fixed to the left open end of the differential case 2, the left half shaft passes through the differential cover 1 and extends into the differential case 2, and the right half shaft passes through the differential case 2 from the right side and extends into the differential case 2. The left half shaft end is provided with a left half shaft gear 9, and the right half shaft end 12-1 is provided with a right half shaft gear 12.

[0036] The planetary gear shaft adopts a cross shaft assembly 11, such as Figure 6 As shown, it includes a long shaft 11-1, two short shafts 11-3 and a positioning sleeve 11-2. The length of the long shaft 11-1 is the same as that of the differential case 2 ( Figure 2 The locating sleeve 11-2 is a sleeve structure, and the middle position of the locating sleeve 11-2 has a radial hole to fit the long shaft 11-1. The axial through hole of the locating sleeve 11-2 is respectively connected with one end of the two short shafts 11-3, and the other end of the short shaft 11-3 is provided with a pin hole, which is fixedly connected to the differential case 2 through a pin shaft. Pin holes are provided at both ends of the long shaft 11-1, which is fixedly connected to the differential case through a pin shaft. The long shaft 11-1 is equipped with two planetary bevel gears 10 ( Figure 2 ), each short shaft 11-3 is provided with a planetary bevel gear 10, and the planetary bevel gear 10 cooperates with the left half shaft gear 9 and the right half shaft gear 12.

[0037] The cross shaft assembly of this embodiment is fixedly connected to the differential housing 2, so it can solve the problem that the existing planetary bevel gear moves left and right, affects the meshing performance of the differential gear, and reduces the reliability of the gear.

[0038] During assembly, first install the long shaft 11-1 into the differential housing, and then put on the positioning sleeve 11-2 and two planetary bevel gears 10. The positioning sleeve 11-2 is located between the two planetary bevel gears 10, and the positioning pins are installed in the corresponding pin holes of the differential housing. The positioning pins must pass through the pin holes of the long shaft 11-1; then install the short shaft 11-3 and the planetary bevel gears 10, and the positioning pins must pass through the pin holes of the short shaft 11-3, and seal the pin holes with screws to prevent the positioning pins from falling out and rotating.

[0039] like Figure 1 As shown, a main reducer driven wheel 3 is provided on the outside of the differential housing 2 for meshing with the input gear 16. The input gear 16 transmits power to the main reducer driven wheel 3 to realize transmission, so that the differential housing 2 rotates.

[0040] The locking clutch assembly is used to achieve locking and limited slip, wherein a master-slave friction plate 6 is provided inside the differential housing 2, including an active friction plate and a driven friction plate. The differential housing 2 is connected to the active friction plate through an internal spline, and the left half-shaft gear 9 is connected to the driven friction plate set through an external spline. The left end of the left half-shaft gear 9 is assembled with the differential housing cover 1.

[0041] The outer diameter of the driven friction plate is smaller than that of the active friction plate. The wave spring 7 is sleeved on the outer side of the driven friction plate. Both sides of the wave spring abut against the active friction plate. The wave spring has a certain preload force.

[0042] A group of pressure plates 8 are abutted against the inner side of the differential housing 2, and the pressure plate 8 abuts against the right side of the friction plate to support the rightmost friction plate. To ensure that the piston 4 and the pressure plate 8 do not rotate relative to the differential housing 2, the rightmost and leftmost friction plates are active friction plates, and the active friction plates and the driven friction plates are arranged alternately.

[0043] like Figure 2 As shown, a step structure is provided on the inner side of the differential housing near one end of the differential housing cover, and the cross-section of the piston is convex, which is convenient for adapting to the step structure. The reset structure is a disc spring 5, and one end of the disc spring 5 abuts and is sleeved on the step formed by the convex shape of the piston, and the other end abuts the step structure on the inner side of the differential housing.

[0044] like Figure 2 As shown, a sealing ring is arranged between the piston 4 and the inner side of the differential housing to prevent leakage of hydraulic oil. An oil chamber is formed between the piston inside the differential housing and the differential housing cover, and the locking clutch oil passage extends to the oil chamber.

[0045] The lock-up clutch oil passage is a passage that penetrates the differential housing cover, so a plug 18 is provided at the left end of the lock-up clutch oil passage for blocking, and the right end extends to the oil chamber 14. The lock-up clutch oil passage 13 is provided with an oil passage inlet 13-1.

[0046] When the hydraulic oil enters the oil chamber 14 through the locking clutch oil passage 13, the piston is pushed to move right, the disc spring 5 is compressed, and the master and slave friction plates 6 are compressed together, the wave spring 7 is also compressed, the active friction plate and the driven friction plate are tightly attached, the friction plate, the differential case, and the side gears are locked as a whole, and the locking limited slip is achieved. The piston of this embodiment can press the friction plate to connect the side gears and the differential case into one body, forming a locked state.

[0047] The disc spring 5 is used to realize the piston return. The locking clutch oil passage 13 of this embodiment is both a hydraulic oil inlet passage and an oil outlet passage, so its principle is similar to that of a single-tube hydraulic cylinder.

[0048] The hydraulic oil comes from the hydraulic oil tank and enters the oil chamber through the hydraulic oil pump and solenoid valve. Figure 4As shown, the differential assembly is connected to the bracket with a bearing, and the bracket is fixedly connected to the outer box of the drive axle. A clutch oil channel is provided on the bracket 17, and an oil sleeve 20 is provided between the bracket 17 and the differential housing cover 1, that is, the bracket is provided on the side of the oil sleeve 20, and the oil sleeve 20 is provided on the side of the differential housing cover 1. An O-shaped sealing ring and an O-ring seat ring are provided between the bracket 17 and the oil sleeve for sealing. There is a sealing ring 19 between the oil sleeve 5 and the differential housing cover 6, which is a pressure rotating sealing ring for sealing the pressure oil channel. The installation position of the O-ring seat ring corresponding to the bracket needs to be processed with a flat mouth, and the corresponding position of the oil sleeve needs to be milled flat.

[0049] The clutch oil channel is connected to the locking clutch oil channel through an oil sleeve, and the outer end of the clutch oil channel is connected to the hydraulic oil circuit through a clutch oil interface, and the hydraulic oil enters the oil chamber through a hydraulic oil pump and a solenoid valve.

[0050] It can be understood that the clutch oil channel is used to connect the oil pump assembly through the oil circuit. The oil pump assembly is controlled by the solenoid valve. The hydraulic pump in the hydraulic system extracts the hydraulic oil in the hydraulic oil tank and controls the flow direction and flow rate through the solenoid valve. The hydraulic oil passes through the clutch oil channel, the oil sleeve 20, the oil channel inlet 13-1, and the locking clutch oil channel 13 into the oil chamber 14, pushing the piston to overcome the resistance of the disc spring 5 and move right, pressing the friction plate, and interlocking the differential gear with the differential housing and the half-axle into one. When one side of the wheel slips, because the left and right half-axle gears are connected to the differential housing as a whole, the torque transmitted from the main reduction is fully distributed to the driving wheel on the other side, driving the vehicle to run normally. On a non-slip road, by cutting off the pressure oil circuit, under the action of the disc spring 5, the pressure oil in the cylinder returns through the solenoid valve, the piston returns, and the friction plate can be completely separated under the action of the wave spring 7 to avoid friction of the friction plate and high temperature.

[0051] The solenoid valve can be equipped with a manual switch as needed. When the driver encounters a wheel slip on one side, the driver can operate the manual switch as needed to lock the limited slip. In other examples, the differential lock can also be operated by an electronically controlled hydraulic (or electronically controlled pneumatic) method in the slip condition.

[0052] In a preferred example, a speed sensor 12-2 is provided on the left and right half-axles. The speed sensor 12-2 is used to detect the speed of the left and right half-axles and compare them through the control system. When the difference between the two speed values ​​exceeds the set range, or the time exceeds the set range, the control system can control the solenoid valve to lock and limit slip.

[0053] This embodiment uses a hydraulic locking clutch structure to connect the differential gear and the differential housing into one body, the locking coefficient is significantly improved, the driving capacity of the engine is maximized, and the problem of road slip is effectively solved; in addition, by setting a wave spring, the friction plate sliding time can be effectively reduced, the disadvantage of easy wear of the limited slip differential friction plate can be overcome, and the problem of the limited slip differential increasing the steering force when turning in the prior art can be solved, thereby improving the traction performance and working efficiency of the loader. The cross shaft assembly of this embodiment is fixedly connected to the differential housing, which will not affect the meshing performance of the differential gear and ensure reliability.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A locking differential structure for a loader drive axle, characterized in that: It includes a differential case, a left half-shaft gear, a right half-shaft gear, a planetary bevel gear and a locking clutch assembly arranged in the differential case, the left side of the differential case is fixedly connected to the differential case cover, the planetary bevel gear is installed on the planetary gear shaft, and the planetary gear shaft is fixedly connected to the differential case; the locking clutch assembly includes a piston arranged inside the differential case near the differential case cover, and active friction plates and driven friction plates arranged in a staggered manner; The piston is connected to the reset structure, and a wave spring is arranged between two adjacent active friction plates. The active friction plate is fixedly connected to the differential housing, and the driven friction plate is fixedly connected to the left half-shaft gear. A locking clutch oil passage is arranged on the differential housing cover, and the hydraulic oil enters the differential housing through the locking clutch oil passage to push the piston. The piston pushes the friction plate to compress the wave spring, and the active friction plate and the driven friction plate come into contact to realize locking and limited slip.

2. The locking differential structure for a loader drive axle according to claim 1, characterized in that: An oil chamber is formed between the piston inside the differential housing and the differential cover, and the locking clutch oil passage extends to the oil chamber.

3. The locking differential structure for a loader drive axle according to claim 1, characterized in that: A step structure is provided on the inner side of the differential housing near one end of the differential housing cover, the piston cross-section is convex and matches the step structure, and the reset structure is a disc spring, one end of the disc spring is sleeved on the piston, and the other end abuts the step structure.

4. The locking differential structure for a loader drive axle according to claim 1, characterized in that: The differential housing is fixedly connected to the active friction plate through an internal spline, the active friction plate is sleeved on the left half-shaft gear, and the left half-shaft gear is fixedly connected to the driven friction plate through an external spline.

5. The locking differential structure for a loader drive axle according to claim 4, characterized in that: The outer diameter of the driven friction plate is smaller than the outer diameter of the driving friction plate, and the wave spring is sleeved on the peripheral side of the driven friction plate.

6. The locking differential structure for a loader drive axle according to claim 1, characterized in that: The planetary gear shaft includes a long shaft, a positioning sleeve and a short shaft. The positioning sleeve is arranged in the middle of the long shaft, the two sides of the positioning sleeve cooperate with one end of the short shaft, the other end of the short shaft is fixedly connected to the differential housing, and the two ends of the long shaft are fixedly connected to the differential housing.

7. The locking differential structure for a loader drive axle according to claim 1, characterized in that: A pressure plate is arranged inside the differential housing, and the pressure plate is located against the right side of the friction plate away from the piston.

8. The locking differential structure for a loader drive axle according to claim 1, characterized in that: The half-shaft gear is installed on the half-shaft. Speed ​​sensors are provided on the left and right half-shafts. The speeds of the two speed sensors are compared to determine the degree of slippage.

9. The locking differential structure for a loader drive axle according to claim 1, characterized in that: It also includes a bracket, which is located on the peripheral side of the differential housing cover. The bracket is provided with a clutch oil channel. An oil sleeve is provided between the bracket and the differential housing cover. The clutch oil channel is connected to the locking clutch oil channel through the oil sleeve.

10. The locking differential structure for a loader drive axle according to claim 9, characterized in that: The clutch oil passage is used to connect the oil pump assembly through the oil circuit. The oil pump assembly is controlled by a solenoid valve, and the solenoid valve is equipped with a manual switch.

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