Electric fork four-wheel drive rear axle assembly

Abstract

The utility model relates to four drive rear axle assembly technical field, and disclose a kind of electric fork four drive rear axle assembly, the electric fork four drive rear axle assembly, including bridge body assembly, long form air plug is installed on the bridge body assembly, bridge body assembly two ends are respectively rotatedly connected with left knuckle assembly and right knuckle assembly by lower pin assembly, first lower pin adjusting pad and second lower pin adjusting pad are respectively equipped between lower pin assembly and left knuckle assembly and right knuckle assembly.The electric fork four drive rear axle assembly, for reducing energy consumption, improve vehicle endurance, by adopting the rear reduction gearbox structure of bridge structure, half shaft assembly is sequentially passed through outer half shaft inner blocking ring, planetary gear carrier assembly and then connected with wheel rim reducer transmission in bridge body assembly inside and both ends, so that rear box does not participate in power transmission work when normal driving, reduce unnecessary energy loss, to better reduce energy consumption, improve vehicle endurance.

Description

Technical Field

[0001] This utility model relates to the field of four-wheel drive rear axle assembly technology, specifically an electric fork four-wheel drive rear axle assembly. Background Technology

[0002] The four-wheel drive rear axle assembly of the electric fork is a core component that determines the vehicle's power transmission, steering agility, and range. The rear axle assembly must simultaneously meet multiple requirements such as stable power output, precise steering, and low energy loss. In particular, under different loads and road conditions, higher standards are placed on the transmission efficiency, sealing performance, and structural stability of the rear axle.

[0003] However, existing electric fork four-wheel drive rear axle assemblies have certain shortcomings in practical applications: On the one hand, traditional rear axles mostly adopt an integrated reduction gearbox structure, and the reduction gearbox is always involved in power transmission during normal driving, resulting in significant energy loss and seriously affecting the vehicle's range; on the other hand, some rear axle main reducers are not equipped with effective anti-slip differential locks, or the coordination between the steering mechanism and the differential lock is poor. When the front and rear tires slip, not only is the power distribution uneven, but the steering function of the rear axle is also easily restricted, reducing the reliability of the equipment in complex road conditions. In addition, the assembly gaps of some connecting components of existing rear axles cannot be flexibly adjusted, and the sealing structure design is unreasonable, which can easily lead to problems such as lubricating oil leakage and excessive wear of components, affecting service life.

[0004] In view of this, we propose an electric fork four-wheel drive rear axle assembly. Utility Model Content

[0005] The purpose of this invention is to provide an electric fork four-wheel drive rear axle assembly to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: An electric fork four-wheel drive rear axle assembly includes an axle body assembly. An elongated vent plug is mounted on the axle body assembly. Both ends of the axle body assembly are rotatably connected to a left steering knuckle assembly and a right steering knuckle assembly respectively via lower support pin assemblies. A first lower support pin adjusting shim and a second lower support pin adjusting shim are respectively provided between the lower support pin assembly and the left and right steering knuckle assemblies. Dustproof rings are fixed to the outer sides of the left and right steering knuckle assemblies via first and second hexagonal flange bolts, respectively. The inner sides are rotatably connected to a first wheel hub assembly via wheel hub bearings. A wheel hub bearing adjusting shim is provided between the wheel hub bearing and the first wheel hub assembly. Steering knuckle adjusting shims are also provided between the left and right steering knuckle assemblies and the first wheel hub assembly. The half-shaft assembly is installed inside the axle body assembly. Both ends pass through the inner retaining ring of the outer half-shaft and the planetary gear carrier assembly in sequence and are then connected to the wheel-side reducer for transmission. The end of the half-shaft assembly is limited by a type II hexagonal nut. An outer retaining ring of the outer half-shaft is provided on the outside of the inner retaining ring of the outer half-shaft. The outer retaining ring of the outer half-shaft is fixed to the half-shaft assembly by a shaft elastic retaining ring. The wheel-side reducer is integrated inside the first wheel hub assembly and includes a planetary gear carrier assembly, a gear ring assembly, and an end cover. The end cover is fixed to the end of the first wheel hub assembly by a first bolt and a first spring washer, and a first O-ring seal is clamped inside. The planetary gear carrier assembly is splined to the half shaft assembly and has steel balls inside. The gear ring assembly is fixedly connected to the inner wall of the first wheel hub assembly. The wheel-side reducer housing has a wheel-side oil drain hole and a wheel-side oil level hole, both of which are equipped with screw plugs. The main reducer is located in the middle of the axle assembly and is equipped with a limited anti-slip differential lock. The axle assembly has an oil well hole corresponding to the main reducer and is equipped with a plug. The steering mechanism includes a steering cylinder assembly, a left steering knuckle arm, a right steering knuckle arm, and a connecting rod body. The left steering knuckle arm is fixed to the left steering knuckle assembly by a first cylindrical pin, and the right steering knuckle arm is fixed to the right steering knuckle assembly by a second cylindrical pin. The two ends of the connecting rod body are hinged to the left and right steering knuckle arms respectively by connecting rod pins. A joint bearing is provided at the hinge point, and a bushing is sleeved on the inner side of the joint bearing. The two ends of the connecting rod pin are provided with baffles and fixed by hexagon countersunk screws. The output end of the steering cylinder assembly is connected to the middle of the connecting rod body. The rear support assembly is fixed to the axle assembly by a first hexagonal head bolt and a second spring washer, with a rear support adjusting shim between them. The axle assembly is also connected to the external structure by a second hexagonal head bolt, a main bolt, a third spring washer, and a main shim. A front support adjusting shim and a second O-ring are provided at the connection. The second O-ring is limited by an internal hexagonal head screw. The end of the first wheel hub assembly is fixed by a wheel hub nut. A first adjusting shim is provided at the gap between the axle assembly and related components. The lower support pin assembly is equipped with a straight-through pressure injection cup.

[0007] In a further embodiment, when adding oil to the wheel-side oil filling hole, it needs to be rotated to a vertically upward position, directly facing the wheel-side reducer end cover, and lubricating oil is injected until the oil overflows from the wheel-side oil level hole. The main reducer is then filled with oil through the bridge oil hole until it overflows.

[0008] In a further embodiment, the spherical bearing is interference-fitted with the connecting rod pin, the left steering knuckle arm, and the right steering knuckle arm, while the bushing is clearance-fitted with the inner wall of the spherical bearing to ensure smooth rotation of the connecting rod pin.

[0009] In a further embodiment, both the first and second O-rings are made of oil-resistant rubber to achieve sealing between the end cap and the first wheel hub assembly, and between the axle assembly and the external structure, respectively, to prevent lubricating oil leakage.

[0010] In a further embodiment, the wheel hub bearing adjusting shim, steering knuckle adjusting shim, first adjusting shim, front support adjusting shim, and rear support adjusting shim are all thin metal shims. The assembly clearance of the corresponding components is adjusted by increasing or decreasing the number of shims to ensure transmission accuracy and steering flexibility.

[0011] In a further embodiment, the straight-through pressure injection cup is connected to the internal oil passage of the lower support pin assembly. Lubricating grease is injected through the cup to lubricate the rotating connection between the lower support pin assembly and the left steering knuckle assembly and the right steering knuckle assembly, thereby reducing wear.

[0012] In a further embodiment, the elongated vent plug is connected to the internal cavity of the axle assembly to balance the air pressure inside the axle assembly and the outside environment, preventing excessive internal pressure caused by temperature changes from damaging the sealing structure, and preventing external impurities from entering.

[0013] Compared with the prior art, this utility model provides an electric fork four-wheel drive rear axle assembly, which has the following beneficial effects: 1. In order to reduce energy consumption and improve the overall vehicle range, the electric fork four-wheel drive rear axle assembly adopts a decoupled rear reduction gearbox structure, which is paired with a half-shaft assembly that passes through the axle assembly and is connected to the wheel-side reducer after passing through the inner retaining ring of the outer half-shaft and the planetary gear carrier assembly at both ends. This allows the rear gearbox to not participate in power transmission during normal driving, reducing unnecessary energy loss, thereby better reducing energy consumption and improving the overall vehicle range.

[0014] 2. To ensure rear axle steering function even when the front and rear tires slip, this electric fork four-wheel drive rear axle assembly employs a main reducer located in the middle of the axle assembly and equipped with a limited anti-slip differential lock. This is combined with a steering mechanism consisting of a steering cylinder assembly, left steering knuckle arm, right steering knuckle arm, and connecting rod body. The steering knuckle arm is fixed to the left steering knuckle assembly via a first cylindrical pin, and the right steering knuckle arm is fixed to the right steering knuckle assembly via a second cylindrical pin. The connecting rod body is hinged to the left and right steering knuckle arms at both ends via connecting rod pins with spherical bearings. When the front and rear axle differential locks are working synchronously, the steering mechanism can normally drive the left and right steering knuckle assemblies to rotate, thus better ensuring rear axle steering function even when the front and rear tires slip. Attached Figure Description

[0015] Figure 1 This is a first-view schematic diagram of the overall structure of this utility model; Figure 2 This is a second-view schematic diagram of the overall structure of this utility model; Figure 3This is a cross-sectional view of part of the structure of this utility model; Figure 4 This is a cross-sectional view of part of the structure of this utility model; Figure 5 This is a third-view schematic diagram of the overall structure of this utility model; Figure 6 This is a fourth-view schematic diagram of the overall structure of this utility model; Figure 7 This is a schematic diagram showing the oil drain hole and oil level hole on the wheel side of the present invention. Figure 8 This is a schematic diagram of the joint bearing and some structural connections of this utility model.

[0016] Explanation of icon numbers: 1. Steel ball; 2. First bolt; 3. First spring washer; 4. End cap; 5. Half-shaft assembly; 6. Gear ring assembly; 7. Type II hexagonal nut; 8. Outer half-shaft inner retaining ring; 9. Planetary gear carrier assembly; 10. First O-ring seal; 11. First wheel hub assembly; 12. Left steering knuckle assembly; 13. First cylindrical pin; 14. Left steering knuckle arm; 15. First hexagonal flange bolt; 16. Dust seal; 17. First adjusting shim; 18. Axle assembly; 19. Wheel rim drain hole; 20. Steering cylinder assembly; 21. Second cylindrical pin; 22. Long breather plug; 23. Right steering knuckle arm; 24. Right steering knuckle assembly; 25. Second hexagonal flange bolt; 26. Lower support pin assembly; 27. Straight-through pressure injection cup; 28. Socket head cap screw; 29. ​​Outer half-shaft retaining ring; 30. Shaft retaining ring; 31. Plug; 32. Rear support assembly; 33. Second spring washer; 34. First hex head bolt; 36. Wheel rim oil hole; 37. Spherical plain bearing; 38. Bushing; 39. Connecting rod pin; 40. Baffle; 41. Connecting rod body; 42. Main bolt; 43. Third spring washer; 44. Second hex head bolt; 45. Main washer; 47. Rear support adjusting shim; 48. Wheel hub nut; 49. First lower support pin adjusting shim; 50. Second lower support pin adjusting shim; 51. Wheel hub bearing adjusting shim; 52. Steering knuckle adjusting shim; 53. Front support adjusting shim; 54. Second O-ring seal; 55. Socket head cap screw. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] In this application, the term "above" indicates the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is primarily used to better describe this application and its embodiments, and is not intended to limit the indicated device, element, or component to having a specific orientation, or to construct and operate in a specific orientation. Furthermore, the term "above" may also be used in certain circumstances to indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0019] Please see Figures 1-8 This utility model provides a technical solution: An electric fork four-wheel drive rear axle assembly includes an axle body assembly 18, on which an elongated vent plug 22 is installed. The two ends of the axle body assembly 18 are rotatably connected to a left steering knuckle assembly 12 and a right steering knuckle assembly 24 respectively via a lower support pin assembly 26. A first lower support pin adjusting shim 49 and a second lower support pin adjusting shim 50 are respectively provided between the lower support pin assembly 26 and the left steering knuckle assembly 12 and the right steering knuckle assembly 24. Dustproof rings 16 are fixed to the outer sides of the left steering knuckle assembly 12 and the right steering knuckle assembly 24 respectively via a first hexagonal flange bolt 15 and a second hexagonal flange bolt 25. The inner sides are rotatably connected to a first wheel hub assembly 11 via a wheel hub bearing. A wheel hub bearing adjusting shim 51 is provided between the wheel hub bearing and the first wheel hub assembly 11. A steering knuckle adjusting shim 52 is also provided between the left steering knuckle assembly 12, the right steering knuckle assembly 24 and the first wheel hub assembly 11. The half-shaft assembly 5 is installed inside the bridge body assembly 18. Its two ends pass through the outer half-shaft inner retaining ring 8 and the planetary gear carrier assembly 9 in sequence and are then connected to the wheel-side reducer for transmission. The end of the half-shaft assembly 5 is limited by the type II hexagonal nut 7. An outer half-shaft outer retaining ring 29 is provided on the outer side of the outer half-shaft inner retaining ring 8. The outer half-shaft outer retaining ring 29 is fixed to the half-shaft assembly 5 by the shaft elastic retaining ring 30. The wheel-side reducer is integrated inside the first wheel hub assembly 11, including a planetary gear carrier assembly 9, a gear ring assembly 6, and an end cover 4. The end cover 4 is fixed to the end of the first wheel hub assembly 11 by a first bolt 2 and a first spring washer 3. A first O-ring seal 10 is clamped inside. The planetary gear carrier assembly 9 is splined to the half shaft assembly 5 and has a steel ball 1 inside. The gear ring assembly 6 is fixedly connected to the inner wall of the first wheel hub assembly 11. The wheel-side reducer housing has a wheel-side oil drain hole 19 and a wheel-side oil level hole 36, both of which are equipped with screw plugs. The main reducer is located in the middle of the axle assembly 18 and is equipped with a limited anti-slip differential lock. The axle assembly 18 has an axle oil hole corresponding to the position of the main reducer and is equipped with a plug 31. The steering mechanism includes a steering cylinder assembly 20, a left steering knuckle arm 14, a right steering knuckle arm 23 and a connecting rod body 41. The left steering knuckle arm 14 is fixed to the left steering knuckle assembly 12 by a first cylindrical pin 13. The right steering knuckle arm 23 is fixed to the right steering knuckle assembly 24 by a second cylindrical pin 21. The two ends of the connecting rod body 41 are hinged to the left steering knuckle arm 14 and the right steering knuckle arm 23 respectively by connecting rod pins 39. A spherical bearing 37 is provided at the hinge. A bushing 38 is sleeved on the inner side of the spherical bearing 37. The two ends of the connecting rod pin 39 are provided with baffles 40 and fixed by hexagon countersunk screws 28. The output end of the steering cylinder assembly 20 is connected to the middle of the connecting rod body 41. The rear support assembly 32 is fixed to the axle assembly 18 by the first hexagonal head bolt 34 and the second spring washer 33, with a rear support adjustment shim 47 between them. The axle assembly 18 is also connected to the external structure by the second hexagonal head bolt 44, the main bolt 42, the third spring washer 43, and the main washer 45. The connection is provided with a front support adjustment shim 53 and a second O-ring seal 54. The second O-ring seal 54 is limited by the internal hexagonal head screw 55. The end of the first wheel hub assembly 11 is fixed by the wheel hub nut 48. The gap between the axle assembly 18 and related components is provided with a first adjustment shim 17. The lower support pin assembly 26 is equipped with a straight-through pressure injection cup 27.

[0020] In one embodiment of this utility model, when adding oil, the wheel-side oil drain hole 19 needs to be rotated to the vertically upward position, directly facing the wheel-side reducer end cover 4, and lubricating oil is injected until the oil level hole 36 on the wheel side overflows. The amount of oil added to a single wheel-side reducer is 0.5L, and the main reducer is filled with oil through the axle housing oil hole until overflows, with an oil volume of 3L. The spherical bearing 37 and the connecting rod pin 39, the left steering knuckle arm 14 and the right steering knuckle arm 23 are all interference fit, and the bushing 38 and the inner wall of the spherical bearing 37 are clearance fit to ensure smooth rotation of the connecting rod pin 39. The first O-ring seal 10 and the second O-ring seal 54 are both made of oil-resistant rubber material, which respectively achieves the sealing between the end cover 4 and the first wheel hub assembly 11, and the axle assembly 18 and the external structure to prevent lubricating oil leakage.

[0021] In one embodiment of this utility model, the wheel hub bearing adjusting shim 51, steering knuckle adjusting shim 52, first adjusting shim 17, front support adjusting shim 53, and rear support adjusting shim 47 are all thin metal shims. The assembly gap of the corresponding components is adjusted by increasing or decreasing the number of shims to ensure transmission accuracy and steering flexibility. The straight-through pressure injection cup 27 is connected to the internal oil passage of the lower support pin assembly 26. Lubricating grease is injected through the cup to lubricate the rotating connection between the lower support pin assembly 26 and the left steering knuckle assembly 12 and the right steering knuckle assembly 24, reducing wear. The elongated vent plug 22 is connected to the internal cavity of the axle assembly 18 to balance the air pressure inside the axle assembly 18 and the outside, preventing the internal pressure from being too high due to temperature changes and damaging the sealing structure, while also preventing external impurities from entering.

[0022] Working Principle: The power output from the external power source is first transmitted to the main reducer located in the middle of the axle assembly 18. The main reducer adjusts the speed and torque of the power through its internal gear structure to adapt to the wheel requirements for subsequent transmission. When the equipment is in normal driving condition, the rear reduction gearbox, which is detached from the axle structure, remains in a non-working state. Only the main reducer and the wheel-side reducer form the basic power transmission path, avoiding energy loss caused by the rear reduction gearbox idling. Only under conditions requiring enhanced power, such as heavy loads or climbing, does the rear reduction gearbox activate to participate in power amplification, achieving "on-demand power supply." The power regulated by the main reducer is transmitted to the half-shaft assembly 5, which passes through the axle assembly 18. The end of the half-shaft assembly 5 is limited by a type II hexagonal nut 7 to ensure its own positional stability during power transmission. The two ends of the half-shaft assembly 5 pass through the outer half-shaft inner retaining ring 8 and the planetary gear carrier assembly 9 in sequence, and are rigidly connected to the planetary gear carrier assembly 9 through splines. The planetary gear carrier assembly 9 rotates synchronously, and the steel ball 1 inside the planetary gear carrier assembly 9 rotates with the planetary gear carrier assembly 9. Through the meshing of the steel ball 1 and the gear ring assembly 6, the power is transmitted to the gear ring assembly 6, which is fixedly connected to the inner wall of the first wheel hub assembly 11. At this time, the power direction and speed are further optimized by the planetary gear system to adapt to the wheel driving requirements. The gear ring assembly 6 is rigidly fixed to the first wheel hub assembly 11. The rotation of the gear ring assembly 6 directly drives the first wheel hub assembly 11 to rotate, thereby driving the wheel assembled with the first wheel hub assembly 11 to rotate, completing the complete transmission process from power input to wheel drive. During this process, the inner retaining ring 8 of the outer half shaft and the outer retaining ring 29 of the outer half shaft cooperate to limit the axial displacement of the outer half shaft in the axle assembly 18. The shaft elastic retaining ring 30 is engaged in the slot of the half shaft assembly 5 to fix the position of the outer retaining ring 29 of the outer half shaft, avoiding transmission failure caused by component loosening during power transmission. After the driver issues a steering command, the steering cylinder assembly 20 receives the signal and outputs linear power. This power acts directly on the middle position of the connecting rod body 41, pushing or pulling the connecting rod body 41 to reciprocate horizontally. The connecting rod body 41, as the core connecting component of the steering transmission, has its two ends hinged to the left steering knuckle arm 14 and the right steering knuckle arm 23 respectively via connecting rod pins 39. The movement of the connecting rod body 41 synchronously drives the left steering knuckle arm 14 and the right steering knuckle arm 23 to swing around the hinge point. The left steering knuckle arm 14 is fixedly connected to the left steering knuckle assembly 12 via the first cylindrical pin 13. The swing of the left steering knuckle arm 14 is transmitted to the left steering knuckle assembly 12 via the first cylindrical pin 13, causing the left steering knuckle assembly 12 to rotate around the axis of the lower support pin assembly 26. Similarly, the right steering knuckle arm 23 is connected to the left steering knuckle assembly 23 via the second cylindrical pin 39. The pin 21 is fixed to the right steering knuckle assembly 24. The swing of the right steering knuckle arm 23 drives the right steering knuckle assembly 24 to rotate synchronously around the lower support pin assembly 26. The rotation of the left steering knuckle assembly 12 and the right steering knuckle assembly 24 directly drives the wheels assembled with them to change the direction of travel, thereby realizing the steering of the equipment. The connecting rod pin 39 and the spherical bearing 37 adopt an interference fit to ensure that the two are tightly connected without relative looseness, and to avoid play during steering. The bushing 38 sleeved on the inner side of the spherical bearing 37 has a clearance fit with the inner wall of the spherical bearing 37, which can reduce the frictional resistance when the connecting rod pin 39 rotates, making the steering action smoother. The baffles 40 at both ends of the connecting rod pin 39 are fixed by the internal hexagon countersunk screws 28 to axially limit the spherical bearing 37 and the bushing 38, prevent the components from falling off during steering, and further ensure the stability of the steering system. When the equipment travels on slippery, muddy or other complex road surfaces, and a speed difference occurs between the front and rear tires (i.e., slippage), the limited-slip differential lock configured in the main reducer detects the speed difference through internal sensors and automatically triggers the locking function. The locking mechanism of the limited-slip differential lock fixes the differential gear set in the main reducer, keeping the power output shafts of the front and rear axles at synchronous speeds. This avoids the waste of power caused by concentrated power transmission to the slipping tires. During the operation of the limited-slip differential lock, the steering system can still operate normally. The power output from the steering cylinder assembly 20 is transmitted to the left steering knuckle assembly 12 and the right steering knuckle assembly 24 through the connecting rod body 41, the left steering knuckle arm 14 and the right steering knuckle arm 23, without being affected by the limited-slip function of the main reducer. This "limited-slip does not affect steering" design ensures that the equipment can obtain balanced power through the limited-slip differential lock and flexibly adjust the driving direction through the steering system in slippery road conditions, improving the safety and reliability of the equipment in complex road conditions. At the rotating connection between the lower support pin assembly 26 and the left steering knuckle assembly 12 and the right steering knuckle assembly 24, grease is injected into the internal oil passage through the straight-through pressure injection cup 27. The grease penetrates along the oil passage to the rotating friction surface, forming an oil film on the contact surface, reducing direct friction between metal parts, lowering the wear rate, and extending the service life of the parts. Lubrication of the wheel-side reducer is carried out through the wheel-side oil filling and draining hole 19. Before filling with oil, the wheel-side oil filling and draining hole 19 needs to be rotated to the vertically upward position and directly facing the end cover 4. Lubricating oil is then injected into the hole. Oil overflows from the oil hole 36 on the wheel rim to ensure sufficient lubrication of components such as the planetary gear train and ring gear assembly 6 inside the wheel rim reducer. Oil is injected into the main reducer through the oil hole on the axle assembly 18 until overflow, ensuring sufficient lubrication of the gear set inside the main reducer. A first O-ring seal 10 is clamped at the connection between the end cover 4 and the first wheel hub assembly 11. The first O-ring seal 10 is made of oil-resistant rubber. Under the tightening action of the first bolt 2 and the first spring washer 3, the first O-ring seal 10... The end cap 4 and the first hub assembly 11 are tightly sealed by elastic deformation, blocking the leakage of lubricating oil from the wheel-side reducer. A second O-ring 54 is installed at the connection between the axle assembly 18 and the external structure. The second O-ring 54 is fixed by a hexagonal head screw 55. The elastic sealing properties of the oil-resistant rubber are also used to prevent the leakage of lubricating oil inside the axle assembly 18 and to block external dust and moisture from entering the internal structure. The elongated vent plug 22 is installed on the axle assembly 18 and communicates with the internal cavity. When the internal temperature of the axle assembly 18 rises during equipment operation, the air expands due to heat, causing the pressure to rise. Excess gas can be discharged through the elongated vent plug 22 to balance the internal and external air pressure and prevent excessive air pressure from damaging the sealing structure. When the temperature drops and the internal air pressure drops, the outside air enters the interior after being filtered by the filter structure of the elongated vent plug 22. This replenishes the air pressure and prevents dust and impurities from entering the axle assembly 18 with the air, protecting the internal transmission components from wear by impurities. The assembly clearance between the first wheel hub assembly 11 and the wheel hub bearing is adjusted by increasing or decreasing the number of wheel hub bearing adjusting shims 51—increasing the number of shims when the clearance is too large and decreasing the number of shims when the clearance is too small, ensuring that the wheel hub bearing operates without play and with moderate frictional resistance. The assembly clearance between the left steering knuckle assembly 12, the right steering knuckle assembly 24 and the first wheel hub assembly 11 is optimized by increasing or decreasing the number of steering knuckle adjusting shims 52, ensuring smooth relative rotation of the two during steering without jamming or loosening. The connection clearance between the axle assembly 18 and related components is adjusted by the first adjusting shim 17 to ensure that all components are properly assembled. The overall structure is compact and free from relative sway. The connection gap between the rear support assembly 32 and the bridge body assembly 18 is adjusted by the rear support adjusting shim 47. Combined with the fastening effect of the first hexagonal head bolt 34 and the second spring washer 33, the rear support assembly 32 is installed stably. The connection gap between the bridge body assembly 18 and the external structure is adjusted by the front support adjusting shim 53. Combined with the fastening of the second hexagonal head bolt 44, the main bolt 42, the third spring washer 43 and the main shim 45, the assembly accuracy of the bridge body assembly 18 and the external structure is ensured, avoiding vibration or noise caused by improper clearance, while ensuring the overall transmission accuracy.

[0023] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.

Claims

1. An electric fork four-wheel drive rear axle assembly, characterized in that, The axle assembly includes a bridge body assembly (18), on which a long vent plug (22) is installed. Both ends of the bridge body assembly (18) are rotatably connected to the left steering knuckle assembly (12) and the right steering knuckle assembly (24) respectively via a lower support pin assembly (26). A first lower support pin adjusting shim (49) and a second lower support pin adjusting shim (50) are respectively provided between the lower support pin assembly (26) and the left steering knuckle assembly (12) and the right steering knuckle assembly (24). The left steering knuckle assembly (12)... The outer side of the right steering knuckle assembly (24) is fixed with dust rings (16) by first hexagonal flange bolts (15) and second hexagonal flange bolts (25), and the inner side is rotatably connected to the first wheel hub assembly (11) by wheel hub bearings. A wheel hub bearing adjusting pad (51) is provided between the wheel hub bearing and the first wheel hub assembly (11). A steering knuckle adjusting pad (52) is also provided between the left steering knuckle assembly (12), the right steering knuckle assembly (24) and the first wheel hub assembly (11). The half-shaft assembly (5) passes through the inside of the bridge body assembly (18), and its two ends pass through the inner retaining ring (8) of the outer half-shaft and the planetary gear carrier assembly (9) in sequence before being connected to the wheel-side reducer. The end of the half-shaft assembly (5) is limited by a type II hexagonal nut (7). An outer retaining ring (29) of the outer half-shaft is provided on the outside of the inner retaining ring (8). The outer retaining ring (29) of the outer half-shaft is fixed to the half-shaft assembly (5) by a shaft elastic retaining ring (30). The wheel-side reducer is integrated inside the first wheel hub assembly (11), including a planetary gear carrier assembly (9), a gear ring assembly (6), and an end cover (4). The end cover (4) is fixed to the end of the first wheel hub assembly (11) by a first bolt (2) and a first spring washer (3). A first O-ring seal (10) is clamped inside. The planetary gear carrier assembly (9) is splined to the half shaft assembly (5) and has a steel ball (1) inside. The gear ring assembly (6) is fixedly connected to the inner wall of the first wheel hub assembly (11). The wheel-side reducer housing is provided with a wheel-side oil drain hole (19) and a wheel-side oil surface hole (36), both of which are equipped with screw plugs. The main reducer is located in the middle of the axle assembly (18) and is equipped with a limited anti-slip differential lock. The axle assembly (18) has an axle oil hole corresponding to the position of the main reducer and is equipped with a plug (31). The steering mechanism includes a steering cylinder assembly (20), a left steering knuckle arm (14), a right steering knuckle arm (23), and a connecting rod body (41). The left steering knuckle arm (14) is fixed to the left steering knuckle assembly (12) by a first cylindrical pin (13), and the right steering knuckle arm (23) is fixed to the left steering knuckle assembly (12) by a second cylindrical pin. (21) Fixed on the right steering knuckle assembly (24), the two ends of the connecting rod body (41) are respectively hinged to the left steering knuckle arm (14) and the right steering knuckle arm (23) through connecting rod pins (39), and a joint bearing (37) is provided at the hinge. A bushing (38) is sleeved on the inner side of the joint bearing (37). The two ends of the connecting rod pin (39) are provided with baffles (40) and fixed by internal hexagon countersunk screws (28). The output end of the steering cylinder assembly (20) is connected to the middle of the connecting rod body (41). The rear support assembly (32) is fixed to the axle assembly (18) by the first hexagonal head bolt (34) and the second spring washer (33), with a rear support adjustment shim (47) between them. The axle assembly (18) is also connected to the external structure by the second hexagonal head bolt (44), the main bolt (42), the third spring washer (43), and the main washer (45). The connection is provided with a front support adjustment shim (53) and a second O-ring seal (54). The second O-ring seal (54) is limited by an internal hexagonal head screw (55). The end of the first wheel hub assembly (11) is fixed by a wheel hub nut (48). The gap between the axle assembly (18) and related components is provided with a first adjustment shim (17). The lower support pin assembly (26) is equipped with a straight-through pressure injection cup (27).

2. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: When adding oil to the wheel-side oil drain hole (19), it needs to be rotated to the vertical upward position, facing the wheel-side reducer end cover (4), and lubricating oil is injected until the oil overflows from the wheel-side oil level hole (36). The main reducer is then filled with oil through the bridge oil hole until the overflow occurs.

3. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: The spherical bearing (37) is interference-fitted with the connecting rod pin (39), the left steering knuckle arm (14) and the right steering knuckle arm (23), and the bushing (38) is clearance-fitted with the inner wall of the spherical bearing (37).

4. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: The first O-ring (10) and the second O-ring (54) are both made of oil-resistant rubber, which respectively achieve the sealing between the end cap (4) and the first wheel hub assembly (11), and between the bridge assembly (18) and the external structure.

5. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: The wheel hub bearing adjusting shim (51), steering knuckle adjusting shim (52), first adjusting shim (17), front support adjusting shim (53), and rear support adjusting shim (47) are all thin metal shims.

6. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: The straight-through pressure injection cup (27) is connected to the internal oil passage of the lower support pin assembly (26). Lubricating grease is injected through the cup to lubricate the rotating connection between the lower support pin assembly (26) and the left steering knuckle assembly (12) and the right steering knuckle assembly (24).

7. The electric fork four-wheel drive rear axle assembly according to claim 1, characterized in that: The elongated vent plug (22) is connected to the internal cavity of the bridge assembly (18) to balance the air pressure inside the bridge assembly (18) and the outside.

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