Double-oil-seal wet-type drive axle

Abstract

The invention discloses a double-oil-seal wet-type drive axle, and belongs to the field of drive axles. The device comprises a hub and a double-lip sealing ring, a wet brake and the hub are sealed and isolated through the double-lip sealing ring to form a lubricating oil cavity, the other end of the double-lip sealing ring and an axle housing are sealed and isolated to form a wet brake sealing cavity, and a box type oil seal and a rotating shaft lip type sealing ring are arranged at a brake gear ring. A lubricating oil cavity is formed by sealing and isolating a double-lip sealing ring and a hub, a wet brake sealing cavity is formed by sealing and isolating the other end of the double-lip sealing ring and an axle housing, and a sealing mode of combining a high-temperature-resistant fluororubber rotating shaft lip-type sealing ring and a box-type oil seal is utilized; the box type oil seal is installed on the outer side of the rotating shaft lip type sealing ring to enhance the sealing performance, the wet type brake is independently sealed, a forklift is provided with an independent oil way to supply oil to the wet type brake, the heat dissipation performance is better, the cleanliness of oil in a wet type brake cavity is guaranteed, and the service life of the wet type brake is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of drive axle, in particular to a double oil seal wet drive axle. BACKGROUND

[0002] The forklift drive axle is one of the core components of the forklift power transmission system, which transmits power from the gearbox or motor to the drive wheel, and undertakes the key functions of supporting the vehicle body, reducing speed and increasing torque, realizing differential and braking.

[0003] The oil seal structure of the existing forklift drive axle is similar in basic principle to that of ordinary vehicle drive axle, but due to its harsh working conditions (frequent start-stop, high load, dusty / humid environment, possible contact with corrosive liquid) and compact structure design, its sealing scheme has distinctive features, with more emphasis on robustness, anti-pollution and ease of maintenance. The existing forklift drive axle wheel end seal generally adopts a structure of single lip seal ring combined with external metal dust cover. This structure prevents the leakage of gear oil inside the axle housing through a main sealing lip, and blocks external dust and water splashes through a separate dust cover. In a certain period of time, it meets the basic sealing requirements, and it constitutes the first physical barrier, effectively blocking large particles and direct flushing.

[0004] In summary, in the prior art, when the forklift frequently wades, washes or is in a high humidity environment, the external dust cover can only provide physical shielding, and there is a problem that an effective secondary sealing barrier cannot be formed, condensed water vapor and high-pressure water mist can still penetrate the gap between the dust cover and the main sealing lip, invade the working surface of the main sealing lip, and the dry-wet alternating environment can accelerate the aging of the rubber material and wash away the lubricating oil film at the lip, causing dry friction, early wear and sealing failure of the sealing lip. SUMMARY

[0005] The present application provides a double oil seal wet drive axle, which can solve the problem that in the prior art, an effective secondary sealing barrier cannot be formed, condensed water vapor and high-pressure water mist can still penetrate the gap between the dust cover and the main sealing lip, invade the working surface of the main sealing lip, and the dry-wet alternating environment can accelerate the aging of the rubber material and wash away the lubricating oil film at the lip, causing dry friction, early wear and sealing failure of the sealing lip.

[0006] A double oil seal wet drive axle, comprising a drive axle body for bearing and transmitting the vertical load acting on the drive wheel when the forklift is fully loaded, and a double oil seal assembly for double oil seal is symmetrically arranged at both ends of the drive axle body; The drive axle body comprises an axle housing, and a half shaft sleeve is arranged in the middle of the axle housing; The double oil seal assembly comprises a hub and a double-lip seal ring, the wet brake is sealed from the hub by the double-lip seal ring to form a lubricating oil cavity, the other end of the double-lip seal ring is sealed from the axle housing to form a wet brake sealing cavity, the wet brake sealing cavity is provided with a brake gear ring on the peripheral side, the brake gear ring is provided with a box oil seal and a rotating shaft lip seal ring, and the box oil seal is installed on the outside of the rotating shaft lip seal ring to strengthen the sealing performance.

[0007] Preferably, the rotating shaft lip seal ring is made of fluororubber material, which is resistant to high temperature and can withstand a pressure difference of not less than 0.5 MPa between the wet brake sealing cavity and the lubricating oil cavity.

[0008] Preferably, the box oil seal and the rotating shaft lip seal ring are sealed on the outside of the brake gear ring, a double-lip seal ring is arranged between the inside of the brake gear ring and the axle sleeve, and the lower lip is deformed to a preset compression position under stress during installation.

[0009] Preferably, the wet brake sealing cavity is provided with a brake hydraulic oil inlet at one end, an air vent plug is arranged above the brake hydraulic oil inlet, and an oil delivery pipe for hydraulic oil is arranged below the brake hydraulic oil inlet.

[0010] Preferably, a brake piston is arranged at the connection between the brake hydraulic oil inlet and the wet brake sealing cavity, the brake piston is provided with three, and a star-shaped seal ring for maintaining oil pressure sealing and a retainer ring close to the star-shaped seal ring are arranged between the brake piston and the shell of the wet brake sealing cavity.

[0011] Preferably, the side surface of the brake piston is provided with a clutch piece, the one side of the clutch piece is alternately provided with a dynamic friction piece and a static friction piece, and the brake gear ring is fixedly connected with the axle sleeve.

[0012] Preferably, the wet brake sealing cavity is connected with an external hydraulic pump and a cooling system through the brake hydraulic oil inlet to form an independent circulating oil circuit.

[0013] Preferably, the two sides of the dynamic friction piece are provided with porous fiber surfaces.

[0014] Preferably, the brake oil in the cavity of the wet brake sealing cavity is hydraulic oil or gear oil, and the lubricating oil in the cavity of the lubricating oil cavity is 85W / 90 lubricating oil.

[0015] Preferably, a second O-ring for sealing is arranged between the axle housing and the wet brake sealing cavity, and a first O-ring for sealing is arranged between the brake gear ring and the lubricating oil cavity.

[0016] Beneficial effects: 1. The application forms a lubricating oil cavity by sealing isolation of the double-lip sealing ring and the wheel hub, and forms a wet brake sealing cavity by sealing isolation of the other end of the double-lip sealing ring and the axle housing, uses the high-temperature-resistant fluorine rubber material rotating shaft lip seal ring and the box oil seal in combination to strengthen the sealing performance of the box oil seal installed outside the rotating shaft lip seal ring, seals the wet brake separately, and the forklift has a separate oil path to supply oil for the wet brake, so that the heat dissipation performance is better, the cleanliness of the oil in the wet brake cavity is ensured, and the service life of the wet brake is increased.

[0017] 2. The application has two lips provided by the double-lip sealing ring, and the wet brake sealing cavity and the lubricating oil cavity at both ends of the double-lip sealing ring store two different oil liquids, and the two oil liquids have a pressure difference, the inside of the lip is designed as a semicircular reinforced structure, the structure increases the strength and stability of the inside of the double lip when the double lip is compressed to the preset position during assembly, increases the contact area between the double lip and the axle body, can withstand greater external oil pressure, can well support the external oil pressure, and isolates the two oil conditions. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A schematic diagram of the overall structure of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 2 A partial sectional view of the top structure of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 3 A partial sectional view of the front structure of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 4 An enlarged view of the structure at B of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 5 A schematic diagram of the oil seal structure of a double-lip sealing ring of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 6 An enlarged view of the structure at A of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 7 An enlarged view of the structure at C of a double-oil-liquid sealed wet drive axle is provided for the application. Figure 8 A side view of the main structure of a double-oil-liquid sealed wet drive axle is provided for the application.

[0019] MARKING OF THE DRAWINGS: 1. Drive axle body; 2. Dual oil sealing assembly; 3. Wet brake sealing chamber; 4. Lubricating oil chamber; 11. Axle housing; 12. Half-shaft sleeve; 21. Brake hydraulic oil inlet; 22. Breather plug; 23. Brake piston; 24. Star-shaped seal ring; 240. Retaining ring; 25. Clutch disc; 26. Brake gear ring; 27. First O-ring; 29. ​​Wheel hub; 210. Dynamic friction plate; 211. Static friction plate; 212. Second O-ring; 213. Oil supply pipe; 214. Box-type oil seal; 215. Rotary shaft lip seal ring; 217. Double lip seal ring. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0021] like Figures 1 to 7 As shown, an embodiment of the present invention provides a dual-oil-sealed wet drive axle, including a drive axle body 1 for bearing and transmitting the vertical load acting on the drive wheels when the forklift is fully loaded, and dual-oil-sealing assemblies 2 for dual-oil sealing are symmetrically arranged at both ends of the drive axle body 1. The drive axle body 1 includes an axle housing 11, and a half-shaft sleeve 12 is provided in the middle of the axle housing 11. The dual-oil sealing assembly 2 includes a wheel hub 29 and a double-lip seal ring 217. The wet brake is sealed and isolated from the wheel hub 29 by the double-lip seal ring 217, forming a lubricating oil cavity 4. The other end of the double-lip seal ring 217 is sealed and isolated from the axle housing 11, forming a wet brake sealing cavity 3. A brake toothed ring 26 is provided on the peripheral side of the wet brake sealing cavity 3. A box-type oil seal 214 and a rotating shaft lip seal 215 are provided at the brake toothed ring 26. The box-type oil seal 214 is installed outside the rotating shaft lip seal 215 to enhance the sealing performance. It is simple to install, reduces costs compared to using a floating oil seal, and provides good sealing performance at a lower cost. Mass production at a lower cost allows for the separate sealing of wet brakes. Forklifts have a separate oil circuit supplying oil to the wet brakes, resulting in better heat dissipation, ensuring the cleanliness of the oil in the wet brake chamber, and increasing the service life of the wet brakes. The brake tooth ring 26 and the wet brake are doubly sealed by a rotating shaft lip seal 215 and a box-type oil seal 214, which solves the problems of wet brakes in terms of sealing, stability, heat dissipation, and anti-contamination ability. The rotating shaft lip seal 215 and the box-type oil seal 214 are simple to assemble and moderately cost-effective while ensuring high sealing performance.

[0022] The rotating shaft lip seal ring 215 is made of fluororubber material, which is resistant to high temperature and can withstand a pressure difference of not less than 0.5 MPa between the wet brake sealing cavity 3 and the lubricating oil cavity 4. The box oil seal 214 and the rotating shaft lip seal ring 215 are sealed on the outside of the brake gear ring 26. The double-lip seal ring 217 is arranged between the inside of the brake gear ring 26 and the half shaft sleeve 12. The double-lip seal ring 217 is provided with two lips. During installation, the lower lip is deformed under stress to a preset compression position. Since the double-lip seal ring 217 is in contact with two different oils, and there is a pressure difference between the two oils, the inside of the double-lip seal ring 217 is designed as a semicircular structure to increase the strength and stability of the double-lip seal ring 217 and increase the contact area between the double-lip seal ring 217 and the axle housing 11, so that it can withstand greater external oil pressure and can well support the external oil pressure.

[0023] The wet brake sealing cavity 3 is provided with a brake hydraulic oil inlet 21 at one end. An air vent plug 22 is arranged above the brake hydraulic oil inlet 21. An oil delivery pipe 213 for hydraulic oil is arranged below the brake hydraulic oil inlet 21. The brake hydraulic oil inlet 21 is connected to the wet brake sealing cavity 3 at one end and is provided with a brake piston 23. The brake piston 23 is provided with three brake pistons 23. The brake piston 23 is provided with a star-shaped seal ring 24 and a retaining ring 240 arranged close to the star-shaped seal ring 24 for maintaining oil pressure sealing between the brake piston 23 and the housing of the wet brake sealing cavity 3. The side surface of the brake piston 23 is provided with a clutch plate 25. The clutch plate 25 is alternately provided with a dynamic friction plate 210 and a static friction plate 211 on one side. The brake gear ring 26 is fixedly connected to the half shaft sleeve 12. The arrangement of multiple dynamic friction plates 210 and static friction plates 211 can easily increase the friction area, so as to generate a large braking torque and obvious braking effect. The pressure borne by each dynamic friction plate 210 and static friction plate 211 is reduced, and the unit specific pressure of the friction plate is small. The number of friction pairs can be adjusted to adjust the braking torque.

[0024] The wet brake sealing cavity 3 is connected with the external hydraulic pump and the cooling system through the brake hydraulic oil inlet 21 to form an independent circulating oil path, the both sides of the dynamic friction plate 210 are provided with porous fiber surfaces, the oil in the wet brake and the hub 29 is different, the brake oil in the cavity of the wet brake sealing cavity 3 is hydraulic oil or gear oil, the cavity of the lubricating oil cavity 4 and the inside of the axle housing 11 are provided with 85W / 90 lubricating oil, the second O-ring 212 for sealing is arranged between the axle housing 11 and the wet brake sealing cavity 3, the first O-ring 27 for sealing is arranged between the brake gear ring 26 and the lubricating oil cavity 4, since the dynamic friction plate 210 and the static friction plate 211 work in the sealed oil bath, the porous fiber surfaces on the both sides of the dynamic friction plate 210 can ensure that an oil film separates the dynamic friction plate 210 and the static friction plate 211 to minimize the friction, since it is immersed in the oil bath, the heat dissipation is strong, the heat transfer coefficient is increased by 2-4 times, the thermal stability is good, the brake failure is effectively prevented, and the service life is long, since the separate oil path for oil supply is arranged in the wet drive, the cleanliness of the whole brake is ensured, the maintenance cost is greatly reduced, the anti-pollution ability is strong, meanwhile, the separate oil return path can ensure that the oil amount in the brake is sufficient, the dynamic friction plate 210 and the static friction plate 211 can be fully immersed in the oil, the brake can be fully cooled, compared with the traditional wet drive axle, the cooling performance is good, the brake performance is long-term stable and reliable, and the use environment is not limited.

[0025] Working principle: first by the operator to step on the brake, forklift hydraulic pump system work, push hydraulic oil from the oil pipe 213 into the wet brake, hydraulic oil through the brake hydraulic oil inlet 21 to push three brake pistons 23, the sealing of hydraulic oil by star seal ring 24 and the blocking ring 240 to seal, to ensure the sealing performance and oil pressure of continuous and stable, three brake pistons 23 generated pressure on the clutch plate 25, again by the clutch plate 25 on the 7 static friction plate 211 and 6 dynamic friction plate 210, make static friction plate 211 and dynamic friction plate 210 extrusion generate friction, prevent dynamic friction plate 210 rotation, because the dynamic friction plate 210 is connected to the brake ring 26, brake ring 26 is connected to the wheel hub 29, after the dynamic friction plate 210 stop rotating, drive wheel hub 29 stop rotating, thus realizing the effect of forklift brake, because the double lip seal ring 217 and wheel hub 29 sealed isolation formed lubricating oil cavity 4, and the double lip seal ring 217 the other end and axle housing 11 sealed isolation formed wet brake sealing cavity 3, using high temperature resistant fluorine rubber material rotary shaft lip seal ring 215 and box type oil seal 214 combined sealing method, box type oil seal 214 is installed outside rotary shaft lip seal ring 215 to strengthen the sealing performance, the wet brake is sealed up, because the wet brake sealing cavity 3 and lubricating oil cavity 4 inside there are two different oil, and the two kinds of oil pressure difference, double lip seal ring 217 will be designed as semicircular lip inside to strengthen the structure, this structure in assembly double lip compression to the preset position increases the strength and stability of the double lip inside, increase the contact area between the double lip and axle body, so that it can withstand greater external oil pressure, can well support the external oil pressure, isolation of two kinds of oil; Forklift hydraulic pump system stop working, because there is no oil pressure, spring rebound brake driven clutch plate 25 reset, clutch plate 25 will push three brake pistons 23 back to the original position, brake liquid back to the hydraulic pump system, the brake dynamic friction plate 210 and static friction plate 211 separate, release the brake.

[0026] The above disclosed is only a few specific embodiments of the present application, but the embodiment of the present application is not limited to this, any person skilled in the art can think of the change should fall within the scope of the present application.

Claims

1. A dual-oil-sealed wet drive axle, comprising a drive axle body (1) for bearing and transmitting the vertical load acting on the drive wheels when a forklift is fully loaded, characterized in that, The two ends of the drive axle body (1) are symmetrically provided with dual oil sealing components (2) for dual oil sealing. The drive axle body (1) includes an axle housing (11), and a half-shaft sleeve (12) is provided in the middle of the axle housing (11). The dual oil sealing assembly (2) includes a hub (29) and a double-lip seal ring (217). The wet brake is sealed and isolated from the hub (29) by the double-lip seal ring (217) to form a lubricating oil cavity (4). The other end of the double-lip seal ring (217) is sealed and isolated from the axle housing (11) to form a wet brake sealing cavity (3). A brake toothed ring (26) is provided on the peripheral side of the wet brake sealing cavity (3). A box-type oil seal (214) and a rotating shaft lip seal ring (215) are provided at the brake toothed ring (26). The box-type oil seal (214) is installed on the outside of the rotating shaft lip seal ring (215) to enhance the sealing performance.

2. The dual-oil-sealed wet drive axle as described in claim 1, characterized in that, The rotary shaft lip seal (215) is made of fluororubber material, which is resistant to high temperature and can withstand a pressure difference of not less than 0.5 MPa between the wet brake sealing cavity (3) and the lubricating oil cavity (4).

3. The dual-oil-sealed wet drive axle as described in claim 2, characterized in that, The box-type oil seal (214) and the rotating shaft lip seal (215) are sealed on the outside of the brake tooth ring (26). A double lip seal (217) is provided between the inner side of the brake tooth ring (26) and the half shaft sleeve (12). The double lip seal (217) has two lips. During installation, the lower lip is deformed to a preset compression position.

4. The dual-oil-sealed wet drive axle as described in claim 1, characterized in that, One end of the wet brake sealing cavity (3) is provided with a brake hydraulic oil inlet (21), a vent plug (22) is provided above the brake hydraulic oil inlet (21), and an oil supply pipe (213) for hydraulic oil to pass through is provided below the brake hydraulic oil inlet (21).

5. The dual-oil-sealed wet drive axle as described in claim 4, characterized in that, A brake piston (23) is provided at the connection between one end of the brake hydraulic oil inlet (21) and the wet brake sealing cavity (3). There are three brake pistons (23). A star-shaped sealing ring (24) for maintaining oil pressure sealing and a retaining ring (240) that is in close contact with the star-shaped sealing ring (24) are provided between the brake piston (23) and the housing of the wet brake sealing cavity (3).

6. The dual-oil-sealed wet drive axle as described in claim 5, characterized in that, The brake piston (23) has a clutch plate (25) on its side. The clutch plate (25) has a dynamic friction plate (210) and a static friction plate (211) alternately arranged on one side. The brake gear ring (26) is fixedly connected to the half shaft sleeve (12).

7. The dual-oil-sealed wet drive axle as described in claim 5, characterized in that, The wet brake sealing cavity (3) is connected to the external hydraulic pump and cooling system through the brake hydraulic oil inlet (21) to form an independent circulating oil circuit.

8. The dual-oil-sealed wet drive axle as described in claim 6, characterized in that, The dynamic friction plate (210) has porous fiber surfaces on both sides.

9. The dual-oil-sealed wet drive axle as described in claim 1, characterized in that, The brake fluid inside the wet brake sealing cavity (3) is hydraulic oil or gear oil, and the lubricating oil cavity (4) is 85W / 90 lubricating oil.

10. A dual-oil-sealed wet drive axle as described in claim 6, characterized in that, A second O-ring (212) for sealing is provided between the axle housing (11) and the wet brake sealing cavity (3), and a first O-ring (27) for sealing is provided between the brake tooth ring (26) and the lubricating oil cavity (4).

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