Exhaustible long-life universal joint

Abstract

The application discloses a long-life universal joint capable of exhausting, which comprises a cross shaft, a needle bearing is arranged on the journal of the cross shaft, an oil seal is arranged on the inner side of the bearing outer ring mouth of the needle bearing, a dust cover is arranged on the bearing outer ring mouth of the needle bearing, a needle retainer is arranged between the needle and the oil seal, a gasket is arranged between the side, away from the dust cover, of the needle bearing and the inner wall of the bearing outer ring, a bearing outer ring inner groove is arranged on the side, close to the oil seal, of the bearing outer ring mouth, and a bearing outer ring outer groove is arranged on the outer side of the bearing outer ring mouth; and a dust cover outer lip is arranged on the outer end of the dust cover, and a dust cover inner lip is arranged on the inner end of the dust cover. The application effectively solves the problem of difficult exhaust of the universal joint, and forms an exhaust micro channel through the combination of the structure of the sealing element, the cooperation design of the inner circle of the bearing outer ring, the cooperation of the bearing outer ring inner groove and the setting of the cavity of the dust cover, so that the excess gas in the universal joint can be exhausted through the micro channel.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of universal joint, in particular to a long-life universal joint with exhaust function. BACKGROUND

[0002] Universal joint is an important joint component in automobile, and universal joint is combined with transmission shaft to realize power output in different directions. Common universal joint generally includes a cross shaft, a needle bearing sleeved on the neck of the cross shaft, an outer end of the needle bearing is closed, an inner end of the needle bearing is open, and a sealing ring is arranged at the opening. The cross shaft universal joint needs to transmit power during operation. During power transmission, the universal joint is subjected to complex force movement due to the influence of angular velocity, which has both radial force and axial force, and the maximum force is the static torsional force of the cross shaft. In the process of use, the neck of the cross shaft universal joint is in contact with the inner complex circle of the bearing, and the end face of the cross shaft is in contact with the bottom face of the bearing. During the movement, the load is uneven, which leads to serious wear and failure of the universal joint, and the service life is short.

[0003] The prior art patent with publication number CN110043570A discloses a long-life universal joint with exhaust function and no oil leakage. A exhaust groove is formed in the oil seal to communicate the inside of the bearing with the outside, and the gas generated in the bearing is discharged to the outside. However, the invention has a curved exhaust groove in the oil seal, which is difficult to manufacture.

[0004] The prior art with publication number CN104696380A discloses a long-life cross shaft universal joint. The cross shaft body and the shaft arm are integrated, the shaft arm includes a neck and a shoulder, the neck is connected to the cross shaft body through the shoulder, the outer side of the neck is a tapered surface, the diameter of the root of the neck is larger than the diameter of the outer end of the neck, a sealing ring is arranged on the inner side of the open end of the needle bearing, the inner side of the sealing ring is in contact with the surface of the shoulder, and a dustproof ring is arranged at the end of the open end of the needle bearing. It has good sealing performance, but does not consider the influence of the contact between the needle and the inner wall of the bearing outer ring.

[0005] The prior art with publication number CN111442033A relates to a cross shaft assembly for reducing stress concentration of universal joint. An intermediate part micro-arc groove is formed in the shaft sleeve raceway, which is integrated with the shaft sleeve raceway. The intermediate part micro-arc groove and the compression elastic pad are connected by a shaft sleeve near the root micro-arc groove. It has the characteristics of compact structure, good running stability and long service life. It solves the problem of stress concentration. Avoids the occurrence of indentation, sintering, fatigue peeling, fracture and damage of the needle, and improves the service life of the cross shaft assembly.

[0006] In general, the existing long-life universal joint structure mainly has the following defects:

[0007] 1. After the universal joint assembly, there is some air inside, which is difficult to exhaust, or after improvement, there is a curved exhaust groove in the oil seal, but the manufacturing difficulty is great;

[0008] 2. The outer mouth of the bearing outer ring is chamfered, there is a sharp edge, the rubber part of the dust cover wears out quickly during use, the sealing system fails early, and the service life of the universal joint is reduced;

[0009] 3. The inner circle of the bearing outer ring and the contact surface of the needle roller exist sharp edges, which are prone to stress concentration, resulting in early wear and looseness. SUMMARY

[0010] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a long-life universal joint with exhaust function, which can exhaust and has long service life, is easy to manufacture, and is convenient to assemble, solves the problem of difficult exhaust inside the universal joint, and improves the service life of the universal joint.

[0011] The purpose of the present application is achieved by the following technical scheme: the long-life universal joint with exhaust function comprises a cross shaft, a needle bearing is arranged on the shaft neck of the cross shaft, an oil seal is arranged on the inner side of the bearing outer ring of the needle bearing, a dust cover is arranged on the bearing outer ring of the needle bearing, a needle roller retainer is arranged between the needle roller and the oil seal, a gasket is arranged between the side of the needle bearing away from the dust cover and the inner wall of the bearing outer ring, a bearing outer ring inner groove is arranged on the side of the bearing outer ring close to the oil seal, and a bearing outer ring outer groove is arranged on the outer side of the bearing outer ring.

[0012] As a preferred technical scheme, the oil seal skeleton outer circle and the bearing outer ring inner circle face gap fit, and an exhaust passage is formed between the bearing outer ring inner groove and the dust cover cavity.

[0013] As a preferred technical scheme, the bearing outer ring inner circle face is provided with a convexity, the convexity amount a is 10′-60′, and the convexity length L is 0.2-2mm.

[0014] As a preferred technical scheme, the oil seal skeleton is provided with a protrusion, the protrusion and the bearing outer ring inner circle face are interference fit, and the number of protrusions on the oil seal skeleton is determined according to the size of the product.

[0015] As a preferred technical scheme, the inner side and the outer side of the bearing outer ring mouth are provided with round corners.

[0016] As a preferred technical solution, the needle roller bearing adopts rounded needle rollers.

[0017] As a preferred technical solution, the oil seal adopts a pre-tightened oil seal structure.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. It solves the problem of difficult air venting inside the universal joint. By combining the design of the sealing structure, the fit design of the bearing outer ring inner circle, the fit of the bearing outer ring inner groove, and the setting of the dust cover cavity, an exhaust microchannel is formed. This allows excess gas inside the universal joint to be discharged through the microchannel, while preventing foreign objects from entering the universal joint through the exhaust microchannel, thus providing a better environment for lubrication inside the universal joint.

[0020] 2. The dust cover is a weak link in the universal joint assembly and is prone to premature failure. Improving the chamfer at the outer ring of the bearing to a radius (R) can greatly reduce wear on the dust cover and extend its service life.

[0021] 3. The convexity design at the edge of the inner circle of the bearing is used to avoid the problem of stress concentration caused by the sharp edge of the inner circle of the bearing contacting the needle roller. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0024] Figure 3 This is a schematic diagram of the outer ring of the bearing.

[0025] Figure 4 for Figure 3 A magnified view of a portion of region A in the middle.

[0026] Figure 5 This is a schematic diagram of the oil seal structure.

[0027] Figure 6 This is a schematic diagram of the dust cover.

[0028] Explanation of reference numerals in the attached drawings: 1. Cross shaft; 2. Needle roller bearing; 3. Bearing outer ring; 3. Inner groove of bearing outer ring; 3-1. Outer groove of bearing outer ring; 3-2. Inner circular surface of bearing outer ring; 3-3. Convexity; 3-4. Fillet; 3-5. Oil seal; 4. Oil seal skeleton; 4-1. Outer flared part of skeleton; 4-2. Protrusion; 4-3. Needle roller retainer ring; 5. Gasket; 6. Dust cover; 7. Outer lip of dust cover; 7-1. Inner lip of dust cover; 7-2. Cavity of dust cover; 7-3. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings:

[0030] Example: As attached Figure 1 As shown, this ventable, long-life universal joint includes a cross shaft 1. A needle roller bearing 2 is mounted on the journal of the cross shaft 1. An oil seal 4 is installed on the inner side of the outer ring 3 of the needle roller bearing 2. A dust cover 7 is provided at the opening of the outer ring 3 of the needle roller bearing 2. A needle roller retainer ring 5 is located between the needle roller and the oil seal 4. A gasket 6 is provided between the side of the needle roller bearing 2 away from the dust cover 7 and the inner wall of the outer ring 3. An inner groove 3-1 is formed on the side of the opening of the outer ring 3 near the oil seal 4, and an outer groove 3-2 is formed on the outer side of the opening of the outer ring 3. The oil seal 4 is interference-fitted with the journal of the cross shaft 1. An oil seal skeleton 4-1 is provided on the side of the oil seal 4 near the outer ring 3. The opening of the oil seal skeleton 4-1 is turned outward to form an outwardly turned part 4-2, which is inserted into the inner groove 3-1 of the outer ring to position and fix the oil seal 4. (See attached diagram) Figure 6 The outer end of the dust cover 7 is provided with a dust cover outer lip 7-1, which is embedded in the outer groove 3-2 of the bearing outer ring to fix the dust cover 7. The inner end of the dust cover 7 is provided with a dust cover inner lip 7-2, which rests on the outer flange 4-2 of the frame. The two are press-fitted to form a seal. The inner wall of the dust cover 7 and the opening of the bearing outer ring 3 are clearance-fitted to form a dust cover cavity 7-3.

[0031] like Figure 2 As shown, the outer ring of the oil seal skeleton 4-1 is clearance-fitted with the inner circular surface 3-3 of the bearing outer ring, forming an exhaust microchannel between the inner groove 3-1 of the bearing outer ring and the dust cover cavity 7-3. This allows excess gas inside the universal joint to be discharged through the microchannel, while preventing external foreign objects from entering the universal joint through the exhaust microchannel, thus providing a better environment for lubrication inside the universal joint.

[0032] like Figure 4 As shown, a convexity 3-4 is provided on the inner circular surface 3-3 of the outer ring of the bearing. The convexity a is 10′~60′, and the convexity length L is 0.2~2mm. This is to avoid the problem of stress concentration caused by sharp edges in the contact between the inner circle of the bearing and the needle roller.

[0033] like Figure 5 As shown, the oil seal skeleton 4-1 has protrusions 4-3, which are interference-fitted with the inner circular surface 3-3 of the bearing outer ring. The number of protrusions is set according to the actual needs of the product. Preferably, the oil seal 4 can be used in conjunction with the pre-tightened oil seal in the prior art to achieve a better sealing effect.

[0034] like Figure 3 As shown, the inner and outer sides of the outer ring 3 of the bearing are provided with fillets of 3-5, which can reduce the wear of the dust cover and extend its service life.

[0035] Preferably, the needle bearing 2 adopts round-cornered needle, which can reduce the contact stress between the sharp corner of the inner circle of the bearing outer ring and the needle, and prolong the service life. The oil seal 4 adopts a pre-tightening type oil seal structure to achieve better sealing effect.

[0036] The application effectively solves the problem of internal exhaust of the universal joint. By combining the structure of the sealing element, the matching design of the inner circle of the bearing outer ring, the matching of the inner groove of the bearing outer ring and the setting of the cavity of the dust cover, the exhaust micro-channel is formed, which can make the excess gas in the universal joint exhaust through the micro-channel, and the foreign matters outside cannot enter the universal joint through the exhaust micro-channel, thus providing a better environment for the lubrication of the universal joint. In use, the dust cover is the weak link in the universal joint assembly and is prone to early failure. The chamfering of the bearing outer ring port to R round corner can greatly improve the matching wear of the dust cover and prolong the service life. The convexity design at the edge of the inner circle of the bearing can avoid the stress concentration problem caused by the sharp edge between the inner circle of the bearing and the needle.

[0037] It can be understood that equivalent replacement or change of the technical solutions and inventive concepts of the application by those skilled in the art shall belong to the protection scope of the claims attached to the application.

Claims

1. A long-life greaseless universal joint comprising a cross shaft (1), a needle bearing (2) is arranged on the journal of the cross shaft (1), an oil seal (4) is arranged on the inner side of the mouth of the bearing outer ring (3) of the needle bearing (2), a dust cover (7) is arranged on the mouth of the bearing outer ring (3) of the needle bearing (2), a needle retainer (5) is arranged between the needle and the oil seal (4), and a gasket (6) is arranged between the inner wall of the bearing outer ring (3) and the side of the needle bearing (2) away from the dust cover (7), characterized in that: The mouth of the bearing outer ring (3) is provided with a bearing outer ring inner groove (3-1) near the side of the oil seal (4), and the outer side of the mouth of the bearing outer ring (3) is provided with a bearing outer ring outer groove (3-2); the oil seal (4) is in interference fit with the journal of the cross shaft (1), the oil seal (4) is provided with an oil seal framework (4-1) near the side of the bearing outer ring (3), the outer side of the mouth of the oil seal framework (4-1) is outwardly turned to form a framework outward turning part (4-2), the framework outward turning part (4-2) is clamped into the bearing outer ring inner groove (3-1) to position and fix the oil seal (4); the outer end part of the dust cover (7) is provided with a dust cover outer lip (7-1), the dust cover outer lip (7-1) is embedded into the bearing outer ring outer groove (3-2) to fix the dust cover (7), the inner end part of the dust cover (7) is provided with a dust cover inner lip (7-2), the dust cover inner lip (7-2) is in interference fit with the framework outward turning part (4-2) to form a seal, and the inner wall of the dust cover (7) is provided with a dust cover cavity (7-3) at the position where the inner wall contacts the mouth of the bearing outer ring (3). The outer circle of the oil seal framework (4-1) is in clearance fit with the inner circular surface (3-3) of the bearing outer ring, and an exhaust passage is formed between the bearing outer ring inner groove (3-1) and the dust cover cavity (7-3). The oil seal framework (4-1) is provided with a protrusion (4-3), the protrusion (4-3) is in interference fit with the inner circular surface (3-3) of the bearing outer ring, and the number of the protrusions on the oil seal framework is determined according to the size of the product.

2. The ventable long-life universal joint of claim 1, wherein: The inner circular surface (3-3) of the bearing outer ring is provided with a convexity (3-4), the amount a of the convexity is 10′~60′, and the length L of the convexity is 0.2~2mm.

3. The ventable long-life universal joint of claim 1, wherein: The inner side and the outer side of the mouth of the bearing outer ring (3) are both provided with a round corner (3-5).

4. The ventable long-life universal joint of claim 1, wherein: The oil seal (4) adopts a pre-tightening type oil seal structure.

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