Bearing sleeve and cross universal joint

Abstract

The invention discloses a bearing sleeve and a cross universal joint, and relates to the technical field of couplings. The bearing sleeve comprises a bearing outer ring, a bearing inner ring, an end cover and a pin roller which form an independent modular unit. The rolling type plane bearing is integrated on the inner side of the bearing end cover, the rolling body is matched with the buffering cushion, traditional axial sliding friction is converted into rolling friction, axial impact is absorbed, and the problems that the universal joint is seriously abraded in the axial direction and shakes due to abnormal sound are effectively solved. Meanwhile, the sealing structure adopts the main sealing ring and the auxiliary sealing ring which are both matched with the outer cylindrical surface of the bearing inner ring for sealing, so that the sealing stability and the lubricating effect are improved. In addition, the fork head of the cross universal joint and the shaft head of the cross shaft are both provided with an oil injection hole and an oil groove, a lubricating oil film is formed on a matching surface by injecting oil, and lossless disassembly of the bearing sleeve and the bearing inner ring is assisted. The manufacturing difficulty of the cross shaft body is reduced, the service life is prolonged, and maintenance and replacement are convenient and fast.

Description

Technical Field

[0001] This invention relates to the field of coupling technology, and in particular to a bearing sleeve and a universal joint. Background Technology

[0002] With the development of technology in the field of mechanical transmission, universal joint technology has emerged. This technology features high load-bearing capacity, long service life, high transmission efficiency, and smooth transmission, and is widely used in metallurgy, mining, engineering transportation, and other fields. As a core component for realizing variable-angle power transmission, the universal joint is used to connect two shafts that are not on the same axis or have a large angle between their axes, enabling them to rotate continuously at a constant angular velocity. It is currently the most critical device in mechanical transmission systems.

[0003] In traditional technology, universal joint bearings typically employ a close-packed roller structure without an inner ring. In this structure, the rollers directly contact the end surface of the universal joint for rolling contact. To meet contact strength requirements, the universal joint body must be made of low-carbon alloy steel and undergo carburizing and quenching treatment. Axial positioning is usually achieved using copper alloy washers, relying on sliding friction to withstand axial forces. For sealing, a double-lip seal is generally used, with the seal positioned on the arcuate surface of the universal joint end.

[0004] However, the current traditional universal joint device has many problems. First, because the rollers directly contact the cross shaft, the manufacturing cost of the cross shaft is high and the cycle is long. Furthermore, once surface indentations or peeling occur, the number of repairs is extremely limited, resulting in high maintenance costs. Second, the sliding friction method using copper alloy gaskets in the axial direction is prone to wear, leading to increased axial clearance and consequently causing abnormal noise and vibration during operation. Third, the sealing lip is located on the arc surface of the shaft end; manufacturing errors make it difficult to control the sealing pressure, resulting in unstable sealing performance and potential lubrication failure. Finally, the traditional interference fit structure is difficult to disassemble, often requiring forceful pulling, which can easily damage the mating surfaces. Summary of the Invention

[0005] Therefore, it is necessary to provide a bearing sleeve and a cross universal joint to address the above problems.

[0006] This application provides a bearing sleeve, which is sleeved on a cross shaft and nested in the bearing hole of the fork head. It includes an outer bearing ring, an inner bearing ring, a bearing end cap, and rollers. The inner bearing ring is sleeved on the shaft head of the cross shaft. The outer bearing ring and the bearing end cap are connected and together with the inner bearing ring form a cavity suitable for accommodating the rollers, so as to rotatably connect with the inner bearing ring through the rollers. The bearing sleeve also includes a planar bearing disposed inside the bearing end cover. The planar bearing includes a cage and rolling elements. The rolling elements are disposed in the holes of the cage and are rotatably connected to the cage to reduce the friction between the bearing sleeve and the cross shaft.

[0007] Optionally, the bearing end cover has a mounting groove on the end face facing the outer ring of the bearing for mounting a planar bearing, and a keyway on the end face away from the outer ring of the bearing for mounting an anti-rotation key.

[0008] Optionally, the plane containing the planar bearing is parallel to the plane containing the end cap.

[0009] Optionally, the planar bearing further includes wear-resistant pads disposed on both sides of the cage for the rolling elements to roll. The planar bearing also includes a buffer pad, which is disposed on the side of the wear-resistant pad away from the rolling element to reduce the axial impact on the planar bearing.

[0010] Optionally, the bearing may also include a seal, which includes a main sealing ring. The outer ring of the bearing has a sealing groove at its end. The main sealing ring is installed in the sealing groove and abuts against the inner ring of the bearing for oil storage and lubrication.

[0011] Optionally, the sealing element further includes a sealing gland and a secondary sealing ring. The sealing gland is fixed to the end face of the outer ring of the bearing. The sealing gland has an inner ring groove. The secondary sealing ring is installed in the inner ring groove and abuts against the inner ring of the bearing for waterproofing and dustproofing.

[0012] Optionally, the mounting surfaces of both the sealing groove and the inner ring groove are cylindrical surfaces.

[0013] Optionally, it also includes a gland and a retaining ring, wherein the bearing end cover is disposed between the bearing outer ring and the retaining ring, and is connected to the bearing outer ring via the gland.

[0014] This application also provides a universal joint, including a fork head, a cross shaft, and the aforementioned bearing sleeve. The fork heads are arranged in pairs, and the pair of fork heads are rotatably connected to the cross shaft through the bearing sleeve. A first oil groove is provided in the bearing hole, and a first oil injection hole is provided on the fork head. The first oil injection hole is connected to the first oil groove and is used to inject oil into the first oil groove to form an oil film on the inner wall of the bearing hole, so as to facilitate the disassembly of the bearing sleeve assembly.

[0015] Optionally, the cross shaft has a second oil groove on its outer edge and a second oil injection hole on its outer edge. The second oil injection hole is connected to the second oil groove and is used to inject oil into the second oil groove to form an oil film on the outer edge sidewall of the cross shaft, so as to facilitate the disassembly of the bearing inner ring.

[0016] Optionally, the bearing end cover is provided with an anti-rotation key, and the outer side of the bearing hole of the fork head is provided with an anti-rotation keyway, which is used to cooperate with the bearing end cover to limit the rotation of the bearing end cover in the bearing sleeve.

[0017] Optionally, the bearing end cap, the bearing inner ring, and the shaft head of the cross shaft together form a cavity for containing oil, and the bearing end cap is provided with an oil filling hole for injecting oil into the cavity.

[0018] Compared with the prior art, the technical solution provided in this application has the following advantages: The aforementioned bearing sleeve, as an independent functional module, is fitted onto the cross shaft and is integrally nested within the bearing bore of the fork head. Structurally, the bearing sleeve includes an outer bearing ring, an inner bearing ring, a bearing end cap, and rollers. The inner bearing ring is tightly fitted onto the shaft head of the cross shaft, while the outer bearing ring is connected to the bearing end cap. Together with the inner bearing ring, they form a closed annular cavity. The rollers are housed within this cavity, enabling rotational connection between the outer and inner bearing rings. Specifically, a planar bearing is integrated inside the bearing end cap. This planar bearing primarily consists of a cage and rolling elements installed within the cage bore. The technical advantages of this embodiment are: First, by introducing an independent inner bearing ring, the rollers no longer directly contact the cross shaft head, thus protecting the cross shaft body from wear and reducing the material and processing requirements of the cross shaft. Second, the planar bearing located inside the end cap utilizes the rolling friction of rolling elements (such as needle rollers or balls) instead of the sliding friction of copper washers in traditional technology to bear axial force. This improvement significantly reduces the frictional resistance between the bearing sleeve and the cross shaft assembly when transmitting axial loads, avoiding excessive wear and heat generation caused by sliding friction, thereby solving the problem of abnormal noise caused by increased bearing clearance and improving the flexibility and lifespan of the universal joint. Attached Figure Description

[0019] Figure 1 A three-dimensional structural schematic diagram of a bearing sleeve assembly provided in an embodiment of this application (first view, showing the roller side); Figure 2 A three-dimensional structural schematic diagram of a bearing sleeve assembly provided in an embodiment of this application (second view, showing the end cap side); Figure 3 This is a schematic diagram of the planar structure of a planar bearing provided in an embodiment of this application; Figure 4 A three-dimensional structural schematic diagram of a planar bearing provided in an embodiment of this application; Figure 5 A three-dimensional structural schematic diagram of a bearing end cap provided in an embodiment of this application; Figure 6 A cross-sectional structural schematic diagram of a bearing sleeve assembly provided in an embodiment of this application; Figure 7 An exploded three-dimensional structural diagram of a universal joint provided in an embodiment of this application; Figure 8 A three-dimensional structural diagram of a fork head provided in an embodiment of this application; Figure 9 A three-dimensional structural schematic diagram of a cross shaft assembly provided in an embodiment of this application; Figure 10 This is a cross-sectional structural diagram of a cross shaft assembly provided in an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 1. Bearing outer ring; 2. Bearing inner ring; 3. Bearing end cap; 31. Mounting groove; 32. Keyway; 33. Anti-rotation key; 34. Oil filling hole; 4. Roller; 5. Surface bearing; 51. Cage; 52. Rolling element; 53. Wear-resistant pad; 54. Buffer pad; 6. Seal; 61. Main seal ring; 62. Seal groove; 63. Seal gland; 64. Secondary seal ring; 7. Gland; 8. Retaining ring; 9. Fork head; 91. First oil groove; 92. First oil filling hole; 93. Anti-rotation keyway; 10. Cross shaft; 1001. Second oil groove; 1002. Second oil filling hole. Detailed Implementation

[0021] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] See Figure 1 , Figure 2 and Figure 6An embodiment of the present invention provides a bearing sleeve, which is fitted onto a cross shaft 10 and nested within the bearing hole of a fork head 9. The bearing sleeve includes an outer bearing ring 1, an inner bearing ring 2, a bearing end cap 3, and rollers 4. The inner bearing ring 2 is fitted onto the shaft head of the cross shaft 10. The outer bearing ring 1 and the bearing end cap 3 are connected and together with the inner bearing ring 2 form a cavity suitable for accommodating the rollers 4, so that the rollers 4 are rotatably connected to the inner bearing ring 2. The bearing sleeve also includes a planar bearing 5 disposed inside the bearing end cap 3. The planar bearing 5 includes a cage 51 and rolling elements 52. The rolling elements 52 are disposed within the hole of the cage 51 and rotatably connected to the cage 51 to reduce friction between the bearing sleeve and the cross shaft 10.

[0023] See Figure 6 and Figure 7 The bearing sleeve provided in this embodiment is fitted onto the cross shaft 10 as an independent functional module and is integrally nested within the bearing hole of the fork head 9. Structurally, the bearing sleeve includes an outer bearing ring 1, an inner bearing ring 2, a bearing end cap 3, and rollers 4. The inner bearing ring 2 is tightly fitted onto the shaft head of the cross shaft 10. The outer bearing ring 1 is connected to the bearing end cap 3, and together with the inner bearing ring 2, they form a closed annular cavity. The rollers 4 are housed within this cavity, enabling rotational connection between the outer and inner bearing rings. Specifically, a planar bearing 5 is integrated inside the bearing end cap 3. This planar bearing 5 mainly consists of a cage 51 and rolling elements 52 installed within the holes of the cage 51. The technical advantages of this embodiment are: firstly, by introducing an independent inner bearing ring 2, the rollers 4 no longer directly contact the shaft head of the cross shaft 10, thereby protecting the cross shaft 10 body from wear and reducing the material and processing requirements of the cross shaft 10. Secondly, the planar bearing 5 located inside the end cover utilizes the rolling friction of rolling elements 52 (such as needle rollers or balls) instead of the sliding friction of copper washers in traditional technology to bear axial force. This improvement significantly reduces the frictional resistance between the bearing sleeve and the cross shaft 10 assembly when transmitting axial loads, avoids excessive wear and heat generation caused by sliding friction, thereby solving the problem of abnormal noise caused by increased bearing clearance and improving the flexibility and lifespan of the universal joint.

[0024] See Figure 5 and Figure 6In one embodiment, the bearing end cover 3 has a mounting groove 31 on the side facing the outer ring 1 of the bearing for mounting the planar bearing 5, and a keyway 32 on the side away from the outer ring 1 of the bearing end cover 3 for mounting the anti-rotation key 33. This embodiment is a further optimization of the structure of the bearing end cover 3. A dedicated mounting groove 31 is provided on the side of the bearing end cover 3 facing the inner side of the outer ring 1 of the bearing for precisely placing and positioning the planar bearing 5; while a keyway 32 is provided on the outer side of the bearing end cover 3 away from the outer ring 1 of the bearing for mounting the anti-rotation key 33. The inner mounting groove 31 provides a stable mounting base for the planar bearing 5, preventing radial displacement during operation and ensuring the stability of the rolling element 52's trajectory. The outer keyway 32, in conjunction with the anti-rotation key 33, can form a rigid connection with the corresponding keyway 32 on the outer fork 9, thereby effectively limiting the rotation of the bearing end cover 3 relative to the fork 9. This mechanical locking method is more reliable than simple interference fit or bolt connection, preventing wear on the mating surfaces caused by loosening or rotation of the end cap, and ensuring the accuracy of the overall positioning of the bearing sleeve assembly.

[0025] See Figure 6 In one embodiment, the plane of the planar bearing 5 is parallel to the plane of the end cap. This embodiment relates to the arrangement geometry of the planar bearing 5, where the plane of the planar bearing 5 is parallel to the plane of the bearing end cap 3. This parallel geometry ensures that the axial thrust from the cross shaft 10 can be transmitted perpendicularly to the rolling elements 52 of the planar bearing 5. The uniform force distribution avoids edge stress concentration in the rolling elements 52 due to eccentric loading or overturning moments, thereby preventing early fatigue spalling of the rolling elements 52 or raceways and ensuring the stability and durability of the axial load-bearing system.

[0026] See Figure 4 and Figure 6In one embodiment, the planar bearing 5 further includes wear-resistant pads 53 disposed on both sides of the cage 51 for the rolling elements 52 to roll. The planar bearing 5 also includes a buffer pad 54 disposed on the side of the wear-resistant pad 53 away from the rolling elements 52 to reduce axial impact on the planar bearing 5. This embodiment further refines the internal components of the planar bearing 5. The planar bearing 5 includes not only the cage 51 and the rolling elements 52, but also wear-resistant pads 53 and buffer pads 54. The wear-resistant pads 53 are disposed on both sides of the cage 51, providing a high-hardness rolling raceway for the rolling elements 52; the buffer pad 54 is disposed on the side of the wear-resistant pad 53 away from the rolling elements 52 (usually located on the outermost side, fitting against the bottom of the bearing end cap 3 groove). The technical advantage of this embodiment is that the wear-resistant pads 53 are typically made of carburized and quenched low-carbon alloy steel, possessing extremely high surface hardness, effectively resisting contact fatigue wear of the rolling elements 52, and protecting the relatively low-hardness bearing end cap 3 from crushing. The introduction of the buffer pad 54 (such as a polymer material or elastic metal material) gives the rigid bearing system a certain degree of flexibility, enabling it to absorb and dissipate the axial impact load and vibration energy generated by the universal joint during operation, thereby preventing the impact force from directly damaging precision parts and significantly extending the service life of the entire bearing sleeve assembly.

[0027] See Figure 1 and Figure 6 In one embodiment, a seal 6 is also included, comprising a main sealing ring 61. A sealing groove 62 is provided at the end of the outer ring 1 of the bearing. The main sealing ring 61 is installed within the sealing groove 62 and abuts against the inner ring 2 of the bearing for oil storage and lubrication. This embodiment relates to a sealing and lubrication retention structure for a bearing sleeve. The bearing sleeve assembly also includes a seal 6, specifically comprising a main sealing ring 61. A sealing groove 62 is provided on the inner wall of the end of the outer ring 1 of the bearing. The main sealing ring 61 (typically a skeleton oil seal) is installed within this sealing groove 62, with its lip directly abutting against the outer surface of the inner ring 2 of the bearing. The main function of the main sealing ring 61 is "oil storage." Because it is installed between the outer ring 1 and the inner ring of the bearing, it can effectively seal the grease inside the cavity accommodating the rollers 4, preventing leakage of the lubricating medium under centrifugal force or gravity. This ensures that the rollers 4 and the thrust bearing 5 are always in a good lubrication state, reducing the risk of dry friction and burning due to lack of oil.

[0028] See Figure 6In one embodiment, the seal 6 further includes a sealing cap 63 and a secondary sealing ring 64. The sealing cap 63 is fixed to the end face of the outer ring 1 of the bearing. The sealing cap 63 has an inner ring groove, and the secondary sealing ring 64 is installed in the inner ring groove and abuts against the inner ring 2 of the bearing for waterproofing and dustproofing. This embodiment is a double-seal upgrade based on the aforementioned embodiment. The seal 6 further includes a sealing cap 63 and a secondary sealing ring 64. The sealing cap 63 is fixedly installed on the end face of the outer ring 1 of the bearing. The inner side of the cap 7 has an inner ring groove, and the secondary sealing ring 64 (usually a dustproof ring) is installed in the inner ring groove, with its lip also abutting against the inner ring 2 of the bearing. The main function of the secondary sealing ring 64 is "dustproof and waterproof". It is located outside the main sealing ring 61, forming the first line of defense, which can effectively prevent dust, mud, metal shavings and other impurities in the external environment from entering the bearing. This dual-sealing structure of "inner oil sealing and outer dust prevention" greatly improves the bearing sleeve assembly's adaptability to harsh working conditions, prevents impurities from contaminating the lubricating grease, and thus ensures the cleanliness of the precision mating surfaces inside the bearing.

[0029] See Figure 6 In one embodiment, both the mounting surfaces of the sealing groove 62 and the inner ring groove are cylindrical surfaces. This embodiment clearly defines the geometric characteristics of the sealing mating surfaces. Both the mating surface corresponding to the sealing groove 62 where the main sealing ring 61 is located, and the mating surface corresponding to the inner ring groove where the secondary sealing ring 64 is located (i.e., the outer surface of the bearing inner ring 2), are standard cylindrical surfaces. In the prior art, the sealing lip often presses against the arc transition surface at the root of the cross shaft 10. Due to machining errors, the arc curvature is inconsistent, resulting in uneven contact pressure of the sealing lip and a high risk of leakage. This embodiment utilizes the standard cylindrical surface provided by the bearing inner ring 2 as the sealing mating surface, eliminating the influence of positional errors on sealing performance. The cylindrical surface ensures that the interference fit of the sealing lip in the circumferential direction is uniform, thereby achieving a more reliable sealing effect and allowing users to select standard sealing ring parts, reducing maintenance costs.

[0030] See Figure 6In one embodiment, the bearing sleeve assembly further includes a gland 7 and a retaining ring 8. The bearing end cap 3 is disposed between the bearing outer ring 1 and the retaining ring 8, and is connected to the bearing outer ring 1 via the gland 7. This embodiment relates to an overall encapsulated structure of the bearing sleeve assembly, which also includes a gland 7 and a retaining ring 8. The bearing end cap 3 is installed between the stepped surface inside the bearing outer ring 1 and the retaining ring 8, and is axially limited and fixed by the retaining ring 8 being engaged in a groove in the inner wall of the bearing outer ring 1, with screws or the gland 7 used for connection if necessary. The retaining ring 8 provides a simple and reliable axial locking mechanism to prevent the bearing end cap 3 from dislodging from the bearing outer ring 1 under the pressure of internal grease or external axial force. This integrated encapsulation design allows the bearing sleeve assembly (including the outer ring, rollers 4, inner ring, seal 6, end cap, and thrust bearing 5) to be assembled into a complete independent unit at the factory. Users only need to replace the entire assembly on-site, without having to assemble individual parts, which greatly improves maintenance efficiency and ensures assembly accuracy.

[0031] See Figure 7 and Figure 8 An embodiment of the present invention also provides a universal joint, including a fork head 9, a cross shaft 10, and the aforementioned bearing sleeve. The fork heads 9 are arranged in pairs, and the pair of fork heads 9 are rotatably connected to the cross shaft 10 through the bearing sleeve. A first oil groove 91 is provided in the bearing hole, and a first oil injection hole 92 is provided on the fork head 9. The first oil injection hole 92 is connected to the first oil groove 91 and is used to inject oil into the first oil groove 91 to form an oil film on the inner wall of the bearing hole. The universal joint provided in this embodiment adopts the integrated bearing sleeve assembly described in any of the embodiments of claims 1-8. The universal joint includes a pair of fork heads 9 and a cross shaft 10, and the pair of fork heads 9 are rotatably connected to the cross shaft 10 through the bearing sleeve assembly. A first oil groove 91 is provided on the inner wall of the bearing hole of the fork head 9, and a first oil injection hole 92 communicating with the oil groove is machined on the body of the fork head 9. This oil passage structure is mainly used to improve the fit between the bearing sleeve assembly and the fork head 9. When the universal joint needs to be disassembled and maintained, oil is injected through the first oil injection hole 92. The oil quickly fills the first oil groove 91 and spreads between the inner wall of the bearing hole and the outer surface of the bearing sleeve, forming a continuous oil film. This oil film effectively isolates the mating metal surfaces, not only softening any rust or adhesion that may occur after long-term use, but also playing a crucial lubricating role during mechanical disassembly, significantly reducing frictional resistance. This allows the bearing sleeve assembly to be smoothly removed from the fork head 9 hole, avoiding damage to the precision of the inner hole of the fork head 9 caused by forceful disassembly.

[0032] See Figure 9 and Figure 10In one embodiment, a second oil groove 1001 is provided on the outer edge of the shaft head of the cross shaft 10, and a second oil injection hole 1002 is provided on the cross shaft 10. The second oil injection hole 1002 is connected to the second oil groove 1001 and is used to inject oil into the second oil groove 1001 to form an oil film on the outer edge sidewall of the shaft head of the cross shaft 10. This embodiment focuses on the lubrication and protection of the mating surface between the cross shaft 10 and the inner ring 2 of the bearing. A second oil groove 1001 is provided on the outer edge surface of the shaft head of the cross shaft 10, and a second oil injection hole 1002 communicating with the oil groove is provided inside the cross shaft 10. The technical effect of this feature is that oil is injected into the surface of the shaft head through the second oil injection hole 1002, so that a uniform oil film is formed between the outer edge sidewall of the shaft head of the cross shaft 10 and the inner wall of the tightly fitted inner ring 2 of the bearing. The main function of this oil film is to prevent rust and reduce friction. During long-term operation of the equipment, the oil film prevents fretting wear or cold welding between the tightly mating surfaces. When repairing or replacing the inner ring 2 of the bearing, the pre-existing or newly injected oil film can act as a lubricating medium, reducing the frictional force when the inner ring moves axially. This helps maintenance personnel remove the interference-fitted inner ring by mechanical means, thereby protecting the expensive shaft head surface of the cross shaft 10 from being scratched and extending the service life of the cross shaft 10.

[0033] See Figure 2 , Figure 5 and Figure 8 In one embodiment, the bearing end cap 3 is provided with an anti-rotation key 33, and the outer side of the bearing hole of the fork head 9 is provided with an anti-rotation key 33 groove 32, which is used to cooperate with the bearing end cap 3 to limit the rotation of the bearing sleeve. In this embodiment, the bearing end cap 3 is provided with an anti-rotation key 33, and correspondingly, the outer end face of the bearing hole of the fork head 9 is provided with an anti-rotation key 33 groove 32. When the bearing sleeve assembly is installed in place, the anti-rotation key 33 is simultaneously embedded in the keyway 32 of the bearing end cap 3 and the fork head 9. This embodiment provides a reliable circumferential fixing mechanism. Since the bearing sleeve assembly is an independently packaged unit and there is a possibility of oil film lubrication between it and the fork head 9, mechanical locking is necessary to prevent the bearing outer ring 1 and the end cap from rotating relative to the fork head 9 when the universal joint transmits large torque or rotates at high speed. This anti-rotation structure completely eliminates the risk of the bearing sleeve "slipping" in the hole of the fork head 9, prevents abnormal wear of the mating surfaces, and ensures the stability and reliability of power transmission.

[0034] See Figure 5 , Figure 6 and Figure 10In one embodiment, the bearing end cap 3, the bearing inner ring 2, and the shaft end of the cross shaft 10 together form a cavity for containing oil, which is connected to the second oil injection hole 1002. The bearing end cap 3 is provided with an oil filling hole 34 for injecting oil into the cavity to deliver the oil to the second oil injection hole 1002. This embodiment relates to a lubrication communication design for the internal cavity of the universal joint. After assembly, the bearing end cap 3, the bearing inner ring 2, and the shaft end of the cross shaft 10 together form a closed cavity for containing oil, which is spatially connected to the second oil injection hole 1002 on the cross shaft 10. An oil filling hole 34 is provided at the center of the bearing end cap 3, which constitutes the lubrication inlet for routine maintenance of the universal joint. Grease injected through this hole can not only fill the aforementioned cavity and lubricate the planar bearing 5 and rollers 4, but can also be further delivered and filled into the second oil injection hole 1002. This interconnected design ensures that the grease can cover the end face and internal channels of the cross shaft 10, which on the one hand ensures that all moving parts (including rollers 4 and surface bearings 5) are fully lubricated and cooled, and on the other hand, the grease fills the internal channels such as the second oil injection hole 1002, preventing external moisture from entering and causing rust or blockage inside the channels, thus ensuring the rust prevention performance of the entire system and the unobstructed maintenance channels. After flowing through the rollers 4, the lubricating grease is discharged from the spherical bearing through the seal 6.

[0035] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0036] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A bearing sleeve, fitted onto a cross shaft (10) and nested within a bearing hole of a fork head (9), characterized in that, It includes an outer bearing ring (1), an inner bearing ring (2), a bearing end cap (3), and rollers (4). The inner bearing ring (2) is fitted onto the shaft head of the cross shaft (10). The outer bearing ring (1) and the bearing end cap (3) are connected and together with the inner bearing ring (2) form a cavity suitable for accommodating the rollers (4), so that the rollers (4) can be rotatably connected to the inner bearing ring (2). The bearing sleeve also includes a planar bearing (5) disposed inside the bearing end cover (3). The planar bearing (5) includes a cage (51) and rolling elements (52). The rolling elements (52) are disposed in the hole of the cage (51) and are rotatably connected to the cage (51) to reduce the friction between the bearing sleeve and the cross shaft (10).

2. The bearing sleeve according to claim 1, characterized in that, The bearing end cap (3) has an installation groove (31) on the end face facing the outer ring (1) of the bearing for mounting a planar bearing (5). The bearing end cap (3) has a keyway (32) on the end face away from the outer ring (1) of the bearing for mounting an anti-rotation key (33).

3. The bearing sleeve according to claim 2, characterized in that, The plane where the planar bearing (5) is located is parallel to the plane where the end cap is located.

4. The bearing sleeve according to claim 1, characterized in that, The planar bearing (5) also includes a wear-resistant pad (53), which is disposed on both sides of the cage (51) for the rolling elements (52) to roll. The planar bearing (5) further includes a buffer pad (54), which is disposed on the side of the wear-resistant pad (53) away from the rolling element (52) to reduce the axial impact on the planar bearing (5).

5. The bearing sleeve according to claim 1, characterized in that, It also includes a seal (6), which includes a main sealing ring (61). The end of the outer ring (1) of the bearing is provided with a sealing groove (62). The main sealing ring (61) is installed in the sealing groove (62) and abuts against the inner ring (2) of the bearing for oil storage and lubrication.

6. The bearing sleeve according to claim 5, characterized in that, The sealing element (6) further includes a sealing cap (63) and a secondary sealing ring (64). The sealing cap (63) is fixed on the end face of the outer ring (1) of the bearing. The sealing cap (63) has an inner ring groove. The secondary sealing ring (64) is installed in the inner ring groove and abuts against the inner ring (2) of the bearing for waterproofing and dustproofing.

7. The bearing sleeve according to claim 6, characterized in that, The mounting surfaces of the sealing groove (62) and the inner ring groove are both cylindrical surfaces.

8. The bearing sleeve according to claim 1, characterized in that, It also includes a pressure cap (7) and a retaining ring (8). The bearing end cap (3) is disposed between the bearing outer ring (1) and the retaining ring (8) and is connected to the bearing outer ring (1) through the pressure cap (7).

9. A universal joint, comprising fork heads (9), a cross shaft (10), and a bearing sleeve according to any one of claims 1-8, wherein the fork heads (9) are arranged in pairs, and a pair of fork heads (9) are rotatably connected to the cross shaft (10) via the bearing sleeve, characterized in that, The bearing hole is provided with a first oil groove (91), and the fork head (9) is provided with a first oil injection hole (92). The first oil injection hole (92) is connected to the first oil groove (91) and is used to inject oil into the first oil groove (91) and form an oil film on the inner wall of the bearing hole to facilitate the disassembly of the bearing sleeve.

10. The universal joint according to claim 9, characterized in that, The cross shaft (10) has a second oil groove (1001) on the outer edge of the shaft head and a second oil injection hole (1002) on the cross shaft (10). The second oil injection hole (1002) is connected to the second oil groove (1001) and is used to inject oil into the second oil groove (1001) and form an oil film on the side wall of the outer edge of the shaft head of the cross shaft (10) to facilitate the disassembly of the bearing inner ring (2).

11. The universal joint according to claim 10, characterized in that, The bearing end cover (3) is provided with an anti-rotation key (33), and the bearing hole of the fork head (9) is provided with an anti-rotation key (33) groove (32) for cooperating with the bearing end cover (3) to limit the rotation of the bearing end cover (3) in the bearing sleeve.

12. The universal joint according to claim 10, characterized in that, The bearing end cap (3), the bearing inner ring (2), and the shaft head of the cross shaft (10) together form a cavity for containing oil. The bearing end cap (3) is provided with an oil filling hole (34) for injecting oil into the cavity.

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