An expansion type self-locking universal joint and a self-locking universal transmission assembly

Abstract

This invention discloses an expandable self-locking universal joint and a self-locking universal transmission assembly, relating to the technical field of universal joints. It includes a cross shaft and a self-locking bearing. At least one pair of opposing journals of the cross shaft are connected to the fork via a self-locking bearing. A fork sleeve is fitted between the bearing ring of the self-locking bearing and the lug of the fork. The fork sleeve cooperates with the self-locking bearing to connect the journal to the lug of the fork. The expandable self-locking universal joint of this invention achieves bidirectional interlocking of the universal joint through the cooperation of the self-locking bearing, the fork sleeve, and the fork, ensuring precise installation and uniform force distribution, and solving problems such as universal joint movement and tilting during assembly.

Description

Technical Field

[0001] This invention relates to the technical field of universal joints, and in particular to an expansion-type self-locking universal joint and a self-locking universal transmission assembly. Background Technology

[0002] Currently, universal joints are installed into the universal joint fork using pressure equipment and axially positioned using snap rings to prevent axial movement during operation. Because the surface hardness of the universal joint bearing is higher than that of the universal joint fork, non-perpendicular force application during fork installation can easily cause tilting. After fork installation, snap rings are installed at the bottom of the universal joint and inside the fork to prevent axial movement during operation. However, this method can lead to uneven force distribution on the universal joint during pressing due to tilting, causing premature failure and significantly reducing its service life. Therefore, a new universal joint design is urgently needed to solve the problems of universal joint movement and tilting during assembly. Summary of the Invention

[0003] The purpose of this invention is to provide an expansion-type self-locking universal joint and a self-locking universal transmission assembly to solve the problems existing in the prior art, so as to ensure uniform force distribution during the assembly process of the universal joint and avoid axial movement and tilting.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] The present invention provides an expansion type self-locking universal joint, including a cross shaft and a self-locking bearing. At least one pair of opposite journals of the cross shaft are respectively connected to the fork through the self-locking bearing. A fork sleeve is sleeved between the bearing ring of the self-locking bearing and the lug of the fork. The fork sleeve cooperates with the self-locking bearing to connect the journal to the lug of the fork.

[0006] Preferably, the self-locking bearing includes a bearing ring, a washer, needle rollers, an oil seal, and a dust cover. The inner end of the bearing ring is provided with a mounting groove. The washer, the needle rollers, the oil seal, and the dust cover are sequentially arranged in the mounting groove. The needle rollers are evenly distributed in a ring along the circumference of the mounting groove. The needle rollers, the oil seal, and the dust cover are all sleeved on the journal.

[0007] Preferably, the oil seal is interference-fitted with the mounting groove of the bearing ring, and the dust cover is fitted onto the outer port of the bearing ring and abuts against the outermost lip of the oil seal.

[0008] Preferably, an elastic gasket is provided between the needle roller and the oil seal.

[0009] Preferably, the needle roller is a cylindrical needle roller with two rings.

[0010] Preferably, the surface of the gasket is provided with a lubricating oil groove, the gasket is made of thermoplastic resin; the gasket is annular, the outer diameter of the gasket is smaller than the inner diameter of the mounting groove, a through hole is provided in the middle of the gasket, the radial width of the gasket is larger than the diameter of the needle roller, and the surface of the gasket abuts against the end face of the journal.

[0011] Preferably, a convex ring is provided on the outer surface of the outer end of the bearing ring, and a plurality of protrusions are movably arranged inside the convex ring. All the protrusions can be spliced ​​together to form a ring. The protrusions can be extended and retracted and are used to engage in the groove of the lug hole of the fork. The outer surface of the convex ring is a conical surface with a smaller inner surface and a larger outer surface.

[0012] Preferably, the outer end of the fork sleeve has several cracks evenly distributed circumferentially, and the depth of the cracks is not less than the axial length of the conical surface; the convex ring is provided with an annular guide groove, and each convex block is slidably inserted into the guide groove by several springs, the bottom of the convex block is always located in the guide groove, the outer diameter of the convex ring is smaller than the inner diameter of the lug hole of the fork, and the outer diameter of the convex block after popping out is larger than the inner diameter of the lug hole of the fork.

[0013] Preferably, the bearing rings are made of alloy steel or titanium alloy.

[0014] The present invention also relates to a self-locking universal joint assembly, including the aforementioned expansion-type self-locking universal joint and fork. The fork has a limiting boss on the side of the lug hole near the center and a groove on the outer side away from the center. The inner diameter of the limiting boss is smaller than the outer diameter of the fork sleeve but not smaller than the inner diameter of the fork sleeve. The outer diameter of the protrusion of the bearing ring of the self-locking bearing is larger than the inner diameter of the lug hole and can abut against the inner bottom of the groove.

[0015] The present invention achieves the following technical effects compared to the prior art:

[0016] The expansion-type self-locking universal joint of the present invention achieves bidirectional interlocking of the universal joint through the cooperation of self-locking bearing, fork sleeve and joint fork, ensuring accurate installation and uniform force distribution, and solving problems such as universal joint movement and tilting during assembly. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1This is a schematic diagram of the assembly structure of the expansion-type self-locking universal joint in Embodiment 1 of the present invention;

[0019] Figure 2 This is a schematic diagram of the exploded structure of the expansion-type self-locking universal joint in Embodiment 1 of the present invention. Figure 1 ;

[0020] Figure 3 This is a schematic diagram of the exploded structure of the expansion-type self-locking universal joint in Embodiment 1 of the present invention. Figure 2 ;

[0021] Figure 4 This is a schematic diagram of the cross-sectional structure of the self-locking bearing in Embodiment 1 of the present invention;

[0022] Figure 5 This is a schematic diagram of the telescopic protrusion in Embodiment 1 of the present invention. Figure 1 ;

[0023] Figure 6 This is a schematic diagram of the telescopic protrusion in Embodiment 1 of the present invention. Figure 2 ;

[0024] Figure 7 This is a schematic diagram of the segmented fork structure in Embodiment 2 of the present invention;

[0025] In the diagram: 1-cross shaft, 2-bearing ring, 3-shield, 4-needle roller, 5-elastic washer, 6-oil seal, 7-dust cover, 8-guide groove, 9-protrusion, 10-spring, 11-split sleeve, 12-segment fork, 13-ear hole, 14-slot, 15-limiting boss. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The purpose of this invention is to provide an expansion-type self-locking universal joint and a self-locking universal transmission assembly to solve the problems existing in the prior art, so as to ensure uniform force distribution during the assembly process of the universal joint and avoid axial movement and tilting.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] like Figures 1 to 6As shown, this embodiment provides an expansion type self-locking universal joint, including a cross shaft 1 and a self-locking bearing. At least one pair of opposite journals of the cross shaft 1 are respectively connected to the fork 12 through a self-locking bearing. A fork sleeve 11 is sleeved between the bearing ring 2 of the self-locking bearing and the lug 13 of the fork 12. The fork sleeve 11 cooperates with the self-locking bearing to connect the journal to the lug 13 of the fork 12.

[0031] As an optional embodiment, the self-locking bearing includes a bearing ring 2, a washer 3, needle rollers 4, an oil seal 6, and a dust cover 7. The inner end of the bearing ring 2 is provided with a mounting groove. The washer 3, needle rollers 4, oil seal 6, and dust cover 7 are sequentially arranged within the mounting groove (on its inner circumferential surface). The needle rollers 4 are evenly distributed in a ring shape along the circumference of the mounting groove. The needle rollers 4, oil seal 6, and dust cover 7 are all fitted onto the journal. The mounting groove is open at one end and open at the other to ensure the sealing of the outer end. The needle rollers 4, oil seal 6, and dust cover 7 are located between the journal and the inner circumferential surface of the mounting groove.

[0032] As an optional solution, in this embodiment, the oil seal 6 is interference-fitted with the mounting groove of the bearing ring 2, and the dust cover 7 is fitted on the outer end of the bearing ring 2 and abuts against the outermost lip of the oil seal 6 to achieve sealing of the inner end of the self-locking bearing and ensure its service life.

[0033] As an optional solution, in this embodiment, an elastic washer 5 is provided between the needle roller 4 and the oil seal 6. During operation, the rotation between the journal of the cross shaft 1 and the needle roller 4 will cause the needle roller 4 to move towards the bearing port, and the elastic washer 5 can return the needle roller 4 to its original position.

[0034] As an optional solution, in this embodiment, the needle rollers 4 are cylindrical and have two rings. This embodiment has two rows of needle rollers 4. By increasing the axial number of needle rollers 4, the bearing can withstand higher radial loads, improving the overall load-bearing capacity of the bearing; it helps to distribute the load, reducing stress concentration in a single row of needle rollers 4, preventing premature failure due to excessive load, thereby improving the stability and lifespan of the bearing; it makes the load distribution more uniform, avoiding local overload and reducing wear and failure risks; it effectively reduces deformation caused by excessive load due to excessive length of a single row of needle rollers 4, ensuring the geometric accuracy and performance of the bearing; and it extends the bearing's service life by improving the overall load-bearing capacity, enhancing stability, improving load distribution, and maintaining bearing accuracy and performance.

[0035] As an optional solution, in this embodiment, the surface of the gasket 3 is provided with a lubricating oil groove, and the material of the gasket 3 is thermoplastic resin. The gasket 3 is annular, and the outer diameter of the gasket 3 is smaller than the inner diameter of the mounting groove, and the inner diameter is smaller than the inner diameter of the needle roller ring after the needle roller 4 is formed (the radial width of the gasket 3 is larger than the diameter of the needle roller 4). A through hole is provided in the middle of the gasket 3 to store and circulate lubricating oil. The surface of the gasket 3 abuts against the end face of the journal. During operation, the end face of the cross shaft 1 will rub and impact with the bottom of the bearing ring 2. The gasket 3, located between the end face of the cross shaft 1 and the bottom of the bearing ring 2, plays a role in wear resistance, buffering and vibration absorption. In addition, the gasket 3 is provided with a lubricating oil groove, and the lubricating oil at the end of the cross shaft 1 can be used during assembly to reduce relative friction.

[0036] As an optional embodiment, a convex ring is provided on the outer surface of the outer end of the bearing ring 2 in this embodiment. Several protrusions 9 are movably disposed within the convex ring. All the protrusions 9 can be spliced ​​together to form a circular ring, enabling the circular ring to expand and contract in diameter. The protrusions 9 are expandable and contractible and are used to engage with the grooves 14 of the lug holes 13 of the fork 12, forming a telescopic protrusion. The outer surface of the convex ring is a tapered surface, smaller on the inside and larger on the outside, facilitating unidirectional force insertion into the lug holes 13 of the fork 12. In this embodiment, the protrusions 9 are connected to the outer end of the bearing ring 2 by several springs 10, enabling the protrusions to deform inward during assembly. When the protrusions 9 are engaged with the grooves 14 of the lug holes 13 of the fork 12, they can axially limit the bearing ring 2.

[0037] As an optional embodiment, in this embodiment, the outer end of the split sleeve 11 has several cracks evenly distributed circumferentially, and the depth of the cracks is not less than the axial length of the conical surface; a ring guide groove 8 is provided on the convex ring, and each protrusion 9 is slidably inserted into the guide groove 8 by several springs 10. The bottom of the protrusion 9 is always located in the guide groove 8. The outer diameter of the convex ring is smaller than the inner diameter of the ear hole 13 of the fork 12, and the outer diameter of the protrusion 9 after popping out is larger than the inner diameter of the ear hole 13 of the fork 12. In this embodiment, the depth of the cracks in the split sleeve 11 is preferably 1 / 3 to 3 / 5 of the axial length of the split sleeve 11; the outer diameter of the split sleeve 11 is interference-fitted with the inner diameter of the fork 12, and the forked end of the split sleeve 11 contacts the boss of the bearing ring 2. When the boss outside the bearing ring 2 is locked in the groove 14 of the fork 12, the self-locking bearing can no longer move inward in the ear hole 13 of the fork 12. The fork opening part in front of the fork sleeve 11 expands and locks, and the inner end of the fork sleeve 11 cannot move inward along the ear hole 13 of the fork 12 under the action of the limiting step. In this way, the boss of the self-locking bearing and the groove 14 of the fork 12 form two interlocks in opposite directions, ensuring that the universal joint will not move or shake in the ear hole 13 of the fork 12 during operation.

[0038] As an optional solution, in this embodiment, the bearing ring 2 is made of alloy steel or titanium alloy, and the boss is preferably made of alloy steel or titanium alloy, which is easy to deform during installation to complete the interference fit assembly.

[0039] Example 2

[0040] like Figure 1 and Figure 7 As shown, this embodiment provides a self-locking universal joint assembly, including the aforementioned expansion-type self-locking universal joint and fork 12. The lug 13 of the fork 12 has a limiting boss 15 on the side near the center and a groove 14 on the outer side away from the center. The inner diameter of the limiting boss 15 is smaller than the outer diameter of the fork sleeve 11 but not smaller than the inner diameter of the fork sleeve 11. The outer diameter of the protrusion 9 of the bearing ring 2 of the self-locking bearing is larger than the inner diameter of the lug 13 and can abut against the inner bottom of the groove 14.

[0041] During the assembly of the fork 12 onto the cross shaft 1, after the two ends of the cross shaft 1 are inserted into the ear holes 13 of the fork 12, the self-locking bearing and the fork sleeve 11 are pressed into the ear holes 13 from the outer end of the fork 12. The outer diameter of the fork sleeve 11 is interference-fitted with the inner diameter of the fork 12 for circumferential positioning. The fork sleeve 11 is subjected to the force of the limiting boss 15 on the inner wall of the ear hole 13. The direction of this force is opposite to the pressing direction. The boss of the self-locking bearing applies a force in the same direction as the pressing direction. Under the action of the two opposite forces, the fork sleeve 11... The crack will gradually deform. When the inner end of the fork sleeve 11 comes into contact with the limiting step in the fork 12 and cannot move, and the boss of the self-locking bearing is also stuck in the groove 14 of the fork 12 and cannot move, the deformation of the fork sleeve 11 reaches its maximum. At this time, through the expansion deformation of the fork sleeve 11 and the interference fit between the bearing ring 2 and the fork sleeve 11, the bearing ring 2 is locked in the ear hole 13 of the fork 12, thereby ensuring that the universal joint will not move, tilt or move along the axis during operation, which may cause the universal joint to fail.

[0042] The present invention solves the problems of universal joint movement and tilting during assembly by means of the boss of the self-locking bearing, the groove 14 of the fork sleeve 11 and the fork 12, the axial bidirectional limiting interlocking structure of the limiting boss 15, and the clamping and locking structure formed in the radial direction of the fork 12 after the fork sleeve 11 opens.

[0043] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An expansion-type self-locking universal joint, characterized in that: The device includes a cross shaft and a self-locking bearing. At least one pair of opposing journals of the cross shaft are connected to the fork via a self-locking bearing. A fork sleeve is fitted between the bearing ring of the self-locking bearing and the lug of the fork. The fork sleeve cooperates with the self-locking bearing to connect the journal to the lug of the fork. A convex ring is provided on the outer surface of the outer end of the bearing ring. Several protrusions are movably disposed inside the convex ring. The protrusions are telescopic and are used to engage with the grooves of the lug holes of the fork. The outer surface of the convex ring is a conical surface with a smaller inner diameter and a larger outer diameter. Several cracks are evenly distributed circumferentially on the outer end of the fork sleeve. The depth of the cracks is not less than the axial length of the conical surface. The outer diameter of the fork sleeve is interference-fitted with the inner diameter of the fork, and the forked end of the fork sleeve contacts the protrusions of the bearing ring.

2. The expansion-type self-locking universal joint according to claim 1, characterized in that: The self-locking bearing includes a bearing ring, a washer, needle rollers, an oil seal, and a dust cover. The inner end of the bearing ring is provided with a mounting groove. The washer, the needle rollers, the oil seal, and the dust cover are arranged sequentially in the mounting groove. The needle rollers are evenly distributed in a ring along the circumference of the mounting groove. The needle rollers, the oil seal, and the dust cover are all sleeved on the journal.

3. The expansion-type self-locking universal joint according to claim 2, characterized in that: The oil seal is interference-fitted with the mounting groove of the bearing ring, and the dust cover is fitted onto the outer port of the bearing ring and abuts against the outermost lip of the oil seal.

4. The expansion-type self-locking universal joint according to claim 2, characterized in that: An elastic gasket is provided between the needle roller and the oil seal.

5. The expansion-type self-locking universal joint according to claim 2, characterized in that: The needle roller is a cylindrical needle roller with two rings.

6. The expansion-type self-locking universal joint according to claim 2, characterized in that: The surface of the gasket is provided with a lubricating oil groove, and the gasket is made of thermoplastic resin. The gasket is annular, the outer diameter of the gasket is smaller than the inner diameter of the mounting groove, a through hole is provided in the middle of the gasket, the radial width of the gasket is larger than the diameter of the needle roller, and the surface of the gasket abuts against the end face of the journal.

7. The expansion-type self-locking universal joint according to claim 2, characterized in that: All of the aforementioned bumps can be joined together to form a ring.

8. The expansion-type self-locking universal joint according to claim 7, characterized in that: The convex ring is provided with an annular guide groove. Each convex block is slidably inserted into the guide groove by several springs. The bottom of the convex block is always located in the guide groove. The outer diameter of the convex ring is smaller than the inner diameter of the lug hole of the fork. The outer diameter of the convex block after it pops out is larger than the inner diameter of the lug hole of the fork.

9. The expansion-type self-locking universal joint according to claim 2, characterized in that: The bearing rings are made of alloy steel or titanium alloy.

10. A self-locking universal joint assembly, comprising the expandable self-locking universal joint and the fork as described in any one of claims 1-9, characterized in that: The fork has a limiting boss on the side of the ear hole near the center and a slot on the outer side away from the center. The inner diameter of the limiting boss is smaller than the outer diameter of the fork sleeve but not smaller than the inner diameter of the fork sleeve. The outer diameter of the protrusion of the bearing ring of the self-locking bearing is larger than the inner diameter of the ear hole and can abut against the inner bottom of the slot.

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