Bearing outer ring anti-rotation structure and cross shaft type universal joint

Abstract

The utility model discloses a bearing outer ring anti -rotation structure and cross axle type universal joint, and the anti -rotation structure includes the end cover of setting on the bearing outer ring, and the outer circumferential surface of end cover includes first curved surface and second curved surface, and second curved surface is eccentric to first curved surface and is set up, and the curvature radius of second curved surface and eccentric distance sum is greater than the curvature radius of first curved surface, and first curved surface and second curved surface are connected by smooth surface transition, still include the anti -rotation groove of setting on the prong, and the outer circumferential surface of anti -rotation groove is adapted with end cover, and end cover is embedded in the anti -rotation groove setting. The outer circumferential surface of end cover is designed as a kind of non -circular contour, make it have asymmetry or non -circular. When this end cover with non -circular outer contour is embedded in the anti -rotation groove of the prong and is opened, with the adaptation thereof, a kind of mechanical interlocking locking is formed between the two. This non -circular interlocking structure restricts the circumferential rotation of end cover relative to anti -rotation groove (i. e. prong).

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission components, and in particular to a bearing outer ring anti-rotation structure and a cross-shaped universal joint. Background Technology

[0002] With the development of mechanical transmission component technology, the universal joint, as a core component in couplings that enables tilting and oscillation, has been widely used in metallurgy, heavy industry, and other fields. In the universal joint structure, the assembly and fit between the universal bearing assembly and the fork bearing bore is crucial to ensuring its transmission accuracy and service life. Currently, a common assembly method is to use an interference fit between the bearing outer ring and the fork bearing bore, relying on the friction generated between their mating surfaces to achieve radial positioning and circumferential anti-rotation of the bearing outer ring.

[0003] Traditional technologies have recognized the limitations of a single interference fit and proposed solutions to add anti-rotation devices. For example, Chinese patent CN118705284A discloses a solution that limits the rotation of the outer ring of the bearing by setting an anti-rotation device between the bearing and the fork. One specific solution is to set a coaxial external threaded hole and an internal threaded hole at the top of the fork (i.e., the position where the fork is subjected to the least force), and to machine a flat surface (1011) on the corresponding outer circle of the bearing outer ring (101). During assembly, an internal set screw (601) is screwed into the internal threaded hole (203) and pressed against the flat surface (1011), and then an external set screw (602) is used to press the internal set screw to prevent loosening, thereby achieving the limiting effect.

[0004] However, while the anti-rotation device provided by the aforementioned patent (CN118705284A) can limit rotation after interference fit failure, its design suffers from relatively complex structure. For example, in the embodiment of its fork top limiting device, this structure requires the addition of two extra inner and outer set screws, and a corresponding flat surface must be machined on the outer circle of the bearing outer ring for screw tightening. Similarly, in the embodiments of its outer end face limiting device and inner orifice limiting device, independent anti-rotation components such as limiting plates or limiting blocks are also required, and correspondingly, opening grooves or L-grooves must be machined on the bearing outer ring. This design not only increases the number of additional parts and machining steps but also correspondingly increases the overall assembly complexity and manufacturing cost. Utility Model Content

[0005] Therefore, it is necessary to provide a bearing outer ring anti-rotation structure and a cross-shaped universal joint to address the above problems.

[0006] This application provides a bearing outer ring anti-rotation structure, which is installed in a cross-type universal joint, including an end cap installed on the bearing outer ring. The outer circumferential surface of the end cap includes a first curved surface and a second curved surface. The second curved surface is eccentrically disposed relative to the first curved surface. The sum of the radius of curvature of the second curved surface and the eccentricity is greater than the radius of curvature of the first curved surface. The first curved surface and the second curved surface are connected by a smooth curved surface. It also includes an anti-rotation groove provided on the fork head, the anti-rotation groove being adapted to the outer circumferential surface of the end cap, and the end cap being embedded in the anti-rotation groove.

[0007] Optionally, the end cap is provided with a threaded through hole, and the outer ring of the bearing is provided with a threaded hole. The screw passes through the threaded through hole and is screwed into the threaded hole to press the end cap against the end face of the outer ring of the bearing.

[0008] Optionally, the array of threaded holes and threaded through holes is evenly distributed on a Φ260mm pitch circle, with an adjacent hole spacing tolerance of ±0.05mm.

[0009] Optionally, the depth of the anti-rotation groove is greater than the thickness of the end cap, and the gap between the end cap and the top of the anti-rotation groove after the end cap is embedded in the anti-rotation groove is 0.5-1mm.

[0010] Optionally, the anti-rotation groove and the end cap are H7 / g6 fit.

[0011] Optionally, the end cap and the outer ring of the bearing together form an inner groove, which is used to install a sealing ring to seal the bearing.

[0012] Optionally, the radius of curvature of the first surface is 144.5 mm, the radius of curvature of the second surface is 137 mm, and the eccentricity between the first surface and the second surface is 18 mm.

[0013] This application also provides a cross-shaped universal joint, including the above-mentioned anti-rotation structure for the outer ring of the bearing, and also including a fork head, a cross shaft, and a bearing. The fork head is provided with a bearing hole, and the cross shaft is rotatably connected to the fork head through the bearing.

[0014] Optionally, the end cap is made of carbon steel, the bearing outer ring is made of low-carbon alloy steel, and the fork head is made of alloy steel.

[0015] Optionally, the outer ring of the bearing is disposed within the bearing bore of the fork head and is interference-fitted with the bearing bore.

[0016] Compared with the prior art, the technical solution provided in this application has the following advantages: The aforementioned anti-rotation structure for the bearing outer ring features an end cap with a non-circular outer circumferential surface. This profile is composed of a first curved surface and a second curved surface, with the second curved surface eccentrically positioned relative to the first curved surface, ensuring the asymmetry or non-circularity of the end cap's shape. When this end cap with its non-circular outer contour is inserted into the matching anti-rotation groove on the fork head, a mechanical locking mechanism is formed. This non-circular locking structure restricts the circumferential rotation of the end cap relative to the anti-rotation groove (i.e., the fork head). Since the end cap is mounted on the bearing outer ring, the circumferential locking of the end cap also correspondingly prevents the bearing outer ring from rotating relative to the fork head, thus achieving the structural purpose of preventing bearing outer ring rotation in a cross-type universal joint. Attached Figure Description

[0017] Figure 1 A cross-sectional view of the bearing outer ring anti-rotation structure provided in this application; Figure 2 This is a schematic diagram of the structure of the end cap in the bearing outer ring anti-rotation structure provided in this application. Figure 3 This is a cross-sectional view of the fork head and anti-rotation groove in the bearing outer ring anti-rotation structure provided in this application; Figure 4 A schematic diagram of the overall structure of the cross-shaped universal joint provided in this application.

[0018] Explanation of reference numerals in the attached figures: 100, Bearing outer ring; 200, End cap; 210, First curved surface; 220, Second curved surface; 300, Fork head; 310, Anti-rotation groove; 400, Screw; 500, Sealing ring; 600, Cross shaft. Detailed Implementation

[0019] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model 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 full understanding of this utility model. However, this utility model can be implemented 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 this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0020] See Figures 1 to 3An embodiment of this utility model provides an anti-rotation structure for the outer ring 100 of a bearing, which is installed in a universal joint of a cross shaft 600. It includes an end cap 200 installed on the outer ring 100 of the bearing. The outer circumferential surface of the end cap 200 includes a first curved surface 210 and a second curved surface 220. The second curved surface 220 is eccentrically arranged relative to the first curved surface 210. The sum of the radius of curvature of the second curved surface 220 and the eccentricity is greater than the radius of curvature of the first curved surface 210. The first curved surface 210 and the second curved surface 220 are connected by a smooth curved surface transition. It also includes an anti-rotation groove 310 installed on the fork head 300. The anti-rotation groove 310 is adapted to the outer circumferential surface of the end cap 200, and the end cap 200 is embedded in the anti-rotation groove 310.

[0021] In this embodiment, the outer circumferential surface of the end cap 200 is designed with a non-circular profile, which is composed of a first curved surface 210 and a second curved surface 220, with the second curved surface 220 being eccentrically positioned relative to the first curved surface 210. This specific geometric feature ensures the asymmetry or non-circularity of the end cap 200's shape. When this end cap 200 with its non-circular outer profile is inserted into the anti-rotation groove 310 on the fork 300, a mechanical locking mechanism is formed between them. This non-circular locking structure restricts the circumferential rotation of the end cap 200 relative to the anti-rotation groove 310 (i.e., the fork 300). Since the end cap 200 is mounted on the outer ring 100 of the bearing, the circumferential locking of the end cap 200 also correspondingly prevents the outer ring 100 of the bearing from rotating relative to the fork 300, thereby achieving the structural purpose of preventing the outer ring 100 of the bearing from rotating in the universal joint of the cross shaft 600 type.

[0022] In one embodiment, the end cap 200 has a threaded through hole, and the bearing outer ring 100 has a threaded hole. The screw 400 passes through the threaded through hole and is screwed into the threaded hole to press the end cap 200 against the end face of the bearing outer ring 100. Specifically, in this embodiment, the threaded hole on the end face of the bearing outer ring 100 is an M8 fine thread with a pitch of 1.25 mm and a thread depth of 15 ± 0.5 mm. When screwed in, the preload torque of the M8 screw 400 is 18-22 N·m, and the applied axial clamping force is ≥15 kN.

[0023] In this embodiment, firstly, the screw 400 passes through the threaded through-hole of the end cap 200 and is screwed into the threaded hole of the bearing outer ring 100. Its direct function is to press the end cap 200 against the end face of the bearing outer ring 100. Secondly, the design of using M8 fine threads and a pitch of 1.25mm provides better anti-loosening and self-locking performance compared to coarse threads. This is especially important for mechanical structures subjected to vibration or alternating loads, and also enables more precise preload control. The thread depth of 15±0.5mm ensures that the screw 400 has sufficient engagement length, providing a structural strength basis for applying high preload and preventing thread failure. Finally, by applying a specific preload torque of 18-22 N·m, this structure can generate a quantified axial clamping force of over 15kN, ensuring a tight fit between the end cap 200 and the end face of the bearing outer ring 100, eliminating potential gaps, and making it a functionally rigid whole.

[0024] See Figure 2 In one embodiment, the threaded holes and threaded through holes are evenly distributed on a Φ260mm pitch circle, with an adjacent hole spacing tolerance of ±0.05mm. Specifically, in this embodiment, there are 12 threaded holes.

[0025] The design of this embodiment, with the threaded holes and through-holes evenly distributed on the Φ260mm pitch circle and 12 threaded holes, ensures that the applied clamping force is evenly distributed across the 12 points on the entire circumference. This multi-point distribution ensures uniform force distribution, avoids localized stress concentration or warping deformation of components due to uneven force distribution, and thus achieves a smooth and tight connection.

[0026] Secondly, the tolerance of ±0.05mm between adjacent holes is a high-precision manufacturing requirement, ensuring extremely high alignment accuracy between threaded holes and threaded through holes. This not only ensures smooth installation and good interchangeability of components during assembly, but is also a prerequisite for achieving the aforementioned uniform stress distribution, preventing additional assembly stress caused by hole position deviations, thereby improving the rigidity and reliability of the entire connection structure.

[0027] In one embodiment, the depth of the anti-rotation groove 310 is greater than the thickness of the end cap 200, and the gap between the end cap 200 and the anti-rotation groove 310 after the end cap 200 is embedded in the anti-rotation groove 310 is 0.5-1mm.

[0028] This embodiment ensures that the axial positioning and function of the end cap 200 are not interfered with by the bottom of the anti-rotation groove 310 by setting a precise gap in the axial direction (depth direction). In the design, the depth of the anti-rotation groove 310 is greater than the thickness of the end cap 200, a feature that ensures that the end cap 200 will not contact the bottom of the groove when inserted. The resulting gap range of 0.5-1mm clearly defines the existence of this axial clearance space. The core function of this gap is to ensure that the axial positioning and clamping function of the end cap 200 are entirely determined by the contact between its end face and other components, and will not fail due to accidental contact with the bottom of the anti-rotation groove 310. This not only provides the necessary margin for the manufacturing tolerances of the components, but also ensures that the end cap 200 is in the correct functional position after assembly.

[0029] In one embodiment, the anti-rotation groove 310 and the end cap 200 are H7 / g6 fitted. Specifically, in this embodiment, the contour gap between the anti-rotation groove 310 and the sealing end cap 200 is ≤0.1mm. Specifically, H7 / g6 is a clearance fit, and this embodiment quantifies and limits the final fit gap to within the range of ≤0.1mm, ensuring that the play (circumferential gap) between the end cap 200 and the anti-rotation groove 310 is minimized when the end cap 200 is embedded in the anti-rotation groove 310. This high-precision tight fit allows the end cap 200 to be precisely positioned within the anti-rotation groove 310, thereby achieving an efficient and reliable anti-rotation function and preventing minor rotations or vibrations that may occur between components due to excessive gaps.

[0030] See Figure 1 In one embodiment, the end cap 200 and the bearing outer ring 100 together form an inner groove for mounting the seal ring 500 to seal the bearing. In this embodiment, the receiving space (inner groove) for the seal ring 500 is not machined from a single part, but is formed by the end cap 200 and the bearing outer ring 100. This design utilizes the assembly relationship of the two parts to construct a functional groove specifically for mounting the seal ring 500, ensuring that the seal ring 500 can be stably held in the correct position, thereby effectively achieving its ultimate function of sealing the bearing.

[0031] See Figure 2 In one embodiment, the radius of curvature of the first surface 210 is 144.5 mm, the radius of curvature of the second surface 220 is 137 mm, and the eccentricity between the first surface 210 and the second surface 220 is 18 mm.

[0032] See Figure 4 An embodiment of this utility model also provides a universal joint of type 600 cross shaft, including the above-mentioned anti-rotation structure of bearing outer ring 100, and also including fork head 300, cross shaft 600 and bearing. The fork head 300 is provided with bearing hole, and the cross shaft 600 is rotatably connected to the fork head 300 through the bearing.

[0033] This embodiment clarifies the specific application scenario and integration method of the anti-rotation structure of the bearing outer ring 100. By placing this anti-rotation structure within a complete cross-shaft 600 universal joint assembly and explaining its cooperative relationship with the fork head 300, cross-shaft 600, and bearing, this embodiment demonstrates a fully functional mechanical transmission unit. The description of the bearing hole on the fork head 300 and the rotatable connection between the cross-shaft 600 and the fork head 300 via the bearing establishes the basic transmission structure of the universal joint. Therefore, the effect of this embodiment is to provide a fully structurally complete cross-shaft 600 universal joint that not only achieves a basic rotatable connection but also incorporates the anti-rotation function of the bearing outer ring 100.

[0034] In one embodiment, the end cap 200 is made of carbon steel, the bearing outer ring 100 is made of low-carbon alloy steel, and the fork head 300 is made of alloy steel. This embodiment optimizes the mechanical properties and durability of the entire structure by selecting specific materials for key components. Specifically, using carbon steel for the end cap 200 balances strength and cost; using low-carbon alloy steel for the bearing outer ring 100 provides good toughness and wear resistance, making it suitable as a bearing component; and using alloy steel for the fork head 300 ensures that this main load-bearing component has the high strength and fatigue resistance required to withstand high torque and impact loads. This differentiated material configuration allows for targeted enhancement of the performance of each component, thereby improving the overall mechanical performance and reliability of the entire anti-rotation structure and even the universal joint assembly.

[0035] In one embodiment, the bearing outer ring 100 is disposed within the bearing bore of the fork 300 and is interference-fitted with the bearing bore. This embodiment establishes a robust radial compression connection between the bearing outer ring 100 and the bearing bore of the fork 300 through this specific assembly method of interference fit. This fit causes strong radial pressure and friction between the bearing outer ring 100 and the bearing bore due to the dimensional interference after the bearing outer ring 100 is pressed into the bearing bore by external force. The direct effect is that this pressure and friction are used to achieve radial positioning and fixation of the bearing outer ring 100. This method itself provides a basic anti-rotation force, aiming to prevent undesirable circumferential rotation or axial movement of the bearing outer ring 100 relative to the bearing bore of the fork 300 after assembly.

[0036] The specific assembly process for the aforementioned 600-type universal joint is as follows: First, install the rollers inside the bearing outer ring 100, then install the sealing ring 500 inside the bearing outer ring 100 as well. Next, place the bearing outer ring 100 into the bearing bore of the fork 300. A crucial step is to align the outer circumference of the sealing end cap 200 with the anti-rotation groove 310 of the bearing bore of the fork 300, and then press the end cap 200 firmly. Finally, use an M8 screw 400 to pass through the bolt holes of the sealing end cap 200, screw it into the threaded hole on the end face of the bearing outer ring 100, and tighten it.

[0037] In terms of anti-rotation verification, this structure ensures that the non-circular contour of the sealing end cap 200 can be completely fitted into the anti-rotation groove 310, achieving a tight fit without circumferential clearance. Furthermore, this structure offers excellent maintainability. When maintenance is required, only the M8 screw 400 needs to be removed to easily replace the bearing outer ring 100 or the sealing ring 500, and the anti-rotation structure itself can be reused without damage.

[0038] Taking the SWP universal joint of a steel plant using this structure as an example, after 2,500 hours of full-load testing, the results showed that: zero relative rotation was achieved between the outer ring 100 of the bearing and the fork head 300; the expansion of the fit clearance was less than 0.05mm, which is far superior to the level of more than 0.25mm in the traditional structure; and the joint life reached 2.1 times the original design life.

[0039] 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.

[0040] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A bearing outer ring (100) anti-rotation structure, disposed in a universal joint of type cross shaft (600), comprising an end cap (200) disposed on the bearing outer ring (100), characterized in that, The outer circumferential surface of the end cap (200) includes a first curved surface (210) and a second curved surface (220). The second curved surface (220) is eccentrically disposed relative to the first curved surface (210). The sum of the radius of curvature of the second curved surface (220) and the eccentricity is greater than the radius of curvature of the first curved surface (210). The first curved surface (210) and the second curved surface (220) are connected by a smooth curved surface transition. It also includes an anti-rotation groove (310) provided on the fork head (300), the anti-rotation groove (310) being adapted to the outer circumferential surface of the end cap (200), and the end cap (200) being embedded in the anti-rotation groove (310).

2. The anti-rotation structure of the bearing outer ring (100) according to claim 1, characterized in that, The end cap (200) is provided with a threaded through hole, and the bearing outer ring (100) is provided with a threaded hole. The screw (400) passes through the threaded through hole and is screwed into the threaded hole to press the end cap (200) against the end face of the bearing outer ring (100).

3. The anti-rotation structure of the bearing outer ring (100) according to claim 2, characterized in that, The threaded holes and threaded through holes are evenly distributed on the Φ260mm pitch circle, with an adjacent hole spacing tolerance of ±0.05mm.

4. The anti-rotation structure of the bearing outer ring (100) according to claim 1, characterized in that, The depth of the anti-rotation groove (310) is greater than the thickness of the end cap (200), and the gap between the end cap (200) and the top of the anti-rotation groove (310) after the end cap (200) is embedded in the anti-rotation groove (310) is 0.5-1mm.

5. The anti-rotation structure for the bearing outer ring (100) according to claim 1, characterized in that, The anti-rotation groove (310) and the end cap (200) are H7 / g6 fit.

6. The anti-rotation structure of the bearing outer ring (100) according to claim 1, characterized in that, The end cap (200) and the bearing outer ring (100) together form an inner groove, which is used to install a sealing ring (500) to seal the bearing.

7. The anti-rotation structure for the bearing outer ring (100) according to claim 1, characterized in that, The first surface (210) has a radius of curvature of 144.5 mm, the second surface (220) has a radius of curvature of 137 mm, and the eccentricity between the first surface (210) and the second surface (220) is 18 mm.

8. A universal joint of the cross shaft (600) type, comprising the anti-rotation structure of the bearing outer ring (100) according to any one of claims 1-7, characterized in that, It also includes a fork head (300), a cross shaft (600), and a bearing. The fork head (300) is provided with a bearing hole, and the cross shaft (600) is rotatably connected to the fork head (300) through the bearing.

9. The universal joint of the cross shaft (600) type according to claim 8, characterized in that, The end cap (200) is made of carbon steel, the bearing outer ring (100) is made of low carbon alloy steel, and the fork head (300) is made of alloy steel.

10. The universal joint of the cross shaft (600) type according to claim 8, characterized in that, The outer ring (100) of the bearing is disposed in the bearing hole of the fork head (300) and is interference-fitted with the bearing hole.

Images