A nut anti-loosening structure for needle roller bearings

Abstract

This utility model relates to a nut anti-loosening structure for a needle roller bearing. The nut anti-loosening structure includes a needle roller bearing, a support shaft, an anti-loosening washer, and a nut. One end of the support shaft is interference-fitted with the inner ring of the needle roller bearing, and the other end is adapted to the anti-loosening washer. The anti-loosening washer has a D-shaped through hole, through which it is fitted onto the support shaft. The nut is fitted onto the support shaft and abuts against the anti-loosening washer. The solution provided in this application can form a non-circular fit between the D-shaped anti-loosening washer and the support shaft, and replaces "friction anti-loosening" with "mechanical hard limiting," eliminating the need for material deformation or chemical anti-loosening agents. It is particularly suitable for high-load, high-speed, frequent start-stop, or drastic temperature changes, effectively reducing equipment failures caused by nut loosening, improving production efficiency, and is simple in structure, requires no frequent maintenance, is environmentally friendly, and has low cost.

Description

Technical Field

[0001] This utility model relates to the field of nut anti-loosening technology, and in particular to an anti-loosening structure for a needle roller bearing nut. Background Technology

[0002] Needle roller bearings are rolling bearings used to transmit loads. Due to their excellent load-carrying capacity and space utilization, they are widely used in the automotive, machinery manufacturing, metallurgy, and precision instrument industries. In practical applications, a continuous axial preload is applied to the needle roller bearing using a nut, and the preload and axial position of the needle roller bearing are flexibly adjusted to ensure its stability and precision.

[0003] However, in scenarios involving high loads, high speeds, frequent start-stops, or drastic temperature changes, the risk of nuts loosening becomes prominent. For example, in the application of mold trolleys in foaming production lines, traditional anti-loosening structures such as ordinary locking nuts and spring washers (e.g.) become ineffective. Figure 1 As shown in the image, the nut's preload gradually decreases due to the effects of thermal expansion and contraction caused by frequent heating and cooling cycles. Simultaneously, vibrations and impacts during mold trolley operation further exacerbate the relative displacement between the nut and the ball bearing, easily causing the nut to loosen, leading to equipment failure and impacting production efficiency and safety. Existing technologies also use chemical anti-loosening agents to prevent nut loosening, but this method is not only costly and requires frequent maintenance, but also easily pollutes the environment.

[0004] Therefore, there is an urgent need to design a nut anti-loosening structure for needle roller bearings that can form a non-circular fit with the support shaft through a D-shaped anti-loosening washer and replace "friction anti-loosening" with "mechanical hard limiting". It does not rely on material deformation or chemical anti-loosening agents and is especially suitable for high-load, high-speed, frequent start-stop or drastic temperature change scenarios. It can effectively reduce equipment failures caused by nut loosening, improve production efficiency, and has a simple structure, requires no frequent maintenance, is environmentally friendly and low cost. Utility Model Content

[0005] To overcome the problems existing in related technologies, this application provides a nut anti-loosening structure for needle roller bearings. This nut anti-loosening structure can form a non-circular fit with the support shaft through a D-shaped anti-loosening washer, and replaces "friction anti-loosening" with "mechanical hard limiting". It does not rely on material deformation or chemical anti-loosening agents, and is especially suitable for high-load, high-speed, frequent start-stop or drastic temperature change scenarios. It can effectively reduce equipment failures caused by nut loosening, improve production efficiency, and has a simple structure, requires no frequent maintenance, is environmentally friendly and low in cost.

[0006] This application provides a nut anti-loosening structure for a needle roller bearing, comprising a needle roller bearing, a support shaft, an anti-loosening washer, and a nut; one end of the support shaft is interference-fitted with the inner ring of the needle roller bearing, and the other end is adapted to the anti-loosening washer; wherein, the anti-loosening washer is provided with a D-shaped through hole, and is sleeved on the support shaft through the D-shaped through hole; the nut is sleeved on the support shaft and abuts against the anti-loosening washer.

[0007] In a preferred embodiment of this application, the overall shape of the anti-loosening pad is square or circular; the D-shaped through hole is disposed in the central area of ​​the anti-loosening pad.

[0008] In a preferred embodiment of this application, the thickness of the anti-loosening pad is greater than or equal to 0.5 mm.

[0009] In a preferred embodiment of this application, the support shaft includes a narrow diameter end and a wide diameter end; the narrow diameter end and the wide diameter end are integrally formed; and the cross-section of the narrow diameter end is D-shaped.

[0010] In a preferred embodiment of this application, the narrow-diameter end includes a straight surface and a circular arc surface; the straight surface is a smooth plane; and the circular arc surface is provided with a thread adapted to the nut.

[0011] In a preferred embodiment of this application, an inclined arc surface is provided at the connection between the straight surface and the wide diameter end; a protrusion adapted to the inclined arc surface is also provided on the anti-loosening pad; the protrusion is provided on the side of the anti-loosening pad facing the needle roller bearing.

[0012] In a preferred embodiment of this application, the inclined arc surface is uneven; the surface of the convex part that abuts against the inclined arc surface is provided with an uneven structure adapted to the inclined arc surface.

[0013] The technical solution provided in this application has the following beneficial effects: The anti-loosening structure for the needle roller bearing nut provided in this application includes a needle roller bearing, a support shaft, an anti-loosening washer, and a nut. By providing a D-shaped through hole on the anti-loosening washer and forming a "non-circular fit" with the D-shaped support shaft, the anti-loosening washer cannot rotate circumferentially relative to the support shaft, thereby locking the support shaft. When the nut is subjected to vibration or temperature changes and has a tendency to rotate and loosen, its rotation tendency will be directly blocked by the anti-loosening washer, fundamentally preventing the relative rotation between the nut and the support shaft. This ensures that the preload of the nut remains stable over a long period and is not prone to loosening. Compared with the traditional spring washer structure, the solution provided in this application replaces "friction anti-loosening" with "mechanical hard limiting," eliminating the need for material elasticity or chemical adhesives. It is particularly suitable for high-load, high-speed, frequent start-stop, or drastic temperature changes, effectively reducing equipment failures caused by nut loosening, significantly improving the stability and safety of equipment operation, increasing production efficiency, and is simple in structure, requires no frequent maintenance, is environmentally friendly, and has low cost.

[0014] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0015] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0016] Figure 1 This is an exploded schematic diagram of the nut anti-loosening structure of a needle roller bearing shown in the background section of this application;

[0017] Figure 2 This is an exploded schematic diagram of the nut anti-loosening structure of the needle roller bearing shown in the embodiments of this application;

[0018] Figure 3 This is a schematic diagram of the anti-loosening structure of the nut for the needle roller bearing shown in the embodiments of this application;

[0019] Figure 4 This is a top view schematic diagram of the anti-detachment pad shown in the embodiments of this application;

[0020] Figure 5 This is a front view schematic diagram of the anti-detachment pad shown in the embodiment of this application.

[0021] Explanation of reference numerals in the attached figures:

[0022] 1. Needle roller bearing; 2. Support shaft; 21. Narrow diameter end; 211. Straight face; 212. Circular arc surface; 213. Thread; 22. Wide diameter end; 23. Inclined arc surface; 3. Anti-loosening pad; 31. D-shaped through hole; 32. Protrusion; 4. Nut; 5. Spring washer. Detailed Implementation

[0023] Preferred embodiments of the present application will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0024] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0025] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] In scenarios involving high loads, high speeds, frequent start-stop cycles, or drastic temperature changes, the risk of nuts loosening becomes prominent. For example, in the application of mold trolleys in foaming production lines, traditional anti-loosening structures such as ordinary locking nuts and spring washers (e.g.) are prone to loosening. Figure 1 As shown in the image, the nut's preload gradually decreases due to the effects of thermal expansion and contraction caused by frequent heating and cooling cycles. Simultaneously, vibrations and impacts during mold trolley operation further exacerbate the relative displacement between the nut and the ball bearing, easily causing the nut to loosen, leading to equipment failure and impacting production efficiency and safety. Existing technologies also use chemical anti-loosening agents to prevent nut loosening, but this method is not only costly and requires frequent maintenance, but also easily pollutes the environment.

[0027] To address the aforementioned issues, this application provides a nut anti-loosening structure for needle roller bearings. This structure uses a D-shaped anti-loosening washer to form a non-circular fit with the support shaft and replaces "friction anti-loosening" with "mechanical hard limiting." It does not rely on material deformation or chemical anti-loosening agents and is particularly suitable for scenarios with high loads, high speeds, frequent start-stops, or drastic temperature changes. It can effectively reduce equipment failures caused by nut loosening, improve production efficiency, and is simple in structure, requires no frequent maintenance, is environmentally friendly, and has low cost.

[0028] The technical solutions of the embodiments of this application are described in detail below with reference to the accompanying drawings.

[0029] Example

[0030] Please see Figures 1-5 The present application discloses a nut anti-loosening structure for a needle roller bearing, comprising a needle roller bearing 1, a support shaft 2, an anti-loosening washer 3, and a nut 4. The needle roller bearing 1, the anti-loosening washer 3, and the nut 4 are sequentially sleeved on the support shaft 2, and the nut 4 abuts against the anti-loosening washer 3.

[0031] Specifically, one end of the support shaft 2 is interference-fitted with the inner ring of the needle roller bearing 1, and the other end is adapted to the anti-loosening washer 3. For example, as shown... Figure 2 As shown, the support shaft 2 includes a narrow-diameter end 21 and a wide-diameter end 22, which are integrally formed. The wide-diameter end 22 is connected to the needle roller bearing 1. The cross-section of the narrow-diameter end 21 is D-shaped and is adapted to the anti-loosening pad 3. More specifically, the narrow-diameter end 21 includes a straight surface 211 and a circular arc surface 212. The straight surface 211 is a smooth plane, which facilitates the installation of the anti-loosening pad 3. The circular arc surface 212 is provided with a thread 213 adapted to the nut 4, which facilitates the threaded connection with the nut 4.

[0032] The anti-loosening pad 3 has a D-shaped through hole 31, and is fitted onto the support shaft 2 through the D-shaped through hole 31. Specifically, the anti-loosening pad 3 is made of carbon steel and has an overall square or circular shape. The D-shaped through hole 31 is located in the central area of ​​the anti-loosening pad 3. By making the anti-loosening pad 3 a square or circular plate with a D-shaped through hole 31, the friction between the anti-loosening pad 3 and the nut 4 and other abutting parts can be increased while adapting to the support shaft 2. To further improve the deformation capacity, compressive strength, and friction transmission capacity of the anti-loosening pad 3, the thickness of the anti-loosening pad 3 is greater than or equal to 0.5 mm.

[0033] Furthermore, to simplify the processing and reduce the risk of cuts to users from sharp corners, an inclined arc surface 23 is provided at the connection between the straight surface 211 and the wide-diameter end 22. The anti-loosening pad 3 also has a protrusion 32 adapted to the inclined arc surface 23, and the protrusion 32 is located on the side of the anti-loosening pad 3 facing the needle roller bearing 1. When the anti-loosening pad 3 is fitted onto the support shaft 2, the protrusion 32 faces the inclined arc surface 23 and abuts against it. Even further, to increase the friction between the anti-loosening pad and the support shaft 2, the inclined arc surface 23 is uneven, and the side of the protrusion 32 that abuts against the inclined arc surface 23 has a concave-convex structure adapted to the inclined arc surface 23.

[0034] Assembly steps:

[0035] The inner ring of the needle roller bearing 1 is press-fitted onto the wide-diameter end 22 of the support shaft 2, so that the support shaft 2 can be interference-fitted with the inner ring of the needle roller bearing 1. Then, the support shaft 2 is passed through other components (such as a mold trolley) and extended outward. Then, the anti-loosening pad 3 is fitted into the narrow-diameter end 21 of the support shaft 2 through the D-shaped through hole 31, and the protrusion 32 on the anti-loosening pad 3 abuts against the inclined arc surface 23. Finally, the nut 4 is screwed into the narrow-diameter end 21 of the support shaft 2 and tightened until it is tightly abutted against the end face of the anti-loosening pad 3 (tightening torque: 40 N·m), thereby completing the overall assembly.

[0036] Working principle:

[0037] After the nut 4 abuts against the anti-loosening washer 3, the preload force causes the anti-loosening washer 3 to fit tightly against the shoulder of the support shaft 2, forming a continuous axial pressure. Because the anti-loosening washer 3 forms a non-circular fit with the support shaft 2 through the D-shaped through-hole 31, the anti-loosening washer 3 cannot rotate circumferentially relative to the support shaft 2, thus locking the support shaft 2. (That is, when the needle roller bearing 1 rotates, the support shaft 2, the anti-loosening washer 3, and the nut 4 are all in a "relatively stationary state" and will not rotate with the needle roller bearing 1.) When the nut 4 is subjected to vibration or temperature changes and has a tendency to loosen, this tendency is directly blocked by the anti-loosening washer 3, thereby fundamentally preventing the relative rotation between the nut 4 and the support shaft 2. This ensures that the preload of the nut 4 remains stable over a long period, preventing the axial pressure from significantly decreasing due to thermal expansion and contraction (such as temperature changes when the mold trolley enters and exits the heating furnace). This allows the nut 4 to be stably fixed to the support shaft 2 for a long time under high load, high speed, frequent start-stop, or drastic temperature changes. Furthermore, through the mutual cooperation between the protrusion 32 of the anti-loosening washer and the inclined arc surface 23, the anti-loosening washer 3 is circumferentially fixed to the support shaft 2, further preventing the anti-loosening washer 3 from rotating and thus enhancing its ability to prevent the nut 4 from loosening.

[0038] Experimental verification:

[0039] Experimental group:

[0040] Install the anti-loosening structure of the needle roller bearing provided in this application onto the mold trolley. Then, place the mold trolley into a heating oven at 120°C for curing. After heating for 3 minutes, cool at room temperature for 5 minutes. Then repeat the above heating and cooling operation 100 times.

[0041] Control group:

[0042] Attachment Figure 1 The spring washer structure is installed on the mold trolley. Then the mold trolley is placed in a heating oven at 120°C for curing. After heating for 3 minutes, it is cooled at room temperature for 5 minutes. Then the above heating and cooling operation is repeated 100 times.

[0043] The experimental results are as follows:

[0044] Experimental group: After 100 cycles, the nut did not loosen and the equipment operated stably.

[0045] Control group: After 100 cycles, the nut loosened and the equipment became unstable.

[0046] In this embodiment, the anti-loosening structure for the needle roller bearing provided in this application includes a needle roller bearing, a support shaft, an anti-loosening washer, and a nut. By providing a D-shaped through hole on the anti-loosening washer, and forming a "non-circular fit" with the D-shaped support shaft, the anti-loosening washer cannot rotate circumferentially relative to the support shaft, thus locking the support shaft. When the nut is subjected to vibration or temperature changes and has a tendency to loosen, this tendency is directly blocked by the anti-loosening washer, fundamentally preventing relative rotation between the nut and the support shaft. This ensures that the preload of the nut remains stable over a long period, making it less prone to loosening. Compared to the traditional spring washer structure, the solution provided in this application replaces "friction anti-loosening" with "mechanical hard limiting," eliminating the need for material elasticity or chemical adhesives. It is particularly suitable for high-load, high-speed, frequent start-stop, or drastic temperature changes, effectively reducing equipment failures caused by nut loosening, significantly improving equipment stability and safety, increasing production efficiency, and offering a simple structure, requiring no frequent maintenance, being environmentally friendly, and low-cost.

[0047] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0048] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., may be used here to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figure. It should be understood that spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the figure.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A nut anti-loosening structure of a needle bearing, characterized by comprising: Includes needle roller bearing (1), support shaft (2), anti-loosening washer (3) and nut (4); One end of the support shaft (2) is interference-fitted with the inner ring of the needle roller bearing (1), and the other end is adapted to the anti-loosening pad (3); The anti-loosening pad (3) is provided with a D-shaped through hole (31), and is sleeved on the support shaft (2) through the D-shaped through hole (31); The nut (4) is sleeved on the support shaft (2) and abuts against the anti-loosening pad (3).

2. The anti-loosening structure for the nut of the needle roller bearing according to claim 1, characterized in that, The overall shape of the anti-loosening pad (3) is square or round; The D-shaped through hole (31) is located in the central area of ​​the anti-loosening pad (3).

3. The anti-loosening structure for the nut of the needle roller bearing according to claim 1, characterized in that, The thickness of the anti-loosening pad (3) is greater than or equal to 0.5 mm.

4. The anti-loosening structure for the nut of the needle roller bearing according to claim 1, characterized in that, The support shaft (2) includes a narrow diameter end (21) and a wide diameter end (22); The narrow diameter end (21) and the wide diameter end (22) are integrally formed; Furthermore, the cross-section of the narrow-diameter end (21) is D-shaped overall.

5. The nut anti-loosening structure for the needle roller bearing according to claim 4, characterized in that, The narrow-diameter end (21) includes a straight surface (211) and a circular arc surface (212); The straight surface (211) is a smooth plane; The circular arc surface (212) is provided with a thread (213) that is compatible with the nut (4).

6. The nut anti-loosening structure for the needle roller bearing according to claim 5, characterized in that, An inclined arc surface (23) is also provided at the connection between the straight surface (211) and the wide diameter end (22); The anti-loosening pad (3) is also provided with a protrusion (32) that is adapted to the inclined arc surface (23); The protrusion (32) is provided on the side of the anti-loosening pad (3) facing the needle roller bearing (1).

7. The nut anti-loosening structure for the needle roller bearing according to claim 6, characterized in that, The inclined arc surface (23) is uneven; The protrusion (32) has a concave-convex structure that matches the inclined arc surface (23) on the side that abuts against the protrusion (32).

Images