Shaft sleeve fixing structure
By combining the elastic retaining ring with the anti-rotation structure, the problem of loosening and positioning failure of power tool bushings under long-term impact is solved, thereby achieving bushing stability and extending tool life at a low cost.
Patent Information
- Application Number
- CN202520482802.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-19
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2035-03-19
AI Technical Summary
In existing power tools, the bushing fixing structure is prone to axial positioning failure and loosening under long-term impact use, and the die-casting process of mold insert is complex and costly.
The bushing employs an elastic retaining ring to engage with the anti-rotation structure on the outer wall of the bushing and the inner wall of the bushing mounting hole. The axial positioning of the bushing is achieved through the deformation and rebound of the elastic retaining ring, and circumferential anti-rotation is achieved through the engagement of the straight grooves on the outer wall of the bushing with the inner wall of the mounting hole. Assembly is performed using a combination of interference fit, transition fit, or loose fit.
It effectively solves the problems of bushing loosening and rotation failure, ensures the stability of the structure, extends the service life of the tool, and increases costs by almost nothing.
Smart Images
Figure CN223622008U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power tool technology, specifically to a bushing fixing structure. Background Technology
[0002] Currently, the fixing structure of output bushings, especially for output bushings in electric wrenches and impact bit housings, mainly employs two methods: interference fit and die casting with an integrated mold insert. Interference fit utilizes the dimensional difference between the bushing's outer diameter and the mounting hole's inner diameter to achieve bushing positioning through pressing. This positioning relies entirely on the compression and friction generated by the interference fit between the bushing and the inner wall of the mounting hole. However, under long-term impact conditions, this positioning method is prone to axial positioning failure.
[0003] In contrast, die casting with integrated mold inserts involves die casting the bushing as an insert into the entire structure. While this effectively solves the problem of bushing loosening and failure, aluminum die casting places extremely high demands on the production process and bushing materials. The high temperature and pressure during the die casting process can cause bushing deformation, which in turn affects the concentricity of the entire structure.
[0004] In summary, both of the currently commonly used bushing mounting structures have certain limitations in practical applications. Therefore, it is necessary to design a completely new bushing fixing structure to address the pain points of conventional mounting structures and meet practical application requirements. Utility Model Content
[0005] This utility model provides a bushing fixing structure to solve the problems mentioned in the background art.
[0006] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0007] A bushing fixing structure includes an elastic retaining ring, a bushing, and a head shell. The inner side of the head shell is provided with a bushing mounting hole for installing the bushing. The outer wall of the bushing is provided with an anti-rotation structure, which is used to restrict the rotation of the bushing in the circumferential direction within the inner wall of the bushing mounting hole. The elastic retaining ring is engaged with the outer ring of the bushing and is used to restrict the axial movement of the bushing within the inner wall of the bushing mounting hole.
[0008] Preferably, the inner wall of the bushing mounting hole is provided with a first groove, and the outer wall of the bushing is provided with a second groove. The first groove and the second groove correspond to form a retaining ring groove. When the elastic retaining ring is located between the bushing and the bushing mounting hole, it is disposed in the retaining ring groove.
[0009] Preferably, the anti-rotation structure includes a plurality of straight lines evenly distributed along the circumferential direction of the outer wall of the bushing, and the plurality of straight lines are all parallel to the axis of the bushing.
[0010] Preferably, the anti-rotation structure includes a punch connected to the outer wall of the bushing and teeth provided on the inner wall of the head shell bushing mounting hole and matching the punch.
[0011] Preferably, the anti-rotation structure includes an external spline connected to the outer wall of the bushing and an internal spline disposed on the inner wall of the bushing mounting hole of the head shell and cooperating with the external spline.
[0012] Preferably, the anti-rotation structure includes a dovetail structure disposed on the outer wall of the bushing and a groove disposed on the inner wall of the head shell bushing mounting hole and adapted to the dovetail structure.
[0013] Preferably, the elastic retaining ring is an open wire retaining ring.
[0014] Preferably, the elastic retaining ring is located at the middle position near the outer wall of the bushing in the axial direction, and the anti-rotation structure is divided into a first region and a second region by the elastic retaining ring.
[0015] Preferably, the bushing and the head shell are fitted in any one of the following ways: interference fit, transition fit, or loose fit.
[0016] Preferably, a bushing fixing structure further includes an impact block, a central shaft, and an output shaft, wherein the impact block, the central shaft, and the output shaft all cooperate with the bushing, and the impact block, the central shaft, and the output shaft are used as power transmission components that cooperate with the bushing.
[0017] By adopting the above technical solution, the beneficial effects achieved by this utility model are as follows:
[0018] In this invention, after the bushing is press-fitted into the bushing mounting hole inside the head housing, the straight lines on the outer wall of the bushing cooperate with the inner wall of the bushing mounting hole to prevent the bushing from rotating in the inner circumferential direction of the component. The axial positioning of the bushing is achieved by the springback of the open wire retainer ring into the first groove. Therefore, this fixing structure effectively solves the problems of loosening and rotation failure in the traditional press-fitting structure of bushings, ensures the stability of the entire structure, extends the service life of the tool, and hardly increases the cost. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0020] Figure 2 This is a schematic diagram of the retaining ring groove structure of this utility model.
[0021] Figure 3 This is a schematic diagram of the outer wall structure of the bushing of this utility model.
[0022] In the diagram: 1. Elastic retaining ring; 2. Bushing; 3. Head shell; 4. Impact block; 5. Central shaft; 6. Output shaft; 7. Retaining ring groove; 8. Straight groove. Detailed Implementation
[0023] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.
[0024] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.
[0025] like Figures 1-3 As shown, this utility model provides a bushing fixing structure, including an elastic retaining ring 1, a bushing 2, and a head shell 3. The inner side of the head shell 3 is provided with a bushing mounting hole for installing the bushing 2. The outer wall of the bushing 2 is provided with an anti-rotation structure, which is used to limit the rotation of the bushing 2 in the circumferential direction of the inner wall of the bushing mounting hole. The elastic retaining ring 1 is locked on the outer ring of the bushing 2 and is used to limit the axial movement of the bushing 2 in the inner wall of the bushing mounting hole.
[0026] As a further step, a first groove is provided on the inner wall of the bushing mounting hole, and a second groove is provided on the outer wall of the bushing 2. The first groove and the second groove correspond to form a retaining ring groove 7. When the elastic retaining ring 1 is located between the bushing 2 and the bushing mounting hole, it is placed in the retaining ring groove 7.
[0027] The elastic retaining ring 1 and the bushing 2 are pre-assembled. The outer wall of the bushing 2 has a second groove. Before the bushing 2 is pressed in, the elastic retaining ring 1 is pre-stuck in the second groove. During the pressing process of the bushing 2, the elastic retaining ring 1 is deformed and contracted into the second groove by the squeezing force of the inner wall of the bushing mounting hole. When the bushing 2 is pressed into the designated position, the first groove reserved in the inner wall of the bushing mounting hole provides deformation and rebound space for the elastic retaining ring 1, causing the elastic retaining ring 1 to rebound and be stuck in the retaining ring groove 7 between the bushing 2 and the head shell 3, thereby realizing the axial positioning of the bushing 2.
[0028] As a further step, the anti-rotation structure includes a plurality of straight lines 8 evenly distributed along the circumferential direction of the outer wall of the bushing 2, and the plurality of straight lines 8 are all parallel to the axis of the bushing 2.
[0029] Specifically, the straight grooves 8 on the outer wall of the bushing 2 cooperate with the inner wall of the bushing mounting hole on the head shell 3 to prevent the bushing 2 from rotating in the circumferential direction within the component. The straight grooves 8 provide reliable circumferential positioning, which solves the problems of loosening and rotation failure in the traditional press-fit structure of the bushing 2, extends the service life of the tool, and increases the cost by almost nothing.
[0030] As a first preferred embodiment, the anti-rotation structure includes a punch connected to the outer wall of the bushing 2 and teeth provided on the inner wall of the bushing mounting hole of the head shell 3 and matching the punch.
[0031] As a second preferred embodiment, the anti-rotation structure includes an external spline connected to the outer wall of the bushing 2 and an internal spline provided on the inner wall of the bushing mounting hole of the head shell 3 and cooperating with the external spline.
[0032] As a third preferred embodiment, the anti-rotation structure includes a flat tenon structure disposed on the outer wall of the bushing 2 and a groove disposed on the inner wall of the bushing mounting hole of the head shell 3 and adapted to the flat tenon structure.
[0033] In summary, the anti-rotation assembly methods of bushing 2 and head shell 3 include, but are not limited to, punching ribs and matching teeth, splines and flat tenon structures, and can also be other forms that can achieve circumferential anti-rotation, which will not be pointed out one by one in this article.
[0034] Furthermore, the elastic retaining ring 1 is an open steel wire retaining ring. It is worth noting that the material of the elastic retaining ring 1 can be steel wire or other elastic materials. Among them, the elastic materials can be: spring steel, beryllium bronze, stainless steel spring material, rubber elastomer or polyether ether ketone (PEEK), because the above-mentioned elastic materials all have good elastic recovery performance and certain strength, which can meet the axial positioning of the bushing 2.
[0035] Preferably, the elastic retaining ring 1 is an open steel wire retaining ring, which enables the steel wire to have a certain elastic modulus to meet the requirements of deformation and springback, and ensures the axial positioning of the bushing 2 and the head shell 3 after assembly.
[0036] It should be noted that the depth and width of the second groove on the bushing 2 for pre-clamping the elastic retaining ring 1 are adapted to the size of the elastic retaining ring 1 to ensure the stability of the elastic retaining ring 1 during pre-clamping and deformation processes.
[0037] Combination Figure 3 As shown, as a further step, the elastic retaining ring 1 is located at the middle position of the axial direction near the outer wall of the bushing 2, and the anti-rotation structure is divided into a first region and a second region by the elastic retaining ring 1. This design helps to ensure the stability of the axial positioning of the bushing 2.
[0038] It is worth noting that at least one elastic retaining ring 1 is provided on the outer wall of the bushing 2 in this paper. When there are multiple elastic retaining rings 1, the anti-rotation structure is divided into multiple areas by the elastic retaining rings 1, so that the design of multiple elastic retaining rings 1 can ensure the axial positioning of the bushing 2 and ensure the stability of the entire structure.
[0039] Furthermore, the bushing 2 and the head shell 3 are fitted in any one of the following ways: interference fit, transition fit, or loose fit.
[0040] Combination Figure 1As shown, as a further step, a bushing fixing structure also includes an impact block 4, a central shaft 5, and an output shaft 6. The impact block 4, the central shaft 5, and the output shaft 6 all cooperate with the bushing 2, and the impact block 4, the central shaft 5, and the output shaft 6 are used as power transmission components that cooperate with the bushing 2. One end of the output shaft 6 and the impact block 4 and the central shaft 5 are respectively located inside the head shell 3, and the cooperation of the impact block 4, the central shaft 5, the output shaft 6, and the bushing 2 can achieve stable power transmission.
[0041] The working principle and usage process of this utility model are as follows: First, the open wire retainer is pre-assembled with the bushing 2, so that the open wire retainer is pre-locked in the second groove, which cleverly solves the positioning problem of the open wire retainer during the press-fitting process. Then, during the press-fitting of the bushing 2, the open wire retainer will be deformed and contracted into the second groove by the squeezing force of the inner wall of the bushing mounting hole. When the bushing 2 is pressed into the designated position, the first groove reserved in the inner wall of the bushing mounting hole provides space for the open wire retainer to deform and rebound, causing the open wire retainer to rebound and lock into the first groove, thereby achieving the axial positioning of the bushing 2. The straight groove 8 on the outer wall of the bushing 2 cooperates with the inner wall of the bushing mounting hole on the mounting part to achieve the anti-rotation of the bushing 2 in the inner circumferential direction of the component. This effectively solves the problems of loosening and rotation failure in the traditional press-fitting structure of the bushing 2, ensures the stability of the entire structure, extends the service life of the tool, and the cost is almost not increased.
[0042] In this invention, the term "plural" refers to two or more items unless otherwise expressly defined. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0043] It should be noted that when a component is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0044] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0045] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.
Claims
1. A bushing fixing structure, characterized in that, The device includes an elastic retaining ring (1), a bushing (2), and a head shell (3). The inner side of the head shell (3) is provided with a bushing mounting hole for installing the bushing (2). The outer wall of the bushing (2) is provided with an anti-rotation structure, which is used to limit the rotation of the bushing (2) in the circumferential direction of the inner wall of the bushing mounting hole. The elastic retaining ring (1) is engaged with the outer ring of the bushing (2) and is used to limit the axial movement of the bushing (2) in the inner wall of the bushing mounting hole.
2. The bushing fixing structure according to claim 1, characterized in that, The inner wall of the bushing mounting hole is provided with a first groove, and the outer wall of the bushing (2) is provided with a second groove. The first groove and the second groove correspond to form a retaining ring groove (7). When the elastic retaining ring (1) is located between the bushing (2) and the bushing mounting hole, it is located in the retaining ring groove (7).
3. The bushing fixing structure according to claim 1, characterized in that, The anti-rotation structure includes a plurality of straight lines (8) evenly distributed along the circumferential direction of the outer wall of the bushing (2), and the plurality of straight lines (8) are all parallel to the axis of the bushing (2).
4. The bushing fixing structure according to claim 1, characterized in that, The anti-rotation structure includes a punch connected to the outer wall of the bushing (2) and teeth provided on the inner wall of the bushing mounting hole of the head shell (3) and matching the punch.
5. The bushing fixing structure according to claim 1, characterized in that, The anti-rotation structure includes an external spline connected to the outer wall of the bushing (2) and an internal spline located on the inner wall of the bushing mounting hole of the head shell (3) and cooperating with the external spline.
6. The bushing fixing structure according to claim 1, characterized in that, The anti-rotation structure includes a falcon structure on the outer wall of the bushing (2) and a groove on the inner wall of the bushing mounting hole of the head shell (3) that is adapted to the falcon structure.
7. The bushing fixing structure according to claim 1, characterized in that, The elastic retaining ring (1) is an open wire retaining ring.
8. The bushing fixing structure according to claim 1, characterized in that, The elastic retaining ring (1) is located at the middle position of the outer wall of the bushing (2) in the axial direction, and the anti-rotation structure is divided into a first region and a second region by the elastic retaining ring (1).
9. The bushing fixing structure according to claim 1, characterized in that, The bushing (2) and the head shell (3) are fitted in any one of the following ways: interference fit, transition fit, or loose fit.
10. A bushing fixing structure according to claim 1, characterized in that, It also includes an impact block (4), a central shaft (5) and an output shaft (6), which are all engaged with the bushing (2), and the impact block (4), central shaft (5) and output shaft (6) are used as power transmission components that engage with the bushing (2).