A self-locking bolt connection structure for a speed reducer to prevent loosening
By employing a reverse thread self-locking and mechanical locking structure, the problem of loosening of the connection between the micro motor and the reducer in a vibration environment is solved, achieving a stable connection and long-term reliability. This design is suitable for connection points between micro motors and reducers in space-constrained environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG QINGCHANG TRANSMISSION TECH CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-05-26
AI Technical Summary
The bolted connection between the micro motor and the reducer is prone to loosening in a vibrating environment, leading to transmission failure, noise, and component damage. Traditional anti-loosening measures are difficult to install in space-constrained scenarios.
It adopts a dual mechanism of reverse thread self-locking and mechanical engagement. The reverse thread counteracts the loosening torque, and the mechanical engagement prevents axial movement. Combined with the anti-loosening component, it achieves a self-locking connection.
It maintains stable connection under vibration conditions, prevents loosening, extends equipment reliability and service life, and is easy to operate without taking up extra space.
Smart Images
Figure CN224283190U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of micro motor technology, specifically relating to a self-locking bolt connection structure for a speed reducer to prevent loosening. Background Technology
[0002] The integrated application of micro-motors and reducers is extremely widespread in fields such as micro-automation equipment, precision instruments, and robots. To meet the stringent requirements of miniaturization and lightweighting, the connection structure between the two is typically designed to be extremely compact, with significant space constraints. Therefore, ordinary bolts are commonly used for fastening. However, in actual operation, especially in scenarios such as industrial automation or mobile robots, these devices inevitably operate under continuous or intermittent mechanical vibration for extended periods.
[0003] This vibration environment poses a severe challenge to the bolted connection between the micromotor and the reducer. Ordinary bolts rely on the friction generated by their initial preload to resist loosening, but their anti-loosening performance has inherent limitations. Under long-term, repeated vibration stress, the friction between the bolt connection interface gradually decreases, leading to a reduction in bolt preload and eventually loosening. This loosening process is gradual; initially, it may only manifest as slight axial movement, but if left uncontrolled, it will eventually cause the precision fit between the micromotor's output shaft and the reducer's input hole to fail. Once the two separate or become significantly loose, it not only causes a momentary interruption of transmission or a sharp drop in power transmission efficiency, generating abnormal noise, but may also trigger a chain reaction of failures such as motor shaft freewheeling and damage to the reducer's input shaft, seriously threatening the reliability, accuracy, and service life of the entire transmission system.
[0004] While traditional anti-loosening measures such as spring washers and double nuts exist, their installation is often limited in space-constrained connection scenarios like those between micromotors and reducers. To address these issues, this invention proposes a self-locking bolt connection structure for reducers that is compact, reliable in preventing loosening, and suitable for connections between micromotors and reducers, thus solving the transmission failure problem caused by bolt loosening under vibration conditions. Utility Model Content
[0005] To achieve the above objectives, this utility model provides the following technical solution: a self-locking bolt connection structure for a speed reducer, comprising a motor and a speed reducer. Connecting portions are integrally connected to both sides of the motor output housing, and a positioning groove is provided between the two connecting portions. Positioning plates are integrally connected to both sides of the speed reducer housing, and an anti-loosening component is provided between the positioning plates and the motor housing. Threaded through holes are provided at all four corners of the speed reducer housing. A nut sleeve is threadedly connected to one end of each threaded through hole, and an internal thread groove is provided inside the nut sleeve. A locking bolt is threadedly connected to the other end of each threaded through hole, and an external thread post is integrally connected to the end of the locking bolt. The internal thread groove and the external thread post are compatible.
[0006] As a preferred technical solution of this utility model, the thread directions at both ends of the threaded through hole are opposite, and the threads on the outside of the nut sleeve and the locking bolt are also opposite.
[0007] As a preferred embodiment of this utility model, the internal thread direction of the internal thread groove is consistent with the thread direction of the threaded through hole connecting the locking bolt, and the thread direction of the external threaded column is consistent with the thread direction of the locking bolt.
[0008] As a preferred technical solution of this utility model, the anti-loosening component includes a movable plate and a first anti-loosening tooth. The movable plate and the positioning plate are hinged at their ends, and a torsion spring is installed at the hinge. The first anti-loosening tooth is fixed on both sides of the motor body, and a second anti-loosening tooth is integrally connected to the inner side of the movable plate.
[0009] As a preferred embodiment of this utility model, a lever plate is integrally connected to the hinge joint of the movable plate, and a clearance groove is provided on the positioning plate corresponding to the lever plate.
[0010] Compared with the prior art, the beneficial effects of this utility model are:
[0011] (1) This utility model differs from the traditional bolt structure that relies on friction to prevent loosening. It effectively resists the preload reduction caused by vibration through a dual mechanism of "thread reverse self-locking" and "mechanical locking". The thread reverse design can automatically offset the loosening torque during vibration, while the mechanical locking structure prevents axial movement through physical limitation. The two work together to keep the connection tight under long-term vibration conditions, avoiding transmission interruption, noise and component damage caused by bolt loosening. When the connection interface is slightly loose, the anti-loosening components (first anti-loosening tooth and second anti-loosening tooth) limit the movement before the bolt connection, preventing further loosening. If the vibration intensifies, the thread reverse self-locking mechanism intervenes simultaneously, maintaining the bolt preload through torque interlocking, forming "double insurance", which significantly extends the reliable operation cycle of the equipment under harsh conditions.
[0012] (2) The nut sleeve and locking bolt are integrated at both ends of the threaded through hole, eliminating the need for additional auxiliary anti-loosening parts such as spring washers and double nuts, resulting in a highly integrated structure. The anti-loosening components (movable plate, first anti-loosening clip, etc.) are arranged along the side of the motor and reducer housing, occupying little space. This is particularly suitable for the confined space of the connection between the micro motor and the reducer, solving the problem that traditional anti-loosening measures cannot be installed due to their large size.
[0013] (3) The connection part, positioning groove, and positioning plate work together to achieve precise alignment during installation, ensuring the coaxiality of the bolt connection and the anti-loosening component, and avoiding anti-loosening failure due to installation deviation. At the same time, the positioning structure and the anti-loosening component are independent yet work together, ensuring initial installation accuracy and improving connection stability through a double anti-loosening mechanism. During disassembly, the mechanical locking can be released simply by using a lever, and the bolts can be removed with conventional tools, without the need for special equipment; during installation, the positioning structure assists in alignment, and the bolts and nuts are tightened in sequence to achieve double locking, making the operation process simple and maintenance efficient. Attached Figure Description
[0014] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:
[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0016] Figure 2 This is a schematic cross-sectional view of the threaded through hole in the reducer housing of this utility model.
[0017] Figure 3 This is a schematic diagram of the anti-loosening component in this utility model;
[0018] In the diagram: 1. Motor; 2. Reducer; 3. Connecting part; 4. Positioning groove; 5. Positioning plate; 6. Threaded through hole; 7. Nut sleeve; 8. Internal threaded groove; 9. Locking bolt; 10. External threaded column; 11. Movable plate; 12. First anti-loosening tooth; 13. Torsion spring; 14. Second anti-loosening tooth; 15. Alternating plate; 16. Relief groove. Detailed Implementation
[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0020] Example
[0021] Please see Figure 1-3This utility model provides the following technical solution: a self-locking bolt connection structure for a speed reducer, including a motor 1 and a speed reducer 2. Connecting parts 3 are integrally connected to both sides of the housing at the output end of the motor 1. A positioning groove 4 is provided between the two connecting parts 3. Positioning plates 5 are integrally connected to both sides of the housing of the speed reducer 2. An anti-loosening component is provided between the positioning plates 5 and the housing of the motor 1. Threaded through holes 6 are provided at the four corners of the housing of the speed reducer 2. A nut sleeve 7 is threadedly connected to one end of the threaded through hole 6. An internal thread groove 8 is provided inside the nut sleeve 7. A locking bolt 9 is threadedly connected to the other end of the threaded through hole 6. An external thread post 10 is integrally connected to the end of the locking bolt 9. The internal thread groove 8 and the external thread post 10 are compatible.
[0022] In order to form a self-locking torque through the reverse thread engagement, so that the nut sleeve 7 and the locking bolt 9 abut against each other during vibration to counteract the tendency to loosen, in this embodiment, as a preferred technical solution of the present invention, the thread directions at both ends of the threaded through hole 6 are opposite, and the threads on the outside of the nut sleeve 7 and the locking bolt 9 are also opposite; the internal thread direction of the internal thread groove 8 is consistent with the thread direction of the threaded through hole 6 connecting the locking bolt 9, and the thread direction of the external thread column 10 is consistent with the thread direction of the locking bolt 9.
[0023] In order to construct a mechanical locking anti-loosening structure, the axial relative displacement between the motor 1 and the reducer 2 is prevented by the one-way locking of the second anti-loosening tooth 14 and the first anti-loosening tooth 12. In this embodiment, as a preferred technical solution of the present invention, the anti-loosening component includes a movable plate 11 and a first anti-loosening tooth 12. The movable plate 11 and the positioning plate 5 are hinged at their ends, and a torsion spring 13 is installed at the hinge. The first anti-loosening tooth 12 is fixed on both sides of the motor 1 body, and the second anti-loosening tooth 14 is integrally connected to the inner side of the movable plate 11.
[0024] In order to facilitate the disassembly of the anti-loosening component, the mechanical lock can be quickly released by the cooperation of the lever plate 15 and the clearance groove 16. In this embodiment, as a preferred technical solution of the present invention, the lever plate 15 is integrally connected at the hinge of the movable plate 11, and the clearance groove 16 is opened on the positioning plate 5 corresponding to the lever plate 15.
[0025] In summary, with the help of the above-described technical solution of this utility model,
[0026] The self-locking anti-loosening mechanism of bolted connections: When the equipment is running in a vibrating environment, if the locking bolt 9 tends to loosen due to vibration (such as clockwise rotation), the threads at both ends of the threaded through hole 6 will be reversed, and the nut sleeve 7 will be tightened counterclockwise by the reverse torque. The threaded connection between the internal thread groove 8 and the external threaded column 10 will tighten synchronously, thereby offsetting the loosening tendency through "reverse thread interlocking" and maintaining the stability of the preload.
[0027] Axial force transmission and self-locking: After the locking bolt 9 is screwed into the threaded through hole 6, the external threaded post 10 and the internal threaded groove 8 of the nut sleeve 7 form a secondary lock. When vibration causes the frictional force at the connection interface to decrease, the reverse thread structure of the locking bolt 9 and the nut sleeve 7 will convert the axial force into a mutual tightening torque to prevent the bolt from loosening as a whole. The loosening direction of the locking bolt 9 and the tightening direction of the nut sleeve 7 restrict each other, forming a "dynamic self-locking" effect.
[0028] Working mechanism of the mechanical locking anti-loosening component: In the anti-loosening component, the movable plate 11 is hinged to the positioning plate 5 through the torsion spring 13. Under normal conditions, the torsion spring 13 drives the movable plate 11 to flip inward, so that the second anti-loosening tooth 14 on the inner side engages with the first anti-loosening tooth 12 on both sides of the motor 1 body. The tooth profile of the first anti-loosening tooth 12 and the second anti-loosening tooth 14 is designed as a unidirectional inclined structure. During installation, the second anti-loosening tooth 14 will slide along the inclined surface of the first anti-loosening tooth 12 and eventually engage. When the reducer 2 tends to disengage from the motor 1 (such as axial pull-out), the mechanical engagement is used to prevent the relative movement of the two, thereby preventing the loosening of the connection interface.
[0029] Detachable structure design: During disassembly, by moving the lever 15 to press it into the relief groove 16, the movable plate 11 is driven to rotate around the hinge axis and compress the torsion spring 13, so that the second anti-loosening tooth 14 is disengaged from the first anti-loosening tooth 12, and the mechanical lock is released. At this time, the locking bolt 9 and the nut sleeve 7 can be disassembled simultaneously to separate the motor 1 from the reducer 2. The operation is convenient and does not damage the components.
[0030] Finally, it should be noted that, in this utility model, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A self-locking bolt connection structure for a speed reducer, comprising a motor (1) and a speed reducer (2), characterized in that: The output end of the motor (1) has a connecting part (3) integrally connected to both sides of the housing. A positioning groove (4) is provided between the two connecting parts (3). The reducer (2) has a positioning plate (5) integrally connected to both sides of the housing. An anti-loosening component is provided between the positioning plate (5) and the housing of the motor (1). Threaded through holes (6) are provided at the four corners of the reducer (2). A nut sleeve (7) is threaded to one end of the threaded through hole (6). An internal thread groove (8) is provided inside the nut sleeve (7). A locking bolt (9) is threaded to the other end of the threaded through hole (6). An external thread post (10) is integrally connected to the end of the locking bolt (9). The internal thread groove (8) and the external thread post (10) are compatible.
2. The anti-loosening self-locking bolt connection structure for a speed reducer according to claim 1, characterized in that: The threads at both ends of the threaded through hole (6) are opposite in direction, and the threads on the outside of the nut sleeve (7) that it is adapted to are also opposite to the threads on the outside of the locking bolt (9).
3. The anti-loosening self-locking bolt connection structure for a speed reducer according to claim 1, characterized in that: The internal thread direction of the internal thread groove (8) is consistent with the thread direction of the locking bolt (9) connected to the threaded through hole (6), and the thread direction of the external threaded column (10) is consistent with the thread direction of the locking bolt (9).
4. The anti-loosening self-locking bolt connection structure for a speed reducer according to claim 1, characterized in that: The anti-loosening component includes a movable plate (11) and a first anti-loosening tooth (12). The movable plate (11) and the positioning plate (5) are hinged at their ends, and a torsion spring (13) is installed at the hinge. The first anti-loosening tooth (12) is fixed on both sides of the motor (1) body. The inner side of the movable plate (11) is integrally connected with a second anti-loosening tooth (14).
5. The anti-loosening self-locking bolt connection structure for a speed reducer according to claim 4, characterized in that: The movable plate (11) is integrally connected to the hinge with a lever plate (15), and the positioning plate (5) is provided with a clearance groove (16) corresponding to the lever plate (15).