A self-locking structure of a linear actuator

Abstract

The present invention provides a self-locking structure for a linear actuator, belonging to the field of linear actuators. The self-locking structure comprises a motor shaft and a friction ring. The friction ring includes friction plates and connecting ribs connected to the friction plates. The friction plates are provided with at least two elastic members, each of which is capable of rebounding after bending. The at least two friction plates are interference-fitted with the motor shaft, and the friction plates achieve self-locking by abutting against the motor shaft through elastic deformation of the connecting ribs. The advantage of the present invention is that this structure is more convenient for users. The present invention is used to achieve self-locking in a linear actuator.

Description

Technical field

[0001] The invention relates to a self-locking structure of a linear actuator and belongs to the field of linear actuators. [Background Technology]

[0002] Linear actuators are currently widely used in various fields, including electric lifting tables, electric beds, electric sofas, etc. The structure of this linear actuator usually includes a drive motor, a rotating screw, and a transmission nut. The drive motor drives the rotating screw to rotate, and when the rotating screw rotates, it drives the transmission nut to move axially. The transmission nut can be connected to the driven object to achieve the driving purpose.

[0003] Typically, linear actuators use torsion springs for self-locking. By utilizing the tightening and loosening properties of the torsion spring, the linear actuator can achieve self-locking. However, when the torsion spring is used for self-locking, collisions between the torsion spring and the worm gear or the torsion spring seat occur when the linear actuator is extended or retracted, generating a loud noise, thereby affecting user use and making it inconvenient for the user. [Summary of the invention]

[0004] The technical problem to be solved by the present invention is to provide a self-locking structure of a linear actuator, which is more convenient for users to use.

[0005] To solve the above technical problems, the self-locking structure of the linear actuator of the present invention includes a motor shaft and a friction ring, the friction ring includes a friction plate and a connecting rib connected to the friction plate, there are at least two friction plates, the connecting rib is an elastic part that can rebound after bending deformation, the at least two friction plates are interference fit with the motor shaft, and the friction plates are self-locking by abutting against the motor shaft through the elastic deformation of the connecting rib.

[0006] Preferably, the connecting rib comprises a fixing section and a connecting section that are bent relative to each other, one end of the connecting section is connected to the friction plate, and the other end is connected to the fixing section.

[0007] Preferably, connecting ribs are provided at both ends of the friction plate.

[0008] Preferably, among the at least two friction plates, the fixed sections of two adjacent friction plates are connected.

[0009] Preferably, the friction ring further comprises a ring body, and the fixing section is fixed on the ring body.

[0010] Preferably, the fixed section is fixed relatively to the upper surface of the ring body, and a positioning groove is formed between the ring body and the friction plate and the two connecting ribs at both ends of the friction plate. The self-locking structure includes a shell, and a positioning protrusion is provided on the shell. The friction ring is axially and circumferentially positioned relative to the shell by engaging the positioning protrusion with the positioning groove.

[0011] Preferably, the two fixed sections at both ends of the friction plate are distributed in an eight-shaped shape.

[0012] Preferably, the friction plate is an arc-shaped plate.

[0013] Preferably, an oil groove for accommodating high-temperature resistant grease is provided on the inner surface of the arc-shaped plate.

[0014] Preferably, the friction ring is a PPS plastic ring or a PEEK plastic ring.

[0015] Beneficial effects of the present invention:

[0016] First, compared with the torsion spring self-locking in the prior art, the present invention achieves self-locking through the friction between the motor shaft and the friction plate, so that the linear actuator can achieve self-locking. At the same time, the linear actuator makes less noise when extending and contracting, making it more convenient for users to use. Secondly, the friction plate abuts against the motor shaft through the elastic deformation of the connecting rib, so that the friction plate can squeeze the motor shaft, thereby increasing the friction between the friction plate and the motor shaft and improving the self-locking ability of the linear actuator. The connecting rib is an elastic part that can rebound after bending deformation, so that the connecting rib can bend and deform to reduce the overall length of the friction plate and the connecting rib to facilitate the installation of the friction plate, and a pressure can be applied to the friction plate through the rebound force after bending, so that the friction plate can squeeze the electrode shaft to achieve self-locking. In addition, there are at least two friction plates, so that self-locking can be achieved by friction between multiple friction plates and the motor shaft, thereby improving the self-locking ability of the friction ring.

[0017] These features and advantages of the present invention will be disclosed in detail in the following specific embodiments and drawings.

Brief Description of the Drawings

[0018] The present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0019] Figure 1 Schematic diagram of the self-locking structure of the present invention;

[0020] Figure 2 for Figure 1 An enlarged schematic diagram at point A;

[0021] Figure 3 Schematic diagram of the friction ring in the present invention;

[0022] Figure 4 It is the front view of the friction ring in the present invention.

[0023] Reference numerals:

[0024] 1 motor shaft, 2 friction ring, 3 positioning protrusion, 4 housing, 5 friction plate, 6 fixed section, 7 connecting section, 8 ring body, 9 oil groove. [Specific implementation method]

[0025] The following is an explanation and description of the technical solutions of the embodiments of the present invention in conjunction with the drawings of the embodiments of the present invention. However, the following embodiments are only preferred embodiments of the present invention and are not exhaustive. Based on the embodiments in the implementation manner, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0026] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0027] like Figures 1 to 4 As shown, the preferred structure of the self-locking structure of the linear actuator of this embodiment includes a motor shaft 1 and a friction ring 2. The friction ring 2 includes a friction plate 5 and a connecting rib connected to the friction plate 5. There are at least two friction plates 5. The connecting rib is an elastic member that can rebound after bending deformation. The at least two friction plates 5 are interference fit with the motor shaft 1. The friction plates 5 are self-locking by abutting against the motor shaft 1 through the elastic deformation of the connecting rib.

[0028] Beneficial effects of the present invention:

[0029] First, compared with the torsion spring self-locking in the prior art, the present invention uses the friction between the motor shaft 1 and the friction plate 5 to achieve self-locking, so that the linear actuator can achieve self-locking. At the same time, the linear actuator makes less noise when extending and retracting, making it more convenient for users to use. Secondly, the friction plate 5 abuts against the motor shaft 1 through the elastic deformation of the connecting rib, so that the friction plate 5 can squeeze the motor shaft 1, thereby increasing the friction between the friction plate 5 and the motor shaft 1 and improving the self-locking ability of the linear actuator. The connecting rib is an elastic member that can rebound after bending deformation, so that the connecting rib can bend and deform to reduce the overall length of the friction plate 5 and the connecting rib to facilitate the installation of the friction plate 5, and a pressure can be applied to the friction plate 5 through the rebound force after bending, so that the friction plate 5 can squeeze the electrode shaft to achieve self-locking. In addition, there are at least two friction plates 5, so that self-locking can be achieved by friction between multiple friction plates 5 and the motor shaft 1, thereby improving the self-locking ability of the friction ring 2.

[0030] In order to optimize the structure of the connecting rib, in this embodiment, the connecting rib preferably includes a relatively bent fixed section 6 and a connecting section 7, one end of the connecting section 7 is connected to the friction plate 5, and the other end is connected to the fixed section 6. When the friction plate 5 is installed, the connecting rib is deformed by being squeezed by the motor shaft 1 and the housing 4. At this time, the connecting section 7 on the connecting rib can squeeze the fixed section 6, so that the connecting section 7 can move in a direction close to the fixed section 6, thereby changing the bending angle between the connecting section 7 and the fixed end, so that the connecting rib is bent and deformed. The relatively bent fixed section 6 and the connecting section 7 are used to achieve bending deformation, so that the connecting rib can be deformed by shortening its own length. The length of the connecting rib refers to the shortest distance between its two ends. At this time, the connecting rib can be bent in multiple directions.

[0031] In order to optimize the structure of the friction ring 2, in this embodiment, it is preferred that both ends of the friction plate 5 are provided with connecting ribs. The friction plate 5 is supported by the two connecting ribs, so that the friction plate 5 is subjected to more uniform force, and it is prevented that when only one end is supported by the connecting rib, the pressure of the other end squeezing the motor shaft 1 is small and easy to change due to the lack of support from the connecting rib, thereby causing unstable self-locking. By providing connecting ribs at both ends, the pressure of the friction plate 5 squeezing the motor shaft 1 can be large and not easy to change, so that the friction force between the friction plate 5 and the motor shaft 1 can be increased and not easy to change, thereby making the self-locking more stable. In addition, the connecting ribs at both ends of the friction ring 2 include relatively bent fixed sections 6 and connecting sections 7. When the friction ring 2 is subjected to pressure perpendicular to its surface, When a force is applied to the friction ring 2, the friction ring 2 can squeeze the connecting ribs at both ends thereof, so that the fixed section 6 and the connecting section 7 in the connecting rib are brought closer to each other to reduce the length of the connecting rib, thereby allowing the friction plate 5 to reduce the overall length of the friction plate 5 and the connecting rib through the deformation of the connecting rib, thereby allowing the friction plate 5 to be interference fitted between the motor shaft 1 and the housing 4. At the same time, with the connecting rib of this structure, when the friction ring 2 is subjected to a force along the tangential direction of the motor shaft 1, the friction plate 5 can move together with the motor shaft 1 through the deformation of the connecting rib and undergo a slight displacement or a tendency to slightly displace relative to the original position, so that the friction force between the friction plate 5 and the motor shaft 1 along the tangential direction of the motor shaft 1 can be increased through the deformation elastic force of the connecting rib, thereby further enhancing the self-locking ability of the friction ring 2.

[0032] To facilitate the installation of the friction ring 2, in this embodiment, it is preferred that the fixed sections 6 of two adjacent friction plates 5 of the at least two friction plates 5 are connected, that is, multiple friction plates 5 can be connected end to end to form a ring body 8, so that the friction ring 2 only needs to be sleeved on the motor shaft 1 when installing, which facilitates the installation of the friction ring 2.

[0033] In order to facilitate the installation and positioning of the friction ring 2, in this embodiment, the friction ring 2 preferably further includes a ring body 8. The fixing section 6 is fixed to the ring body 8. Each connecting rib is fixed by the ring body 8, so that multiple friction plates 5 can be connected through the ring body 8, thereby making it more convenient to install the friction ring 2. At the same time, the ring body 8 is sleeved inside the outer shell 4, making it more convenient to position the friction ring 2. In addition, the ring body 8 can also limit the axial movement of the friction ring 2.

[0034] In order to enable the friction ring 2 to be positioned, in this embodiment, the fixing section 6 is preferably fixed relatively to the upper surface of the ring body 8, and a positioning groove is formed between the ring body 8 and the friction plate 5 and the two connecting ribs at both ends of the friction plate 5. The self-locking structure includes a shell 4, and the shell 4 is provided with a positioning protrusion 3. The friction ring 2 is axially and circumferentially positioned relative to the shell 4 by engaging the positioning protrusion 3 with the positioning groove. The engagement of the positioning protrusion 3 with the positioning groove enables the friction ring 2 to be positioned relative to the shell 4, thereby facilitating the installation of the friction ring 2.

[0035] In order to optimize the distribution position of the two connecting ribs at both ends of the friction plate 5, in this embodiment, the two fixed sections 6 at both ends of the friction plate 5 are preferably distributed in an eight-shaped shape. With this structure, the two connecting ribs at both ends of the friction plate 5 are bent in opposite directions, so that when the connecting ribs are bent and deformed, the bending angles between the two fixed sections 6 and the connecting sections 7 can move in opposite directions, which facilitates the bending deformation of the connecting ribs. At the same time, it can prevent the two connecting ribs from bending in directions away from each other, which will cause them to contact and form a limit with the connecting ribs on the adjacent friction plates 5, resulting in the connecting ribs being unable to bend and deform, and thus causing the friction ring 2 to be unable to be interference fitted with the motor shaft 1.

[0036] In order to optimize the shape of the friction plate 5, in this embodiment, the friction plate 5 is preferably an arc-shaped plate. The shape of the arc-shaped plate can increase the contact area between the friction plate 5 and the motor shaft 1, thereby increasing the friction force between the friction plate 5 and the motor shaft 1 and improving the self-locking ability. In this embodiment, the diameter of the arc-shaped plate is preferably equal to the diameter of the motor shaft 1.

[0037] In order to prevent the friction ring 2 from being damaged and causing a decrease in the self-locking ability when the motor shaft 1 rotates at high speed, in this embodiment, an oil groove 9 for accommodating high-temperature resistant grease is preferably provided on the inner surface of the arc plate. By arranging heat-resistant high-temperature grease in the oil groove 9, the heat-resistant high-temperature grease can be used for lubrication without affecting the self-locking ability of the friction ring 2, thereby preventing the high-speed friction between the motor shaft 1 and the friction plate 5 from causing smoke and the like when the motor shaft 1 rotates at high speed, thereby preventing the friction plate 5 from being damaged.

[0038] For this purpose, in this embodiment, the friction ring 2 is preferably a PPS plastic ring or a PEEK plastic ring. PPS plastic (polyphenylene sulfide) is a thermoplastic special engineering plastic with excellent comprehensive performance. Its outstanding features are high temperature resistance, corrosion resistance and excellent mechanical properties. Polyetheretherketone (PEEK) resin is a special engineering plastic with excellent performance. Compared with other special engineering plastics, it has more significant advantages, such as resistance to high temperatures of 260 degrees, excellent mechanical properties, good self-lubrication, resistance to chemical corrosion, flame retardancy, peeling resistance, wear resistance, resistance to strong nitric acid, concentrated sulfuric acid, radiation resistance and super mechanical properties. PPS plastic ring or PEEK plastic ring is selected so that when the motor is continuously running at 200-300°C, the friction ring 2 can be unaffected by the heat of the motor, and the inner hole formed by its multiple arc plates will not change due to the influence of motor heat, so that the friction ring 2 can still be used normally at high temperatures.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art will understand that the present invention includes, but is not limited to, the contents described in the drawings and the above specific embodiments. Any modifications that do not deviate from the functional and structural principles of the present invention are intended to be included within the scope of the claims.

Claims

1. A self-locking structure for a linear actuator, comprising a motor shaft and a friction ring, wherein the friction ring comprises a friction plate and a connecting rib connected to the friction plate, characterized in that: The friction plates have at least two, and the connecting ribs are elastic parts that can rebound after bending deformation. The at least two friction plates are interference fitted with the motor shaft, and the friction plates are self-locking by abutting against the motor shaft through the elastic deformation of the connecting ribs; the connecting ribs include a relatively bent fixed section and a connecting section, one end of the connecting section is connected to the friction plate, and the other end is connected to the fixed section; the friction ring also includes a ring body, and the fixed section is fixed on the ring body; the fixed section is relatively fixed to the upper surface of the ring body, and a positioning groove is formed between the ring body and the friction plate and the two connecting ribs at both ends of the friction plate. The self-locking structure includes a shell, and a positioning protrusion is provided on the shell. The friction ring is axially and circumferentially positioned relative to the shell by engaging the positioning protrusion with the positioning groove, and multiple friction plates are connected through the ring body.

2. The self-locking structure of a linear actuator according to claim 1, wherein: Both ends of the friction plate are provided with connecting ribs.

3. The self-locking structure of a linear actuator according to claim 2, wherein: Among the at least two friction plates, the fixed sections of two adjacent friction plates are connected.

4. The self-locking structure of a linear actuator according to claim 1, wherein: The two fixing sections at both ends of the friction plate are distributed in an eight-shaped pattern.

5. The self-locking structure of a linear actuator according to claim 1, wherein: The friction plate is an arc-shaped plate.

6. The self-locking structure of a linear actuator according to claim 5, characterized in that: An oil groove for accommodating high-temperature resistant grease is provided on the inner surface of the arc-shaped plate.

7. The self-locking structure of a linear actuator according to claim 1, wherein: The friction ring is a PPS plastic ring or a PEEK plastic ring.

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