A one-way self-locking device for linear drive motor

Abstract

The present invention discloses a one-way self-locking device for a linear drive motor. The device comprises a friction ring fitted over the rear end of the motor shaft. The friction ring is an elastic circular ring composed of multiple arc-shaped pieces connected end to end. The friction ring and the motor shaft have an interference fit, resulting in a pre-tightened friction force. The device also comprises an elastic externally threaded sleeve on the outer circumference of the friction ring. The friction ring and the elastic externally threaded sleeve have circumferential limiting structures. The outer circumference of the elastic externally threaded sleeve is a conical shape with a smaller top and a larger bottom. The device also comprises an internally threaded sleeve fixed to the first end cap of the motor. The internal threads of the internally threaded sleeve engage with the external threads of the externally threaded sleeve. When the friction ring rotates in one direction with the motor shaft, the elastic externally threaded sleeve loosens. When the friction ring rotates in the opposite direction with the motor shaft, the externally threaded sleeve tightens and annularly compresses the friction ring, resulting in one-way self-locking. The friction ring of this one-way self-locking device possesses radial elastic force, a complete and continuous friction surface, stable friction, and relatively low wear.

Description

Technical Field

[0001] The invention relates to the technical field of linear drive, in particular to a one-way self-locking device used on a linear drive motor. Background Art

[0002] Linear drive mechanisms are widely used. For example, in the field of electric lift tables, the linear drive mechanism's motor, also known as a linear drive motor, drives the screw in the screw-nut assembly via a worm gear to raise or lower the table legs, which in turn drives the table top. To slow down the rotational speed in one direction, such as during descent, for a smoother descent and a better customer experience, and / or to prevent the table top from automatically sinking due to an overload when the motor is not rotating, a one-way self-locking device is typically included. During the ascent, the one-way self-locking device is inactive, resulting in higher transmission efficiency and faster speeds. During the descent, the one-way self-locking device operates, but the motor's driving energy exceeds the friction of the self-locking device, resulting in relatively weak transmission efficiency and slower speeds. If the table top is overloaded or vibrates, the screw rotates, simultaneously driving the worm gear, worm, and motor shaft. However, the friction of the self-locking device exceeds the rotational force of the shaft, causing the table top to self-lock, or brake, to prevent it from automatically sinking.

[0003] The traditional one-way self-locking device used on linear drive motors uses a torsion spring that is sleeved on the rotating shaft at the end of the motor shaft away from the worm to achieve self-locking of the motor shaft. However, friction between the torsion spring and the motor shaft easily generates heat, causing the torsion spring to anneal and wear out quickly, shortening the service life of the torsion spring. Moreover, since the effective contact area between the torsion spring and the motor shaft is small during the self-locking process of the torsion spring, the self-locking force is insufficient and prone to failure.

[0004] Later, technicians added an annular friction member between the torsion spring and the motor shaft. This member has a notch or is composed of several curved plates. The rotation of the torsion spring generates radial pressure on the member, achieving self-locking, or braking. Compared to traditional one-way self-locking devices, this design eliminates frictional heat that can cause annealing of the torsion spring, significantly extending the spring's service life.

[0005] However, the above-mentioned prior art one-way self-locking devices for linear drive motors still have the following shortcomings: the annular friction member is a circular sleeve with a notch or is composed of several arcuate blocks. Therefore, the following: 1. Axially, the line contact area is increased compared to traditional torsion spring brake structures. However, circumferentially, the friction surface is still incomplete, discontinuous, uneven, unstable, and the force applied is inconsistent, resulting in insufficient self-locking force. Furthermore, local wear caused by local friction of the line reduces the service life of the annular friction member. 2. The annular friction member itself lacks radial elastic force and preload friction, relying entirely on the torsion spring to provide the preload friction force. The torsion spring is always in operation and easily fatigued, which affects the self-locking effectiveness and service life of the torsion spring. 3. Because the annular friction member itself does not produce radial elastic deformation, the preload force is provided entirely by the torsion spring. Therefore, the torsion spring has very strict and precise requirements for dimensions and mechanical properties, high machining accuracy requirements, and is difficult to process. Furthermore, the material and processing costs are high. Furthermore, to achieve a uniform friction surface, a structure with multiple arcuate blocks is generally used, which is relatively cumbersome to install. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a one-way self-locking device for a linear drive motor, in which the friction ring itself has radial elastic force, the friction surface is complete and continuous, the friction force is stable and the wear is relatively small.

[0007] A technical solution of the present invention is to provide a one-way self-locking device for a linear drive motor, including a friction ring that is sleeved on the tail end of the motor shaft away from the output end of the motor shaft, the friction ring is an elastic circular ring composed of multiple arc-shaped pieces connected end to end, the friction ring and the motor shaft have an interference fit and have a pre-tightening friction force; the one-way self-locking device of the present invention also includes an elastic external threaded sleeve on the outer circumference of the friction ring, the friction ring and the elastic external threaded sleeve have a circumferential limiting structure, and the outer circle of the elastic external threaded sleeve is a cone with a smaller upper part and a larger lower part; the one-way self-locking device of the present invention also includes an internal threaded sleeve fixed on the first end cover of the motor, the internal thread of the internal threaded sleeve is screwed together with the external thread of the external threaded sleeve; when the friction ring rotates in one direction with the motor shaft, the elastic external threaded sleeve is relaxed, and when the friction ring rotates in the opposite direction with the motor shaft, the external threaded sleeve is tightened and annularly compresses the friction ring for one-way self-locking.

[0008] After adopting the above structure, the one-way self-locking device for a linear drive motor of the present invention has the following advantages:

[0009] Since the friction ring is an elastic circular ring composed of multiple arc-shaped pieces connected end to end, it can produce radial elastic deformation. The friction ring and the motor shaft have an interference fit and pre-tightening friction. When the shaft rotates in one direction, the external threaded sleeve is relaxed, and only the warning friction of the elastic friction ring is on the shaft, which basically does not affect the rotational energy output of the shaft, and the transmission efficiency is large and the speed is fast; when the shaft rotates in the opposite direction, the external threaded sleeve is tightened and annularly compresses the friction ring for one-way self-locking, but during the descent process, the motor driving energy is greater than the friction force of the self-locking device, the transmission efficiency is relatively weak, and the speed is relatively slow, making it more in line with the requirements of slow and smooth descent, and improving the customer's good psychological experience; after the motor stops rotating, when the load is too large and braking is required, such as when the table top of the electric lifting table is too heavy or the table top vibrates, the screw rotates, and at the same time drives the worm gear, worm and the motor shaft to rotate, but at this time, the friction force between the friction ring and the motor shaft under the annular pressure of the external threaded sleeve is greater than the rotational force of the shaft, and self-locking or braking is performed to prevent the table top from sinking automatically.

[0010] When the external threaded sleeve rotates relative to the motor shaft and the internal threaded sleeve fixed to the first end cap under the pre-tightening force of the friction ring, the external threaded sleeve is subjected to elastic deformation, so that the inner diameter can be increased or decreased. When the inner diameter of the external threaded sleeve is reduced, the friction ring can be annularly compressed to generate friction with the motor shaft, thereby increasing the self-locking force, and vice versa. After adopting this structure, a force is applied to the elastic friction ring through the thread engagement to reduce its inner diameter. This force value is stable, has a small fluctuation range, and is controllable. The friction surface of the friction ring of this one-way self-locking device is complete, continuous in the circumferential and axial directions, comprehensive, uniform, stable, and the force applied is consistent. The friction ring has good elastic deformation performance and the self-locking force of the self-locking device is strong, providing a stable, continuous, and durable friction force for the motor shaft, thereby improving the self-locking performance of the entire linear drive mechanism.

[0011] This effectively prevents local wear of the friction ring caused by local friction, significantly extending the service life of the friction ring. Furthermore, since the elastic external threaded sleeve replaces the torsion spring, the drawback of the torsion spring being constantly in operation and susceptible to fatigue, which affects its self-locking effectiveness and service life, is overcome. This significantly improves the self-locking effectiveness of the one-way self-locking device and significantly extends its service life.

[0012] Since the elastic external threaded sleeve replaces the torsion spring, the processing accuracy requirement is relatively low, the processing difficulty is relatively small, and the installation of the friction ring, the elastic external threaded sleeve and the internal threaded sleeve is simple and convenient.

[0013] Furthermore, when the motor is vertical and the rear end of the motor shaft is at the top, the elastic outer threaded sleeve loosens when the friction ring rotates clockwise with the motor shaft. When the friction ring rotates counterclockwise with the motor shaft, the outer threaded sleeve tightens and annularly compresses the friction ring, achieving one-way self-locking. This structure is more convenient for installation and better matches the rotation direction when the motor stops and is braked due to excessive load.

[0014] Furthermore, the friction ring has a radial projection at its lower end, and the bottom end of the internally threaded sleeve has an arc-shaped receiving cavity formed between two limiting surfaces, allowing the radial projection of the friction ring to rotate within a range of 90°-120°. When the motor shaft rotates, driving the elastic friction ring with a preload in one direction, the elastic externally threaded sleeve, which is circumferentially limited to the friction ring, loosens and is retained by the first limiting surface. When the motor shaft rotates, driving the elastic friction ring with a preload in the opposite direction, the externally threaded sleeve tightens, annularly compressing the friction ring and being retained by the second limiting surface. With this structure, the externally threaded sleeve, under the action of the friction ring's warning force, rotates clockwise with the motor shaft to loosen or counterclockwise to tighten, more stably and reliably.

[0015] Furthermore, the elastic externally threaded sleeve has a structure as follows: a first opening axially extending through the circumference of the separate externally threaded sleeve, the outer circumference of the externally threaded sleeve being a conical shape with a smaller top and a larger bottom. The externally threaded sleeve also has a second opening disposed on the circumference of the axially raised ring below the external threads and adapted to accommodate the radial projection of the friction ring, thereby circumferentially limiting the position of both the externally threaded sleeve and the friction ring. The above structure provides a specific structure of the elastic externally threaded sleeve, namely, a separate elastic threaded sleeve, wherein both the separate elastic threaded sleeve and the elastic friction ring have circumferential limiting structures that restrict their circumferential rotation. This specific structure facilitates processing and installation, and provides stable and reliable operation when the motor shaft rotates clockwise for loosening or counterclockwise for tightening.

[0016] Furthermore, the end-to-end connection structure comprises two single-arc-shaped pieces connected at the top to form an N-shaped inward-concave arc-shaped piece, two single-arc-shaped pieces connected at the bottom to form a U-shaped inward-concave arc-shaped piece, and these pieces are arranged in this order until a complete and continuous elastic circular ring is formed. This structure further ensures that the friction surface of the friction ring is complete, continuous in both the circumferential and axial directions, and that the friction ring has a comprehensive, uniform, stable, and consistent force application, good elastic deformation performance, and a strong self-locking force of the self-locking device.

[0017] Furthermore, the number of N-shaped inwardly concave arcuate pieces is 6-8, and the number of U-shaped inwardly concave arcuate pieces is also 6-8. With the above structure, the number and ring density further ensure that the friction surface of the friction ring of the one-way self-locking device is complete, continuous in the circumferential and axial directions, comprehensive, uniform, stable, and consistent in force application, the friction ring has good elastic deformation performance, and the self-locking force of the self-locking device is strong.

[0018] Furthermore, the lower end of the N-shaped inwardly concave arc piece opens into a bell mouth, while the upper end of the U-shaped inwardly concave arc piece opens into a bell mouth. The above structure further ensures that the friction surface of the friction ring of the one-way self-locking device is complete, continuous in both the circumferential and axial directions, and that the friction ring has a comprehensive, uniform, stable and consistent force application, good elastic deformation performance, and a strong self-locking force of the self-locking device.

[0019] Furthermore, the elastic threaded sleeve has an external thread directly disposed on the outer surface above the radial projection of the friction ring. The outer diameter of the external thread on the friction ring is a conical shape with a smaller top and a larger bottom. Another specific structure of the elastic external threaded sleeve is provided, namely, an integrated structure that is integrated with the elastic friction ring. Compared to a separate elastic threaded sleeve, this structure offers greater elasticity and more uniform annular elastic force. The process is stable and reliable, with clockwise rotation of the motor shaft for loosening and counterclockwise rotation for tightening. However, machining and installation are slightly more difficult than with a separate elastic threaded sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The figure is a schematic structural diagram of a one-way self-locking device for a linear drive motor according to the present invention.

[0021] Figure 2 yes Figure 1 A schematic diagram of the enlarged structure of a one-way self-locking device for a linear drive motor from above (the motor part is omitted).

[0022] Figure 3 It is a schematic diagram of the exploded structure of a one-way self-locking device for a linear drive motor according to the present invention (screws are not shown).

[0023] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure of the internal thread sleeve in the figure.

[0024] Figure 5 yes Figure 3 Schematic diagram of the enlarged structure of the external threaded sleeve in the top view.

[0025] Figure 6 yes Figure 3 The friction ring in the figure is an enlarged structural diagram looking upwards.

[0026] Figure 7 yes Figure 3 The friction ring in the figure is viewed from above and is an enlarged structural diagram.

[0027] Figure 8 It is a schematic diagram of another specific structure of the friction ring in the present invention when viewed from above.

[0028] As shown in the figure: 1. tail end, 2. internal thread sleeve, 3. first end cover of the motor, 4. motor stator, 5. second end cover of the motor, 6. output end, 7. radial protrusion, 8. first limiting surface, 9. arc-shaped receiving cavity, 10. second limiting surface, 11. motor shaft, 12. external thread sleeve, 13. friction ring, 14. internal thread, 15. axial protrusion ring, 16. external thread, 17. cone with small upper part and large lower part, 18. first opening, 19. second opening, 20. bell mouth, 21. N-shaped concave arc piece, 22. U-shaped concave arc piece, 23. overall concave arc piece. DETAILED DESCRIPTION

[0029] The following is a further description of specific embodiments of the present invention with reference to the accompanying drawings. It should be noted that the description of these specific embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. Furthermore, the technical features involved in the various specific embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 Figure 7 、 Figure 8 shown.

[0031] The present invention provides a one-way self-locking device for a linear drive motor, comprising a friction ring 13 that is sleeved on the tail end 1 of the motor shaft 11, which is away from the output end 6 of the motor shaft 11, such as a worm. The friction ring 13 is an elastic circular ring composed of multiple arc-shaped pieces connected end to end. The friction ring 13 has an interference fit with the motor shaft 11 and has a pre-tightened friction force. The present invention provides a one-way self-locking device for a linear drive motor, further comprising an elastic externally threaded sleeve on the outer circumference of the friction ring 13, a circumferential limiting structure being provided on the friction ring 13 and the elastic externally threaded sleeve, and the outer circle of the elastic externally threaded sleeve is a cone with a smaller upper portion and a larger lower portion. The present invention provides a one-way self-locking device for a linear drive motor, further comprising an internally threaded sleeve 2 that is fixed, such as welded, on the first end cover 3 of the motor, and the internal thread 14 of the internally threaded sleeve 2 is screwed together with the external thread of the externally threaded sleeve. When the friction ring 13 rotates in one direction with the motor shaft 11, the elastic externally threaded sleeve loosens. When the friction ring 13 rotates in the opposite direction, the externally threaded sleeve tightens and compresses the friction ring in an annular manner, achieving one-way self-locking. The friction ring 13 can be made of metal materials such as spring steel, plastic, or nylon. The motor's first end cap 3 is screwed to the motor stator 4 and the second end cap 5 via a screw and nut (the screw and nut are not shown).

[0032] When the motor is vertical and the tail end 1 of the motor shaft 11 is at the top, the elastic external threaded sleeve is preferably loosened when the friction ring 13 rotates clockwise with the motor shaft 11, and the external threaded sleeve is tightened and annularly compresses the friction ring 13 for one-way self-locking when the friction ring 13 rotates counterclockwise with the motor shaft 11.

[0033] The lower end of the friction ring 13 has a radial projection 7, and the bottom end of the internal threaded sleeve 2 has two limiting surfaces, namely the first limiting surface 8 and the second limiting surface 10, which form an arc-shaped receiving cavity 9 for the radial projection 7 of the friction ring 13 to rotate within the range of 90°-120°. Figure 2 、 Figure 3 、 Figure 4 The figure shows an arcuate receiving cavity 9, which allows the radial projection 7 of the friction ring 13 to rotate within a range of approximately 90 degrees. When the motor shaft 11 rotates, driving the preloaded elastic friction ring 13 in one direction, such as clockwise, the elastic externally threaded sleeve (externally threaded sleeve 12, described below) that circumferentially limits the friction ring 13 is loosened and retained by the first limiting surface 8. When the motor shaft 11 rotates, driving the preloaded elastic friction ring 13 in the opposite direction, such as counterclockwise, the elastic externally threaded sleeve (externally threaded sleeve 12, described below) tightens, annularly compressing the friction ring 13 and retaining it by the second limiting surface 10. The arcuate receiving cavity 9 can also be referred to as an arcuate opening or arcuate notch.

[0034] The first specific structure of the elastic externally threaded sleeve is as follows: a separate externally threaded sleeve 12 has a first opening 18 axially extending through it. The outer circumference of the externally threaded sleeve 12 is a conical shape 17 that is smaller at the top and larger at the bottom. The outer circumference of the externally threaded sleeve 12 also includes a second opening 19, located on the axially raised ring 15 below the external threads 16 and used to accommodate the radial projection 7 of the friction ring 13, thereby circumferentially limiting the position of the externally threaded sleeve 12 and the friction ring 13. During installation, the elastic friction ring 13 is interference-fitted onto the tail end 1 of the motor shaft 11. The externally threaded sleeve 12 is screwed into the internally threaded sleeve 2. The radial projection 7, which radially protrudes beyond the outer circumference of the externally threaded sleeve 12, is then aligned with the arcuate receiving cavity 9 of the internally threaded sleeve 2 and inserted. The first end cap 3, the motor stator 4, and the second end cap 5 are then secured. The externally threaded sleeve 12 is generally made of metal.

[0035] The specific structure of the end-to-end connection is preferably: two single arc-shaped pieces are connected at the top to form an N-shaped concave arc-shaped piece 21, and two single arc-shaped pieces are connected at the bottom to form a U-shaped concave arc-shaped piece 22, and they are arranged in sequence until a complete and continuous elastic circular ring is formed. It is not difficult to understand that it can be seen as the axial upper half being the N-shaped concave arc-shaped piece 21, and the axial lower half being the U-shaped concave arc-shaped piece 22. One single concave arc-shaped piece in each of the N-shaped concave arc-shaped pieces 21 in the upper half is connected to a single concave arc-shaped piece in the U-shaped concave arc-shaped piece 22 in the lower half to form a whole. Another single concave arc-shaped piece in the U-shaped concave arc-shaped piece 22 in the lower half is connected to a single concave arc-shaped piece in the N-shaped concave arc-shaped piece 21 in the upper half to form a whole. They are connected in sequence until a complete and continuous elastic circular ring is formed. The N-shaped shape is also called an arch shape. The concave arc-shaped piece is also called a convex arc-shaped piece.

[0036] The n-shaped concave arcuate pieces 21 are 6-8 pieces, and the U-shaped concave arcuate pieces 22 are also 6-8 pieces. Figure 3 、 Figure 6 、 Figure 7 The figures are all 6 pieces: two single arc pieces are connected at the top to form a first n-shaped concave arc piece 21, two single arc pieces are connected at the bottom to form a first U-shaped concave arc piece 20, two single arc pieces are connected at the top to form a second n-shaped concave arc piece 21, two single arc pieces are connected at the bottom to form a second U-shaped concave arc piece 20, two single arc pieces are connected at the top to form a third n-shaped concave arc piece 21, two single arc pieces are connected at the bottom to form a third U-shaped concave arc piece 20, two single arc pieces are connected at the top The tops of the two single arc pieces are connected to form the fourth N-shaped concave arc piece 21, the bottoms of the two single arc pieces are connected to form the fourth U-shaped concave arc piece 22, the tops of the two single arc pieces are connected to form the fifth N-shaped concave arc piece 21, the bottoms of the two single arc pieces are connected to form the fifth U-shaped concave arc piece 22, the tops of the two single arc pieces are connected to form the sixth N-shaped concave arc piece 21, and the bottoms of the two single arc pieces are connected to form the sixth U-shaped concave arc piece 22 (not marked in the first to sixth figures, just for convenience of expression).

[0037] like Figure 6 、 Figure 7 、 Figure 8 As shown, the lower end opening of the N-shaped inwardly concave arc piece 21 is a bell mouth 20. The upper end opening of the U-shaped inwardly concave arc piece is a bell mouth 20.

[0038] Of course, if Figure 8 As shown, the end-to-end connection structure also allows one of the top-connected concave arc-shaped pieces to be a single piece of concave arc-shaped piece 23, with no vertical groove in the middle of the width, and the concave arc-shaped piece does not form an N shape. This structure is also within the scope of protection of the present invention.

[0039] Another specific structure of the elastic threaded sleeve is that external threads are directly provided on the outer surface above the radial projection of the friction ring. Specifically, external threads are directly provided on the outer surfaces of the U-shaped inwardly concave arcuate piece and the N-shaped inwardly concave arcuate piece above the radial projection of the friction ring, forming an elastic externally threaded sleeve integral with the elastic friction ring. The outer diameter of the external threads on the friction ring is a conical shape that is smaller at the top and larger at the bottom. Of course, the circumferential retaining structure of this integrated elastic externally threaded sleeve directly secures the external threads to the friction ring. During installation, the friction ring and the integrated externally threaded sleeve can be interference fit onto the rear end of the motor shaft. The externally threaded sleeve, which is the first motor end cap to which it is secured, is then screwed in. The radial projection is then secured by screwing screws through the arc-shaped receiving cavity, i.e., the arc-shaped notch, through the threaded hole in the radial projection and the thread on the bottom end of the friction ring. Two screws and two corresponding threaded holes can be used (not shown in this structural diagram).

[0040] The opening is also called a gap. The external thread sleeve 12 can also be called an external thread ring. The internal thread sleeve 2 can also be called a fixed ring.

[0041] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 As shown, the working process of the present invention is roughly as follows:

[0042] When the motor is energized and the motor shaft 11 rotates in one direction, such as when driving the electric lifting table to rise, the rotation of the motor shaft 11 drives the elastic friction ring 13 with its own pre-tightening force to rotate synchronously in one direction, such as clockwise, and the external threaded sleeve 12 is relaxed. When the radial protrusion 7 of the friction ring 13 reaches the first limit surface 8, the external threaded sleeve 12 remains in a relaxed state. The motor operates normally, and only the warning friction force of the elastic friction ring 13 is on the motor shaft 11, which basically does not affect the rotational energy output of the motor shaft 11, and the transmission efficiency is greater and the speed is faster.

[0043] When the motor is energized and the motor shaft 11 rotates in the opposite direction, such as when driving the electric lifting table to descend, the rotation of the motor shaft 11 drives the friction ring 13 with its own pre-tightening force to rotate synchronously in the opposite direction, such as counterclockwise, and the external threaded sleeve 12 is tightened. When the radial protrusion 7 reaches the second limit surface 10, the external threaded sleeve 12 remains in a tightened state and annularly compresses the friction ring 13 for one-way self-locking. However, during the descent process, the motor driving energy is greater than the friction force of the self-locking device, the transmission efficiency is relatively weak, and the speed is relatively slow, which makes it more in line with the requirements of slow and steady descent, and improves the customer's good psychological experience.

[0044] When the motor stops rotating and the load is too large and braking is required, such as when the load on the desktop of the electric lifting table is too large or the desktop vibrates, the screw in the nut screw pair of the electric lifting table rotates, and at the same time drives the worm gear, worm and motor shaft 11 to rotate. The rotation of the motor shaft 11 drives the friction ring 13 with its own pre-tightening force to rotate synchronously in the opposite direction, such as counterclockwise, and the external threaded sleeve 12 is tightened. When the radial protrusion 7 reaches the second limit surface 10, the external threaded sleeve 12 remains in a tightened state and annularly compresses the friction ring 13 for one-way self-locking. At this time, the friction force between the friction ring 13 and the motor shaft 11 under the annular pressure of the external threaded sleeve 12 is greater than the rotational force of the motor shaft 11, and self-locking or braking is used to prevent the table top from sinking automatically.

[0045] It is not difficult to understand that the drawings are only schematic. If there is any inconsistency between the drawings and the text description, the text description shall prevail.

[0046] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A one-way self-locking device for a linear drive motor, comprising a friction ring sleeved on the rear end of the motor shaft away from the output end of the motor shaft, characterized in that: The friction ring is an elastic circular ring composed of multiple arc-shaped pieces connected end to end. The friction ring and the motor shaft have an interference fit to generate pre-tightened friction force. It also includes an elastic externally threaded sleeve on the outer circumference of the friction ring. The friction ring and the elastic externally threaded sleeve have a circumferential limit structure. The outer circumference of the elastic externally threaded sleeve is a cone with a smaller top and a larger bottom. It also includes an internally threaded sleeve fixed to the first end cover of the motor. The internal thread of the internally threaded sleeve is screwed together with the external thread of the externally threaded sleeve. When the friction ring rotates in one direction with the motor shaft, the elastic externally threaded sleeve is loosened. When the friction ring rotates in the opposite direction with the motor shaft, the externally threaded sleeve is tightened and annularly compresses the friction ring to achieve one-way self-locking. The specific structure of the end-to-end connection is: the tops of two single arc-shaped pieces are connected to form an N-shaped concave arc-shaped piece, the bottoms of two single arc-shaped pieces are connected to form a U-shaped concave arc-shaped piece, and the N-shaped concave arc-shaped pieces and the U-shaped concave arc-shaped pieces are alternately arranged in sequence until a complete and continuous elastic circular ring is formed.

2. The one-way self-locking device for a linear drive motor according to claim 1, characterized in that: When the motor is vertical and the tail end of the motor shaft is upward, the elastic external threaded sleeve is loosened when the friction ring rotates clockwise with the motor shaft. When the friction ring rotates counterclockwise with the motor shaft, the external threaded sleeve is tightened and annularly compresses the friction ring to achieve one-way self-locking.

3. The one-way self-locking device for a linear drive motor according to claim 1, characterized in that: The friction ring has a radial protrusion at its lower end, and an arc-shaped receiving cavity is formed between two limiting surfaces at the bottom end of the internal threaded sleeve for the radial protrusion of the friction ring to rotate within the range of 90°-120°. When the motor shaft rotates and drives the elastic friction ring with a preload force to rotate in one direction, the elastic external threaded sleeve that limits the friction ring circumferentially is loosened and retained by the first limiting surface. When the motor shaft rotates and drives the elastic friction ring with a preload force to rotate in the opposite direction, the external threaded sleeve is tightened and annularly compresses the friction ring and is retained by the second limiting surface.

4. The one-way self-locking device for a linear drive motor according to claim 3, characterized in that: The structure of the elastic external threaded sleeve is as follows: a first opening is provided on the circumference of the separate external threaded sleeve and axially penetrates the external threaded sleeve; the outer circle of the external threaded sleeve is a cone with a small top and a large bottom; and a second opening is provided on the circumference of the external threaded sleeve and is provided on the axial convex ring below the external thread and is used to accommodate the radial convex block of the friction ring so as to limit the circumferential position of the external threaded sleeve and the friction ring.

5. The one-way self-locking device for a linear drive motor according to claim 1, characterized in that: The number of N-shaped inwardly concave arc pieces is 6-8, and the number of U-shaped inwardly concave arc pieces is also 6-8.

6. The one-way self-locking device for a linear drive motor according to claim 1, characterized in that: The lower end opening of the N-shaped inwardly concave arc piece is a bell mouth; the upper end opening of the U-shaped inwardly concave arc piece is a bell mouth.

7. The one-way self-locking device for a linear drive motor according to claim 3, characterized in that: The structure of the elastic threaded sleeve is as follows: an external thread is directly provided on the outer surface above the radial protrusion of the friction ring, and the outer circle of the external thread on the friction ring is a cone with a small upper part and a large lower part.

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