Self-locking output shaft structure of electric actuating mechanism

Abstract

The invention relates to the technical field of output shafts, in particular to an electric actuating mechanism self-locking type output shaft structure which comprises a shaft body and a self-locking structure integrally and fixedly connected with the shaft body, the self-locking structure comprises an outer shaft sleeve and an inner shaft sleeve which are integrally formed, and a plurality of cylindrical cavities with outward openings are symmetrically formed in the front end face and the rear end face of the inner shaft sleeve; a plurality of oil outlets communicated with the cylindrical cavity are formed in the inner wall of the inner shaft sleeve and used for supplying oil to the inner wall of the inner shaft sleeve, a plurality of heat dissipation holes communicated with the cylindrical cavity are formed in the outer wall of the inner shaft sleeve and used for dissipating heat to the outer wall of the inner shaft sleeve, and the rubber piston converts the plugging state of the oil outlets and the heat dissipation holes in the initial state into an open state. On one hand, lubricating oil is squeezed out along the oil outlet holes to lubricate the connecting face, friction is reduced, abrasion is greatly relieved, on the other hand, part of heat in the expansion cavity is diffused outwards along the heat dissipation holes, the temperature is reduced, and harm caused by friction of the connecting face under the high-temperature condition is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of output shafts, and in particular to a self-locking output shaft structure of an electric actuator. Background Art

[0002] The electrically driven multi-turn actuator is one of the most commonly used and reliable types of actuators. It uses a single-phase or three-phase motor to drive a gear or worm gear through the output shaft and finally drives the valve stem nut. The valve stem nut causes the valve stem to move to open or close the valve. The output shaft plays an extremely important connecting drive role in the electric actuator.

[0003] The output shaft and the worm gear are connected and driven, which is a common driving method. When connected, one end of the worm gear is locked in the self-locking structure at one end of the output shaft. For example, an invention patent application disclosed in the publication number CN116707218A proposes a self-locking mechanism applied to a rotating shaft. The technical problem proposed by the patent is: self-locking is usually achieved by a friction ring mounted on the rotating shaft. The friction ring holds the rotating shaft tightly to generate a self-locking force. When the product is working, the rotating shaft rotates, and the friction ring and the rotating shaft continue to generate friction. After the product has been used for a period of time, the friction ring will have greater wear, resulting in a weakening of the holding force and ultimately reducing the self-locking force of the product. At the same time, when the product continues to work for a long time, the friction between the friction ring and the rotating shaft will generate high temperature and aggravate the wear of the friction ring. In order to extend the service life of the product, the product needs to rest for a long time after working for a short time before it can work again, which causes certain troubles to the user; the beneficial effect is: by filling a resistance filler between the fixed shell and the reduction shell, the rotating shaft generates resistance when rotating in any direction, so as to achieve the effect of self-locking force. This structure is not easy to wear, can work continuously for a long time, and has a long service life.

[0004] However, in actual use, the method of reducing wear by filling resistance fillers in the above patent has the following defects: first, the resistance fillers will be worn out after a long period of work, and the resistance fillers in the self-locking structure need to be removed and replaced, which is cumbersome; secondly, the method of filling resistance fillers cannot solve the problem of high temperature generated during friction mentioned above, and high temperature will still aggravate wear; finally, when the resistance fillers are damaged, the gap between the self-locking structure and the locked part may increase instantly, increasing the possibility of unlocking and even directly damaging the connected equipment. Summary of the invention

[0005] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a self-locking output shaft structure of an electric actuator, which solves the problem of wear and high temperature caused by friction between the self-locking component of the existing output shaft structure and the locked component after continuous operation.

[0006] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a self-locking output shaft structure of an electric actuator, comprising a shaft body and a self-locking structure integrally fixedly connected thereto, the self-locking structure comprising an outer sleeve and an inner sleeve integrally formed, the front and rear end surfaces of the inner sleeve are symmetrically provided with a plurality of cylindrical cavities opening outward, and the front and rear end surfaces of the inner sleeve are also respectively provided with annular covers for sealing the plurality of cylindrical cavities, the inner wall of the inner sleeve is provided with a plurality of oil outlet holes penetrating the cylindrical cavities for supplying oil to the inner wall of the inner sleeve, and the outer wall of the inner sleeve is provided with a plurality of A heat dissipation hole connected with the cylindrical cavity is used for dissipating heat toward the outer wall of the inner sleeve. A sealing plug is fixedly provided on the bottom surface of each cylindrical cavity. A plurality of conical seats for sealing the cylindrical cavity are fixedly provided on one end surface of the annular cover. One end of each conical seat is fixedly connected to a spring 2, and the other end of the spring 2 is fixedly connected to a rubber piston. An expansion cavity is formed between the rubber piston and the sealing plug. An isolation layer fixedly connected to the rubber piston and the sealing plug respectively is provided in the expansion cavity. The isolation layer separates the expansion cavity into an oil storage cavity and a heat collection cavity which are independent of each other.

[0007] Preferably, the cone seat, spring 2 and rubber piston are all located in the cylindrical cavity, the rubber piston and the sealing plug have the same diameter but different thicknesses, and both the rubber piston and the sealing plug are interference fit with the cylindrical cavity.

[0008] Preferably, the rubber piston divides the cylindrical cavity into an expansion cavity and a heat dissipation cavity, the heat dissipation cavity is located between the rubber piston and the cone seat, and the oil outlet hole and the heat dissipation hole are respectively communicated with the inside of the heat dissipation cavity.

[0009] Preferably, the oil outlet holes and the heat dissipation holes have the same diameter and quantity, and the positions of the oil outlet holes and the heat dissipation holes are symmetrical about the central axis of the cylindrical cavity.

[0010] Preferably, the isolation layer is made of silicone rubber, and in a natural state the isolation layer has a zigzag structure, and the oil storage cavity is filled with lubricating oil.

[0011] Preferably, the connecting surface between the annular cover and the inner sleeve is fixed by bolts, one end of the inner sleeve is fixedly connected to one end of the shaft body, and the inner diameter of the inner sleeve is larger than the outer diameter of the shaft body, and the annular cover is movablely sleeved outside the shaft body.

[0012] Preferably, the inner diameter of the outer sleeve is the same as that of the inner sleeve, and the outer diameter of the outer sleeve is larger than the outer diameter of the inner sleeve. The inner walls of the outer sleeve and the inner sleeve are jointly provided with three recessed placement grooves and three raised stop platforms.

[0013] Preferably, the three placement grooves and baffles are distributed in a circular array, and the cross-sections of the placement grooves and baffles are arranged crosswise, and the rear end surfaces of the three baffles and the front end surfaces of the three placement grooves are at different positions on the same plane.

[0014] Preferably, the outer wall of the outer sleeve is provided with three groups of limit holes respectively connected with the three placement grooves, each group of limit holes has two limit holes and each limit hole has a limit pin movably passing through it, and one end of the two limit pins is fixedly connected to a locking block located in the placement groove.

[0015] Preferably, the other end of each of the limit pins extends to the outside of the outer sleeve, and a spring 1 is movably sleeved on each limit pin, and the two ends of the spring 1 are respectively fixedly connected to the surface of the locking block and the inner wall of the placement groove, and a limit ring is threadedly sleeved on the outer surface of the outer sleeve, which is used to limit the limit pin extending to the outside of the outer sleeve.

[0016] (III) Beneficial effects Compared with the prior art, the present invention provides a self-locking output shaft structure of an electric actuator, which has the following beneficial effects: By setting a cylindrical cavity inside the self-locking structure, the cylindrical cavity is divided into an expansion cavity mainly filled with lubricating oil and a heat dissipation cavity with oil outlet holes and heat dissipation holes. When the connection surface between the self-locking structure and the worm gear generates high temperature during continuous operation, the pressure inside the expansion cavity increases and drives the rubber piston to move, so that the rubber piston changes the initial blocking state of the oil outlet hole and the heat dissipation hole into an open state. On the one hand, the lubricating oil is squeezed out along the oil outlet hole to lubricate the connection surface, reducing friction and greatly alleviating wear; on the other hand, part of the heat in the expansion cavity diffuses outward along the heat dissipation hole to reduce the temperature, further reducing the damage caused by friction under high temperature conditions on the connection surface. When the heat in the expansion chamber diffuses outward, the internal pressure decreases, and the rubber piston returns to its original position under the elastic action of spring 2. The rubber piston reseals the expansion chamber, and the lubricating oil is no longer squeezed out. The heat in the expansion chamber is collected again, waiting for the temperature to rise again before entering the next cycle, so that the lubricating oil supply process is carried out in stages to avoid waste caused by continuous oil supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 This is the overall appearance diagram of the shaft body and the self-locking structure of the present invention; Figure 2 This is a partial structural exploded view of the outer sleeve and the inner sleeve of the present invention; Figure 3 It is a schematic diagram of the structure of the inner sleeve end face and the axial face of the present invention; Figure 4 It is a schematic diagram of the annular cover and its end surface structure of the present invention; Figure 5This is a self-locking structural connection diagram of the worm and the shaft body of the present invention; Figure 6 It is a partial cross-sectional view of the inner sleeve and the outer sleeve of the present invention; Figure 7 For the present invention Figure 6 Enlarged view of part a; Figure 8 For the present invention Figure 6 Front view of .

[0018] Description of reference numerals: 1. Shaft body; 2. Outer sleeve; 21. Limit hole; 22. Limit pin; 23. Spring 1; 24. Locking block; 25. Limit ring; 3. Inner sleeve; 31. Cylindrical cavity; 311. Oil outlet hole; 312. Heat dissipation hole; 32. Sealing plug; 33. Isolation layer; 331. Oil storage cavity; 332. Heat collection cavity; 34. Placement groove; 35. Stop platform; 4. Ring cover; 41. Conical seat; 42. Spring 2; 43. Rubber piston; 5. Worm. DETAILED DESCRIPTION

[0019] The following will describe the implementation methods of the present application in detail with the help of accompanying drawings and examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0020] like Figure 1-8The figure shows the first embodiment of the present invention. To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a self-locking output shaft structure of an electric actuator, comprising a shaft body 1 and a self-locking structure integrally fixedly connected thereto, the self-locking structure comprising an outer sleeve 2 and an inner sleeve 3 integrally formed, the front and rear end surfaces of the inner sleeve 3 are symmetrically provided with a plurality of cylindrical cavities 31 opening outward, and the front and rear end surfaces of the inner sleeve 3 are also respectively provided with annular covers 4 for sealing the plurality of cylindrical cavities 31, the inner wall of the inner sleeve 3 is provided with a plurality of oil outlet holes 311 penetrating the cylindrical cavities 31 for supplying oil to the inner wall of the inner sleeve 3, the outer wall of the inner sleeve 3 is provided with a plurality of heat dissipation holes 312 penetrating the cylindrical cavities 31 for dissipating heat to the outer wall of the inner sleeve 3, a sealing plug 32 is fixedly provided on the bottom surface of each cylindrical cavity 31, and a plurality of A conical seat 41 for sealing the cylindrical cavity 31, one end of each conical seat 41 is fixedly connected to a spring 2 42, the other end of the spring 2 42 is fixedly connected to a rubber piston 43, an expansion cavity is formed between the rubber piston 43 and the sealing plug 32, an isolation layer 33 is provided in the expansion cavity, which is respectively fixedly connected to the rubber piston 43 and the sealing plug 32, the isolation layer 33 separates the expansion cavity into an oil storage cavity 331 and a heat collection cavity 332 which are independent of each other, the four surfaces of the isolation layer 33 are respectively fixedly connected to the sealing plug 32, the rubber piston 43 and the symmetrical surfaces on both sides of the expansion cavity, under normal conditions, the expansion cavity is closed, when under high temperature conditions, the heat in the expansion cavity increases and the pressure increases, the rubber piston 43 moves, and the rubber piston 43 changes from the initial blocking state of the oil outlet hole 311 and the heat dissipation hole 312 to the open state, thereby balancing the pressure of the expansion cavity; Furthermore, the cone seat 41, the spring 42 and the rubber piston 43 are all located in the cylindrical cavity 31. The rubber piston 43 and the sealing plug 32 have the same diameter but different thicknesses. The rubber piston 43 and the sealing plug 32 are both interference fit with the cylindrical cavity 31, wherein one end of the sealing plug 32 is fixedly connected to the bottom surface of the cylindrical cavity 31, so that the position of the sealing plug 32 remains unchanged. When the temperature in the expansion cavity rises, the internal pressure increases, thereby causing the rubber piston 43 to move. The rubber piston 43 divides the cylindrical cavity 31 into an expansion cavity and a heat dissipation cavity. The heat dissipation cavity is located between the rubber piston 43 and the cone seat 41. The oil hole 311 and the heat dissipation hole 312 are respectively communicated with the inside of the heat dissipation cavity. Under normal conditions, the rubber piston 43 completely blocks the oil outlet hole 311 and the heat dissipation hole 312. When the friction between the connection surface of the inner sleeve 3 and the worm 5 is small, the heat generated is relatively small. A small amount of heat can directly enter the heat dissipation cavity along the heat dissipation hole 312, and then diffuse to the outside of the inner sleeve 3 along the oil outlet hole 311 through the heat dissipation cavity, so as to achieve the effect of heat balance. The diameter and number of the oil outlet hole 311 and the heat dissipation hole 312 are the same, and the positions of the oil outlet hole 311 and the heat dissipation hole 312 are symmetrical about the central axis of the cylindrical cavity 31. When the rubber piston 43 is subjected to the pressure generated by the pressure increase in the expansion chamber, it moves to the area where the heat dissipation chamber and the heat dissipation hole 312 communicate with each other. The pressure in the expansion chamber varies according to the temperature. Therefore, the moving distance of the rubber piston 43 is controlled by the temperature. When the rubber piston 43 moves to the point where it no longer blocks the oil outlet hole 311 and the heat dissipation hole 312, the isolation layer 33 is stretched by the rubber piston 43 and affected by the internal pressure. At this time, the isolation layer 33 is deformed and squeezes the oil storage chamber 331. The internal pressure of the inner sleeve 3 is greater than the external pressure. On the one hand, the oil storage chamber 331 is compressed. The lubricating oil is squeezed out along the oil outlet hole 311 to the connecting surface of the inner sleeve 3 and the worm 5, thereby achieving the lubrication effect of the connecting surface, reducing friction and thus greatly alleviating the wear of the two. On the other hand, a part of the heat in the expansion chamber diffuses outward along the heat dissipation hole 312, balancing the internal pressure of the expansion chamber. After the pressure in the expansion chamber is reduced, the rubber piston 43 is reset to its original position under the elastic action of the spring 42, and the rubber piston 43 reseals the expansion chamber, and the lubricating oil is no longer squeezed out. The heat in the expansion chamber is recollected by the heat collection chamber 332, and the next cycle begins after the temperature rises again. Furthermore, the isolation layer 33 is made of silicone rubber, and in its natural state, the isolation layer 33 is a zigzag structure. The silicone rubber can still maintain a certain flexibility, resilience and surface hardness under high and low temperature environments, and the mechanical properties do not change significantly. At the same time, it also has the advantages of impact resistance, oil resistance and good sealing. The oil storage chamber 331 is filled with lubricating oil, and the connecting surface between the annular cover 4 and the inner sleeve 3 is fixed by bolts. One end of the inner sleeve 3 is fixedly connected to one end of the shaft body 1, and the inner diameter of the inner sleeve 3 is larger than the outer diameter of the shaft body 1. The annular cover 4 is movably sleeved on the outside of the shaft body 1. The annular cover 4 and the inner sleeve 3 are detachably connected to facilitate the assembly of the components located in the cylindrical cavity 31, wherein the conical seat 41, the spring 2 42 and the rubber piston 43 located inside the cylindrical cavity 31 are all connected to the end face of the annular cover 4, and can be installed and connected along with the annular cover 4 and disassembled and removed.

[0021] When the above embodiment is working, under normal conditions, the rubber piston 43 completely blocks the oil outlet hole 311 and the heat dissipation hole 312. When the friction between the connection surface of the inner sleeve 3 and the worm 5 is small, the heat generated is relatively small. A small amount of heat can directly enter the heat dissipation cavity along the heat dissipation hole 312, and then diffuse to the outside of the inner sleeve 3 along the oil outlet hole 311 through the heat dissipation cavity, so as to achieve the effect of heat balance. After continuous operation, the connection surface of the inner sleeve 3 and the worm 5 continues to rub and generate a large amount of heat. At this time, the temperature in the expansion cavity rises, the internal pressure increases, and then the rubber piston 43 is displaced. When the rubber piston 43 moves to no longer block the oil outlet hole 311 and the heat dissipation hole 312, the isolation layer 33 is affected by the rubber Due to the stretching of the rubber piston 43 and the influence of the internal pressure, the isolation layer 33 is deformed and squeezes the oil storage chamber 331. The internal pressure of the inner sleeve 3 is greater than the external pressure, and the lubricating oil in the oil storage chamber 331 is squeezed out along the oil outlet hole 311 to the connecting surface of the inner sleeve 3 and the worm 5, so as to achieve the lubrication of the connecting surface. A part of the heat in the expansion chamber diffuses outward along the heat dissipation hole 312, and the internal pressure of the expansion chamber is balanced. After the pressure in the expansion chamber is reduced, the rubber piston 43 is reset to its original position under the elastic action of the spring 42, and the rubber piston 43 reseals the expansion chamber, and the lubricating oil is no longer squeezed out. The heat in the expansion chamber is recollected by the heat collection chamber 332, and waits for the temperature to rise again before entering the next cycle.

[0022] like Figure 1-5 As shown, it is the second embodiment of the present invention, the inner diameter of the outer sleeve 2 is the same as that of the inner sleeve 3, the outer diameter of the outer sleeve 2 is larger than that of the inner sleeve 3, the inner walls of the outer sleeve 2 and the inner sleeve 3 are jointly provided with three concave placement grooves 34, and three convex stoppers 35 are also jointly provided, the three placement grooves 34 and the stoppers 35 are all distributed in a circular array, and the cross-sections of the placement grooves 34 and the stoppers 35 are arranged crosswise, the rear end faces of the three stoppers 35 and the front end faces of the three placement grooves 34 are at different positions on the same plane, when the structure is used to connect the worm 5, one end of the worm 5 is also correspondingly set to a slot that can be adapted and engaged with the three stoppers 35, and the length of the slot is equal to the length of the stopper 35; Furthermore, the outer wall of the outer sleeve 2 is provided with three groups of limiting holes 21 respectively connected with the three placement grooves 34, each group of limiting holes 21 has two limiting holes 21 and each limiting hole 21 is movably penetrated with a limiting pin 22, one end of the two limiting pins 22 is commonly fixedly connected with a locking block 24 located in the placement groove 34, and the end surface position of the card slot opened on the worm 5 is provided with a notch along its outer surface for the three locking blocks 24 to be inserted, so that the depth of the notch is less than the thickness of the locking block 24, so that it can be ensured that the locking block 24 firmly locks the notch of the worm 5, the other end of each limiting pin 22 extends to the outside of the outer sleeve 2, and each limiting A spring 23 is movably sleeved on the positioning pin 22, and two ends of the spring 23 are respectively fixedly connected to the surface of the locking block 24 and the inner wall of the placement groove 34. A limiting ring 25 is threadedly sleeved on the outer surface of the outer sleeve 2, which is used to limit the limiting pin 22 extending to the outside of the outer sleeve 2. In a normal state, the limiting ring 25 is completely separated from the limiting hole 21, and the locking block 24 is completely in the placement groove 34, which will not restrict the inserted worm 5. The three locking blocks 24 and the three stoppers 35 are themselves distributed in a triangular shape, so that the worm 5 has higher stability after being connected, and the two intersect with each other on different planes, which further enhances the stability of the worm 5 after being connected.

[0023] When the above embodiment is working, when the worm 5 is connected to the self-locking mechanism, the three grooves on the worm 5 are first aligned with the three stoppers 35 on the inner wall of the inner sleeve 3 and the two are engaged, and then the worm 5 is gradually pushed into the inner part of the inner sleeve 3 until the stopper 35 is disengaged from the groove and the worm 5 can rotate. At this time, the inner sleeve 3 is immediately rotated clockwise or counterclockwise, and the rotation angle is limited to between 30° and 60°. At this time, the inner sleeve 3 is blocked by the stopper 35 when it is pulled outward, and the initial self-locking of the worm 5 after the connection is completed. Then, the rotating limit ring 25 moves on the outer surface of the outer sleeve 2 so that it completely covers one end of the three groups of limit pins 22, and the other end of the limit pin 22 drives the locking block 24 to be stuck in the recess of the worm 5. At this time, the worm 5 can be reinforced after the initial self-locking, and the three stoppers 35 and the three locking blocks 24 form a "cross" structure for the fixing direction of the worm 5, which has a high connection stability.

[0024] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-locking output shaft structure of an electric actuator, comprising a shaft body (1) and a self-locking structure integrally fixedly connected thereto, characterized in that: The self-locking structure comprises an outer sleeve (2) and an inner sleeve (3) formed integrally, the front and rear end surfaces of the inner sleeve (3) are symmetrically provided with a plurality of cylindrical cavities (31) opening outward, and the front and rear end surfaces of the inner sleeve (3) are respectively provided with annular covers (4) for sealing the plurality of cylindrical cavities (31), the inner wall of the inner sleeve (3) is provided with a plurality of oil outlet holes (311) penetrating the cylindrical cavities (31) and used for supplying oil to the inner wall of the inner sleeve (3), the outer wall of the inner sleeve (3) is provided with a plurality of heat dissipation holes (312) penetrating the cylindrical cavities (31) and used for dissipating heat to the outer wall of the inner sleeve (3), and the bottom surface of each cylindrical cavity (31) is provided with a plurality of oil outlet holes (311) penetrating the cylindrical cavities (31) and used for dissipating heat to the outer wall of the inner sleeve (3), A sealing plug (32) is fixedly provided on each of the two sealing surfaces. A plurality of conical seats (41) for sealing the cylindrical cavity (31) are fixedly provided on one end surface of the annular cover (4). One end of each conical seat (41) is fixedly connected to a spring (42). The other end of the spring (42) is fixedly connected to a rubber piston (43). An expansion cavity is formed between the rubber piston (43) and the sealing plug (32). An isolation layer (33) is provided in the expansion cavity and is respectively fixedly connected to the rubber piston (43) and the sealing plug (32). The isolation layer (33) separates the expansion cavity into an oil storage cavity (331) and a heat collection cavity (332) that are independent of each other.

2. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The conical seat (41), the second spring (42) and the rubber piston (43) are all located in the cylindrical cavity (31); the rubber piston (43) and the sealing plug (32) have the same diameter but different thicknesses; the rubber piston (43) and the sealing plug (32) are both interference fit with the cylindrical cavity (31).

3. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The rubber piston (43) divides the cylindrical cavity (31) into an expansion cavity and a heat dissipation cavity. The heat dissipation cavity is located between the rubber piston (43) and the cone seat (41). The oil outlet hole (311) and the heat dissipation hole (312) are respectively communicated with the interior of the heat dissipation cavity.

4. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The oil outlet holes (311) and the heat dissipation holes (312) have the same diameter and the same number, and the positions of the oil outlet holes (311) and the heat dissipation holes (312) are symmetrical about the central axis of the cylindrical cavity (31).

5. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The isolation layer (33) is made of silicone rubber, and in a natural state the isolation layer (33) has a zigzag structure, and the oil storage cavity (331) is filled with lubricating oil.

6. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The connecting surfaces of the annular cover (4) and the inner shaft sleeve (3) are fixed by bolts, one end of the inner shaft sleeve (3) is fixedly connected to one end of the shaft body (1), the inner diameter of the inner shaft sleeve (3) is larger than the outer diameter of the shaft body (1), and the annular cover (4) is movably sleeved outside the shaft body (1).

7. The self-locking output shaft structure of an electric actuator according to claim 1, characterized in that: The outer sleeve (2) and the inner sleeve (3) have the same inner diameter, the outer sleeve (2) has a larger outer diameter than the inner sleeve (3), and the inner walls of the outer sleeve (2) and the inner sleeve (3) are jointly provided with three recessed placement grooves (34) and three raised stop platforms (35).

8. The self-locking output shaft structure of an electric actuator according to claim 7, characterized in that: The three placement grooves (34) and the baffles (35) are all distributed in a circular array, and the cross sections of the placement grooves (34) and the baffles (35) are arranged crosswise, and the rear end surfaces of the three baffles (35) and the front end surfaces of the three placement grooves (34) are located at different positions on the same plane.

9. The self-locking output shaft structure of an electric actuator according to claim 7, characterized in that: The outer wall of the outer sleeve (2) is provided with three groups of limiting holes (21) respectively connected with the three placement grooves (34), each group of limiting holes (21) has two limiting holes (21) and each limiting hole (21) has a limiting pin (22) movably passing through it, and one end of the two limiting pins (22) is fixedly connected to a locking block (24) located in the placement groove (34).

10. The self-locking output shaft structure of an electric actuator according to claim 9, characterized in that: The other end of each of the limit pins (22) extends to the outside of the outer sleeve (2), and each limit pin (22) is movably sleeved with a spring (23), the two ends of the spring (23) being respectively fixedly connected to the surface of the locking block (24) and the inner wall of the placement groove (34), and the outer surface of the outer sleeve (2) is threadedly sleeved with a limit ring (25) for limiting the limit pin (22) extending to the outside of the outer sleeve (2).

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