Pneumatic actuator with manual control device

Abstract

The utility model discloses a pneumatic actuator with a manual control device, belongs to the technical field of valve actuators, and aims to solve the problem that the pneumatic actuator with the manual control device is inconvenient to switch. Comprising a pneumatic device, a manual device and a spring reset device, the manual device is provided with a transmission screw, the lower end of the transmission screw is provided with a flange structure, the spring reset device comprises a shaft sleeve assembly, the manual device, the spring reset device and the pneumatic device are sequentially connected from top to bottom, and the transmission screw penetrates through an upper wall plate of a spring cover. According to the utility model, when a driving mode is replaced, switching operations such as pin pulling and the like do not need to be carried out, the operation can be directly carried out, and the operation is simple, convenient and rapid.

Description

Technical Field

[0001] The utility model belongs to the technical field of valve actuators, and in particular relates to a pneumatic actuator with a manual control device. Background Art

[0002] In the control valve industry, the actuator is the key component that determines the valve switching speed and adjustment accuracy. Pneumatic actuators have the characteristics of strong adaptability and fast switching speed, and are widely used in control valves in power stations, petrochemical systems, etc.

[0003] Most of the existing actuators for opening and closing valves are electric actuators, which are limited by power supply and cannot be used under no-power conditions, which brings many inconveniences to people. For this reason, technical personnel in this field have studied pneumatic actuators with manual control devices. For example, the utility model patent with announcement number CN215110863U discloses a straight-stroke pneumatic actuator that can realize switching operations between manual and pneumatic control. When the actuator is switched manually or pneumatically, it is necessary to pull out and plug the pin to release or rebuild the linkage between the inner rod body and the outer screw sleeve to achieve switching. However, the pin and the pin hole are tightly matched, and the plug-in operation is difficult, and the pin is easily lost when it is pulled out. In addition, the inner rod body and the outer screw sleeve are slidably matched, the contact area is large, and the friction effect is large. Utility Model Content

[0004] The purpose of the utility model is to provide a pneumatic actuator with a manual control device to solve the problem of inconvenience in switching pneumatic actuators with manual control devices. The technical solution adopted by the utility model is as follows:

[0005] A pneumatic actuator with a manual control device, comprising a pneumatic device, a manual device and a spring reset device;

[0006] The pneumatic device includes a cylinder assembly, a piston assembly and a piston shaft. The outer periphery of the piston assembly is in sliding and sealing cooperation with the inner periphery of the cylinder assembly. The piston shaft penetrates the cylinder assembly and is sealedly connected with the piston assembly. An exhaust hole is provided on the upper cylinder cover of the cylinder assembly, an air inlet hole is provided on the lower cylinder cover of the cylinder assembly, and the piston shaft is in sliding and sealing cooperation with the lower cylinder cover.

[0007] The manual device includes a handwheel, a gear shaft, a gear box, a limit cover, a limit pin, a transmission nut, a bevel gear structure and a driven gear plate. The gear box is provided with a first shaft hole which runs through from top to bottom, and a second shaft hole is provided on one side of the gear box. A transmission nut is rotatably arranged in the gear box, and a transmission screw is threadedly matched with the transmission nut. The driven gear plate is sleeved on the transmission nut. A gear shaft is rotatably arranged in the second shaft hole, and a bevel gear structure is provided at the inner end of the gear shaft. A handwheel is sleeved at the outer end of the gear shaft, and the bevel gear structure is meshed with the driven gear plate. The lower edge of the limit cover is connected to the upper end of the first shaft hole, and a vertically opened slide groove is provided on the limit cover. A limit pin is provided at the upper end of the transmission screw, and the limit pin is slidably matched with the slide groove.

[0008] The spring return device includes a spring cover, a sleeve assembly, a large spring and a small spring. The gear box, spring cover and cylinder assembly are connected in sequence from top to bottom. The small spring and the large spring are connected to the outer periphery of the sleeve assembly from inside to outside. A flange structure is provided at the lower end of the transmission screw. The transmission screw passes through the upper wall plate of the spring cover and the end cover at the top of the sleeve assembly. The flange structure is slidably matched with the sleeve assembly. The flange structure is abutted or separated from the lower and upper ends of the end cover. The upper end of the piston shaft passes through the upper cylinder cover and is connected to the lower end of the sleeve assembly. The spring seat is sleeved on the piston shaft. The shoulders of the sleeve assembly, the spring seat and the piston shaft are abutted in sequence from top to bottom. The two ends of the large spring are respectively abutted against the top cover and the spring seat of the spring cover, and the two ends of the small spring are respectively abutted against the top cover and the spring seat of the spring cover.

[0009] Furthermore, an air chamber sealing gland is provided on the lower cylinder head of the cylinder assembly, an oil seal is provided between the air chamber sealing gland and the lower cylinder head, and the piston shaft is slidably sealed with the cylinder assembly through the oil seal.

[0010] Furthermore, the piston assembly includes a two-piece clamping ring, a piston disc and a clamping ring pressure cover. The axis of the piston disc is provided with a stepped inner hole, the piston shaft is provided with an annular groove, the two-piece clamping ring is cooperatively connected to the annular groove, the piston shaft passes through the stepped inner hole, the clamping ring pressure cover is seal-connected to the piston disc, the clamping ring pressure cover presses the two-piece clamping ring into the stepped inner hole, and the clamping ring pressure cover is sealingly sleeved on the piston shaft.

[0011] Furthermore, the outer periphery of the piston disc is provided with two air chamber sealing rings, a guide ring is provided between the two air chamber sealing rings, and the piston assembly is slidingly sealed with the cylinder assembly through the two air chamber sealing rings and the guide ring.

[0012] Furthermore, the spring cover also includes an outer cylinder, a top cover seals the upper end opening of the outer cylinder, the top cover is connected to the upper cylinder cover through a long stud, and the lower edge of the top cover is sealed with the upper cylinder cover through a sealing ring.

[0013] Furthermore, the shaft sleeve assembly also includes a positioning sleeve and a sleeve, the outer periphery of the positioning sleeve cooperates with the inner periphery of the lower end of the sleeve, the sleeve and the lower ends of the positioning sleeve are flush welded and connected, the inner periphery of the positioning sleeve is provided with a threaded structure, the positioning sleeve is threadedly connected to the piston shaft, the positioning sleeve, the sleeve and the piston shaft are fixed by a set screw, the end cover is coaxially threadedly connected to the upper end of the sleeve, the end cover and the sleeve are fixed to stop retreat by a set screw, and the flange structure is slidably matched with the inner periphery of the sleeve, or is abutted against the lower and upper parts of the end cover.

[0014] Furthermore, the gear shaft and the second shaft hole are rotatably connected via two deep groove ball bearings, an inner ring spacer is provided between the two deep groove ball bearings, a shaft end cover is sleeved on the gear shaft, the gear shaft and the shaft end cover are rotatably sealed via a sealing ring, and the shaft end cover is connected to the outer edge of the hole wall of the second shaft hole.

[0015] Furthermore, a base is provided at the lower end of the gear box, a thrust bearing is provided between the base and the driven gear plate, and a thrust bearing is provided between the upper end of the transmission nut and the top end of the gear box.

[0016] Furthermore, a top cover is sleeved on the outside of the limiting cover, an upper wall plate of the top cover is connected to an upper wall plate of the limiting cover by screws, and a lower edge of the top cover is sealed to an upper end of the first shaft hole by a sealing ring.

[0017] Furthermore, it also includes a lower flange, which is connected to the lower cylinder head through connecting studs.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. The utility model provides a pneumatic actuator with a manual control device, which uses compressed air as a power source. By increasing the pressure in the cylinder, the piston disc overcomes the elastic force of the spring and moves upward, thereby driving the valve stem of the regulating valve to accurately move and adjust the valve to the required opening. When the pneumatic device is used to control the valve stem of the regulating valve to slide upward, the piston shaft drives the sleeve assembly to move upward, and there is enough space in the sleeve for the flange structure under the transmission screw to slide. Therefore, the manual device does not affect the operation of the pneumatic device. When the pneumatic device fails, the hand wheel is shaken to move the transmission screw upward. The flange structure is against the top cover, and the manual device can drive the valve stem of the regulating valve to slide upward. When changing the drive mode, the utility model does not need to perform switching operations such as pulling out and inserting pins, and can be performed directly, which is simple and quick to operate.

[0020] 2. The transmission screw is matched with the sleeve through the flange structure, the contact area between the flange structure and the inner wall of the sleeve is small, and the friction effect is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model;

[0022] Figure 2 It is a schematic diagram of the structure of the pneumatic device;

[0023] Figure 3 It is a schematic diagram of the structure of the spring return device;

[0024] Figure 4 It is a structural diagram of the manual device.

[0025] In the figure, 1. pneumatic device, 11. piston shaft, 12. cylinder assembly, 13. piston assembly, 14. lower cylinder head, 15. cylinder body, 16. upper cylinder head, 17. snap ring gland, 18. piston disc, 19. guide ring, 110. air chamber sealing ring, 111. air inlet hole, 112. two-in-one snap ring, 113. air chamber sealing gland, 114. oil seal, 2. spring return device, 21. spring seat, 22. large spring, 23. small spring, 24. spring cover, 25. shaft sleeve Assembly, 26. Outer cylinder, 27. Top cover, 28. End cover, 29. Long stud, 210. Sleeve, 211. Positioning sleeve, 3. Manual device, 31. Transmission screw, 32. Driven gear plate, 33. Gear box, 34. Transmission nut, 35. Limit cover, 36. Bevel gear structure, 37. Gear shaft, 38. Handwheel, 39. Shaft end cover, 310. Deep groove ball bearing, 311. Base, 312. Limit pin, 313. Top cover, 41. Lower flange, 42. Connecting stud. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is described below by specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0027] The connection mentioned in the present utility model is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection, including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but is not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: choose welding connection for fixed connection and bolt connection for detachable connection.

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0029] Example: Figure 1 to Figure 4As shown, a pneumatic actuator with a manual control device comprises a pneumatic device 1, a manual device 3 and a spring return device 2;

[0030] The pneumatic device 1 includes a cylinder assembly 12, a piston assembly 13 and a piston shaft 11. The cylinder assembly 12 includes a cylinder body 15, an upper cylinder cover 16 and a lower cylinder cover 14. The cylinder body 15 is a round tube member. The upper cylinder cover 16 seals the upper opening of the cylinder body 15, and the lower cylinder cover 14 seals the lower opening of the cylinder body 15. The outer periphery of the piston assembly 13 is slidably sealed with the inner periphery of the cylinder assembly 12. The piston shaft 11 passes through the cylinder assembly 12 and is sealedly connected to the piston assembly 13. The upper cylinder cover 16 of the cylinder assembly 12 is provided with an exhaust hole, and the lower cylinder cover 14 of the cylinder assembly 12 is provided with an air inlet hole 111. The piston shaft 11 is slidably sealed with the lower cylinder cover 14.

[0031] The manual device 3 includes a handwheel 38, a gear shaft 37, a gear box 33, a limit cover 35, a limit pin 312, a transmission nut 34, a bevel gear structure 36 and a driven gear plate 32. The gear box 33 is provided with a first axial hole that runs through from top to bottom, and a second axial hole is provided on one side of the gear box 33. A transmission nut 34 is rotatably provided in the gear box 33, and a transmission screw 31 is threadedly matched with the transmission nut 34. The driven gear plate 32 is sleeved on the transmission nut 34. A gear shaft 37 is rotatably provided in the second axial hole. A bevel gear structure 36 is provided at the inner end of the gear shaft 37. A handwheel 38 is sleeved at the outer end of the gear shaft 37. The bevel gear structure 36 meshes with the driven gear plate 32. The lower edge of the limit cover 35 is connected to the upper end of the first axial hole. A vertically opened slide groove is provided on the limit cover 35. A limit pin 312 is provided at the upper end of the transmission screw 31, and the limit pin 312 is slidably matched with the slide groove.

[0032] The spring return device 2 includes a spring cover 24, a sleeve assembly 25, a large spring 22 and a small spring 23. The gear box 33, the spring cover 24 and the cylinder assembly 12 are connected in sequence from top to bottom. The small spring 23 and the large spring 22 are connected to the outer periphery of the sleeve assembly 25 from inside to outside. The lower end of the transmission screw 31 is provided with a flange structure. The transmission screw 31 passes through the upper wall plate of the spring cover 24 and the end cover 28 at the top of the sleeve assembly 25. The flange structure is slidably matched with the sleeve assembly 25. The flange structure is abutted against or separated from the end cover 28 at the bottom and top. The upper end of the piston shaft 11 passes through the upper cylinder cover 16 and is connected to the lower end of the shaft sleeve assembly 25. The spring seat 21 is sleeved on the piston shaft 11. The shaft sleeve assembly 25, the spring seat 21 and the shoulders of the piston shaft 11 are abutted against each other from top to bottom. The two ends of the large spring 22 are respectively abutted against the top cover 27 of the spring cover 24 and the spring seat 21, and the two ends of the small spring 23 are respectively abutted against the top cover 27 of the spring cover 24 and the spring seat 21.

[0033] An air chamber sealing gland 113 is provided on the lower cylinder head 14 of the cylinder assembly 12 , an oil seal 114 is provided between the air chamber sealing gland 113 and the lower cylinder head 14 , and the piston shaft 11 is slidably sealed with the cylinder assembly 12 via the oil seal 114 .

[0034] The piston assembly 13 includes a two-piece snap ring 112, a piston disc 18 and a snap ring cover 17. The axis of the piston disc 18 is provided with a stepped inner hole, and the piston shaft 11 is provided with an annular groove. The two-piece snap ring 112 is connected to the annular groove in cooperation with the piston shaft 11. The piston shaft 11 passes through the stepped inner hole. The snap ring cover 17 is sealed and connected to the piston disc 18. The snap ring cover 17 presses the two-piece snap ring 112 into the stepped inner hole, and the snap ring cover 17 is sealingly sleeved on the piston shaft 11.

[0035] Two air chamber sealing rings 110 are sleeved on the outer periphery of the piston disc 18 , and a guide ring 19 is arranged between the two air chamber sealing rings 110 . The piston assembly 13 is slidably sealed with the cylinder assembly 12 through the two air chamber sealing rings 110 and the guide ring 19 .

[0036] The spring cover 24 also includes an outer tube 26, and a top cover 27 seals the upper end opening of the outer tube 26. The top cover 27 is connected to the upper cylinder cover 16 through a long stud 29. The lower edge of the top cover 27 is sealed to the upper cylinder cover 16 through a sealing ring, so that the spring cover 24 and the cylinder assembly 12 are sealed.

[0037] The shaft sleeve assembly 25 includes a positioning sleeve 211, a sleeve 210 and an end cover 28. The outer periphery of the positioning sleeve 211 cooperates with the inner periphery of the lower end of the sleeve 210. The sleeve 210 and the lower ends of the positioning sleeve 211 are flush welded and connected. The inner periphery of the positioning sleeve 211 is provided with a threaded structure. The positioning sleeve 211 is threadedly connected to the piston shaft 11. The positioning sleeve 211, the sleeve 210 and the piston shaft 11 are fixed by set screws. The end cover 28 is coaxially threadedly connected to the upper end of the sleeve 210. The end cover 28 and the sleeve 210 are fixed and prevented from retreating by set screws after being drilled. A space is provided in the sleeve 210 for the flange structure to slide. The flange structure is slidably matched with the inner periphery of the sleeve 210, or is abutted against the end cover 28 from top to bottom, so that the plunger at the lower part of the central axis can slide up and down along the inner wall of the sleeve without falling out of the sleeve.

[0038] The gear shaft 37 and the second shaft hole are rotationally connected via two deep groove ball bearings 310, an inner ring spacer is provided between the two deep groove ball bearings 310, a shaft end cover 39 is sleeved on the gear shaft 37, the gear shaft 37 and the shaft end cover 39 are rotationally sealed via a sealing ring, and the shaft end cover 39 is connected to the outer edge of the hole wall of the second shaft hole.

[0039] A base 311 is provided at the lower end of the gear box 33, a thrust bearing is provided between the base 311 and the driven gear plate 32, a thrust bearing is provided between the upper end of the transmission nut 34 and the top end of the gear box 33, the base 311 pushes the driven gear plate 32 upward through the thrust bearing, and the transmission nut 34 pushes the gear box 33 upward through the thrust bearing, so that the actuator has better load-bearing capacity and is easy to drive the valve stem of the regulating valve to slide.

[0040] The outer cover 35 is provided with a top cover 313, the upper wall plate of the top cover 313 is connected to the upper wall plate of the limit cover 35 by screws, and the lower edge of the top cover 313 is sealed to the upper end of the first shaft hole by a sealing ring. The top cover 313 is used for dustproof sealing of the top end of the actuator.

[0041] It also includes a lower flange 41, which is connected to the lower cylinder head 14 through a connecting stud 42. The lower flange 41 is used to provide mounting support for the actuator.

[0042] The utility model is used to drive the valve stem of the regulating valve to control the opening of the valve flap of the regulating valve. During installation, the lower flange 41 is connected and fixed to the valve body of the regulating valve, and the piston shaft 11 is connected to the valve stem of the regulating valve through a connecting piece.

[0043] The pneumatic device 1 uses compressed air as a power source. When the regulating valve is in a fully closed state, no compressed air is introduced into the cylinder assembly 2, and the piston assembly 13 is pressed to the bottom of the cylinder assembly 2 by the elastic force of the large spring 22 and the small spring 23; when the regulating valve is opened, compressed air enters the cylinder assembly 2 through the air inlet 111 on the lower cylinder cover 14, generating an upward thrust on the bottom surface of the piston assembly 13, and the piston assembly 13 moves upward against the elastic force of the large spring 22 and the small spring 23, and the piston shaft 11 can drive the valve stem of the regulating valve to move upward, and open the regulating valve to a specified opening; when the regulating valve is closed, the air supply to the air inlet 111 is stopped, and the piston assembly 13 moves downward under the elastic force of the large spring 22 and the small spring 23, thereby driving the regulating valve to gradually close.

[0044] In addition to the pneumatic device 1, the present invention can also be operated by the manual device 3. The hand wheel 38 is rotated, and the driving nut 34 is driven to rotate by the meshing of the bevel gear structure 36 and the driven gear plate 32, thereby driving the driving screw 31 to move upward. After the flange structure abuts against the end cover 28, the valve stem of the regulating valve can be lifted up through the shaft sleeve assembly 25 to adjust the valve opening.

[0045] The utility model provides a pneumatic actuator with a manual control device, which uses compressed air as a power source, and by increasing the pressure in the cylinder, the piston disc 18 overcomes the elastic force of the spring to move upward, thereby driving the valve stem of the regulating valve to accurately move and adjust the valve to the required opening. When the pneumatic device 1 is used to control the valve stem of the regulating valve to slide upward, the piston shaft 11 drives the shaft sleeve assembly 25 to move upward, and there is enough space in the sleeve 210 for the flange structure below the transmission screw 31 to slide, so the manual device 3 does not affect the operation of the pneumatic device 1. When the pneumatic device 1 fails, the hand wheel 38 is shaken to make the transmission screw 31 move upward, and the flange structure and the top cover 28 are abutted from top to bottom, and the manual device 3 can drive the valve stem of the regulating valve to slide upward. When changing the drive mode, the utility model does not need to perform switching operations such as pulling out and inserting pins, and can be performed directly, which is simple and quick to operate.

[0046] The transmission screw 31 cooperates with the sleeve 210 through the flange structure. The contact area between the flange structure and the inner wall of the sleeve 210 is small, and the influence of friction is small.

[0047] The above embodiments are merely illustrative of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A pneumatic actuator with a manual control device, characterized in that: It comprises a pneumatic device (1), a manual device (3) and a spring return device (2); The pneumatic device (1) comprises a cylinder assembly (12), a piston assembly (13) and a piston shaft (11); the outer periphery of the piston assembly (13) and the inner periphery of the cylinder assembly (12) are slidably sealed; the piston shaft (11) passes through the cylinder assembly (12) and is sealedly connected to the piston assembly (13); an exhaust hole is provided on the upper cylinder cover (16) of the cylinder assembly (12); an air inlet hole (111) is provided on the lower cylinder cover (14) of the cylinder assembly (12); and the piston shaft (11) and the lower cylinder cover (14) are slidably sealed. The manual device (3) comprises a hand wheel (38), a gear shaft (37), a gear box (33), a limit cover (35), a limit pin (312), a transmission nut (34) and a driven gear plate (32). The gear box (33) is provided with a first shaft hole which passes through the gear box (33) from top to bottom. A second shaft hole is provided on one side of the gear box (33). A transmission nut (34) is rotatably arranged in the gear box (33). The transmission screw (31) is threadedly matched with the transmission nut (34). The driven gear plate (32) is sleeved on the transmission nut (34). 34), a gear shaft (37) is rotatably arranged in the second shaft hole, a bevel gear structure (36) is arranged at the inner end of the gear shaft (37), a hand wheel (38) is sleeved at the outer end of the gear shaft (37), the bevel gear structure (36) is meshed with the driven gear plate (32), the lower edge of the limit cover (35) is connected to the upper end of the first shaft hole, a vertically opened slide groove is arranged on the limit cover (35), a limit pin (312) is arranged at the upper end of the transmission screw (31), and the limit pin (312) is slidably matched with the slide groove; The spring return device (2) comprises a spring cover (24), a shaft sleeve assembly (25), a large spring (22) and a small spring (23); the gear box (33), the spring cover (24) and the cylinder assembly (12) are connected in sequence from top to bottom; the small spring (23) and the large spring (22) are connected to the outer periphery of the shaft sleeve assembly (25) from inside to outside; a flange structure is provided at the lower end of the transmission screw (31); the transmission screw (31) passes through the upper wall plate of the spring cover (24) and the end cover (28) at the top end of the shaft sleeve assembly (25); the flange structure is slidably matched with the shaft sleeve assembly (25) The flange structure is abutted against or separated from the end cover (28) at the bottom and top. The upper end of the piston shaft (11) passes through the upper cylinder cover (16) and is connected to the lower end of the shaft sleeve assembly (25). The spring seat (21) is sleeved on the piston shaft (11). The shaft shoulders of the shaft sleeve assembly (25), the spring seat (21) and the piston shaft (11) are abutted against each other from top to bottom. The two ends of the large spring (22) are respectively abutted against the top cover (27) of the spring cover (24) and the spring seat (21). The two ends of the small spring (23) are respectively abutted against the top cover (27) of the spring cover (24) and the spring seat (21).

2. A pneumatic actuator with a manual control device according to claim 1, characterized in that: An air chamber sealing gland (113) is provided on the lower cylinder cover (14) of the cylinder assembly (12), an oil seal (114) is provided between the air chamber sealing gland (113) and the lower cylinder cover (14), and the piston shaft (11) is slidably sealed with the cylinder assembly (12) via the oil seal (114).

3. A pneumatic actuator with a manual control device according to claim 2, characterized in that: The piston assembly (13) comprises a two-piece clamping ring (112), a piston disc (18) and a clamping ring cover (17); the axis of the piston disc (18) is provided with a stepped inner hole; an annular groove is provided on the piston shaft (11); the two-piece clamping ring (112) is connected to the annular groove in cooperation; the piston shaft (11) passes through the stepped inner hole; the clamping ring cover (17) is sealedly connected to the piston disc (18); the clamping ring cover (17) presses the two-piece clamping ring (112) into the stepped inner hole; and the clamping ring cover (17) is sealingly sleeved on the piston shaft (11).

4. A pneumatic actuator with a manual control device according to claim 3, characterized in that: The outer periphery of the piston disc (18) is provided with two air chamber sealing rings (110), a guide ring (19) is provided between the two air chamber sealing rings (110), and the piston assembly (13) is slidably sealed with the cylinder assembly (12) via the two air chamber sealing rings (110) and the guide ring (19).

5. The pneumatic actuator with a manual control device according to claim 1, characterized in that: The spring cover (24) further comprises an outer cylinder (26), a top cover (27) sealing the upper end opening of the outer cylinder (26), the top cover (27) being connected to the upper cylinder cover (16) via a long stud (29), and the lower edge of the top cover (27) and the upper cylinder cover (16) being sealed via a sealing ring.

6. A pneumatic actuator with a manual control device according to claim 1, characterized in that: The shaft sleeve assembly (25) further comprises a positioning sleeve (211) and a sleeve (210); the outer periphery of the positioning sleeve (211) matches the inner periphery of the lower end of the sleeve (210); the sleeve (210) and the lower ends of the positioning sleeve (211) are connected by flush welding; the inner periphery of the positioning sleeve (211) is provided with a threaded structure; the positioning sleeve (211) is threadedly connected to the piston shaft (11); the positioning sleeve (211), the sleeve (210) and the piston shaft (11) are fixed by means of set screws; the end cover (28) is coaxially threadedly connected to the upper end of the sleeve (210); the end cover (28) and the sleeve (210) are fixed by means of set screws to prevent retreat; the flange structure is slidably matched with the inner periphery of the sleeve (210), or is abutted against the end cover (28) from top to bottom.

7. A pneumatic actuator with a manual control device according to claim 1, characterized in that: The gear shaft (37) and the second shaft hole are rotatably connected via two deep groove ball bearings (310), an inner ring spacer is provided between the two deep groove ball bearings (310), a shaft end cover (39) is sleeved on the gear shaft (37), a sealing ring is rotatably sealed between the gear shaft (37) and the shaft end cover (39), and the shaft end cover (39) is connected to the outer edge of the hole wall of the second shaft hole.

8. The pneumatic actuator with a manual control device according to claim 1, characterized in that: A base (311) is provided at the lower end of the gear box (33), a thrust bearing is provided between the base (311) and the driven gear plate (32), and a thrust bearing is provided between the upper end of the transmission nut (34) and the top end of the gear box (33).

9. The pneumatic actuator with a manual control device according to claim 1, characterized in that: The outer portion of the limiting cover (35) is provided with a top cover (313), the upper wall plate of the top cover (313) is connected to the upper wall plate of the limiting cover (35) by screws, and the lower edge of the top cover (313) is sealedly connected to the upper end of the first shaft hole by a sealing ring.

10. A pneumatic actuator with a manual control device according to any one of claims 1 to 9, characterized in that: It also includes a lower flange (41), which is connected to the lower cylinder cover (14) via a connecting stud (42).

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