Pneumatic actuator

Abstract

The invention relates to the technical field of actuators, in particular to a pneumatic actuator which comprises an air cylinder body, two symmetrical piston assemblies, a rotating shaft assembly and an end cover. The air cylinder body is divided into a rotating shaft assembly working cavity and piston assembly working cavities on the two sides. The rotating shaft assembly working cavity is provided with an air inlet hole and an air outlet hole. The piston assembly comprises a piston and an elastic supporting mechanism composed of a flat spring, a guide sleeve and a guide rod. The rotating shaft assembly is accurately assembled through the tooth path and the fool-proof structure. During air intake, the working cavity of the rotating shaft assembly is pressurized to drive the double pistons to move reversely and compress the spring, and the shifting fork drives the rotating shaft to rotate to open the valve; during pressure relief, the spring resets to drive the double pistons to move oppositely and reversely drive the rotating shaft to close the valve. The reset reliability, the power transmission efficiency and the control precision are improved, the service life of equipment is prolonged, and the device is suitable for high-precision valve control scenes.

Description

Technical Field

[0001] The present invention relates to the technical field of actuators, and in particular to a pneumatic actuator. Background Art

[0002] In the field of industrial automation control, pneumatic actuators are the core equipment for driving valve movements. Their performance is directly related to the stability and safety of industrial processes. However, their existing structures have significant defects in the elastic support at the piston end and the connection between the rotating shaft assembly.

[0003] In terms of elastic support on the piston end, traditional single-acting pneumatic actuators mostly use a single spring between the piston and the end cover to achieve elastic reset. This structure is prone to fatigue failure due to the long-term unidirectional compression force on the spring, resulting in poor reset reliability; the concentrated force on the single spring can easily cause the piston to tilt, resulting in eccentric wear of the cylinder wall, air leakage and increased component loss; the reset force varies dramatically with the compression amount, and the impact force at the initial stage of valve closing is too large to easily damage the valve, while insufficient force in the later stage may cause the valve to not close tightly; and the spring installation space is limited, making it difficult to provide a large reset torque, and it is not suitable for large-diameter valves. At the same time, the coaxiality requirements of the spring and the piston are high, and assembly deviations can easily cause jamming, which greatly reduces the stability and life of the actuator.

[0004] In terms of the connection of the rotating shaft components, the rotating shaft, shift block and angular adjustment block of the existing actuators are mostly connected by pins. The pins are assembled by setting pin holes at the corresponding positions of the components and inserting cylindrical or conical pins. The structure is simple but the positioning guidance is poor, which leads to the rotating shaft being easily installed upside down or crooked during assembly, and the shift block and the angular adjustment block being misaligned, thereby destroying the coordination relationship with the shift fork, making it impossible to effectively transmit the piston power, and unable to accurately control the opening and closing of the valve, affecting the on-off accuracy and parameter stability of the industrial process; at the same time, installation deviations will aggravate the uneven force of the components, accelerate the wear of components such as the rotating shaft, shift fork, and shift block, cause abnormal vibration, noise and even jamming, increase maintenance costs and downtime, reduce production and maintenance efficiency, and destroy product performance stability.

[0005] These problems seriously restrict the reliable application of pneumatic actuators and urgently need to be solved through structural optimization. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problems of the above-mentioned prior art and provide a pneumatic actuator to solve the problems of easy failure, uneven force, unstable reset, insufficient torque and easy jamming of the single spring connection between the piston and the end cover of the existing pneumatic actuator; the rotating shaft, the shift block and the angular adjustment block pin connection are easy to be installed upside down, crookedly and misplaced, resulting in poor power transmission and inaccurate valve control; and the cylinder body chamber is not reasonably divided, resulting in an unreasonable layout, which affects the stability, precision and life of the actuator.

[0007] The above objectives are achieved through the following technical solutions: A pneumatic actuator comprises a cylinder body, two symmetrically arranged piston assemblies, a rotating shaft assembly and two end covers; the two ends of the cylinder body are sealed by the end covers to form a working chamber, the working chamber comprises a central rotating shaft assembly working chamber and a piston assembly working chamber on both sides, the rotating shaft assembly working chamber is communicated with the piston assembly working chambers on both sides, the rotating shaft assembly is arranged in the rotating shaft assembly working chamber, the two piston assemblies are respectively arranged in the piston assembly working chambers on both sides and are transmission connected to the rotating shaft assembly; an air inlet and an air outlet are opened on the cylinder body corresponding to the rotating shaft assembly working chamber; the piston assembly comprises a piston and a piston end elastic support mechanism, the rotating shaft assembly comprises a rotating shaft, a shift block and an angular adjustment block; the air inlet and the air outlet are used to control external pressure input and pressure relief, driving the two piston assemblies to move in opposite directions or towards each other at both ends, the piston end elastic support mechanism is used to realize the elastic reset of the piston, and the rotating shaft assembly is used to convert the linear motion of the two pistons into rotational motion to drive the valve action.

[0008] Furthermore, the piston end elastic support mechanism includes a spring assembly, a first spring assembly slot arranged on the outer wall of the piston, and a second spring assembly slot arranged on the inner wall of the end cover, one end of the spring assembly is plugged into the first spring assembly slot, and the other end is plugged into the second spring assembly slot.

[0009] Furthermore, the spring assembly includes four flat springs arranged parallel to each other, one end of each flat spring is sleeved on the first guide sleeve, and the other end is sleeved on the second guide sleeve, and the first guide sleeve and the second guide sleeve are respectively movably sleeved on the two ends of the same guide rod.

[0010] Furthermore, the first guide sleeve is T-shaped, including a first guide sleeve seat and a first guide sleeve rod connected to each other, and a first guide rod through-hole for the guide rod to pass through; the second guide sleeve is T-shaped, including a second guide sleeve seat and a second guide sleeve rod connected to each other, and a second guide rod through-hole for the guide rod to pass through; the length of the guide rod is greater than the length of the flat spring in the contracted state and less than the length in the extended state.

[0011] Furthermore, a circular piston groove is provided on the outer wall of the piston, and the first spring assembly slot is arranged in the piston groove, including four first spring slots symmetrically arranged with the center of the piston groove, the outer edge of each first spring slot is connected to the inner wall of the piston groove, the side edges of adjacent first spring slots are connected by a first reinforcing rib, and the bottom wall of the first spring slot is provided with a first bottom wall guide groove for inserting the guide rod.

[0012] Furthermore, the end cover includes a circular end cover cavity with an opening toward the piston, and a second spring assembly slot is provided in the end cover cavity; the second spring assembly slot includes four second spring slots symmetrically arranged with the center of the end cover cavity, for inserting the second guide sleeve and the end of the spring; the outer edges of each second spring slot are respectively connected to the inner wall of the end cover cavity, and the side edges of adjacent second spring slots are connected by second reinforcing ribs; the bottom wall of the second spring slot is also provided with a second bottom wall guide groove for inserting the guide rod.

[0013] Furthermore, the outer wall of the rotating shaft is provided with a tooth path extending in the axial direction, the shift block is provided with a shift block socket, and the hole wall of the shift block socket is provided with a shift block tooth groove adapted to the tooth path; the angular position adjustment block is provided with an angular position adjustment block socket, and the hole wall of the angular position adjustment block socket is provided with an angular position adjustment block tooth groove adapted to the tooth path, and the tooth path is engaged with the shift block tooth groove and the angular position adjustment block tooth groove to realize power transmission; the inner sides of the two pistons are connected with a shift fork, and the shift fork is transmission connected to the shift block.

[0014] Furthermore, the tooth path of the rotating shaft is provided with an anti-study ridge, the inner wall of the shift block tooth groove is provided with a shift block anti-study groove adapted to the anti-study ridge, and the inner wall of the angular adjustment block tooth groove is provided with an angular adjustment block anti-study groove adapted to the anti-study ridge.

[0015] Furthermore, the cylinder body, the rotating shaft, the shift block, the angular adjustment block and the end cover are all made of metal materials.

[0016] Furthermore, an arrow mark for indicating the installation direction is provided on the shift block.

[0017] The pneumatic actuator provided by the present invention brings significant technical effects by integrating the optimized design of the elastic support mechanism at the piston end and the rotating shaft assembly. The piston end adopts four symmetrically distributed flat spring assemblies, which cooperate with the guide sleeve and guide rod to disperse the force to reduce the risk of fatigue failure. The reset force changes smoothly, avoiding valve impact and loose closing problems, improving reset reliability and life, and at the same time providing a larger reset torque in a limited space, adapting to large-caliber valves, reducing piston tilt and cylinder wall eccentric wear, and reducing the probability of sticking. The rotating shaft assembly ensures the precise assembly of the rotating shaft, shift block, and angular adjustment block through tooth meshing and anti-foolproof structure, avoiding reverse installation and misalignment, improving power transmission efficiency and valve control accuracy, reducing component wear, shortening assembly and maintenance time, and overall enhancing the stability and service life of the actuator to meet the needs of complex industrial environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a pneumatic actuator according to the present invention; Figure 2 This is an exploded view of a pneumatic actuator according to the present invention; Figure 3 A cross-sectional view from a first perspective of a pneumatic actuator according to the present invention; Figure 4 A cross-sectional view from a second perspective of a pneumatic actuator according to the present invention; Figure 5 This is a schematic diagram of the assembly of a rotating shaft assembly and a shift fork in a pneumatic actuator according to the present invention; Figure 6 This is an exploded view of a rotating shaft assembly in a pneumatic actuator according to the present invention; Figure 7 This is a schematic structural diagram from a first perspective of a spring assembly in a pneumatic actuator according to the present invention; Figure 8 This is a schematic structural diagram from a second perspective of a spring assembly in a pneumatic actuator according to the present invention; Figure 9 This is a schematic diagram of the connection between the guide rod and the guide sleeve in the pneumatic actuator of the present invention; Figure 10 This is a schematic diagram of the structure of the first spring assembly slot of the piston in the pneumatic actuator of the present invention; Figure 11 This is a schematic diagram of the second spring assembly slot structure of the end cover of a pneumatic actuator described in the present invention.

[0019] Graphic mark: 1- cylinder body, 101- rotating shaft assembly working chamber, 102- piston assembly working chamber, 103- air inlet, 104- air outlet; 2-Piston assembly; 3-piston, 301-piston groove, 302-first spring assembly slot, 303-first spring slot, 304-first reinforcing rib, 305-first bottom wall guide groove; 4- piston end elastic support mechanism, 401- spring assembly, 402- flat spring, 403- first guide sleeve, 404- second guide sleeve, 405- guide rod, 406- first guide sleeve seat, 407- first guide sleeve rod, 408- first guide rod through hole, 409- second guide sleeve seat, 410- second guide sleeve rod, 411- second guide rod through hole; 5-end cover, 501-end cover cavity, 502-second spring assembly slot, 503-second spring slot, 504-second reinforcing rib, 505-second bottom wall guide groove; 6-rotating shaft assembly, 601-rotating shaft, 602-shift block, 603-angular adjustment block, 604-tooth path, 605-anti-idiot ridge, 606-shift block socket, 607-shift block tooth groove, 608-shift block anti-idiot groove, 609-angular adjustment block socket, 610-angular adjustment block tooth groove, 611-angular adjustment block anti-idiot groove; 7-shift fork; 8-Adjusting screw. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below with reference to the figures and embodiments.

[0021] like Figures 1 to 4 As shown, a pneumatic actuator includes a cylinder body 1, two symmetrically arranged piston assemblies 2, a rotating shaft assembly 6 and two end covers 5; the two ends of the cylinder body 1 are sealed by the end covers 5 to form a working chamber, the working chamber includes a rotating shaft assembly working chamber 101 in the middle and piston assembly working chambers 102 on both sides, the rotating shaft assembly working chamber 101 is communicated with the piston assembly working chambers 102 on both sides, the rotating shaft assembly 6 is arranged in the rotating shaft assembly working chamber 101, and the two piston assemblies 2 are respectively arranged in the piston assembly working chambers 102 on both sides and are transmission-connected to the rotating shaft assembly 6; An air inlet 103 and an air outlet 104 are provided on the cylinder body 1 corresponding to the working chamber 101 of the rotary shaft assembly; The piston assembly 2 includes a piston 3 and a piston end elastic support mechanism 4, and the rotating shaft assembly 6 includes a rotating shaft 601, a shift block 602 and an angular adjustment block 603; The air inlet 103 and the air outlet 104 are used to control external pressure input and pressure relief, driving the two piston assemblies 2 to move in opposite directions or towards each other at both ends. The piston end elastic support mechanism 4 is used to achieve elastic reset of the piston 3. The rotating shaft assembly 6 is used to convert the linear motion of the two pistons 3 into rotational motion to drive the valve action.

[0022] Working principle: When external pressure is input into the air inlet 103, the pressure in the working chamber 101 of the rotating shaft assembly increases, driving the two piston assemblies 2 to move in opposite directions at both ends and compressing the spring assembly 401. The piston 3 drives the shift block 602 to rotate through the shift fork 7, and then drives the rotating shaft 601 to rotate to open the valve; when the air outlet 104 is depressurized, the spring assembly 401 resets and drives the two piston assemblies 2 to move in opposite directions. The shift fork 7 drives the shift block 602 and the rotating shaft 601 to rotate in the opposite direction to close the valve.

[0023] In this embodiment, the piston end elastic support mechanism 4 includes a spring component 401, a first spring component slot 302 arranged on the outer wall of the piston 3, and a second spring component slot 502 arranged on the inner wall of the end cover 5. One end of the spring component 401 is plugged into the first spring component slot 302, and the other end is plugged into the second spring component slot 502.

[0024] like Figures 7-9 As shown, specifically, the spring assembly 401 includes four flat springs 402 arranged parallel to each other, one end of each flat spring 402 is sleeved on the first guide sleeve 403, and the other end is sleeved on the second guide sleeve 404, and the first guide sleeve 403 and the second guide sleeve 404 are respectively movably sleeved on the two ends of the same guide rod 405.

[0025] Specifically, a flat spring is made of a flat metal strip wound in a helical pattern with gaps between adjacent turns. Unlike circular springs, its rectangular cross-section allows for more balanced stress distribution during axial compression, while also resulting in a compact design that allows for deployment within limited spaces.

[0026] Its advantages in actuators are as follows: Stress and life: The flat cross-section makes the spring more uniformly stressed. Compared with the circular cross-section spring, it has better fatigue resistance. When subjected to unidirectional force for a long time, it is not easy to fail quickly due to stress concentration, which improves the reset reliability and life of the actuator.

[0027] Reset characteristics: The reset force changes relatively slowly with the compression amount. When closing the valve, the initial impact force is small, and there is also stable force in the later stage, which can avoid valve impact and loose closing problems and make the actuator movement more stable.

[0028] Space and torque: The compact structure adapts to the limited space of the actuator, and can be designed with larger wire diameters and numbers of turns, providing greater reset torque in a small installation space, meeting the needs of large-diameter valves, and broadening the application scenarios of the actuator.

[0029] Coaxiality and stability: During installation, the coaxiality of the flat spring and the piston is easy to ensure, and it is not easy to get stuck due to assembly deviation, which improves the operating stability of the actuator, reduces component wear, and ensures long-term reliable operation.

[0030] In this embodiment, the first guide sleeve 403 is T-shaped, including a first guide sleeve seat 406 and a first guide sleeve rod 407 connected to each other, and a first guide rod through hole 408 for the guide rod 405 to pass through; the second guide sleeve 404 is T-shaped, including a second guide sleeve seat 409 and a second guide sleeve rod 410 connected to each other, and a second guide rod through hole 411 for the guide rod 405 to pass through; the length of the guide rod 405 is greater than the length of the flat spring 402 in the contracted state and less than the length in the extended state.

[0031] like Figure 2 and 10 As shown, in this embodiment, a circular piston groove 301 is formed on the outer wall of the piston 3, and the first spring assembly slot 302 is arranged in the piston groove 301, including four first spring slots 303 symmetrically arranged with the center of the piston groove 301, and the outer edge of each first spring slot 303 is connected to the inner wall of the piston groove 301, and the side edges of adjacent first spring slots 303 are connected by a first reinforcing rib 304, and the bottom wall of the first spring slot 303 is provided with a first bottom wall guide groove 305 for inserting the guide rod 405.

[0032] like Figure 2 and 11 As shown, in this embodiment, the end cover 5 includes a circular end cover cavity 501 with an opening toward the piston 3, and a second spring assembly slot 502 is provided in the end cover cavity 501; the second spring assembly slot 502 includes four second spring slots 503 symmetrically arranged with the center of the end cover cavity 501, for inserting the second guide sleeve 404 and the end of the flat spring 402; the outer side of each second spring slot 503 is respectively connected to the inner wall of the end cover cavity 501, and the side edges of adjacent second spring slots 503 are connected by second reinforcing ribs 504; the bottom wall of the second spring slot 503 is also provided with a second bottom wall guide groove 505 for inserting the guide rod 405.

[0033] The first bottom wall guide groove 305 and the second bottom wall guide groove 505 are used to provide storage space for the guide rod 405 when the spring contracts, thereby facilitating the expansion and contraction control of the spring.

[0034] like Figure 5 and 6 As shown, as an optimization of the rotating shaft assembly 6 in this embodiment, the outer wall of the rotating shaft 601 is provided with a tooth path 604 extending in the axial direction, the shift block 602 is provided with a shift block socket 606, and the hole wall of the shift block socket 606 is provided with a shift block tooth groove 607 adapted to the tooth path 604; the angular position adjustment block 603 is provided with an angular position adjustment block socket 609, and the hole wall of the angular position adjustment block socket 609 is provided with an angular position adjustment block tooth groove 610 adapted to the tooth path 604, and the tooth path 604 is engaged with the shift block tooth groove 607 and the angular position adjustment block tooth groove 610 to realize power transmission; the inner sides of the two pistons 3 are connected with a shift fork 7, and the shift fork 7 is transmission-connected to the shift block 602.

[0035] In addition, an anti-foolproof ridge 605 is provided on the tooth path 604 of the rotating shaft 601, and the inner wall of the shift block tooth groove 607 is provided with a shift block anti-foolproof groove 608 adapted to the anti-foolproof ridge 605, and the inner wall of the angular adjustment block tooth groove 610 is provided with an angular adjustment block anti-foolproof groove 611 adapted to the anti-foolproof ridge 605; as an embodiment of this scheme, there are two anti-foolproof ridges 605, which are symmetrically arranged on the outer wall of the rotating shaft 601, and there are two shift block anti-foolproof grooves 608 and two angular adjustment block anti-foolproof grooves 611 respectively.

[0036] It should be noted that the cylinder body 1, the rotating shaft 601, the shift block 602, the angular adjustment block 603 and the end cover 5 are all made of metal materials, such as stainless steel; the inner walls of the rotating shaft assembly working chamber 101 and the piston assembly working chamber 102 are both provided with an anti-corrosion coating.

[0037] As an optimization of the shift block, an arrow mark for identifying the installation direction is provided on the shift block 602.

[0038] As a further illustration of this solution, a pneumatic actuator includes a cylinder body 1, two symmetrically arranged piston assemblies 2, a rotating shaft assembly 6 and two end covers 5, and the specific structure is as follows: (1) Cylinder block 1 The cylinder block 1 is a hollow cavity, sealed at both ends by end caps 5 to form a working chamber. The working chamber is divided into three parts along the axial direction: a central rotating shaft assembly working chamber 101 and two symmetrical piston assembly working chambers 102. The inner diameter of the rotating shaft assembly working chamber 101 is smaller than that of the piston assembly working chamber 102, forming a stepped structure to ensure the sealing of the piston assembly 2 during movement. The side wall of the cylinder block 1 corresponding to the rotating shaft assembly working chamber 102 is provided with an air inlet 103 and an air outlet 104, respectively, for inputting compressed air (external pressure) and exhausting gas, thereby controlling the movement of the piston assembly 2. The inner wall of the cylinder block 1 is precision machined and sprayed with an anti-corrosion coating to improve corrosion resistance and wear resistance.

[0039] (2) Piston assembly 2 The two piston assemblies 2 are symmetrically arranged in the piston assembly working chambers 102 on both sides. Each piston assembly 2 includes a piston 3 and a piston end elastic support mechanism 4. Specifically: Piston 3: Made of corrosion-resistant and high-pressure resistant material, such as rubber, it is disc-shaped, and its outer wall is sealed with the inner wall of the piston assembly working chamber 102 (achieved by a sealing ring). The inner side (the side facing the rotating shaft assembly 6) is provided with a fork connecting seat for installing the fork 7; the outer wall (the side away from the rotating shaft assembly 6) is provided with a circular piston groove 301 for accommodating the elastic support mechanism.

[0040] The piston end elastic support mechanism 4 includes a first spring assembly slot 302, a second spring assembly slot 502, and a spring assembly 401. The first spring assembly slot 302 is disposed within the piston groove 301 and includes four first spring slots 303 symmetrically distributed about the center of the groove 301. Adjacent slots are connected by a first reinforcing rib 304, and the bottom wall is provided with a first bottom wall guide groove 305. The second spring assembly slot 502 is disposed on the inner wall of the end cap 5, corresponding one-to-one with the first spring assembly slot 302. It includes four symmetrically distributed second spring slots 503, adjacent slots are connected by a second reinforcing rib 504, and the bottom wall is provided with a second bottom wall guide groove 505. The spring assembly 401 is composed of four parallel flat springs 402, each end of which is respectively sleeved on a T-shaped first guide sleeve 403 and a second guide sleeve 404. A guide rod 405 passes through the through-holes of the two guide sleeves and is inserted into the first and second bottom wall guide grooves at both ends to ensure coaxiality and stability during spring expansion and contraction.

[0041] (3) Rotating shaft assembly 6 The rotating shaft assembly 6 is disposed in the rotating shaft assembly working chamber 101 and includes a rotating shaft 601, a shift block 602 and an angular adjustment block 603. Specifically: Rotating shaft 601: The bottom end is connected to the valve, and the outer wall is provided with a tooth path 604 extending along the axial direction. Two anti-fool ridges 605 are symmetrically provided on the tooth path 604 for precise positioning and assembly.

[0042] Shift block 602: It is provided with a shift block socket 606, the shift block tooth groove 607 on the hole wall is engaged with the tooth path 604 of the rotating shaft, and the two shift block anti-idiot grooves 608 on the inner wall are adapted to the anti-idiot convex strips; the two sides of the shift block 602 are in contact with the shift forks 7 connected to the two pistons 3, which is used to convert the linear motion of the piston into the rotational motion of the rotating shaft 601. The shift block 602 is provided with an arrow mark to assist in installation and positioning.

[0043] Angular adjustment block 603: It is sleeved on the rotating shaft 601, the angular adjustment block tooth groove 610 on the hole wall is engaged with the tooth path 604, and the two angular adjustment block anti-idiot grooves 611 on the inner wall are adapted to the anti-idiot convex strips; by adjusting the screw 8 and cooperating with the angular adjustment block 603 in the working chamber 101 of the rotating shaft assembly, the rotation angle of the rotating shaft 601 is limited (0°-90°) to ensure that the valve is fully opened and closed.

[0044] Assembly process of the rotating shaft assembly 6: Align the anti-mistake ridge 605 of the rotating shaft 601 with the anti-mistake groove 608 of the shift block 602 to engage the teeth, and sleeve the shift block 602 on the middle of the rotating shaft 601; assemble the angular adjustment block 603 in the same way and pre-tighten it by adjusting the screw 8.

[0045] The working principle of this pneumatic actuator: 1. Valve opening process: External compressed air enters the working chamber 101 of the rotating shaft assembly through the air inlet 103, increasing the pressure in the chamber, pushing the piston assemblies 2 on both sides to move in opposite directions (away from the rotating shaft assembly 6). When the piston 3 moves, it compresses the spring assembly 401 (the spring stores elastic potential energy), and at the same time drives the shift block 602 to rotate through the inner shift fork 7. The shift block 602 engages with the rotating shaft 601 through the tooth path 604, driving the rotating shaft 601 to rotate 90° clockwise to open the valve. At this time, one side of the angular adjustment block 603 contacts the adjusting screw 8, limiting excessive rotation of the rotating shaft.

[0046] 2. Valve closing process: The air outlet 104 opens, the working chamber 101 of the rotating shaft assembly is depressurized, and the pressure in the chamber drops to atmospheric pressure; the spring assembly 401 releases its elastic potential energy, driving the piston assemblies 401 on both sides to move towards each other (close to the rotating shaft assembly 6); the piston 3 drives the shift block 602 to rotate in the opposite direction through the shift fork 7, and the shift block 602 drives the rotating shaft 601 to rotate 90° counterclockwise to close the valve; the other side of the angular adjustment block 603 contacts another adjusting screw 8 to complete the limit.

[0047] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be conceived by anyone skilled in the art within the technical scope disclosed by the present invention are also included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A pneumatic actuator, characterized in that: It comprises a cylinder body (1), two symmetrically arranged piston assemblies (2), a rotating shaft assembly (6) and two end covers (5); the two ends of the cylinder body (1) are sealed by the end covers (5) to form a working chamber, the working chamber comprising a central rotating shaft assembly working chamber (101) and piston assembly working chambers (102) on both sides, the rotating shaft assembly (6) is arranged in the rotating shaft assembly working chamber (101), and the two piston assemblies (2) are respectively arranged in the piston assembly working chambers (102) on both sides and are transmission-connected to the rotating shaft assembly (6); An air inlet (103) and an air outlet (104) are provided on the cylinder body (1) corresponding to the working chamber (101) of the rotating shaft assembly; The piston assembly (2) includes a piston (3) and a piston end elastic support mechanism (4); the rotating shaft assembly (6) includes a rotating shaft (601), a shift block (602) and an angular position adjustment block (603); The air inlet (103) and the air outlet (104) are used to control external pressure input and pressure relief, driving the two piston assemblies (2) to move in opposite directions or towards each other at both ends, the piston end elastic support mechanism (4) is used to achieve elastic reset of the piston (3), and the rotating shaft assembly (6) is used to convert the linear motion of the two pistons (3) into rotational motion to drive the valve action.

2. A pneumatic actuator according to claim 1, characterized in that: The piston end elastic support mechanism (4) comprises a spring assembly (401), a first spring assembly slot (302) provided on the outer side wall of the piston (3), and a second spring assembly slot (502) provided on the inner side wall of the end cover (5), one end of the spring assembly (401) being plugged into the first spring assembly slot (302), and the other end being plugged into the second spring assembly slot (502).

3. A pneumatic actuator according to claim 2, characterized in that: The spring assembly (401) includes four flat springs (402) arranged parallel to each other, one end of each flat spring (402) is sleeved on a first guide sleeve (403), and the other end is sleeved on a second guide sleeve (404), and the first guide sleeve (403) and the second guide sleeve (404) are movably sleeved on the two ends of the same guide rod (405).

4. A pneumatic actuator according to claim 3, characterized in that: The first guide sleeve (403) is T-shaped, comprising a first guide sleeve seat (406) and a first guide sleeve rod (407) connected to each other, and a first guide rod through hole (408) for the guide rod (405) to pass through; the second guide sleeve (404) is T-shaped, comprising a second guide sleeve seat (409) and a second guide sleeve rod (410) connected to each other, and a second guide rod through hole (411) for the guide rod (405) to pass through.

5. The pneumatic actuator according to claim 2, characterized in that: The outer wall of the piston (3) is provided with a circular piston groove (301), and the first spring assembly slot (302) is arranged in the piston groove (301), including four first spring slots (303) symmetrically arranged with the center of the piston groove (301), the outer side of each first spring slot (303) is connected to the inner wall of the piston groove (301), and the side edges of adjacent first spring slots (303) are connected by a first reinforcing rib (304), and the bottom wall of the first spring slot (303) is provided with a first bottom wall guide groove (305) for inserting the guide rod (405).

6. A pneumatic actuator according to claim 2, characterized in that: The end cover (5) includes a circular end cover cavity (501) with an opening toward the piston (3), and a second spring assembly slot (502) is provided in the end cover cavity (501); the second spring assembly slot (502) includes four second spring slots (503) symmetrically arranged with respect to the center of the end cover cavity (501), the outer side of each second spring slot (503) is respectively connected to the inner wall of the end cover cavity (501), and the side edges of adjacent second spring slots (503) are connected by a second reinforcing rib (504); the bottom wall of the second spring slot (503) is also provided with a second bottom wall guide groove (505) for inserting the guide rod (405).

7. The pneumatic actuator according to claim 1, characterized in that: The outer wall of the rotating shaft (601) is provided with a tooth path (604) extending in the axial direction; the shift block (602) is provided with a shift block socket (606); the hole wall of the shift block socket (606) is provided with a shift block tooth groove (607) adapted to the tooth path (604); the angular position adjustment block (603) is provided with an angular position adjustment block socket (609); the hole wall of the angular position adjustment block socket (609) is provided with an angular position adjustment block tooth groove (610) adapted to the tooth path (604); the tooth path (604) is meshed with the shift block tooth groove (607) and the angular position adjustment block tooth groove (610) to achieve power transmission; the inner sides of the two pistons (3) are both connected with a shift fork (7), and the shift fork (7) is transmission-connected to the shift block (602).

8. A pneumatic actuator according to claim 7, characterized in that: The tooth path (604) of the rotating shaft (601) is provided with an anti-fool convex strip (605), the inner wall of the shift block tooth groove (607) is provided with a shift block anti-fool convex strip (608) adapted to the anti-fool convex strip (605), and the inner wall of the angular adjustment block tooth groove (610) is provided with an angular adjustment block anti-fool convex strip (605).

9. The pneumatic actuator according to claim 8, characterized in that: The cylinder body (1), the rotating shaft (601), the shifting block (602), the angular position adjustment block (603) and the end cover (5) are all made of metal material.

10. The pneumatic actuator according to claim 1, characterized in that: The shift block (602) is provided with an arrow mark for identifying the installation direction.

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