Axial piston type pneumatic actuator

Abstract

The utility model provides an axial piston type pneumatic actuator. The axial piston type pneumatic actuator comprises a shell; the rotating shaft is rotationally mounted in the shell; the cylinder body is arranged in the working cavity, the cylinder body and the rotating shaft are fixedly connected and can rotate synchronously, a plurality of piston holes are formed in the lower end of the cylinder body, and the piston holes are circumferentially and uniformly distributed around the axis of the rotating shaft; the piston unit is arranged in the piston hole in a sleeved mode and can slide in the axial direction, and the sliding direction of the piston unit is parallel to the rotating axis of the rotating shaft; the guide curved surface is arranged in the working cavity and can be in contact with the end part of the piston unit; the air distribution disc is arranged in the shell and used for supplying air to the piston holes and exhausting air from the piston holes, so that the piston units sequentially move in a reciprocating mode and drive the cylinder body and the rotating shaft to rotate. The axial piston type pneumatic actuator is compact in structure, small in occupied space, suitable for various narrow installation environments, high in axial force transmission efficiency and capable of effectively reducing energy loss.

Description

Technical Field

[0001] This utility model relates to a pneumatic actuator, and more particularly to an axial piston pneumatic actuator. Background Technology

[0002] In industrial fluid control systems, valves, as the core actuators for fluid on / off control or flow regulation, directly affect the system's automation level, ease of operation, and safety. Traditional valves mainly rely on manual operation or a single power source (such as pneumatic or electric), which has significant limitations in practical applications.

[0003] Traditional manual valves have limitations and low operating efficiency. For large-diameter, high-pressure valves, manual operation requires a lot of manpower, and the valve opening and closing speed is slow, which is difficult to meet the needs of modern industry for rapid response. At the same time, manual valves rely on on-site personnel for operation and cannot be connected to automated control systems. They pose safety hazards in hazardous environments (such as high temperature, high pressure, toxic media) or remote unattended scenarios, and it is difficult to achieve real-time monitoring and data feedback.

[0004] In some hazardous environments, pneumatic motors, as the driving source of actuators, have the advantages of being explosion-proof, safe, and having a fast response. However, most existing pneumatic motor actuators adopt a radial arrangement structure, which is large in size, especially in the diameter direction. Therefore, they are limited in installation in confined spaces, and the output torque to volume ratio is not ideal. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide an axial piston pneumatic actuator that is compact in structure, small in size, has a wide installation range, and large output torque.

[0006] This utility model provides an axial piston pneumatic actuator, which includes:

[0007] A housing, wherein a working cavity is provided within the housing;

[0008] A rotating shaft 7 is rotatably mounted inside the housing. The head of the rotating shaft 7 serves as a manual input end and is connected to a handwheel 8. The tail of the rotating shaft 7 serves as a power output end and is used to connect to the controlled carrier.

[0009] A cylinder body 4 is disposed in the working chamber. The cylinder body 4 is fixedly connected to the rotating shaft 7 and can rotate synchronously. A piston hole 40 is provided at the lower end of the cylinder body 4. There are multiple piston holes 40 and they are evenly distributed around the axis of the rotating shaft 7.

[0010] Piston unit 5 is sleeved in the piston hole 40 and can slide axially. The sliding direction of piston unit 5 is parallel to the rotation axis of rotating shaft 7.

[0011] A guide surface 61a is disposed within the working cavity and can contact the end of the piston unit 5;

[0012] The valve plate 3 is disposed inside the housing and is used to supply and exhaust air to each of the piston holes 40, so that each of the piston units 5 reciprocates in sequence and drives the cylinder 4 and the rotating shaft 7 to rotate.

[0013] Furthermore, the housing includes a cylindrical shell 1, an upper cover 2 disposed at the upper end of the cylindrical shell 1, and a lower cover 6 disposed at the lower end of the cylindrical shell 1. The air distribution plate 3 is mounted on the upper cover 2. The upper cover 2 has air inlets and outlets that are evenly distributed around the circumference and connected to the air distribution plate 3. The upper end face of the lower cover 6 is provided with an annular protrusion 61. The upper surface of the annular protrusion 61 is curved and forms the guide curved surface 61a.

[0014] Furthermore, the end of the piston unit 5 is provided with ball bearings 522 for rolling contact with the guide surface 61a.

[0015] Furthermore, the piston unit 5 includes a piston body 51 that slides within the piston bore 40 and a bullseye bearing 52 mounted on the end of the piston body 51, wherein the bullseye bearing 52 is provided with the ball bearing 522.

[0016] Furthermore, the piston body 51 has a mounting hole 510 at the center of its end, the bullseye bearing 52 includes a bearing seat, the head of the bearing seat is provided with a mounting shaft 521 corresponding to the mounting hole 510, and the ball bearing 522 is rotatably mounted on the tail of the bearing seat.

[0017] Furthermore, the cylinder body 4 is cylindrical and has a shaft hole through the center for mounting the rotating shaft 7. The top surface of the cylinder body 4 is provided with air holes 401 that correspond one-to-one with and communicate with the piston holes 40. The top surface of the cylinder body 4 is in contact with the end face of the air distribution plate 3 and can communicate with the air distribution groove on the air distribution plate 3 in sequence during rotation.

[0018] Furthermore, the lower end face of the air distribution plate 3 is evenly distributed with air distribution grooves in the circumference. The number of air distribution grooves is greater than the number of piston holes 40. The air distribution grooves include alternating air inlet grooves 311 and air outlet grooves 321. The air inlet grooves 311 and the air outlet grooves 321 are respectively connected to the air inlet and air outlet on the housing. During rotation, the piston holes 40 can alternately connect to the air inlet grooves 311 and the air outlet grooves 321.

[0019] Furthermore, the side wall of the air distribution plate 3 is provided with a first annular groove 31 and a second annular groove 32. The first annular groove 31, the second annular groove 32 and the inner wall of the housing form an air intake channel and an air outlet channel. The air intake groove 311 is connected to the air intake channel through a first air passage 310, and the air outlet groove 321 is connected to the air outlet channel through a second air passage 320.

[0020] Furthermore, the number of piston units 5 is N, the number of peaks of the guide surface 61a is n, and N = n + k, where k is a positive integer and less than n.

[0021] Furthermore, the piston unit 5 consists of six units, and the guide surface 61a has four peaks.

[0022] Furthermore, the controlled carrier is a valve.

[0023] This utility model relates to an axial piston pneumatic actuator, where the piston unit slides along the axis of the rotating shaft. This avoids the problem of large radial dimensions caused by the radial distribution of the piston in traditional radial piston actuators, making it suitable for installation space-constrained scenarios. The overall structure is compact, with high space utilization. The axial movement of the piston is converted into rotational power for the rotating shaft through a guide surface, resulting in a more direct force transmission path and reducing the additional load on the rotating shaft from the radial component. Multiple piston units are evenly distributed around the circumference of the rotating shaft, and with the sequential air supply / exhaust of the air distribution plate, the rotating shaft experiences uniform force during rotation, resulting in minimal output torque fluctuations and improved control accuracy of the controlled carrier. The power output is stable, and the torque characteristics are excellent. Simultaneously, the short axial stroke of the piston, combined with the rapid response characteristics of pneumatic drive, significantly increases the actuator's operating speed, making it suitable for applications requiring rapid opening and closing. This utility model of an axial piston pneumatic actuator features a compact structure, small footprint, and suitability for various narrow installation environments. It also boasts high axial force transmission efficiency, effectively reducing energy loss. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the axial piston pneumatic actuator of this utility model;

[0025] Figure 2 This is a schematic diagram of the axial piston pneumatic actuator of this utility model from another angle.

[0026] Figure 3 This is a cross-sectional view of the axial piston pneumatic actuator of this utility model;

[0027] Figure 4 This is another planar sectional view of the axial piston pneumatic actuator of this utility model;

[0028] Figure 5 This is an exploded structural diagram of the axial piston pneumatic actuator of this utility model;

[0029] Figure 6 This is a schematic diagram of the lower cover structure of the axial piston pneumatic actuator of this utility model;

[0030] Figure 7 This is an exploded structural diagram of the piston unit of the axial piston pneumatic actuator of this utility model;

[0031] Figure 8 This is a schematic diagram of the cylinder body of the axial piston pneumatic actuator of this utility model;

[0032] Figure 9 This is a schematic diagram of the air distribution plate of the axial piston pneumatic actuator of this utility model;

[0033] Figure 10 This is another sectional view of the air distribution plate of the axial piston pneumatic actuator of this utility model;

[0034] In the diagram: 1. Cylinder shell, 2. Top cover, 3. Air distribution plate, 31. First annular groove, 310. First air passage, 311. Inlet groove, 32. Second annular groove, 320. Second air passage, 321. Outlet groove, 4. Cylinder body, 40. Piston hole, 401. Air hole, 41. Shaft hole, 411. Keyway, 5. Piston unit, 51. Piston body, 510. Mounting hole, 52. Bullseye bearing, 521. Mounting shaft, 522. Ball bearing, 6. Bottom cover, 61. Annular protrusion, 61a. Guide surface, 7. Rotating shaft, 8. Handwheel. Detailed Implementation

[0035] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0036] See Figures 1-10 This utility model provides an axial piston pneumatic actuator, including a housing, a rotating shaft 7, a cylinder 4, a piston unit 5, and a guide surface 61a.

[0037] The housing serves as an installation carrier and has an internal working cavity for mounting the rotating shaft 7, cylinder 4, piston unit 5, and guide surface 61a. At the same time, the housing can be installed on the controlled carrier to be controlled, thereby realizing the operation and control of the controlled carrier.

[0038] The rotating shaft 7 is rotatably installed inside the housing. Both ends of the rotating shaft 7 extend outside the housing or are exposed outside the housing. Its head serves as a manual input end and is connected to a handwheel 8 as a manual input end. The tail of the rotating shaft 7 serves as a power output end and is used to connect to the controlled carrier. In this embodiment, the controlled carrier is a valve.

[0039] The cylinder body 4 is set in the working chamber. The cylinder body 4 is fixedly connected to the rotating shaft 7 and can rotate synchronously. At the same time, the two are coaxial. A piston hole 40 is provided at the lower end of the cylinder body 4. There are multiple piston holes 40 and they are evenly distributed around the axis of the rotating shaft 7.

[0040] The number of piston units 5 is the same as that of piston holes 40, and they are arranged in each piston hole 40 in a one-to-one correspondence, and can slide axially. The sliding direction of the piston unit 5 is parallel to the rotation axis of the rotating shaft 7.

[0041] The guide surface 61a is disposed in the working cavity, facing the piston unit 5, and can contact the end of the piston unit 5.

[0042] The air distribution plate 3 is installed inside the housing and is used for air distribution, that is, to supply and exhaust air to each piston hole 40 in sequence, so that each piston unit 5 reciprocates in sequence. During the movement, the end of the piston unit 5 contacts the guide surface 61a. Under the action of the guide surface 61a, the cylinder 4 and the rotating shaft 7 are driven to rotate, thereby realizing the control of the controlled carrier.

[0043] This application adopts an axial layout, allowing the piston unit to slide along the axis of the rotating shaft. This avoids the problem of large radial dimensions caused by the radial distribution of the piston in traditional radial piston actuators, making it suitable for scenarios with limited installation space. The overall structure is compact and has high space utilization. The axial movement of the piston is converted into rotational power of the rotating shaft through the guide surface, making the force transmission path more direct and reducing the additional load on the rotating shaft from the radial component force. Multiple piston units are evenly distributed around the circumference of the rotating shaft. With the sequential air supply / exhaust of the air distribution plate, the rotating shaft is subjected to uniform force during rotation, resulting in small output torque fluctuations, improving the control accuracy of the controlled carrier, and providing stable power output and good torque characteristics. At the same time, the short axial stroke of the piston, combined with the fast response characteristics of pneumatic drive, significantly improves the actuator's operating speed, making it suitable for working conditions requiring rapid opening and closing.

[0044] The housing in this application includes a cylindrical shell 1, an upper cover 2 disposed at the upper end of the cylindrical shell 1, and a lower cover 6 disposed at the lower end of the cylindrical shell 1. The cylindrical shell 1 is cylindrical, and multiple bolts pass through the upper cover 2, the cylindrical shell 1, and the lower cover 6 in sequence and are connected to nuts to form an integral structure, i.e., the housing, which forms a working chamber inside. A valve plate 3 is mounted on the upper cover 2, and the upper cover 2 is provided with an air inlet and an air outlet connected to the valve plate 3. An annular protrusion 61 is provided on the upper end face of the lower cover 6. The annular protrusion 61 is coaxial with the cylinder body 4. The upper surface of the cover 61 is curved, with multiple alternating peaks and troughs forming a guide surface 61a. It adopts a split structure, which is easy to process, greatly reduces the processing difficulty and cost, and improves the processing accuracy. At the same time, it is easy to assemble, maintain and repair. The guide surface of the lower cover 6 is integrated, that is, the annular protrusion 61 on the upper end surface of the lower cover is directly processed into the guide surface 61a (a curved surface with peaks and troughs), without the need for additional independent guide components, reducing assembly errors, and reducing the number of components and cost.

[0045] To reduce friction, a ball bearing 522 is provided at the end of the piston unit 5. This ball bearing 522 can roll into contact with the guide surface 61a. The contact mode between the ball bearing 522 and the guide surface 61a changes from traditional sliding friction to rolling friction, significantly reducing the coefficient of friction and friction loss. At the same time, the lower friction loss allows pneumatic energy to be converted into rotational power of the shaft more efficiently, improving the working efficiency of the actuator and reducing the heat generated by friction. Furthermore, the rolling contact avoids direct sliding wear between the piston end and the guide surface, significantly reducing surface damage to the piston unit and the guide surface, extending the service life of core components. Reduced wear means longer component replacement cycles, reducing downtime and maintenance time and costs. Meanwhile, the spherical structure of the ball bearing can better conform to the crests and troughs of the guide surface, ensuring stable contact throughout the entire stroke. This rolling contact reduces the lateral pressure of the piston unit on the cylinder, reducing the risk of eccentric wear between the cylinder and the shaft, and improving the overall operational reliability of the structure.

[0046] In this embodiment, the piston unit 5 includes a piston body 51 slidably fitted within a piston bore 40 and a bullseye bearing 52 mounted on the end of the piston body 51. The bullseye bearing 52 has balls 522 mounted on it. The bullseye bearing is a precision component integrating balls; its internal balls 522 can achieve micro-rolling in three-dimensional directions. It can not only slide axially but also adapt to minute angle changes in the guiding surface, further reducing frictional resistance. Furthermore, the bullseye bearing is an existing standard component, requiring no additional design or manufacturing, thus reducing production costs. Specifically, a mounting hole 510 is provided at the center of the end of the piston body 51. The bullseye bearing 52 includes a bearing seat, which is a cylindrical structure. A mounting shaft 521 is provided at the head of the bearing seat, corresponding to the mounting hole 510 and enabling installation. The balls 522 are rotatably mounted on the tail of the bearing seat.

[0047] The cylinder body 4 in this application is cylindrical, with a shaft hole 41 penetrating through its center. The shaft hole 41 is used to install the rotating shaft 7. At the same time, a keyway 411 is provided on the side wall of the shaft hole 41, and the rotating shaft 7 is circumferentially fixed to the cylinder body 4 through the keyway 411. The piston holes 40 are evenly distributed circumferentially on the bottom surface of the cylinder body 4. Meanwhile, the top surface of the cylinder body 4 is provided with air holes 401 that correspond one-to-one with each piston hole 40 and are connected to it. That is, one air hole 401 connects to one piston hole 40, and the air holes are also evenly distributed circumferentially. The top surface of the cylinder body 4 is in contact with the end face of the valve plate 3, and the piston holes 40 are connected to the valve grooves on the valve plate 3 in sequence, thereby realizing rotation.

[0048] The valve plate 3 is circular with a central hole through it for the rotating shaft 7 to pass through. The valve plate, cylinder block, and rotating shaft are coaxially arranged. Multiple valve grooves are evenly distributed circumferentially on the lower end face of the valve plate 3, and the number of valve grooves is greater than the number of piston holes 40. In this embodiment, the valve groove is a waist-shaped hole or an arc-shaped hole, which will be continuously connected with the valve groove for a certain period of time during the rotation of the cylinder block. Specifically, the valve groove includes an alternately arranged intake groove 311 and an exhaust groove 321. The intake groove 311 and the exhaust groove 321 are respectively connected to the intake port and exhaust port on the housing, and are used for the supply and exhaust of air to the piston hole 40, respectively. During rotation, the piston hole 40 can alternately connect the intake groove 311 and the exhaust groove 321 and realize reciprocating sliding.

[0049] To facilitate the processing of internal pipelines and reduce processing difficulty and cost, in this embodiment, a first annular groove 31 and a second annular groove 32 are provided on the side wall of the air distribution plate 3. The first annular groove 31 and the second annular groove 32 form an air intake channel and an air outlet channel respectively between them and the inner wall of the housing. The air intake channel is connected to the air inlet of the side wall of the housing for supplying air, and the air outlet channel is connected to the air outlet of the side wall of the housing for exhausting air. Both the air intake channel and the air outlet channel are annular. A first air passage 310 is provided in the air intake groove 311, which is connected to the first annular groove 31, i.e., connected to the air intake channel. A second air passage 320 is provided in the air outlet groove 321, which is connected to the second annular groove 32, i.e. connected to the air outlet channel. The processing difficulty and manufacturing cost are low. At the same time, multiple sealing ring grooves are provided on the air distribution plate for sealing with the upper cover to form an air passage.

[0050] To ensure smooth overall operation, the number of piston units 5 in this embodiment is N, the number of peaks of the guide surface 61a is n, and N = n + k, where k is a positive integer and less than n. Preferably, there are six piston units 5 and four peaks of the guide surface 61a. Furthermore, in this embodiment, there are eight air distribution grooves, specifically four alternating air inlet grooves and four air outlet grooves, which ensures that the air supply and exhaust of the piston unit alternates during the reciprocating motion, thereby improving pneumatic efficiency.

[0051] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. An axial piston pneumatic actuator, characterized in that, include: A housing, wherein a working cavity is provided within the housing; A rotating shaft is rotatably mounted inside the housing. The head of the rotating shaft serves as a manual input end and is connected to a handwheel, while the tail of the rotating shaft serves as a power output end and is used to connect to the controlled carrier. A cylinder body is disposed in the working chamber. The cylinder body is fixedly connected to the rotating shaft and can rotate synchronously. A piston hole is provided at the lower end of the cylinder body. There are multiple piston holes, which are evenly distributed around the axis of the rotating shaft. A piston unit is fitted inside the piston hole and can slide axially, the sliding direction of the piston unit being parallel to the rotation axis of the rotating shaft; A guide surface is provided within the working cavity and can contact the end of the piston unit; The valve plate, located inside the housing, is used to supply and exhaust air to each of the piston holes, causing each piston unit to reciprocate in sequence and drive the cylinder and the shaft to rotate.

2. The axial piston pneumatic actuator as described in claim 1, characterized in that: The housing includes a cylindrical shell, an upper cover disposed at the upper end of the cylindrical shell, and a lower cover disposed at the lower end of the cylindrical shell. The air distribution plate is mounted on the upper cover, and the upper cover is provided with an air inlet and an air outlet connected to the air distribution plate. The upper end face of the lower cover is provided with an annular protrusion, and the upper surface of the annular protrusion is curved and forms the guide surface.

3. The axial piston pneumatic actuator as described in claim 1, characterized in that: The piston unit is provided with balls at its end for rolling contact with the guide surface.

4. The axial piston pneumatic actuator as described in claim 3, characterized in that: The piston unit includes a piston body that slides within the piston bore and a bullseye bearing mounted on the end of the piston body, wherein the bullseye bearing is provided with the ball bearing.

5. The axial piston pneumatic actuator as described in claim 4, characterized in that: The piston body has a mounting hole at the center of its end. The bullseye bearing includes a bearing housing. The head of the bearing housing has a mounting shaft corresponding to the mounting hole. The ball bearing is rotatably mounted at the tail of the bearing housing.

6. The axial piston pneumatic actuator as described in claim 1, characterized in that: The cylinder body is cylindrical and has a shaft hole through the center for mounting the rotating shaft. The top surface of the cylinder body has air holes that are evenly distributed around the circumference and correspond one-to-one with the piston holes and communicate with them. The top surface of the cylinder body is in contact with the end face of the valve plate and communicates with the valve groove of the valve plate in sequence during rotation.

7. The axial piston pneumatic actuator as described in claim 1, characterized in that: The lower end face of the air distribution plate is evenly distributed with air distribution grooves in the circumference. The number of air distribution grooves is greater than the number of piston holes. The air distribution grooves include alternating air inlet grooves and air outlet grooves. The air inlet grooves and the air outlet grooves are respectively connected to the air inlet and air outlet on the housing. During rotation, the piston holes can alternately connect to the air inlet grooves and the air outlet grooves.

8. The axial piston pneumatic actuator as described in claim 7, characterized in that: The side wall of the air distribution plate is provided with a first annular groove and a second annular groove. The first annular groove, the second annular groove and the inner wall of the housing form an air intake channel and an air outlet channel. The air intake groove is connected to the air intake channel through a first air passage, and the air outlet groove is connected to the air outlet channel through a second air passage.

9. The axial piston pneumatic actuator as described in claim 1, characterized in that: The number of piston units is N, the number of peaks of the guide surface is n, and N = n + k, where k is a positive integer and less than n.

10. The axial piston pneumatic actuator as described in claim 1, characterized in that: The controlled carrier is a valve.

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