Single acting pneumatic cylinder actuator
By using a single-acting cylinder configuration and a buffer component design, the problems of large size and poor economy of existing pneumatic actuators have been solved, achieving a compact structure and efficient torque output, and reducing manufacturing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG HUAERSHI AUTOMATIC CONTROL INSTR VALVE
- Filing Date
- 2025-08-26
- Publication Date
- 2026-07-28
AI Technical Summary
Existing pneumatic actuators, due to their use of double-acting cylinders, are bulky and economical.
It adopts a single-acting cylinder configuration, combined with the design of piston rod, main shaft, shift fork and roller, and uses the cycloidal principle to achieve high torque start-up, and reduces impact force through buffer components, and uses elastic elements and sealing rings to improve sealing and buffering effect.
It achieves a compact structure, small size, stable transmission, and sensitive response, reducing manufacturing costs and improving economic efficiency.
Smart Images
Figure CN224566825U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of actuator technology, and in particular to a single-acting cylinder pneumatic actuator. Background Technology
[0002] A pneumatic actuator is an actuator that uses air pressure to open, close, or regulate a valve. It is also called a pneumatic actuator mechanism or pneumatic device, but it is commonly referred to as a pneumatic head. Pneumatic actuators are sometimes equipped with certain auxiliary devices, such as valve positioners and handwheel mechanisms. The function of a valve positioner is to use the feedback principle to improve the performance of the actuator, so that the actuator can achieve accurate positioning according to the control signal of the controller.
[0003] Existing pneumatic actuators typically employ a double-acting cylinder configuration for high-torque starting, which results in drawbacks such as bulky structure and poor economy. Utility Model Content
[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a single-acting cylinder pneumatic actuator. This invention adopts a single-acting cylinder configuration, which has the advantages of small structure and good economy.
[0005] The technical solution adopted by this utility model is as follows: A single-acting cylinder pneumatic actuator includes an actuator body and a main shaft and a piston rod disposed inside the actuator body. The main shaft is connected to the piston rod in a driving manner. A balance seat and a cylinder are respectively provided on both sides of the actuator body. One end of the piston rod extends into the balance seat and the other end extends into the cylinder and is connected to a piston component. It also includes a shift fork component sleeved on the main shaft and a roller passing through the piston rod. The roller moves back and forth axially with the piston rod. One side of the shift fork component is provided with an opening that drives the roller in a driving manner. The piston rod drives the shift fork component and the main shaft to rotate through the roller. When the shift fork component rotates, the roller and the opening slide relative to each other.
[0006] It also includes a buffer assembly and an end cap. The end cap is connected to the balance seat by fasteners. A buffer cavity for installing the buffer assembly is formed between the end cap and the balance seat. The buffer assembly includes a buffer element and an elastic element. The balance seat has an insertion hole for the buffer element to pass through. The elastic element presses the buffer element toward the piston rod.
[0007] The piston rod has a recess for the buffer to slide into, and the edge of the recess has a rounded corner. The buffer is conical.
[0008] The buffer component has a boss at the end away from the balance seat, and a limiting groove is provided on the inner side of the boss for the elastic element to be embedded in. The elastic element is an air cushion.
[0009] The buffer assembly also includes an elastic pad that is sleeved on the outside of the boss and extends to the end face of the boss.
[0010] The outer peripheral wall of the buffer component and the inner peripheral wall of the end cap slide together to separate the buffer cavity. The end cap is also provided with an exhaust hole that communicates with the outside. The exhaust hole communicates with the buffer cavity on the side away from the balance seat.
[0011] A first sealing ring is provided between the buffer and the end cap, and a second sealing ring is provided between the insertion hole and the buffer.
[0012] The beneficial effects of this utility model are as follows: This utility model adopts a single-acting cylinder configuration, that is, a single piston drives the main shaft to rotate, which is compact and significantly reduces the size. The shift fork achieves torque output through the cooperation of the opening and the roller. Based on the principle of cycloid, the valve is opened and closed by utilizing the principle that the longest cycloid has the smallest starting torque. Even the actuator can be easily opened and closed with a large torque. It also has the technical characteristics of cycloid transmission with uniform acceleration and uniform deceleration, which makes the transmission stable and the response sensitive. Under the premise of ensuring torque output capability, the manufacturing cost is reduced and the economy is improved. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.
[0014] Figure 1 This is a schematic diagram of the structure of a single-acting cylinder pneumatic actuator according to the present invention; Figure 2 This is a structural schematic diagram from another perspective of the present invention; Figure 3 for Figure 1 A magnified view of a portion of point A in the middle; In the diagram, 1-actuator body, 2-main shaft, 3-piston rod, 4-balance seat, 5-cylinder, 6-piston component, 7-shift fork component, 8-roller, 9-opening, 10-end cover, 11-fastener, 12-buffer chamber, 13-buffer component, 14-elastic component, 15-insertion hole, 16-recess, 17-rounded corner, 18-bore, 19-limiting groove, 20-elastic gasket, 21-vent hole, 22-first sealing ring, 23-second sealing ring. Detailed Implementation
[0015] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.
[0016] It should be noted that all uses of "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.
[0017] The directional and positional terms used in this utility model, such as "up," "down," "front," "back," "left," "right," "inner," "outer," "top," "bottom," and "side," are merely for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.
[0018] like Figures 1 to 3 As shown, this is an embodiment of the present invention, a single-acting cylinder pneumatic actuator, including an actuator body 1 and a main shaft 2 and a piston rod 3 disposed inside the actuator body 1. The main shaft 2 is operatively connected to the piston rod 3. A balance seat 4 and a cylinder 5 are respectively provided on both sides of the actuator body 1. One end of the piston rod 3 extends into the balance seat 4 and the other end extends into the cylinder 5 and is connected to a piston member 6. It also includes a shift fork 7 sleeved on the main shaft 2 and a roller 8 passing through the piston rod 3. The roller 8 moves axially back and forth with the piston rod 3. One side of the shift fork 7 is provided with an opening 9 that is operatively engaged with the roller 8. The piston rod 3 drives the shift fork 7 and the main shaft 2 to rotate through the roller 8. When the shift fork 7 rotates, the roller 8 and the opening 9 slide relative to each other.
[0019] The beneficial effects of this configuration are as follows: This utility model adopts a single-acting cylinder configuration, that is, a single piston drives the main shaft to rotate, resulting in a compact structure and significantly reduced volume. The shift fork achieves torque output through the cooperation of the opening and the roller. Based on the principle of cycloid, the valve is opened and closed by utilizing the principle that the longest cycloid has the smallest starting torque. Even with a large torque start-up actuator, it can be opened and closed easily. It also has the technical characteristics of cycloid transmission with uniform acceleration and uniform deceleration, resulting in stable transmission and sensitive response. Under the premise of ensuring torque output capability, the manufacturing cost is reduced and the economy is improved.
[0020] Further configuration includes a buffer assembly and an end cap 10. The end cap 10 is connected to the balance seat 4 via a fastener 11. A buffer cavity 12 for installing the buffer assembly is formed between the end cap 10 and the balance seat 4. The buffer assembly includes a buffer member 13 and an elastic member 14. The balance seat 4 has an insertion hole 15 for the buffer member 13 to pass through. The elastic member 14 presses the buffer member 13 toward the piston rod 3.
[0021] The beneficial effects of this design are as follows: the piston rod and the balance seat are connected by a plug-in joint, and the balance seat can guide the movement direction of the piston rod and prevent the piston rod from bending. During the actuator closing process, that is, when the piston rod moves towards the end of the balance seat away from the actuator body, the piston rod is buffered by the buffer component, which reduces the impact brought by the piston rod when closing. The fasteners use bolts of existing technology, and the end caps installed on the balance seat by bolts facilitate the disassembly of the buffer component, making it easy to maintain and replace. The elastic component further helps the buffer component to offset the impact force.
[0022] Furthermore, the piston rod 3 has a recess 16 for the buffer member 13 to slide into, the edge of the recess 16 is provided with an arc angle 17, and the buffer member 13 is conical.
[0023] The beneficial effects of this design are as follows: the recess is more compatible with the conical buffer, the buffer can also guide the piston rod, and the rounded corners facilitate the buffer sliding into the recess.
[0024] In a further configuration, the buffer 13 is provided with a boss 18 at the end away from the balance seat 4, and the inner side of the boss 18 is provided with a limiting groove 19 for the elastic element 14 to be embedded in. The elastic element 14 is an air cushion.
[0025] The beneficial effects of this design are as follows: the elastic element uses an air cushion, which has a good cushioning effect and is durable; the cushioning element is installed through a limiting groove to prevent the air cushion from slipping and failing.
[0026] Furthermore, the buffer assembly also includes an elastic pad 20, which is sleeved on the outside of the boss 18 and extends to the end face of the boss 18.
[0027] The beneficial effects of this design are as follows: the elastic gasket can prevent the buffer from impacting the end cap, further offsetting the impact force and protecting the parts; the elastic gasket adopts an outer sleeve installation method, providing all-round protection for the buffer.
[0028] Furthermore, the outer peripheral wall of the buffer member 13 and the inner peripheral wall of the end cover 10 are slidably engaged to separate the buffer cavity 12. The end cover 10 is also provided with an exhaust hole 21 that communicates with the outside. The exhaust hole 21 communicates with the buffer cavity 12 on the side away from the balance seat 4.
[0029] The beneficial effects of this design are as follows: the buffer chamber is connected to the outside through the vent hole. When the buffer is cushioned, it will compress the buffer chamber, and the air in the buffer chamber will be discharged through the vent hole, reducing the air resistance and making the buffer slide more smoothly.
[0030] Further, a first sealing ring 22 is provided between the buffer 13 and the end cap 10, and a second sealing ring 23 is provided between the insertion hole 15 and the buffer 13.
[0031] The beneficial effects of this design are as follows: the first sealing ring increases the sealing between the buffer and the end cap, and the second sealing ring increases the sealing between the insertion hole and the buffer.
[0032] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.
Claims
1. A single-acting cylinder pneumatic actuator, comprising an actuator body (1) and a main shaft (2) and a piston rod (3) disposed inside the actuator body (1), wherein the main shaft (2) and the piston rod (3) are connected in a driving connection, characterized in that: The actuator body (1) is provided with a balance seat (4) and a cylinder (5) on both sides respectively. One end of the piston rod (3) extends into the balance seat (4) and the other end extends into the cylinder (5) and is connected to a piston member (6). It also includes a shift fork member (7) sleeved on the main shaft (2) and a roller (8) passing through the piston rod (3). The roller (8) moves back and forth along the axial direction with the piston rod (3). One side of the shift fork member (7) is provided with an opening (9) that is in transmission cooperation with the roller (8). The piston rod (3) drives the shift fork member (7) and the main shaft (2) to rotate through the roller (8). When the shift fork member (7) rotates, the roller (8) and the opening (9) slide relative to each other.
2. A single-acting cylinder pneumatic actuator according to claim 1, characterized in that: It also includes a buffer assembly and an end cap (10). The end cap (10) is connected to the balance seat (4) by a fastener (11). A buffer cavity (12) for installing the buffer assembly is formed between the end cap (10) and the balance seat (4). The buffer assembly includes a buffer element (13) and an elastic element (14). The balance seat (4) has an insertion hole (15) for the buffer element (13) to pass through. The elastic element (14) presses the buffer element (13) toward the piston rod (3).
3. A single-acting cylinder pneumatic actuator according to claim 2, characterized in that: The piston rod (3) has a recess (16) for the buffer (13) to slide into, and the edge of the recess (16) is provided with a rounded corner (17). The buffer (13) is conical.
4. A single-acting cylinder pneumatic actuator according to claim 2, characterized in that: The buffer (13) has a boss (18) at one end away from the balance seat (4), and the inner side of the boss (18) has a limiting groove (19) for the elastic element (14) to be embedded. The elastic element (14) is an air cushion.
5. A single-acting cylinder pneumatic actuator according to claim 4, characterized in that: The buffer assembly also includes an elastic pad (20) that is overlaid on the outside of the boss (18) and extends to the end face of the boss (18).
6. A single-acting cylinder pneumatic actuator according to claim 2, characterized in that: The outer peripheral wall of the buffer (13) and the inner peripheral wall of the end cap (10) slide together to separate the buffer cavity (12). The end cap (10) is also provided with an exhaust hole (21) that communicates with the outside. The exhaust hole (21) communicates with the buffer cavity (12) on the side away from the balance seat (4).
7. A single-acting cylinder pneumatic actuator according to claim 6, characterized in that: A first sealing ring (22) is provided between the buffer (13) and the end cap (10), and a second sealing ring (23) is provided between the insertion hole (15) and the buffer (13).