Long life pneumatic actuator for valves
By using a dual guiding structure of PEEK-based composite guide rings and fluororubber O-rings in the pneumatic actuator, the problems of piston eccentricity and leakage are solved, achieving a long-life design for the pneumatic actuator and meeting the high circulation requirements of ALD process valves.
Patent Information
- Authority / Receiving Office
- CN Β· China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI JUKE FLUID CONTROL CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-07-31
AI Technical Summary
Traditional pneumatic actuators have poor piston guide structure wear resistance, which leads to piston eccentric movement and O-ring wear and leakage. Insufficient spring assembly tolerance control exacerbates the eccentric movement problem, making it impossible to meet the ultra-long cycle life requirements of 30 million to 100 million cycles for ALD process valves.
The guide ring and fluororubber O-ring, made of PEEK-based composite material, form a dual guiding structure, which improves the wear resistance of the piston and achieves dynamic sealing through the fluororubber O-ring to prevent piston eccentric movement and leakage.
It extends the service life of pneumatic actuators, meets the ultra-long cycle life requirements of ALD process valves, improves the wear resistance and sealing performance of pistons, and avoids premature wear and leakage.
Smart Images
Figure CN224579835U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pneumatic actuator technology, and more specifically, to a long-life pneumatic actuator for valves. Background Technology
[0002] A pneumatic actuator is an actuating device that uses air pressure to open, close, or regulate valves. It is also called a pneumatic actuator mechanism or pneumatic device, but is commonly referred to as a pneumatic head. Pneumatic actuators are sometimes equipped with auxiliary devices. Commonly used ones include valve positioners and handwheel mechanisms. The function of a valve positioner is to use the feedback principle to improve the performance of the actuator, enabling it to achieve accurate positioning according to the control signal from the controller. The function of a handwheel mechanism is to directly operate the control valve to maintain normal production when the control system is affected by power outages, air supply interruptions, controller output failure, or actuator malfunction.
[0003] Current ALD process valves require pneumatic actuators with an ultra-long cycle life of 30 million to 100 million cycles. Traditional pneumatic actuators have the following drawbacks: 1. The piston guide structure is made of polytetrafluoroethylene, which has poor wear resistance, leading to premature wear and causing eccentric piston movement. 2. O-ring seals leak due to uneven wear on the piston, resulting in one-sided wear. 3. Insufficient tolerance control in spring assembly exacerbates the problem of motion eccentricity.
[0004] Therefore, we provide a pneumatic actuator for long-life valves. Utility Model Content
[0005] The purpose of this invention is to provide a long-life pneumatic actuator for valves to solve the problems mentioned in the background art. Current ALD process valves require pneumatic actuators with an ultra-long cycle life of 30 million to 100 million cycles. Traditional pneumatic actuators have the following drawbacks: 1. The piston guide structure is made of polytetrafluoroethylene, which has poor wear resistance, leading to premature wear and causing eccentric piston movement. 2. O-ring seals leak due to uneven wear on the piston, resulting in one-sided wear. 3. Insufficient tolerance control in spring assembly exacerbates the problem of motion eccentricity.
[0006] To achieve the above objectives, this utility model provides the following technical solution: A pneumatic actuator for a long-life valve includes a cylinder body and an upper end cover. A screw is installed inside the upper end cover, and a lower piston is installed inside the cylinder body. A spring is installed between the lower piston and the upper end cover. A guide ring is fitted on the outer side of the lower piston away from the upper end cover, and a second O-ring is fitted on the outer side of the lower piston near the upper end cover. Both the guide ring and the second O-ring are detachably connected to the lower piston.
[0007] Preferably, the outer wall of the lower piston is in contact with the inner wall of the guide ring.
[0008] Preferably, the guide ring is made of PEEK-based composite material.
[0009] Preferably, a third O-ring is fitted on the outer side of the lower piston near the spring, a first O-ring is fitted on the outer side of the lower piston away from the spring, and a fourth O-ring is fitted on the outer side of the lower piston between the third O-ring and the first O-ring. The third O-ring, the first O-ring, and the fourth O-ring are all detachably connected to the lower piston.
[0010] Preferably, the first O-ring, the second O-ring, the third O-ring, and the fourth O-ring are all made of fluororubber material.
[0011] Compared with the prior art, the beneficial effects of this utility model are: A dual guide structure is set between the lower piston and the cylinder body. Dynamic sealing is achieved by using a first, second, third, and fourth O-ring made of fluororubber. A guide ring made of PEEK-based composite material is set. Under the action of the guide ring, the wear resistance of the lower piston can be improved, premature wear can be avoided, and the piston eccentric movement and one-sided wear leakage can be prevented. Attached Figure Description
[0012] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional schematic diagram of the entire present invention; Figure 3 For the present utility model Figure 2 Enlarged view of point A in the image.
[0013] The numbers in the diagram are as follows: 1. Cylinder body; 2. Upper end cover; 3. Lower piston; 4. First O-ring; 5. Fourth O-ring; 6. Screw; 7. Spring; 8. Guide ring; 9. Third O-ring; 10. Second O-ring. Detailed Implementation
[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0015] Please see Figures 1 to 3 A long-life pneumatic actuator for valves includes a cylinder body 1 and an upper end cover 2. A screw 6 is installed inside the upper end cover 2. A lower piston 3 is installed inside the cylinder body 1. A spring 7 is installed between the lower piston 3 and the upper end cover 2. The spring 7 is assembled using a precision positioning structure, that is, the upper end cover 2 is set as an inclined surface to position the inner diameter of the spring 7, so that the spring 7 is self-centered during installation. A guide ring 8 is fitted on the outer side of the lower piston 3 away from the upper end cover 2, and a second O-ring 10 is fitted on the outer side of the lower piston 3 close to the upper end cover 2. Both the guide ring 8 and the second O-ring 10 are detachably connected to the lower piston 3.
[0016] Furthermore, the outer wall of the lower piston 3 is in contact with the inner wall of the guide ring 8.
[0017] Furthermore, the guide ring 8 is made of PEEK-based composite material, which contains 15-30wt% carbon fiber reinforcement phase, Shore D hardness β₯90, thickness 2-5mm, and clearance fit tolerance between it and the inner wall of cylinder body 1 is controlled within 0.02-0.05mm.
[0018] Furthermore, a third O-ring 9 is fitted on the outer side of the lower piston 3 near the spring 7, a first O-ring 4 is fitted on the outer side of the lower piston 3 away from the spring 7, and a fourth O-ring 5 is fitted on the outer side of the lower piston 3 between the third O-ring 9 and the first O-ring 4. The third O-ring 9, the first O-ring 4, and the fourth O-ring 5 are all detachably connected to the lower piston 3. A double guide structure is set between the lower piston 3 and the cylinder body 1, namely, the main sealing layer, which uses the first O-ring 4, the second O-ring 10, the third O-ring 9, and the fourth O-ring 5 made of fluororubber to achieve dynamic sealing, and the auxiliary guide layer, which is a guide ring 8 made of PEEK-based composite material.
[0019] Furthermore, the first O-ring 4, the second O-ring 10, the third O-ring 9, and the fourth O-ring 5 are all made of fluororubber.
[0020] The steps for using this utility model are as follows: When using this long-life valve pneumatic actuator, a double guiding structure is set between the lower piston 3 and the cylinder body 1. The main sealing layer uses a first O-ring 4, a second O-ring 10, a third O-ring 9, and a fourth O-ring 5 made of fluororubber to achieve dynamic sealing. The auxiliary guiding layer is set with a guide ring 8 made of PEEK-based composite material. Under the action of the guide ring 8, the wear resistance of the lower piston 3 can be improved, premature wear can be avoided, and piston eccentric movement and unilateral wear leakage can be prevented.
[0021] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A long-life pneumatic actuator for valves, comprising a cylinder body (1) and an upper end cover (2), the interior of the upper end cover (2) being provided with a screw (6), characterized in that: The cylinder body (1) is provided with a lower piston (3) inside. A spring (7) is provided between the lower piston (3) and the upper end cover (2). A guide ring (8) is provided on the side of the lower piston (3) away from the upper end cover (2). A second O-ring (10) is provided on the side of the lower piston (3) close to the upper end cover (2). The guide ring (8) and the second O-ring (10) are detachably connected to the lower piston (3).
2. The long-life pneumatic actuator for valves according to claim 1, characterized in that: The outer wall of the lower piston (3) is in contact with the inner wall of the guide ring (8).
3. The long-life pneumatic actuator for valves according to claim 1, characterized in that: The guide ring (8) is made of PEEK-based composite material.
4. The long-life pneumatic actuator for valves according to claim 1, characterized in that: A third O-ring (9) is fitted on the side of the lower piston (3) close to the spring (7), and a first O-ring (4) is fitted on the side of the lower piston (3) away from the spring (7). A fourth O-ring (5) is fitted on the outside of the lower piston (3) between the third O-ring (9) and the first O-ring (4). The third O-ring (9), the first O-ring (4) and the fourth O-ring (5) are all detachably connected to the lower piston (3).
5. A long-life pneumatic actuator for valves according to claim 4, characterized in that: The first O-ring (4), the second O-ring (10), the third O-ring (9) and the fourth O-ring (5) are all made of fluororubber material.