Sanitary pneumatic actuator

Abstract

The present application relates to a kind of sanitary grade pneumatic actuator, it is related to valve actuator technical field, it includes rotating shaft, shell, piston, spring, and respectively sealedly arranged on the base and end cover of shell two ports, gas source access is installed on end cover or shell, gas source access is installed on the base or shell, spiral chute is opened on the circumferential surface of piston, guiding piece is arranged on the inner circumferential side wall of shell, guiding piece is arranged in spiral chute, piston is connected with driving element, fixed plate is fixedly installed on driving element, plane bearing is arranged between fixed plate and base, the end of spring respectively touches the end face of piston and fixed plate, the end of driving element away from and connected with piston penetrates base and is arranged outside base and protrudes, and is fixedly connected with rotating shaft, driving element and base are rotationally sealedly connected.The effect of reducing friction, reducing noise, improving the service life of component, improving transmission efficiency and use stability.

Description

Technical Field

[0001] This invention relates to the technical field of valve actuators, and in particular to a sanitary pneumatic actuator. Background Technology

[0002] Sanitary pneumatic actuators integrate the actuator and regulating mechanism into a single unit. The actuators include diaphragm, piston, and rack and pinion types. Piston actuators have a long stroke and are suitable for applications requiring high thrust; diaphragm actuators have a shorter stroke and can only directly drive the valve stem. Rack and pinion pneumatic actuators, due to their simple structure, high output thrust, smooth and reliable operation, and explosion-proof safety, are widely used in power plants, chemical plants, oil refineries, and other production processes with high safety requirements.

[0003] Traditional pneumatic actuators typically use aluminum or easily machinable metals for their internal pistons due to structural limitations. For example, when aluminum is used in a long-term compressed gas environment, the moisture generated by the compressed air can corrode the rotating grooves on the piston body and the iron spring, severely reducing the service life of the pneumatic actuator. Furthermore, the corrosion residue will be slowly discharged from the vent through the gas outlet during operation, further polluting the workshop environment and causing even more serious consequences.

[0004] For example, Chinese patent CN205781250U, published on December 7, 2016, discloses a sanitary pneumatic head, including a base, a housing, a rotating component, and a piston that drives the rotating component to rotate. The base and housing are integrally formed or sealed welded. One end of the rotating component is integrally connected to a drive shaft, which passes through the base. The drive shaft of the rotating component is sealed to the base, and the rotating component can rotate relative to the base. The piston is sleeved on the outside of the rotating component and can move vertically up and down relative to the housing. The piston and the housing are sealed. At least one slider is provided on the outer side of the rotating component. Correspondingly, a spiral groove is provided on the piston for the slider to slide. A positioning block is provided on the inner wall of the housing. Correspondingly, a positioning groove is provided on the piston for the positioning block to move up and down. The piston moves up and down while driving the rotating component to rotate. An air source inlet is provided on the base or housing.

[0005] By pressurizing the housing with air, the piston is propelled towards the base under the action of the second roller. The rotating component is pressed against the piston's spiral groove by the first roller, causing the rotating component to rotate within the housing. The rotating shaft is connected to the valve stem, thereby controlling the valve's opening and closing. However, the piston is pushed by force, and the first roller moves on the piston's spiral groove due to the action of the resisting force, thus rotating the rotating shaft. This results in a large force between the piston and the rotating component, which can easily cause jamming in multi-stage transmission. The large force can also easily cause the slider on the rotating component to break and generate a lot of noise between the transmission components. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, one of the objectives of this invention is to provide a sanitary pneumatic actuator that has the effects of reducing friction, reducing noise, increasing component lifespan, improving transmission efficiency, and enhancing operational stability.

[0007] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0008] A sanitary pneumatic actuator includes a rotating shaft for connection to a valve, a through-hole housing, a piston and a spring arranged within the housing, and a base and an end cap respectively sealed at both ends of the housing. An air source inlet is installed on the end cap or housing, and an air source outlet is installed on the base or housing. A helical groove is formed on the circumferential surface of the piston. A guide member is provided on the inner circumferential sidewall of the housing, arranged within the helical groove. A driving member is movably connected to the piston. A fixing plate is fixedly installed on the driving member. A plane bearing is provided between the fixing plate and the base. The two ends of the spring respectively abut against the end faces of the piston and the fixing plate. The end of the driving member away from the piston extends through the base and protrudes beyond the base, and is fixedly connected to the rotating shaft. The driving member and the base are rotatably sealed together.

[0009] By adopting the above technical solution, gas is introduced into the air source inlet on the end cover or housing through the pneumatic solenoid valve. During this process, the gas is propelled by the spiral groove and guide member, causing the guide member to move along the groove direction of the spiral groove. This causes the piston inside the housing to be pressurized and pushed towards the base, rotating within the housing. The spring is compressed between the piston and the fixed plate, and gas is discharged from the air source outlet on the base or housing. The piston drives the drive member to rotate, and the drive member moves relative to the piston, realizing the rotation of the rotating shaft and achieving the purpose of controlling the valve opening and closing. When it is necessary to control the valve operation again, the air source inlet stops supplying gas, and the pneumatic solenoid valve is controlled to discharge gas. The spring returns to its original position, and the piston rotates towards the end cover and is pushed forward by the spring force. The guide member moves back along the groove direction of the spiral groove, achieving the effect of valve reset. Through the mutual cooperation of the piston and drive member, the collision and energy loss in the transmission between multiple components are reduced, thereby reducing friction, lowering noise, increasing component lifespan, improving transmission efficiency, and enhancing operational stability.

[0010] In a preferred embodiment, the present invention may be further configured such that: a mounting cavity is formed on the end face of the piston facing the base, and one end of the spring is installed in the mounting cavity and the end abuts against the bottom of the mounting cavity.

[0011] By adopting the above technical solution, the stability of the spring between the fixed plate and the piston is improved by installing the spring in the mounting cavity, and the piston plays a certain guiding and limiting role for the spring.

[0012] In a preferred embodiment, the present invention may be further configured such that: a positioning post is integrally formed on the piston along its axial direction, a positioning hole is formed on the positioning post along its axial direction, and the driving member is slidably inserted into the positioning hole along the piston axial direction.

[0013] By adopting the above technical solution, when the piston moves towards the base under force, the piston and the driving component can cooperate and transmit power by sliding one end of the driving component into the positioning hole on the positioning post.

[0014] In a preferred embodiment, the present invention can be further configured such that: the rod portion of the driving member located between the fixed plate and the end cap is provided with a square rod, and the positioning hole is provided with a square hole to facilitate sliding insertion of the square rod; the rod portion of the driving member located between the fixed plate and the base is provided with a round rod to facilitate rotation between the driving member and the base.

[0015] By adopting the above technical solution, when the piston is driven to move towards the base by force, the square rod of the driving component slides into the positioning hole of the piston along its axial direction, realizing the sliding connection between the piston and the driving component, and at the same time serving the purpose of limiting the circumferential rotation between the square rod and the piston; while the round rod of the driving component rotates on the base, realizing the driving component rotating on the base, and facilitating connection with the rotating shaft.

[0016] In a preferred embodiment, the present invention can be further configured such that one end of the spring is sleeved outside the positioning post.

[0017] By adopting the above technical solution, when the spring is compressed or reset, the spring sleeved outside the positioning post has a guiding, positioning and fixing function, thereby improving the stability of the spring during operation.

[0018] In a preferred embodiment, the present invention may be further configured such that the guide is a rotating roller rotatably arranged on the inner circumferential sidewall of the housing, and the rotating roller is rotatably arranged within the spiral groove.

[0019] By adopting the above technical solution, gas is introduced into the gas source inlet on the end cover or the housing. Under the action of the spiral groove and the guide, the rotating roller is made to roll along the groove direction of the spiral groove, so that the piston in the housing is pressed and pushed towards the base and rotates in the housing. The rolling friction between the rotating roller and the spiral groove reduces the frictional damage of both when under force.

[0020] In a preferred embodiment, the present invention may be further configured such that the piston is made of rigid plastic.

[0021] By adopting the above technical solution, the rigid friction between the piston and the housing and guide components is reduced, avoiding the corrosive effect caused by the reaction with water; at the same time, the piston is made of plastic, and its surface becomes smoother after use, improving the smoothness of piston driving and reducing noise generation.

[0022] In a preferred embodiment, the present invention may be further configured such that: a plurality of the spiral grooves are equidistantly arranged on the circumferential surface of the piston, and a plurality of the guide members are equidistantly arranged on the inner circumferential surface of the housing.

[0023] By adopting the above technical solution, and by arranging multiple spiral grooves and guide components in a one-to-one correspondence, the stress stability between the piston and the guide components is improved when the piston is under force.

[0024] In a preferred embodiment, the present invention may be further configured such that a first sealing ring is provided between the drive member and the base.

[0025] By adopting the above technical solution, the sealing performance between the drive component and the base is improved through the first sealing ring.

[0026] In a preferred embodiment, the present invention may be further configured such that a second sealing ring is provided between the piston and the inner circumferential surface of the housing.

[0027] By adopting the above technical solution, the sealing performance between the piston and the housing during movement is improved.

[0028] In summary, the present invention has at least one of the following beneficial technical effects:

[0029] 1. Through the action of the spiral groove and guide, the rotating roller is made to roll along the groove direction of the spiral groove. The square rod of the driving component slides into the positioning hole of the piston along its axial direction, realizing the sliding connection between the piston and the driving component. At the same time, it serves to limit the circumferential rotation between the square rod and the piston. The round rod of the driving component rotates on the base, realizing the driving component to rotate on the base and facilitating connection with the rotating shaft. This reduces the collision between multiple components, thereby reducing friction, reducing noise, improving component life, improving transmission efficiency and stability.

[0030] 2. By using a hard plastic piston, the rigid friction between the piston and the housing and guide components is reduced, and the material itself can also avoid reacting with water and causing corrosion. At the same time, the piston surface is smoother after use, improving the smoothness of piston driving and reducing noise generation.

[0031] 3. A first sealing ring is provided between the drive component and the base, and a second sealing ring is provided between the piston and the inner circumferential surface of the housing to improve the sealing stability when the piston and the drive component move within the housing. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a sanitary pneumatic actuator;

[0033] Figure 2 This is an exploded view of a sanitary pneumatic actuator;

[0034] Figure 3 This is a cross-sectional view of the drive component of a sanitary pneumatic actuator at the axis.

[0035] Figure 4 This is a structural schematic diagram of the piston, spring, and drive components of a sanitary pneumatic actuator.

[0036] Figure 5 This is a schematic diagram of the piston structure in a sanitary pneumatic actuator;

[0037] Figure 6 This is a schematic diagram of the drive component in a sanitary pneumatic actuator.

[0038] In the diagram, 1. Rotating shaft; 2. Housing; 21. Guide component; 3. Piston; 31. Second sealing ring; 32. Spiral groove; 33. Mounting cavity; 34. Positioning pin; 35. Positioning hole; 36. Driving component; 361. Square rod; 362. Round rod; 37. Fixing plate; 38. First sealing ring; 39. Buffer groove; 4. Spring; 5. Base; 51. Air source inlet; 6. End cap; 61. Air source inlet; 7. Surface bearing. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the accompanying drawings.

[0040] Reference Figure 1 , Figure 2 As shown, this invention discloses a sanitary pneumatic actuator, comprising a rotating shaft 1 for connection to a valve, a housing 2 with a central opening, a piston 3 and a spring 4 arranged within the housing 2, and a base 5 and an end cap 6 respectively sealed and fixedly installed on both ends of the housing 2; an air source inlet 61 is installed on the end cap 6 or the housing 2, and an air source outlet 51 is installed on the base 5 or the housing 2. In this embodiment, the air source inlet 61 is installed on the end cap 6, and the air source outlet 51 is installed on the base 5.

[0041] Reference Figure 2 , Figure 3As shown, the piston 3 is made of rigid plastic, such as carbon plastic or polyphenylene sulfide; at the same time, a second sealing ring 31 is provided between the piston 3 and the inner circumferential surface of the housing 2. The second sealing ring 31 is sleeved on the outer circumferential surface of the piston 3 facing the end cover 6 to improve the sealing performance of the piston 3 during reciprocating motion within the housing 2.

[0042] Reference Figure 3 , Figure 4 As shown, a spiral groove 32 is formed on the circumferential surface of the piston 3. Multiple spiral grooves 32 are equidistantly arranged on the circumferential surface of the piston 3. In this embodiment, two are preferred. A guide member 21 is provided on the inner circumferential side wall of the housing 2. Multiple guide members 21 are equidistantly arranged on the inner circumferential surface of the housing 2 and are arranged in a one-to-one correspondence with the spiral grooves 32. The guide member 21 is a rotating roller rotatably arranged on the inner circumferential side wall of the housing 2, and the rotating roller is rotatably arranged in the spiral groove 32. The rotating roller can also be a roller made of hard plastic or stainless steel.

[0043] Reference Figure 3 , Figure 5 As shown, an installation cavity 33 is provided on the end face of the piston 3 facing the base 5 along its axial direction. A positioning post 34 is integrally formed on the bottom of the installation cavity 33 along its axial direction. A positioning hole 35 is provided on the positioning post 34 along its axial direction. A driving member 36 is slidably inserted into the positioning hole 35 along the axial direction of the piston 3.

[0044] Reference Figures 3 to 5 As shown, a fixing plate 37 is integrally formed at the end of the drive member 36 away from the positioning post 34. One end of the spring 4 is sleeved outside the positioning post 34 and its end abuts against the bottom of the mounting cavity 33. The other end of the spring 4 is pressed against the fixing plate 37. At the same time, a plane bearing 7 is provided between the fixing plate 37 and the base 5.

[0045] Reference Figure 3 , Figure 4 As shown, the end of the drive member 36 away from the piston 3 passes through the base 5 and protrudes out of the base 5 and is fixedly connected to the rotating shaft 1. A first sealing ring 38 is provided between the drive member 36 and the base 5. The first sealing ring 38 is sleeved on the outer circumferential surface of the drive member 36 to seal the drive member 36 and the base 5.

[0046] Reference Figure 3 , Figure 6 As shown, in order to improve the installation stability between the drive component 36 and the piston 3 and the base 5, a square rod 361 is provided in the area between the fixed plate 37 and the end cover 6 of the drive component 36, and the positioning hole 35 is a square hole to cooperate with the sliding insertion of the square rod 361; a round rod 362 is provided in the area between the fixed plate 37 and the base 5 of the drive component 36 to facilitate the rotation between the drive component 36 and the base 5.

[0047] Reference Figure 3 As shown, in order to improve the ventilation stability of the air source inlet 61, a buffer groove 39 is provided on the end face of the piston 3 facing the end cover 6 or on the end face of the end cover 6 facing the piston 3.

[0048] The implementation principle of this embodiment is as follows: Gas is introduced into the air source inlet 61 on the end cover 6 or housing 2 by the pneumatic solenoid valve. During this process, the rotating roller is propelled along the groove direction of the spiral groove 32 by the action of the spiral groove 32 and the guide member 21. This causes the piston 3 inside the housing 2 to be pushed towards the base 5 under pressure and rotate inside the housing 2. The spring 4 is compressed between the piston 3 and the fixed plate 37. Gas is discharged from the air source inlet 51 on the base 5 or housing 2. The piston 3 drives the drive member 36 to rotate, and the drive member 36 is gradually inserted into the positioning hole 35, realizing the rotation of the rotating shaft 1 and achieving the control of the valve opening and closing. The purpose is to: when the valve needs to be controlled again, the air source inlet 61 stops air intake, exhaust is controlled by the pneumatic solenoid valve, the spring 4 resets, the piston 3 rotates and advances towards the end cover 6 under the force of the spring 4, the square rod 361 of the drive component 36 slides in the positioning hole 35, and the rotating roller rolls back along the groove direction of the spiral slide 32, thus achieving the effect of valve reset; through the cooperation between the piston 3 and the drive component 36, the collision and energy loss between multiple components are reduced, which has the effects of reducing friction, reducing noise, improving the service life of components, improving transmission efficiency and stability of use.

[0049] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A sanitary pneumatic actuator comprising a rotary shaft (1) for connecting with a valve, a middle-through housing (2), a piston (3) and a spring (4) arranged in the housing (2), and a base (5) and an end cover (6) respectively sealingly arranged on the two ports of the housing (2), an air inlet (61) is mounted on the end cover (6) or the housing (2), and an air outlet (51) is mounted on the base (5) or the housing (2), characterized in that: A spiral groove (32) is provided on the circumferential surface of the piston (3). A guide (21) is provided on the inner circumferential sidewall of the housing (2). The guide (21) is arranged in the spiral groove (32). The piston (3) is movably connected to a drive (36). A fixing plate (37) is fixedly installed on the drive (36). A plane bearing (7) is provided between the fixing plate (37) and the base (5). The two ends of the spring (4) respectively abut against the end faces of the piston (3) and the fixing plate (37). The end of the drive (36) away from the piston (3) passes through the base (5) and protrudes out of the base (5) and is fixedly connected to the rotating shaft (1). The drive (36) and the base (5) are rotatably sealed. An installation cavity (33) is provided on the end face of the piston (3) facing the base (5). The piston (3) is rotatably sealed with the base (5) along its axial direction. The positioning post (34) is integrally formed, and a positioning hole (35) is provided on the positioning post (34) along its axial direction. The driving member (36) is slidably inserted into the positioning hole (35) along the axial direction of the piston (3). A fixing plate (37) is integrally formed at the end of the driving member (36) away from the positioning post (34). One end of the spring (4) is sleeved outside the positioning post (34) and its end abuts against the bottom of the mounting cavity (33). The other end of the spring (4) is pressed against the fixing plate (37). The piston (3) is made of hard plastic. A square rod (361) is provided on the rod part of the driving member (36) located between the fixing plate (37) and the end cover (6). The positioning hole (35) is set as a square hole to cooperate with the square rod (361) for sliding insertion. The rod part of the driving member (36) located between the fixing plate (37) and the base (5) is set as a round rod (362) to facilitate the rotation between the driving member (36) and the base (5). ​ 2. A sanitary pneumatic actuator according to claim 1, characterized in that: The guide (21) is a rotating roller rotatably arranged on the inner circumferential side wall of the housing (2), and the rotating roller is rotatably arranged in the spiral groove (32).

3. A sanitary pneumatic actuator according to claim 1, characterized in that: Multiple spiral grooves (32) are equidistantly arranged on the circumferential surface of the piston (3), and multiple guide members (21) are equidistantly arranged on the inner circumferential surface of the housing (2).

4. A sanitary pneumatic actuator as claimed in claim 1, wherein: A first sealing ring (38) is provided between the rotating shaft (1) and the base (5).

5. A sanitary pneumatic actuator as claimed in claim 1, wherein: A second sealing ring (31) is provided between the piston (3) and the inner circumferential surface of the housing (2).

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