A self-lubricating piston assembly of a pneumatic actuator

Abstract

The present invention discloses a self-lubricating piston assembly of a pneumatic actuator, which specifically relates to the technical field of valve actuators, including a cylinder body, a piston is sealingly and slidably connected inside the cylinder body, an upper end cover is provided at the upper end of the cylinder body, a lower end cover is provided at the lower end of the cylinder body, and air holes are provided on the upper end cover and the lower end cover. Through the arrangement of the lubrication assembly, when the piston moves upward in the cylinder body, the residual pressure of the gas above the piston in the cylinder body will enter the oil storage tank through multiple air inlet holes, and the residual pressure of the gas entering the oil storage tank will squeeze the grease in the oil storage tank, so that the grease adheres to the inner wall of the cylinder body, which lubricates the sealing ring, and when the piston moves downward in the cylinder body, the grease adhered to the inner wall of the cylinder body can lubricate the guide belt, avoiding wear and rust, thereby extending the service life of the actuator.

Description

Technical Field

[0001] The present invention relates to the technical field of valve actuators, and more particularly to a self-lubricating piston assembly of a pneumatic actuator. Background Art

[0002] Pneumatic actuators are actuators that use air pressure to open, close or adjust valves. They are also called pneumatic actuators or pneumatic devices. Pneumatic actuators are sometimes equipped with certain auxiliary devices, commonly used are valve positioners and handwheel mechanisms. The function of the 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. The function of the handwheel mechanism is to directly manipulate the control valve to maintain normal production when the control system fails due to power outages, gas outages, no output of the controller or failure of the actuator.

[0003] The Chinese patent with application number 202111254768.8 discloses a manual-automatic integrated automatically switchable pneumatic actuator, the lower flange of the lower bracket is fixedly connected to the upper valve cover by bolts, and the upper flange is fixedly connected to the lower end cover, the valve stem connector is an open threaded connector, the lower end cover and the upper end cover are both provided with stepped countersunk holes, the lower end cover and the upper end cover are connected by a pull rod, a main body mechanism is provided between the lower end cover and the upper end cover, the handwheel is fixed above the upper end cover by the main body mechanism, a nut with a cover and an upper pressure plate, an upper air inlet is provided on the side of the upper end cover, and a buffer valve and a lower air inlet are provided on the side of the lower end cover, which belongs to the technical field of pneumatic actuators, and adopts a safe, reliable, simple in structure and low-cost actuator to deal with the shortcomings of the above-mentioned traditional actuators, and finally integrates the manual and automatic functions into one, and realizes automatic switching, does not cause misoperation, has a simple and compact structure, and reduces costs. However, after long-term use, the grease of the piston of the above invention may degrade prematurely and eventually fail under high load, high speed and / or high working cycle, causing wear and corrosion of the moving parts of the actuator, thereby affecting its movement accuracy and service life. In addition, after the grease is used up, it is necessary to add grease manually frequently. When adding grease, the cover plate needs to be removed and the piston needs to be taken out, which is more troublesome.

[0004] The present invention provides a self-lubricating piston assembly for a pneumatic actuator, aiming to solve the problems that after long-term use, the grease of the actuator piston may degrade prematurely and eventually fail, affecting its movement accuracy and service life, and that after the grease is used up, it is necessary to manually add grease, which is rather troublesome. Summary of the invention

[0005] The purpose of the present invention is to provide a self-lubricating piston assembly for a pneumatic actuator to solve the problem that the grease of the piston of the actuator proposed in the above background technology may degrade prematurely and eventually fail after long-term use, affecting its movement accuracy and service life, and that after the grease is used up, it is necessary to manually add grease frequently, which is rather troublesome.

[0006] To achieve the above object, the present invention provides the following technical solution: a self-lubricating piston assembly of a pneumatic actuator, comprising a cylinder body, wherein a piston is sealingly and slidably connected inside the cylinder body, and further comprising: a lubrication assembly, the lubrication assembly being arranged on the piston and being used for self-lubricating the piston when the piston slides; a supplementary component, the supplementary component being disposed in the cylinder body and being used for replenishing grease to the lubricating component when the piston moves; The lubrication assembly includes an oil storage tank provided on the circumferential outer wall of the piston, a plurality of air inlet holes connected to the oil storage tank are equidistantly provided on the top circumference of the piston, a guide belt is embedded in the circumferential outer wall of the piston above the oil storage tank, and a sealing ring is embedded in the circumferential outer wall of the piston below the oil storage tank.

[0007] Preferably, the supplementary component comprises a storage bin fixedly connected to the circumferential inner wall of the cylinder body, the storage bin is arranged in an annular shape, and the interior of the storage bin is divided into a storage chamber and a driving chamber by an annular partition plate.

[0008] Preferably, an oil outlet connected to the plurality of storage chambers is provided at the bottom of the storage bin, and a guide tube is fixedly connected to the bottom of the storage bin below each of the oil outlets, the number of the guide tubes is the same as the number of the air inlets and the positions correspond to each other, and the guide tubes can be inserted into the air inlets.

[0009] Preferably, the storage bin is internally sealed and slidably connected to a piston plate, the bottom of the piston plate is fixedly connected to a support plate, a telescopic groove communicating with the drive chamber is provided at the bottom of the storage bin, and the support plate is slidably connected in the telescopic groove.

[0010] Preferably, a plurality of blocking grooves having the same number as the oil outlets and corresponding positions are provided below the storage bin, each of the blocking grooves penetrates the corresponding oil outlet, and each of the blocking grooves is sealingly and slidably connected with a blocking plate for blocking the oil outlet.

[0011] Preferably, a plurality of first connecting ports connecting the storage chamber and the driving chamber are formed on the annular partition plate, and a plurality of second connecting ports connecting the driving chamber and the plurality of blocking grooves are formed inside the storage bin.

[0012] Preferably, when the piston plate moves upward in the driving chamber, it can squeeze the gas in the driving chamber into the storage chamber through the multiple first connecting ports, and draw the gas in the sealing groove out into the driving chamber through the second connecting port.

[0013] Preferably, a replenishing pipe is fixedly connected to the outer wall of the storage bin, one end of the replenishing pipe is connected to the storage chamber, and the other end of the replenishing pipe extends to the outside of the cylinder body, a one-way valve is arranged in the replenishing pipe, and grease is arranged in the oil storage tank and the storage chamber.

[0014] Preferably, an upper end cover is provided at the upper end of the cylinder body, and a lower end cover is provided at the lower end of the cylinder body, air holes are provided on the upper end cover and the lower end cover, an elastic member is connected between the top of the piston and the bottom of the upper end cover, and a piston rod is installed at the center position of the piston.

[0015] Preferably, a manual switching assembly is installed on the top of the upper end cover via an upper bracket, the manual switching assembly is connected to the piston rod via a connecting piece, and a lower bracket is installed on the bottom of the lower end cover.

[0016] Technical effects and advantages of the present invention: 1. The present invention provides a lubrication component. When the piston moves upward in the cylinder, the residual pressure of the gas above the piston in the cylinder will enter the oil storage tank through multiple air inlet holes. The residual pressure of the gas entering the oil storage tank will squeeze the grease in the oil storage tank, so that the grease adheres to the inner wall of the cylinder and lubricates the sealing ring. When the piston moves downward in the cylinder, the grease adhered to the inner wall of the cylinder can lubricate the guide belt to avoid wear and rust, thereby extending the service life of the actuator.

[0017] 2. The present invention provides a supplementary component. When the piston moves upward in the cylinder body, multiple guide tubes can be inserted into the corresponding air inlet holes, and the piston can push the support plate and the piston plate to move upward in the driving chamber, so that the sealing plate slides in the sealing groove to release the blockage of the oil outlet, and the gas in the driving chamber pushes the grease in the storage chamber into the oil storage tank to replenish the grease in the oil storage tank, thereby eliminating the need for manual frequent replenishment of the grease in the oil storage tank. In addition, the staff can fill the grease into the storage chamber through the supplementary tube, and the grease can be replenished without disassembling the pneumatic actuator, thereby improving work efficiency and further improving service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 It is a cross-sectional view of the internal structure of the cylinder body of the present invention.

[0020] Figure 3 For the present invention Figure 2 A-section structure enlarged view.

[0021] Figure 4 It is a cross-sectional view of the grease replenishment state in the oil storage tank of the present invention.

[0022] Figure 5 It is a partial structural diagram of the piston of the present invention.

[0023] Figure 6 It is a schematic diagram of the structure of the supplementary components of the present invention.

[0024] Figure 7 This is a bottom view of the supplementary components of the present invention.

[0025] Figure 8 It is a partial structural schematic diagram of the piston plate of the present invention.

[0026] The accompanying drawings are marked as follows: 1. cylinder body; 11. upper end cover; 12. lower end cover; 13. air hole; 14. elastic member; 15. piston rod; 16. upper bracket; 17. connecting member; 18. lower bracket; 2. piston; 3. lubrication assembly; 31. oil storage tank; 32. air inlet; 33. guide belt; 34. sealing ring; 4. replenishing assembly; 41. storage bin; 42. annular partition plate; 43. storage chamber; 44. drive chamber; 45. oil outlet; 46. guide tube; 47. piston plate; 48. support plate; 49. telescopic groove; 410. sealing groove; 411. sealing plate; 412. first connecting port; 413. second connecting port; 414. replenishing pipe; 415. one-way valve; 5. manual switching assembly. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Embodiment 1 After long-term use of the piston, under high loads, high speeds and / or high working cycles, the grease may degrade prematurely and eventually fail, causing wear and corrosion of the actuator's moving parts, thus affecting its motion accuracy and service life.

[0029] refer to Figure 1 and Figure 2A self-lubricating piston assembly of a pneumatic actuator according to an embodiment of the present invention comprises a cylinder body 1, a piston 2 is sealingly and slidably connected inside the cylinder body 1, an upper end cover 11 is provided at the upper end of the cylinder body 1, a lower end cover 12 is provided at the lower end of the cylinder body 1, air holes 13 are provided on both the upper end cover 11 and the lower end cover 12, an elastic member 14 is connected between the top of the piston 2 and the bottom of the upper end cover 11, a piston rod 15 is installed at the center of the piston 2, a manual switching component 5 is installed at the top of the upper end cover 11 through an upper bracket 16, the manual switching component 5 is connected to the piston rod 15 through a connecting member 17, the manual switching component 5 is used to switch the manual control of the piston 2, the manual switching component 5 is a prior art (such as a sealed valve switch with a manual switching mechanism disclosed in Chinese patent application No. 202220866451.3), which will not be described in detail here, and a lower bracket 18 is installed at the bottom of the lower end cover 12.

[0030] refer to Figure 2 , Figure 4 and Figure 5 , and also includes a lubrication component 3, which is arranged on the piston 2 and is used to self-lubricate the piston 2 when the piston 2 slides, including an oil storage groove 31 opened on the circumferential outer wall of the piston 2, and a plurality of air inlet holes 32 connected to the oil storage groove 31 are evenly opened on the top circumference of the piston 2, and the circumferential outer wall of the piston 2 is embedded with a guide belt 33 above the oil storage groove 31, and the circumferential outer wall of the piston 2 is embedded with a sealing ring 34 below the oil storage groove 31, and grease is arranged in the oil storage groove 31.

[0031] During actual use, when the air hole 13 of the lower end cover 12 takes in air to push the piston 2 to move upward in the cylinder body 1, the residual pressure of the gas above the piston 2 in the cylinder body 1 will enter the oil storage tank 31 through the multiple air inlet holes 32. The residual pressure of the gas entering the oil storage tank 31 will squeeze the grease in the oil storage tank 31, so that the grease sticks to the inner wall of the cylinder body 1, lubricating the sealing ring 34. When the piston 2 moves downward in the cylinder body 1, the grease stuck to the inner wall of the cylinder body 1 can lubricate the guide belt 33, thereby extending the service life of the actuator.

[0032] To summarize, through the setting of the lubrication component 3, when the piston 2 moves upward in the cylinder body 1, the residual pressure of the gas above the piston 2 in the cylinder body 1 will enter the oil storage tank 31 through the multiple air inlet holes 32. The residual pressure of the gas entering the oil storage tank 31 will squeeze the grease in the oil storage tank 31, so that the grease sticks to the inner wall of the cylinder body 1, and lubricates the sealing ring 34. When the piston 2 moves downward in the cylinder body 1, the grease stuck to the inner wall of the cylinder body 1 can lubricate the guide belt 33 to avoid wear and rust, thereby extending the service life of the actuator.

[0033] Embodiment 2 In actual use, after long-term use, the grease in the oil storage tank 31 will gradually be used up, and it is necessary to manually frequently add lubricating oil to the oil storage tank 31. When adding lubricating oil, the cover plate needs to be removed to take out the piston, which is quite troublesome. Therefore, this embodiment improves the device described in the above embodiment.

[0034] refer to Figure 2 and Figure 3 , and also includes a supplementary component 4, which is arranged in the cylinder body 1 and is used to replenish grease for the lubrication component 3 when the piston 2 moves. It includes a storage bin 41 fixedly connected to the circumferential inner wall of the cylinder body 1, and the storage bin 41 is arranged in a ring shape. The interior of the storage bin 41 is divided into a storage chamber 43 and a driving chamber 44 by an annular partition plate 42.

[0035] refer to Figure 3-Figure 8 The bottom of the storage bin 41 is provided with an oil outlet 45 connected with a plurality of storage chambers 43, and the bottom of the storage bin 41 is fixedly connected with a guide tube 46 below each oil outlet 45. The number of guide tubes 46 is the same as that of the air inlet holes 32 and their positions correspond, and the guide tubes 46 can be inserted into the air inlet holes 32. The interior of the storage bin 41 is sealingly and slidably connected with a piston plate 47, and the bottom of the piston plate 47 is fixedly connected with a support plate 48. The bottom of the storage bin 41 is provided with a telescopic groove 49 connected with the drive chamber 44, and the support plate 48 is slidably connected in the telescopic groove 49. The interior of the storage bin 41 and below the storage bin 41 are provided with a plurality of blocking grooves 410 that are the same as the number of the oil outlets 45 and their positions correspond, and each blocking groove 410 penetrates the corresponding oil outlet 45, and each blocking groove 410 is sealingly and slidably connected with a blocking plate 411 for blocking the oil outlet 45.

[0036] refer to Figure 3 The annular partition plate 42 is provided with a plurality of first connecting ports 412 connecting the storage chamber 43 and the driving chamber 44 , and the storage bin 41 is provided with a plurality of second connecting ports 413 connecting the driving chamber 44 and the plurality of blocking grooves 410 .

[0037] When the piston plate 47 moves upward in the driving chamber 44 , it can squeeze the gas in the driving chamber 44 into the storage chamber 43 through the multiple first connecting ports 412 , and draw the gas in the sealing groove 410 out into the driving chamber 44 through the second connecting ports 413 .

[0038] refer to Figure 1 and Figure 3A replenishing pipe 414 is fixedly connected to the outer wall of the storage bin 41, one end of the replenishing pipe 414 is connected to the storage chamber 43, and the other end of the replenishing pipe 414 extends to the outside of the cylinder body 1. A one-way valve 415 is arranged in the replenishing pipe 414, and grease is arranged in the storage chamber 43. The grease can be directly replenished into the storage chamber 43 through the replenishing pipe 414, and the one-way valve 415 prevents the grease from flowing out of the replenishing pipe 414.

[0039] During actual use, when the piston 2 moves upward in the cylinder body 1, the multiple guide tubes 46 correspond to the positions of the corresponding air inlet holes 32, and the multiple guide tubes 46 can be inserted into the corresponding air inlet holes 32. After the multiple guide tubes 46 are inserted into the corresponding air inlet holes 32, the top of the piston 2 contacts the bottom of the support plate 48, and the support plate 48 and the piston plate 47 are pushed upward in the drive chamber 44 by the piston 2. In the process of the piston plate 47 moving upward in the drive chamber 44, the gas in each sealing groove 410 will be extracted into the drive chamber 44 through the corresponding second connecting port 413, so that the multiple sealing plates 411 slide in the sealing groove 410 to release the blockage of each oil outlet 45.

[0040] At the same time, when the piston plate 47 moves upward in the driving chamber 44, it will squeeze the gas in the driving chamber 44 into the storage chamber 43 through the multiple first connecting ports 412, so that the grease in the storage chamber 43 is pushed by the gas from the oil outlet 45, the guide tube 46 and the air inlet 32 ​​into the oil storage tank 31, and the grease in the oil storage tank 31 is replenished, so that there is no need for manual frequent replenishment of the grease in the oil storage tank 31, and the staff can fill the grease into the storage chamber 43 through the replenishing tube 414, so that there is no need to disassemble the pneumatic actuator when replenishing the grease, thereby improving work efficiency and further improving service life.

[0041] It should be noted that the position of the supplementary component 4 can be adjusted according to the specific internal structure or requirements of the pneumatic actuator. In order to prevent the supplementary component 4 from spraying on the top of the piston 2 and causing waste when replenishing grease, the height of the support plate 48 in the initial position needs to be higher than the guide tube 46, so that after the guide tube 46 is inserted into the air inlet hole 32, the top of the piston 2 contacts the bottom of the support plate 48. By adjusting the length of the support plate 48 or the gas content in the driving chamber 44, the amount of oil replenished by the supplementary component 4 in the oil storage tank 31 can be synchronously adjusted.

[0042] To summarize, through the arrangement of the supplementary component 4, when the piston 2 moves upward in the cylinder body 1, a plurality of guide tubes 46 can be inserted into the corresponding air inlet holes 32, and the piston 2 can push the support plate 48 and the piston plate 47 to move upward in the driving chamber 44, so that the sealing plate 411 slides in the sealing groove 410 to release the blockage of the oil outlet 45, and the gas in the driving chamber 44 pushes the grease in the storage chamber 43 into the oil storage tank 31, thereby replenishing the grease in the oil storage tank 31, so that there is no need for manual frequent replenishment of the grease in the oil storage tank 31, and the staff can fill the storage chamber 43 with grease through the supplementary tube 414, and the grease can be replenished without disassembling the pneumatic actuator, thereby improving work efficiency and further improving service life.

[0043] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-lubricating piston assembly of a pneumatic actuator, comprising a cylinder body (1), wherein a piston (2) is sealingly and slidably connected inside the cylinder body (1), characterized in that: Also includes: a lubrication component (3), the lubrication component (3) being arranged on the piston (2) and being used for self-lubricating the piston (2) when the piston (2) slides; a replenishing component (4), the replenishing component (4) being arranged in the cylinder body (1) and being used for replenishing lubricating grease to the lubricating component (3) when the piston (2) moves; The lubrication assembly (3) comprises an oil storage groove (31) formed on the circumferential outer wall of the piston (2); a plurality of air inlet holes (32) in communication with the oil storage groove (31) are formed at equal intervals on the top circumference of the piston (2); a guide belt (33) is embedded in the circumferential outer wall of the piston (2) above the oil storage groove (31); and a sealing ring (34) is embedded in the circumferential outer wall of the piston (2) below the oil storage groove (31).

2. The self-lubricating piston assembly of the pneumatic actuator according to claim 1, characterized in that: The supplementary component (4) comprises a storage bin (41) fixedly connected to the circumferential inner wall of the cylinder body (1); the storage bin (41) is arranged in an annular shape, and the interior of the storage bin (41) is divided into a storage chamber (43) and a drive chamber (44) by an annular partition plate (42).

3. The self-lubricating piston assembly of the pneumatic actuator according to claim 2, characterized in that: The bottom of the storage bin (41) is provided with a plurality of oil outlets (45) in communication with the storage chamber (43); the bottom of the storage bin (41) is fixedly connected with a guide tube (46) below each of the oil outlets (45); the number of the guide tubes (46) is the same as that of the air inlet holes (32) and their positions correspond; and the guide tubes (46) can be inserted into the air inlet holes (32).

4. The self-lubricating piston assembly of the pneumatic actuator according to claim 3, characterized in that: The storage bin (41) is sealed and slidably connected to a piston plate (47) at the inside, and a support plate (48) is fixedly connected to the bottom of the piston plate (47). A telescopic groove (49) communicating with the drive chamber (44) is formed at the bottom of the storage bin (41), and the support plate (48) is slidably connected in the telescopic groove (49).

5. The self-lubricating piston assembly of the pneumatic actuator according to claim 4, characterized in that: A plurality of blocking grooves (410) having the same number as the oil outlet (45) and corresponding positions are provided below the storage bin (41), each of the blocking grooves (410) passing through the corresponding oil outlet (45), and each of the blocking grooves (410) is sealingly and slidably connected with a blocking plate (411) for blocking the oil outlet (45).

6. The self-lubricating piston assembly of the pneumatic actuator according to claim 5, characterized in that: The annular partition plate (42) is provided with a plurality of first communication ports (412) connecting the storage chamber (43) and the drive chamber (44), and the storage bin (41) is provided with a plurality of second communication ports (413) connecting the drive chamber (44) and the plurality of blocking grooves (410).

7. The self-lubricating piston assembly of the pneumatic actuator according to claim 6, characterized in that: When the piston plate (47) moves upward in the driving chamber (44), the gas in the driving chamber (44) can be squeezed into the storage chamber (43) through the plurality of first connecting ports (412), and the gas in the sealing groove (410) can be drawn out into the driving chamber (44) through the second connecting ports (413).

8. The self-lubricating piston assembly of the pneumatic actuator according to claim 7, characterized in that: A replenishing pipe (414) is fixedly connected to the outer wall of the storage bin (41), one end of the replenishing pipe (414) is in communication with the storage chamber (43), and the other end of the replenishing pipe (414) extends to the outside of the cylinder body (1). A one-way valve (415) is provided in the replenishing pipe (414), and grease is provided in both the oil storage tank (31) and the storage chamber (43).

9. The self-lubricating piston assembly of the pneumatic actuator according to claim 8, characterized in that: An upper end cover (11) is provided at the upper end of the cylinder body (1), and a lower end cover (12) is provided at the lower end of the cylinder body (1). Air holes (13) are provided on the upper end cover (11) and the lower end cover (12). An elastic member (14) is connected between the top of the piston (2) and the bottom of the upper end cover (11). A piston rod (15) is installed at the center of the piston (2).

10. The self-lubricating piston assembly of the pneumatic actuator according to claim 9, characterized in that: A manual switching assembly (5) is mounted on the top of the upper end cover (11) via an upper bracket (16); the manual switching assembly (5) is connected to the piston rod (15) via a connecting piece (17); and a lower bracket (18) is mounted on the bottom of the lower end cover (12).

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