High-precision electric actuators for process control valves

Abstract

The present invention relates to the technical field of electric actuators, and more specifically to an electric actuator for high-precision control of process control valves, comprising a housing and a valve stem, wherein a support sleeve is provided at the bottom of the housing, and the valve stem extends through the support sleeve, a swivel seat is rotatably provided at the upper portion of the housing, one end of the swivel seat extends into the interior of the housing, and a handwheel is fixed to the other end of the swivel seat, a worm gear is provided at the upper end of the support sleeve, and the worm gear is rotatably connected to the support sleeve, a worm is engaged with one side of the worm gear, a motor is mounted on one side of the housing, and the motor is used to drive the worm gear to rotate, a clutch sleeve is provided on the valve stem, and the clutch sleeve can switch between manual and electric modes when sliding up and down, an adjustment member is provided on the housing, and the adjustment member is used to adjust the up and down movement of the clutch sleeve, and a monitoring mechanism is also provided inside the housing. The present invention can observe the height difference between two observation liquid pipes to determine the wear clearance between the worm gear and the worm, thereby avoiding the reduction in accuracy caused by excessive wear.

Description

Technical Field

[0001] The present invention relates to the technical field of electric actuators, in particular to a high-precision controlled electric actuator for a process control valve. Background Art

[0002] Process control valves are also a type of valve that are widely used in chemical processing plants. Process control valves need to be combined with electric actuators to achieve precise opening and closing. Basic actuators are used to drive the valve to the fully open or fully closed position, while actuators used for control valves can accurately move the valve to any position.

[0003] At present, general valve electric actuators basically use worm gears as the main transmission parts. After long-term use, parts will wear out, resulting in inaccurate valve opening and closing angles. Most existing electric actuators do not have external monitoring structures to monitor the accuracy of the worm gears. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an electric actuator with high-precision control for process control valves, so as to solve the problem that the wear of transmission components in existing electric actuators cannot be monitored.

[0005] Based on the above objectives, the present invention provides a high-precision controlled electric actuator for a process control valve.

[0006] The process control valve uses a high-precision controlled electric actuator, which includes a housing and a valve stem. A support sleeve is provided at the bottom of the housing, and the valve stem passes through the support sleeve. A swivel seat is rotatably provided on the upper part of the housing, one end of the swivel seat extends into the interior of the housing, and a handwheel is fixed to the other end of the swivel seat. A worm gear is provided on the upper end of the support sleeve, and the worm gear is rotatably connected to the support sleeve. A worm is engaged with one side of the worm gear, and a motor is installed on one side of the housing, and the motor is used to drive the worm gear to rotate. A clutch sleeve is provided on the valve stem, and the clutch sleeve can switch between manual and electric modes when sliding up and down. An adjusting member is provided on the housing, and the adjusting member is used to adjust the up and down movement of the clutch sleeve. A monitoring mechanism is also provided inside the housing, and the monitoring mechanism can monitor the wear clearance of the worm gear and the worm.

[0007] Furthermore, the outer wall of the valve stem is provided with a plurality of limiting grooves, and the inner wall of the clutch sleeve is provided with a plurality of limiting ridges, and the plurality of limiting ridges are respectively slidably disposed in the plurality of limiting grooves.

[0008] Furthermore, a limit disk is fixed on the upper end of the valve stem, and a spring is sleeved on one end of the valve stem close to the limit disk, and one end of the spring is pressed against the clutch sleeve.

[0009] Furthermore, the clutch sleeve is provided with a plurality of slots on the bottom circle, the worm gear is provided with a plurality of blocks on the upper circle, and the blocks are adapted to the slots, the clutch sleeve is provided with a plurality of first protrusions on the upper part, the swivel seat is provided with a plurality of second protrusions on the bottom, and engaging grooves are formed between the plurality of second protrusions, and the first protrusions can enter the engaging grooves.

[0010] Furthermore, the adjusting member includes an operating rod, one end of which extends into the interior of the shell and is fixed with a top block, a limit ring is fixed on the clutch sleeve, and one end of the top block is tightly pressed against the bottom of the limit ring.

[0011] Furthermore, the monitoring mechanism includes two sealed tanks, one end of each sealed tank is connected to an observation liquid tube, the upper ends of the observation liquid tubes pass through the outer wall of the shell, the sealed tanks are filled with colored liquid, the rotating sleeve on the support sleeve is provided with a second gear, and the second gear is fixedly connected to the bottom of the worm gear, one side of the second gear is meshed with a third gear, one end of the worm is coaxially fixed with a fourth gear, the fourth gear is meshed with the first gear, the first gear and the third gear are coaxially fixed with a threaded sleeve, the other end of the threaded sleeve is threadedly connected to a threaded column, the other end of the threaded column is fixed with a piston rod, and the other ends of the two piston rods extend into the two sealed tanks respectively and are fixed with pistons.

[0012] Furthermore, two cross bars are fixed in the shell, and multiple guide columns are fixed on the cross bars. One end of the threaded column is sleeved with a connecting plate, and the multiple guide columns pass through the connecting plate and are slidably connected thereto.

[0013] Furthermore, two connecting frames are fixed in the shell, and the two threaded sleeves are rotatably connected to the two connecting frames respectively.

[0014] Furthermore, the operating rod is rotatably connected to the housing via a bearing, and a return coil spring is installed at the rotatable connection between the operating rod and the housing.

[0015] Beneficial effects of the present invention:

[0016] 1. The present invention, through the provision of a monitoring mechanism, enables the motor to drive the worm wheel to rotate and drive the worm to rotate, and the two threaded sleeves rotate simultaneously, and the threaded column is limited and moved upward by the connecting plate, so that the piston rod pushes the piston to move upward, and the colored liquid in the sealed tank is pushed out into the observation liquid tube. We can judge the wear gap between the worm wheel and the worm by observing the height difference between the two observation liquid tubes from the outside, and avoid the reduction in accuracy caused by excessive wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 is a schematic three-dimensional cross-sectional view of an embodiment of the present invention;

[0019] Figure 2 is a three-dimensional schematic diagram of an embodiment of the present invention;

[0020] Figure 3 This is a three-dimensional schematic diagram of the internal structure of the housing according to an embodiment of the present invention;

[0021] Figure 4 This is a three-dimensional schematic diagram of a clutch sleeve and a valve stem according to an embodiment of the present invention;

[0022] Figure 5 This is a three-dimensional schematic diagram of a valve stem according to an embodiment of the present invention;

[0023] Figure 6 This is a three-dimensional schematic diagram of a clutch sleeve according to an embodiment of the present invention;

[0024] Figure 7 This is a three-dimensional schematic diagram of a hand wheel according to an embodiment of the present invention;

[0025] Figure 8 3D schematic diagram of a monitoring mechanism according to an embodiment of the present invention.

[0026] The following are marked in the figure:

[0027] 1. Housing; 2. Handwheel; 3. Rotating seat; 4. Motor; 5. Operating lever; 6. Observation liquid pipe; 8. Clutch sleeve; 9. Support sleeve; 10. Worm gear; 11. Valve stem; 12. Worm; 13. Ejector block; 14. Sealing tank; 15. Cross bar; 16. Connecting frame; 17. First gear; 18. Second gear; 19. Third gear; 20. Block; 21. Slot; 22. Limiting ring; 23. First protrusion; 24. Limiting plate; 25. Spring; 26. Limiting slot; 27. Second protrusion; 28. Limiting ridge; 29. Guide column; 30. Connecting plate; 31. Threaded column; 32. Threaded sleeve; 33. Fourth gear. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0029] like Figures 1-8As shown, a high-precision controlled electric actuator for a process control valve includes a housing 1 and a valve stem 11. A support sleeve 9 is provided at the bottom of the housing 1, and the valve stem 11 passes through the support sleeve 9. A swivel seat 3 is rotatably provided on the upper part of the housing 1, and one end of the swivel seat 3 extends into the interior of the housing 1. A handwheel 2 is fixed to the other end of the swivel seat 3. A worm gear 10 is provided on the upper end of the support sleeve 9, and the worm gear 10 is rotatably connected to the support sleeve 9. A worm 12 is engaged with one side of the worm gear 10, and a motor 4 is installed on one side of the housing 1, and the motor 4 is used to drive the worm 12 to rotate. A clutch sleeve 8 is provided on the valve stem 11, and the clutch sleeve 8 can switch between manual and electric modes when sliding up and down. An adjusting member is provided on the housing 1, and the adjusting member is used to adjust the up and down movement of the clutch sleeve 8. A monitoring mechanism is also provided inside the housing 1, and the monitoring mechanism can monitor the wear clearance of the worm gear 10 and the worm 12.

[0030] The outer wall of the valve stem 11 is provided with a plurality of limiting grooves 26, and the inner wall of the clutch sleeve 8 is provided with a plurality of limiting ridges 28. The plurality of limiting ridges 28 are respectively slidably arranged in the plurality of limiting grooves 26, so that the clutch sleeve 8 and the valve stem 11 slide relative to each other but the rotation direction is limited.

[0031] A limit plate 24 is fixed to the upper end of the valve stem 11, and a spring 25 is sleeved on one end of the valve stem 11 close to the limit plate 24. One end of the spring 25 presses against the clutch sleeve 8, so that the clutch sleeve 8 is located in the lower position under normal state.

[0032] A plurality of slots 21 are provided on the bottom of the clutch sleeve 8, a plurality of blocks 20 are fixed on the upper part of the worm gear 10, and the blocks 20 are adapted to the slots 21. A plurality of first protrusions 23 are fixed on the upper part of the clutch sleeve 8, and a plurality of second protrusions 27 are fixed on the bottom of the swivel seat 3. Engaging grooves are formed between the plurality of second protrusions 27, and the first protrusions 23 can enter the engaging grooves.

[0033] The adjusting member includes an operating rod 5, one end of which extends to the inside of the housing 1 and is fixed with a top block 13. A limit ring 22 is fixed on the clutch sleeve 8. One end of the top block 13 is pressed against the bottom of the limit ring 22. Pressing the operating rod 5 causes the top block 13 to lift the clutch sleeve 8, so that the first protrusion 23 is relatively engaged with the swivel seat 3. At this time, the hand wheel 2 can be rotated to drive the valve stem 11 to rotate and open and close.

[0034] The monitoring mechanism includes two sealed tanks 14, one end of each sealed tank 14 is connected to an observation liquid pipe 6, the upper end of each observation liquid pipe 6 passes through the outer wall of the shell 1, and the sealed tanks 14 are filled with colored liquid. A second gear 18 is provided on the support sleeve 9, and the second gear 18 is fixedly connected to the bottom of the worm gear 10. A third gear 19 is engaged with one side of the second gear 18. A fourth gear 33 is coaxially fixed to one end of the worm 12. The fourth gear 33 is engaged with the first gear 17. The first gear 17 and the third gear 19 are coaxially fixed with a threaded sleeve 32. The other side of the threaded sleeve 32 is fixed to the first gear 17. The end is threadedly connected to a threaded column 31, and the other end of the threaded column 31 is fixed with a piston rod, and the other ends of the two piston rods extend into the two sealed tanks 14 respectively and are fixed with pistons. The motor 4 drives the worm gear 10 to rotate and drives the worm 12 to rotate, and the two threaded sleeves 32 rotate simultaneously. The threaded column 31 moves upward under the limiting action of the connecting plate 30, so that the piston rod pushes the piston upward, and the colored liquid in the sealed tank 14 is pushed out into the observation liquid tube 6. The wear gap between the worm gear 10 and the worm 12 can be judged from the outside by observing the height difference between the two observation liquid tubes 6.

[0035] Two cross bars 15 are fixed in the housing 1 , and a plurality of guide posts 29 are fixed on the cross bars 15 . A connecting plate 30 is sleeved on one end of the threaded post 31 , and the plurality of guide posts 29 pass through the connecting plate 30 and are slidably connected thereto.

[0036] Two connecting frames 16 are fixed in the housing 1 , and the two threaded sleeves 32 are rotatably connected to the two connecting frames 16 respectively.

[0037] The operating rod 5 is rotatably connected to the housing 1 through a bearing, and a return coil spring is installed at the rotatable connection between the operating rod 5 and the housing 1.

[0038] Working principle: during use, when the clutch sleeve 8 is at the lower part, the card slot 21 is stuck in the card block, so that the clutch sleeve 8 and the worm gear 10 are relatively meshed. At this time, the driving motor 4 can drive the valve stem 11 to rotate and open and close through the worm gear 10 and the worm 12. When manual control is required, the operating lever 5 can be pressed to make the top block 13 lift the clutch sleeve 8 so that the first protrusion 23 is relatively meshed with the swivel seat 3. At this time, the hand wheel 2 can be rotated to drive the valve stem 11 to rotate and open and close. When controlled by the motor 4, the motor 4 drives the worm gear 10 to rotate and drives the worm 12 to rotate. The two threaded sleeves 32 rotate simultaneously. The threaded column 31 moves upward under the limiting action of the connecting plate 30, so that the piston rod pushes the piston upward, and the colored liquid in the sealing tank 14 is pushed out into the observation liquid pipe 6. The wear gap between the worm gear 10 and the worm 12 can be judged by observing the height difference between the two observation liquid pipes 6 from the outside, and the response time of the worm 12 after the worm gear 10 is started can be timely understood.

[0039] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0040] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electric actuator for high-precision control of a process control valve, comprising a housing (1) and a valve stem (11), characterized in that: The bottom of the housing (1) is provided with a support sleeve (9), and the valve stem (11) passes through the support sleeve (9). The upper part of the housing (1) is rotatably provided with a swivel seat (3), one end of the swivel seat (3) extends into the interior of the housing (1), and the other end of the swivel seat (3) is fixed with a hand wheel (2). The upper end of the support sleeve (9) is provided with a worm gear (10), and the worm gear (10) is rotatably connected to the support sleeve (9). A worm (12) is engaged with one side of the worm gear (10). A motor (4) is installed on one side of the housing (1), and the motor (4) is used to drive the worm (12) to rotate. A clutch sleeve (8) is provided on the valve stem (11), and the clutch sleeve (8) can switch between manual and electric modes when sliding up and down. An adjusting member is provided on the housing (1), and the adjusting member is used to adjust the up and down movement of the clutch sleeve (8). A monitoring mechanism is also provided inside the housing (1), and the monitoring mechanism can monitor the wear clearance of the worm gear (10) and the worm (12). The monitoring mechanism comprises two sealed tanks (14), one end of each sealed tank (14) is connected to an observation liquid pipe (6), the upper end of each observation liquid pipe (6) passes through the outer wall of the shell (1), and the sealed tanks (14) are filled with colored liquid. The upper rotating sleeve of the support sleeve (9) is provided with a second gear (18), and the second gear (18) is fixedly connected to the bottom of the worm gear (10), and one side of the second gear (18) is meshed with a third gear (19), and one end of the worm (12) is coaxially fixed with a fourth gear (33), and the fourth gear (33) is meshed with the first gear (17), and the first gear (17) and the third gear (19) are coaxially fixed with a threaded sleeve (32), and the other end of the threaded sleeve (32) is threadedly connected to a threaded column (31), and the other end of the threaded column (31) is fixed with a piston rod, and the other ends of the two piston rods extend into the two sealed tanks (14) and are fixed with pistons; Two cross bars (15) are fixed in the housing (1), and a plurality of guide posts (29) are fixed on the cross bars (15), one end of each of the threaded posts (31) is sleeved with a connecting plate (30), and the plurality of guide posts (29) pass through the connecting plate (30) and are slidably connected thereto; Two connecting frames (16) are fixed in the housing (1), and two threaded sleeves (32) are rotatably connected to the two connecting frames (16) respectively.

2. The high-precision electric actuator for process control valves according to claim 1, characterized in that: The outer wall of the valve stem (11) is provided with a plurality of limiting grooves (26), and the inner wall of the clutch sleeve (8) is provided with a plurality of limiting ridges (28), and the plurality of limiting ridges (28) are respectively slidably disposed in the plurality of limiting grooves (26).

3. The high-precision electric actuator for process control valves according to claim 1, characterized in that: A limit plate (24) is fixed to the upper end of the valve stem (11), and a spring (25) is sleeved on one end of the valve stem (11) close to the limit plate (24), with one end of the spring (25) pressed against the clutch sleeve (8).

4. The high-precision electric actuator for process control valves according to claim 1, characterized in that: A plurality of slots (21) are formed on the bottom of the clutch sleeve (8), a plurality of blocks (20) are fixed on the upper part of the worm wheel (10), and the blocks (20) are adapted to the slots (21). A plurality of first protrusions (23) are fixed on the upper part of the clutch sleeve (8), and a plurality of second protrusions (27) are fixed on the bottom of the rotating seat (3). Engaging grooves are formed between the plurality of second protrusions (27), and the first protrusions (23) can enter the engaging grooves.

5. The high-precision electric actuator for process control valves according to claim 4, characterized in that: The adjusting member comprises an operating rod (5), one end of which extends into the interior of the housing (1) and is fixed with a top block (13); a limit ring (22) is fixedly mounted on the clutch sleeve (8), and one end of the top block (13) is tightly pressed against the bottom of the limit ring (22).

6. The high-precision electric actuator for process control valves according to claim 5, characterized in that: The operating rod (5) is rotationally connected to the housing (1) via a bearing, and a return coil spring is installed at the rotational connection between the operating rod (5) and the housing (1).

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