A double-rack anti-jamming oil cylinder drive structure

Abstract

The present invention discloses an oil cylinder drive structure with double racks for anti-jamming, belonging to the field of valves. It includes a housing, in which an oil cylinder and an output shaft are installed. The oil cylinder includes a first oil cylinder and a second oil cylinder. A first driving rack is installed on the first oil cylinder, a second driving rack is installed on the second oil cylinder, and a driving gear is installed on the output shaft. A manual locking structure is also installed in the housing. The manual locking structure includes a locking pin shaft, and the movement direction of the locking pin shaft is perpendicular to the piston rod of the first oil cylinder. In this application, two oil cylinders located on both sides of the driving gear are used to drive the two racks respectively. Therefore, during the transmission process, the extrusion between a single rack and the gear is smaller, the wear is smaller, the service life of the gear is increased, and the wear received by the gear is more uniform, solving the problem in the prior art that during the process of driving a valve by an oil cylinder, due to the large pressure generated between the gear and the rack, the gear wears quickly after long-term use.

Description

Technical Field

[0001] The present invention relates to the field of valves, and in particular to a double-rack anti-jamming oil cylinder drive structure. Background Art

[0002] In the prior art, during the opening and closing processes of large valves, due to the pressure of the fluid, a large force is required for driving. Therefore, an oil cylinder is generally used as the driving source for large valves. However, in general, a single oil cylinder is used to drive existing valves. During the driving process of the oil cylinder, due to the large pressure generated between the gear and the rack, the gear wears relatively quickly after long-term use.

[0003] For example, a gear-rack hydraulic transmission valve disclosed in a Chinese patent document with the publication number CN209067923U has an adjustment seat provided at the upper part in the center of its housing. A plurality of first hexagon socket head cap screws are circumferentially and equidistantly distributed on the adjustment seat. The first hexagon socket head cap screws threadedly connect the adjustment seat and the housing. And a tooth guard is provided at the lower part of the adjustment seat. The center of the tooth guard and the adjustment seat are threadedly connected by a second hexagon socket head cap screw; the second adjusting rod passes through the cylinder head and is sealed by a seventh circular sealing ring. The lower part of the rack meshes with the gear. The gear is fixedly connected to a travel switch connection plate through a valve transmission shaft. And the valve transmission shaft passes through the center of the composite sleeve. The composite sleeve is fixedly connected to the housing by a fifth hexagon socket head cap screw. This valve ingeniously uses the second adjusting screw rod and the second adjusting rod to adjust the position of the piston rod so as to drive the rack to move, and uses the movement of the rack to drive the gear to rotate to realize the adjustment of the valve transmission shaft. At the same time, in this application, the first adjusting rod and the first adjusting screw rod are also used to limit the moving distance of the rack; however, the disadvantage of this patent is that during the driving process of the oil cylinder, due to the large pressure generated between the gear and the rack, the gear wears relatively quickly after long-term use. Summary of the Invention

[0004] The present invention is to overcome the problem in the prior art that during the process of driving a valve by an oil cylinder, due to the large pressure generated between the gear and the rack, the gear wears relatively quickly after long-term use, and provides a double-rack anti-jamming oil cylinder drive structure, which can reduce the wear of the gear.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention relates to an oil cylinder drive structure with double racks to prevent jamming, which includes a housing. An oil cylinder and an output shaft are installed inside the housing. The number of oil cylinders is two, including a first oil cylinder and a second oil cylinder. A first transmission rack is installed on the first oil cylinder, and a second transmission rack is installed on the second oil cylinder. A transmission gear is installed on the output shaft, and the transmission gear meshes with both the first transmission rack and the second transmission rack at the same time. A locking block is installed at one end of the piston rod of the first oil cylinder. A manual locking structure is also installed inside the housing, and the manual locking structure includes a locking pin shaft, and the moving direction of the locking pin shaft is perpendicular to the piston rod of the first oil cylinder.

[0007] In this solution, two oil cylinders located on both sides of the transmission gear are used to drive the two racks respectively. Therefore, during the transmission process, the extrusion between a single rack and the gear is relatively small, resulting in less wear, increasing the service life of the gear, and making the wear on the gear more uniform. And the locking block can lock the valve after it is closed. On the one hand, it can avoid continuously causing load on the oil cylinder due to fluid impact, and on the other hand, it can avoid the wear of the gear and rack caused by the vibration of the piston rod.

[0008] Preferably, anti-jamming transmission racks are installed on both oil cylinders, and the transmission gear meshes with the anti-jamming transmission racks on both oil cylinders at the same time. The anti-jamming transmission rack includes a mounting seat and an anti-jamming moving block. The mounting seat is sleeved on the piston rod of the oil cylinder. The anti-jamming moving block and the transmission gear are provided with matching helical teeth. The mounting seat is provided with a moving block guide rail, and the direction of the moving block guide rail is the same as the axial direction of the transmission gear. The moving block is installed on the moving block guide rail. First baffles and second baffles for limiting the anti-jamming moving block are respectively arranged on both sides of the moving block guide rail. A pre-tightening spring is installed between the first baffle and the anti-jamming moving block. During the process of the oil cylinder driving the valve, once the valve is jammed or stuck due to various reasons, it is very easy to cause the piston rod of the oil cylinder or the gear and rack to be overloaded and damaged. To avoid this situation, this solution is provided with an anti-jamming transmission rack. When the valve is normally opened and closed, the resistance received by the valve is relatively small, and the anti-jamming moving block will not move relative to the mounting seat under the pressing action of the pre-tightening spring. When the valve receives a large resistance, the extrusion force of the transmission gear on the anti-jamming moving block is relatively large. Since the two are driven by helical teeth, the extrusion force is inclined. Once the component force of the extrusion force in the direction perpendicular to the movement direction of the transmission rack is greater than the pre-tightening force of the pre-tightening spring, the anti-jamming moving block will move relative to the mounting seat, so that the piston rod of the oil cylinder will not be jammed by the transmission gear, but can continue to move, reducing the possibility of component damage when jamming occurs. Another effect of the anti-jamming structure in this solution is that once the problem of valve jamming or sticking is eliminated, the pre-tightening spring can press the anti-jamming moving block back to its original position again, and will not cause the relative position of the piston rod of the oil cylinder and the output shaft to change due to the valve being jammed.

[0009] Preferably, a jamming detection structure for detecting the movement amount of the anti-jamming moving block on the moving block guide rail is further provided inside the housing; when there are small impurities in the valve, the valve may not be completely jammed but clamped. After clamping, the extrusion force during transmission increases, and the wear rate of each transmission part accelerates; since the larger the movement amount of the anti-jamming moving block, the larger the compression amount of the pre-tightening spring, and the greater the pressure of the pre-tightening spring on the anti-jamming moving block, the degree of valve clamping can be detected by detecting the movement amount of the anti-jamming moving block on the moving block guide rail. When the valve is jammed, the movement amount of the anti-jamming moving block reaches the maximum value.

[0010] Preferably, the jamming detection structure includes a reflection sheet installed on one of the anti-jamming transmission racks and a reflection sensor installed on the detection rack. The detection rack is installed on the detection rack guide rail, and the detection rack guide rail is installed on the inner side of the housing. When the anti-jamming moving block does not move on the moving block guide rail, the detection rack moves synchronously with the anti-jamming transmission rack; in this solution, the movement amount of the anti-jamming moving block on the moving block guide rail is converted into the movement amount of the detection rack relative to the anti-jamming transmission rack, thus solving the problem that it is not convenient to set the detection structure at the anti-jamming moving block.

[0011] Preferably, a follower gear is further connected to the transmission gear, and the follower gear drives the detection rack through the detection transmission gear.

[0012] Preferably, the housing includes a first mounting cover, and a transmission window is provided on the first mounting cover. The detection rack and the detection transmission gear are engaged at the transmission window.

[0013] Preferably, a guide rod is provided on the anti-jamming moving block, a guide hole adapted to the guide rod is provided on the mounting seat, and the pre-tightening spring is sleeved outside the guide rod.

[0014] Therefore, the present invention has the following beneficial effects: (1) It can reduce the wear of the gears; (2) It can lock the valve to avoid potential safety hazards during the valve opening and closing processes; (3) It can reduce the wear on the oil cylinder piston rod and the gear rack when the valve is jammed; (4) After the valve is jammed and repaired, it will not cause the relative position of the oil cylinder piston rod and the output shaft to change; (5) It can detect the degree of valve clamping. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view in a top-down direction of Embodiment 1 of the present invention.

[0016] Figure 2 is a cross-sectional view in a side view direction of Embodiment 1 of the present invention.

[0017] Figure 3 is a cross-sectional view in a side view direction of Embodiment 2 of the present invention.

[0018] Figure 4 It is a schematic structural diagram in the main viewing direction of the anti-jamming transmission rack according to the second embodiment of the present invention.

[0019] In the figure: 1. Outer shell; 2. Output shaft; 3. First oil cylinder; 4. Second oil cylinder; 5. First transmission rack; 6. Second transmission rack; 7. Transmission gear; 8. Piston rod; 9. Locking block; 10. Locking pin shaft; 11. Hand rocker; 12. Locking rod; 13. Slide block; 15. Return spring; 16. Limiting part; 17. First buffer; 18. Second buffer; 19. Buffer mounting cover; 20. Limiting step; 21. Limiting nut; 22. Positioning block; 23. Positioning detector; 24. Mounting seat; 25. Anti-jamming moving block; 26. Helical teeth; 27. Moving block guide rail; 28. First baffle; 29. Second baffle; 30. Pre-tightening spring; 31. Reflective sheet; 32. Detection rack; 33. Reflective sensor; 34. Detection rack guide rail; 35. Follow-up gear; 36. Detection transmission gear; 37. First mounting cover; 38. Transmission window; 39. Guide rod. Specific embodiments

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Embodiment 1, as Figure 1-2 shown, a double-rack anti-jamming oil cylinder drive structure includes an outer shell 1. An oil cylinder and an output shaft 2 are installed inside the outer shell. The oil cylinder includes a first oil cylinder 3 and a second oil cylinder 4. A first transmission rack 5 is installed on the first oil cylinder, a second transmission rack 6 is installed on the second oil cylinder, and a transmission gear 7 is installed on the output shaft. The transmission gear meshes with the first transmission rack and the second transmission rack at the same time. A locking block 9 is installed at one end of the piston rod 8 of the first oil cylinder. A manual locking structure is also installed inside the outer shell. The manual locking structure includes a locking pin shaft 10. The movement direction of the locking pin shaft is perpendicular to the piston rod of the first oil cylinder; the manual locking structure further includes a hand rocker 11 and a locking rod 12. The locking pin shaft is installed at the lower end of the locking rod, and a slide block 13 is installed at the upper end of the locking rod. A telescopic rod rotatably connected to the slide block is installed inside the hand rocker; a return spring 15 is also installed on the locking rod, and a limiting part 16 located below the return spring is provided on the locking rod; a first cylindrical surface is provided on the first transmission rack, and a first buffer 17 covering the outside of the first cylindrical surface is provided inside the outer shell. A second cylindrical surface is provided on the second transmission rack, and a second buffer 18 covering the outside of the second cylindrical surface is provided inside the outer shell; a buffer mounting cover 19 is installed on the outer shell. The first buffer and the second buffer are respectively installed on a buffer mounting cover, and the buffer mounting cover is fixed to the outer shell by bolts; a limiting step 20 is provided on the piston rod of the oil cylinder, and a limiting nut 21 is also installed on the piston rod; a positioning block 22 is installed on the transmission gear, and a positioning detector 23 is fixedly installed inside the outer shell.

[0022] When the valve needs to be opened, the piston rod of the first oil cylinder retracts, and the piston rod of the second oil cylinder extends. Since the piston of the first oil cylinder is limited by the limit pin shaft, the transmission gear will only rotate when the operator turns the hand crank down; while the piston rod of the oil cylinder moves, it drives the transmission rack. One side of the transmission rack is limited by the buffer member, so as to ensure the meshing transmission with the transmission gear; when the operator releases the hand crank, the locking rod moves downward to lock the locking block. When locking, the side surface of the locking pin shaft presses against one side of the locking block, so that the locking block cannot move in the axial direction of the oil cylinder; when the valve is fully closed, the positioning block rotates with the transmission gear to a position in contact with the positioning detector. After the positioning detector contacts the positioning block, it generates a signal and feeds it back through the signal lamp, so that the operator can intuitively understand the valve state.

[0023] Embodiment 2, as Figure 3-4 shown, a double-rack anti-jamming oil cylinder drive structure includes a housing. An oil cylinder and an output shaft are installed in the housing. The number of oil cylinders is two, including a first oil cylinder and a second oil cylinder. A first transmission rack is installed on the first oil cylinder, and a second transmission rack is installed on the second oil cylinder. A transmission gear 7 is installed on the output shaft. The transmission gear meshes with both the first transmission rack and the second transmission rack at the same time. A locking block is installed at one end of the piston rod of the first oil cylinder. A manual locking structure is also installed in the housing. The manual locking structure includes a locking pin shaft. The movement direction of the locking pin shaft is perpendicular to the piston rod of the first oil cylinder; the manual locking structure includes a hand crank and a locking rod. The locking pin shaft is installed at the lower end of the locking rod. A slider is installed at the upper end of the locking rod. A telescopic rod rotatably connected to the slider is installed in the hand crank; a return spring is also installed on the locking rod. A limiting portion located below the return spring is provided on the locking rod; a first cylindrical surface is provided on the first transmission rack, and a first buffer member covering the outside of the first cylindrical surface is provided in the housing. A second cylindrical surface is provided on the second transmission rack, and a second buffer member covering the outside of the second cylindrical surface is provided in the housing; a buffer member mounting cover is installed on the housing. The first buffer member and the second buffer member are respectively installed on a buffer member mounting cover. The buffer member mounting cover is fixed to the housing by bolts; a limiting step is provided on the piston rod of the oil cylinder, and a limiting nut is also installed on the piston rod.

[0024] Anti - jamming drive racks are installed on both cylinders. The first drive rack and the second drive rack are both anti - jamming drive racks. The drive gear meshes with the anti - jamming drive racks on both cylinders simultaneously. The anti - jamming drive rack includes a mounting seat 24 and an anti - jamming moving block 25. The mounting seat is sleeved on the piston rod 8 of the cylinder. The anti - jamming moving block and the drive gear are provided with matching helical teeth 26. The mounting seat is provided with a moving - block guide rail 27. The direction of the moving - block guide rail is the same as the axial direction of the drive gear. The moving block is installed on the moving - block guide rail. On both sides of the moving - block guide rail, there are respectively a first baffle 28 and a second baffle 29 for limiting the anti - jamming moving block. A pre - tightening spring 30 is installed between the first baffle and the anti - jamming moving block. Inside the housing, there is also a jamming detection structure for detecting the moving amount of the anti - jamming moving block on the moving - block guide rail. The jamming detection structure includes a reflecting sheet 31 installed on one of the anti - jamming drive racks, and a plurality of reflection sensors 33 installed on the detection rack 32. The plurality of reflection sensors are arranged at intervals in the length direction of the anti - jamming drive rack. The plurality of reflection sensors are respectively electrically connected to signal lights of different colors, which is convenient for the operator to judge the valve clamping situation. The detection rack is installed on the detection - rack guide rail 34, and the detection - rack guide rail is installed on the inner side of the housing. When the anti - jamming moving block does not move on the moving - block guide rail, the detection rack moves synchronously with the anti - jamming drive rack. A follower gear 35 is also connected to the drive gear, and the follower gear drives the detection rack through the detection drive gear 36. The housing includes a first mounting cover 37. A drive window 38 is provided on the first mounting cover. The detection rack and the detection drive gear mesh at the drive window. A guide rod 39 is provided on the anti - jamming moving block, and a guide hole adapted to the guide rod is provided on the mounting seat. The pre - tightening spring is sleeved outside the guide rod.

[0025] When the valve needs to be opened, the piston rod of the first cylinder retracts, and the piston rod of the second cylinder extends. Since the piston of the first cylinder is limited by the limit pin, the drive gear will rotate only when the operator turns the hand - crank down. While the piston rod of the cylinder is moving, it drives the drive rack. One side of the drive rack is limited by the buffer member, so as to ensure the meshing drive with the drive gear. When the operator releases the hand - crank, the locking rod moves downward to lock the locking block. When locking, the side of the locking pin presses against one side of the locking block, so that the locking block cannot move in the axial direction of the cylinder.

[0026] When the valve is jammed due to various factors, for example, impurities are stuck between the valve core and the valve body, the resistance encountered during valve opening or closing suddenly increases, resulting in an increase in the extrusion force between the transmission gear and the transmission rack. The anti-jamming moving block will move on the moving block guide rail and compress the pre-tightening spring. Since the pre-tightening spring shares the resistance and plays a buffering role, it will reduce the instantaneous pressure on the oil cylinder piston rod. At the same time, due to the movement of the anti-jamming moving block, the relative positions of the detection rack and the anti-jamming transmission rack change. The reflection sensor that could originally receive signals through the reflector can no longer receive signals, but other reflection sensors do. Based on the number of the reflection sensor that receives the signal, the distance the anti-jamming moving block moves can be judged, and then the degree of jamming can be determined. During the valve opening and closing processes, even if the valve can ultimately be fully opened and closed, the operator can judge whether the valve is jammed during the opening and closing processes through the change of the signal lamp, and thus perform maintenance in a timely manner.

[0027] When the valve is completely stuck, the transmission gear no longer rotates, but the oil cylinder will still drive the anti-jamming transmission rack to move and squeeze the pre-tightening spring through the anti-jamming moving block. When the pre-tightening spring is compressed to its maximum amount, the axial force of the anti-jamming transmission rack on the oil cylinder piston rod does not exceed the maximum load of the oil cylinder piston rod, thus avoiding damage to the oil cylinder piston rod. The operator can judge the stuck state of the valve through the signal lamp and thus perform maintenance in a timely manner.

Claims

1. A double-rack anti-jamming oil cylinder drive structure, including a housing, an oil cylinder and an output shaft are installed in the housing, and it is characterized in that, The number of hydraulic cylinders is two, including a first hydraulic cylinder and a second hydraulic cylinder. A first transmission rack is installed on the first hydraulic cylinder, a second transmission rack is installed on the second hydraulic cylinder, and a transmission gear is installed on the output shaft. The transmission gear meshes with both the first transmission rack and the second transmission rack simultaneously. A locking block is installed at one end of the piston rod of the first hydraulic cylinder, and a manual locking structure is also installed inside the housing. The manual locking structure includes a locking pin shaft, and the movement direction of the locking pin shaft is perpendicular to the piston rod of the first hydraulic cylinder; both the first transmission rack and the second transmission rack are anti-jamming transmission racks. The anti-jamming transmission rack includes a mounting seat and an anti-jamming moving block. The anti-jamming moving block and the transmission gear are provided with matching helical teeth. A jamming detection structure for detecting the moving amount of the anti-jamming moving block on the moving block guide rail is also provided inside the housing. A plurality of reflection sensors are installed on the detection rack. When the anti-jamming moving block does not move on the moving block guide rail, the detection rack moves synchronously with the anti-jamming transmission rack.

2. The double-rack anti-jamming oil cylinder drive structure according to claim 1, characterized in that, The transmission gear meshes with the anti-jamming transmission racks on both hydraulic cylinders simultaneously. The mounting seat is sleeved on the piston rod of the hydraulic cylinder. The mounting seat is provided with a moving block guide rail, and the direction of the moving block guide rail is the same as the axial direction of the transmission gear. The moving block is installed on the moving block guide rail. First baffles and second baffles for limiting the anti-jamming moving block are respectively arranged on both sides of the moving block guide rail. A pre-tightening spring is installed between the first baffle and the anti-jamming moving block.

3. The double-rack anti-jamming oil cylinder drive structure according to claim 2, characterized in that, The jamming detection structure includes a reflection sheet installed on one of the anti-jamming transmission racks and a reflection sensor installed on the detection rack.

4. A double-rack anti-jamming oil cylinder drive structure according to claim 3, characterized in that, The detection rack is installed on the detection rack guide rail, and the detection rack guide rail is installed on the inner side of the housing.

5. A double-rack anti-jamming oil cylinder drive structure according to claim 4, characterized in that, A follower gear is also connected to the transmission gear, and the follower gear drives the detection rack through a detection transmission gear.

6. A double-rack anti-jamming oil cylinder drive structure according to claim 5, characterized in that, The housing includes a first mounting cover, and a transmission window is provided on the first mounting cover. The detection rack and the detection transmission gear mesh at the transmission window.

7. A double-rack anti-jamming oil cylinder drive structure according to any one of claims 2-6, characterized in that, The anti-jamming moving block is provided with a guide rod, the mounting seat is provided with a guide hole adapted to the guide rod, and the pre-tightening spring is sleeved outside the guide rod.

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