Shifting fork type pneumatic actuator based on modular design

Abstract

The invention relates to the related technical field of pneumatic actuators, and discloses a shifting fork type pneumatic actuator based on modular design, which comprises a driving box and a cylinder body, a piston is slidably arranged in the cylinder body, a driving rod is fixedly arranged on one side, facing a driving cavity, of the piston, a sliding shaft is fixedly arranged at the end part of the driving rod, and a shaft hole is formed in the side wall of the driving cavity; a driving shaft is rotatably arranged in the shaft hole, a central cylinder is arranged in the driving cavity, the central cylinder is fixedly sleeved with a fixing sleeve, the fixing sleeve is fixedly provided with a crank, a driving sliding groove is formed in the crank, a sliding shaft slides in the driving sliding groove, and a transmission outer cavity and a transmission inner cavity which are communicated with each other are formed in the driving shaft; according to the device, the normally-open or normally-closed state of the two switching valves can be adjusted, a mechanism of the pneumatic actuator does not need to be changed, or the position of the pneumatic actuator does not need to be adjusted, and operation is easy and fast.

Description

Technical Field

[0001] The present invention belongs to the technical field related to pneumatic actuators, and more specifically, particularly relates to a scotch yoke pneumatic actuator based on modular design. Background Art

[0002] Pneumatic actuators are actuators that use air pressure to drive valves to open or close. Pneumatic actuators are mainly composed of cylinders, pistons, gear shafts, end covers, seals, etc. The existing technology still has the following technical problems: The existing pneumatic actuator has two working positions. It is applied to the valve to control the valve to be normally closed. After inflation, the actuator is started to open the valve. Under some specific working conditions, the valve needs to be adjusted to remain in a normally open state. In this case, the structure of the existing actuator needs to be changed, or the actuator installation needs to be turned to change the direction of the drive shaft, which is very inconvenient to use.

[0003] Therefore, in view of this, the existing structure is studied and improved, and a scotch yoke pneumatic actuator based on modular design is provided, in order to achieve a more practical purpose. Summary of the invention

[0004] The present invention provides a scotch yoke pneumatic actuator based on modular design, which is used to overcome the above-mentioned defects in the prior art.

[0005] The purpose and effect of the scotch yoke pneumatic actuator based on modular design of the present invention are achieved by the following specific technical means: The present invention provides a scotch fork pneumatic actuator based on modular design, comprising a drive box and a cylinder body, wherein the drive box has a drive cavity, the drive cavity has a standard joint, one end of the cylinder body has a standard interface, the standard joint and the standard interface are detachably connected to make the drive cavity communicate with the inner cavity of the cylinder body, a piston is slidably arranged in the cylinder body, a return spring is arranged on the side of the piston away from the drive cavity, the two ends of the return spring are respectively connected to the piston and the inner wall of the cylinder body, a pneumatic hole is arranged at the end of the cylinder body away from the drive cavity, a drive rod is fixedly arranged on the side of the piston facing the drive cavity, a sliding shaft is fixedly arranged at the end of the drive rod, an axial hole is arranged on the side wall of the drive cavity, a drive shaft is rotatably arranged in the axial hole, a center tube is arranged in the drive cavity, the center tube is coaxially arranged with the drive shaft, a fixed sleeve is fixed on the center tube, a crank is fixedly arranged on the fixed sleeve, and a driving slide groove is arranged on the crank. The sliding shaft slides in the driving sliding groove, and the driving rod reciprocates and drives the center tube to swing back and forth through the crank. The interior of the driving shaft has a transmission outer cavity and a transmission inner cavity that are connected to each other, and the transmission outer cavity opens toward the driving cavity. The side wall of the transmission outer cavity has an inner tooth portion, and an inner tooth sleeve is embedded in the transmission inner cavity. A transmission groove is provided at the axis of the center tube, and a transmission shaft is slidably arranged in the transmission groove and the center tube rotates synchronously with the transmission shaft. A first gear portion and a second gear portion are fixedly arranged on the transmission shaft at intervals, and the first gear portion is meshed with the inner ring teeth of the inner tooth sleeve, and rolling teeth are meshed between the second gear portion and the inner tooth portion. A telescopic driving device that drives the transmission shaft to slide is also provided inside the center tube, and the transmission shaft is extended to make the second gear portion mesh with the rolling teeth, and the transmission shaft is retracted to disengage the second gear portion from the rolling teeth and make the first gear portion mesh with the inner tooth sleeve.

[0006] A further technical solution is that the inner gear sleeve has a cylindrical cavity, the transmission outer cavity is a conical cavity, the first gear portion is a cylindrical gear, the second gear portion is a bevel gear, and the rolling teeth are cylindrical gears and are respectively meshed with the inner gear portion and the second gear portion; or, the inner gear sleeve and the transmission outer cavity both have conical cavities, and the axes of the two conical cavities coincide, the large openings of the two conical cavities remain consistent and are both facing the drive cavity, and the first gear portion and the second gear portion are both conical gears.

[0007] According to a further technical solution, a spring support plate is arranged on the bottom wall of the transmission cavity, an extrusion spring is arranged inside the spring support plate, one end of the transmission shaft extends into the transmission cavity and abuts against the extrusion spring, and the extrusion spring provides a reset force for the transmission shaft to move away from the bottom wall of the transmission cavity.

[0008] A further technical solution is that a connecting disk is arranged at the opening of the transmission inner cavity, the bottom wall of the connecting disk is attached to the end of the driving shaft, and a circular groove is opened in the center of the bottom wall of the connecting disk, and a plurality of elastic sheets extend inwardly at the edge of the circular groove, the elastic sheets are arranged obliquely and are elastically connected to the bottom wall of the connecting disk, a connecting frame is fixedly arranged on the elastic sheet, a guide shaft is provided in the connecting frame, and the rolling teeth roll freely on the guide shaft.

[0009] A further technical solution is that one end of the connecting disk is a blind cylindrical end, the circular groove is opened in the center of the blind end, a sealing inner cover is sealed at the open mouth of the cylinder, a sealing hole is set in the center of the sealing inner cover, the transmission shaft passes through the sealing hole, and the sealing inner cover isolates the driving cavity and the transmission outer cavity.

[0010] A further technical solution is that the telescopic drive device includes an adjusting shaft and a limiting protrusion fixed at the lower end of the adjusting shaft, the limiting protrusion is arranged in the transmission groove of the center tube, the outer periphery of the limiting protrusion has two rotating disks symmetrically arranged with the radial line of the limiting protrusion as the symmetry center line, the outer peripheral surface of the rotating disk is an arc surface, the drive box is provided with two coaxial axial holes, and a driving shaft is arranged in each of the axial holes, and the ends of the two transmission shafts respectively abut the outer periphery of the limiting protrusion.

[0011] According to a further technical solution, an angle β is formed between the center line of the limiting protrusion and the symmetric center line of the rotating disk, the angle of the arc surface of the limiting protrusion is α, the angle β is 67°, and the angle α is 60°.

[0012] A further technical solution is that the transmission shaft has a threaded head at the end near the rotating disk, the threaded head is externally threaded with a conical head, the conical head has an installation space, the wall of the conical head is provided with a ball hole facing the rotating disk, balls are rolled in the installation space, a locking body is also provided in the installation space, one end of the locking body abuts against the ball so that the ball is exposed through the ball hole and abuts against the outer periphery of the rotating disk.

[0013] A further technical solution is that the central tube is provided with an inner air avoidance groove, the fixed sleeve is provided with an outer air avoidance groove, the inner air avoidance groove and the outer air avoidance groove are aligned and connected, the wall of the drive box is provided with an air avoidance hole, the adjustment shaft passes through the inner air avoidance groove, the outer air avoidance groove and the air avoidance hole from the inside to the outside in sequence, and the outer end of the adjustment shaft extends to the outside of the drive box and is fixedly connected with an adjustment disk.

[0014] A further technical solution is that the drive box is recessed under the positive projection of the adjusting disk to form a locking groove, and a locking sleeve is fixedly installed in the locking groove. An angle limit cylinder is arranged inside the locking sleeve, and the angle limit cylinder is fixedly connected to the adjusting shaft. A plurality of angle limit grooves are circumferentially distributed on the outer circumference of the angle limit cylinder, an annular sleeve is provided at one end of the locking sleeve, and an installation strip is axially extended at the inner ring of the annular sleeve, and the installation strip extends into the movable gap formed between the angle limit cylinder and the locking sleeve. A plurality of the installation strips are circumferentially distributed in the movable gap, and an elastic strip is clamped between two adjacent installation strips. The elastic strip itself is elastic and has a protrusion at the center of the elastic strip that is clamped in the angle limit groove.

[0015] Compared with the prior art, the present invention has the following beneficial effects: In a sprocket fork pneumatic actuator based on modular design of the present invention, the structure of the drive shaft is changed by setting, a transmission outer cavity and a transmission inner cavity are set inside the drive shaft, and a transmission shaft is set, and a first gear part and a second gear part are fixedly set on the transmission shaft, the transmission shaft is extended to make the second gear part mesh with the inner tooth part through the rolling teeth, and the transmission shaft is retracted to make the second gear part disengage from the rolling teeth, and make the first gear part mesh with the inner gear sleeve to realize the switching of synchronous rotation and reverse rotation of the transmission shaft and the drive shaft, and the drive shaft is used to connect the switch valve, which can realize the switching of normally open or open and closed states. For example, the drive shaft is connected to the switch valve in a normally closed state, the device is inflated to drive the transmission shaft to rotate, and the drive shaft and the transmission shaft are switched to reverse rotation to open the switch valve; for another example, the drive shaft is connected to the switch valve in a normally open state, the device is inflated to drive the transmission shaft to rotate, and the drive shaft and the transmission shaft are switched to synchronous rotation to close the switch valve.

[0016] In a slewing fork pneumatic actuator based on modular design of the present invention, two symmetrical driving shafts are set, and two symmetrical transmission shafts are configured, a rotating disk is set between the two transmission shafts, and the rotating disk has two symmetrically distributed limiting protrusions. As the rotating disk rotates, the rotating disk and the transmission shaft abut against each other to form four working states, and can simultaneously adjust the normally open or normally closed state of the two switch valves, for example, the left switch valve is normally open, and the right switch valve is normally closed; the left switch valve is normally closed, and the right switch valve is normally open; the left switch valve is normally closed, and the right switch valve is normally closed; the left switch valve is normally open, and the right switch valve is normally closed, and the left switch valve is normally open, which can adapt to different working conditions.

[0017] In a slewing fork pneumatic actuator based on modular design of the present invention, the drive box has a standard joint, the cylinder body has a standard interface, the interface is modularly standardized in design, has strong versatility, and is convenient for replacing cylinder bodies of different models; the drive box of the device has a pneumatic hole, and the pneumatic generator is connected to the pneumatic hole to fill the drive box with positive pressure gas to prevent external gas and dust from entering the drive cavity and enhance the sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure inside the drive box 10 of the present invention; Figure 3 It is a schematic diagram of the structure of the crank 20, the sliding shaft 19, and the driving rod 18 in the driving box 10 of the present invention; Figure 4 It is a schematic diagram of the internal structure of the cylinder body 11 in the present invention; Figure 5 yes Figure 1 A cross-sectional view is formed by cutting along the axis of the cylinder body 11; Figure 6 yes Figure 1 A cross-sectional view is formed by cutting along the axis of the drive shaft 12; Figure 7 It is a schematic diagram of the internal structure of the drive shaft 12 in the present invention; Figure 8 yes Figure 7 The schematic diagram of the structure after the transmission shaft 29 is removed; Fig. 9 is an exploded view of the drive shaft 12 of the present invention; Fig.10 yes Fig. 9 An enlarged schematic diagram of the structure of the middle connecting plate 37; Fig.11 yes Figure 6 An enlarged schematic diagram of the structure at the middle connecting plate 37; Fig.12 It is a schematic diagram of the structure of the rotating disk 42 and the conical head 52 in the present invention; Fig.13 It is a schematic diagram of the structure of the angle limiting cylinder 46 in the present invention; Fig.14 These are four working states of the cooperation between the conical head 52 and the rotating disk 42 in the present invention.

[0021] Description of reference numerals: Drive box 10, cylinder body 11, drive shaft 12, mounting plate 13, drive chamber 14, standard joint 15, shaft hole 16, center guide shaft 17, drive rod 18, slide shaft 19, crank 20, piston 21, return spring 22, sealing end cover 23, fixing sleeve 24, air leakage hole 25, pneumatic hole 26, center tube 27, adjustment plate 28, transmission shaft 29, ball 30, second gear part 31, connecting shaft 32, first gear part 33, inner gear sleeve 34, extrusion spring 35, spring support plate 36, connecting plate 37 , sealed inner cover 38, connecting frame 39, rolling teeth 40, circular groove 41, rotating disk 42, center hole 43, limiting protrusion 44, locking sleeve 45, angular limiting cylinder 46, elastic strip 47, connecting hole 48, mounting strip 49, angular limiting groove 50, movable gap 51, conical head 52, threaded head 53, locking body 54, transmission inner cavity 55, transmission outer cavity 56, inner tooth portion 57, sealing hole 58, adjusting shaft 60, annular sleeve 61, standard interface 62, driving slide groove 63, elastic sheet 64, outer avoidance groove 65. DETAILED DESCRIPTION

[0022] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] See attached Figure 1-14 The present invention provides a scotch fork pneumatic actuator based on modular design, such as Figure 1-5As shown, it includes a drive box 10 and a cylinder body 11, the drive box 10 has a drive chamber 14, the drive chamber 14 has a standard joint 15, one end of the cylinder body 11 has a standard interface 62, the standard joint 15 and the standard interface 62 are detachably connected to make the drive chamber 14 communicate with the inner chamber of the cylinder body 11, a piston 21 is slidably arranged in the cylinder body 11, a return spring 22 is arranged on the side of the piston 21 away from the drive chamber 14, the two ends of the return spring 22 are respectively connected to the piston 21 and the inner wall of the cylinder body 11, and a pneumatic hole 26 is provided at the end of the cylinder body 11 away from the drive chamber 14, and the piston A driving rod 18 is fixedly arranged on one side of the driving chamber 14, a sliding shaft 19 is fixedly arranged on the end of the driving rod 18, an axial hole 16 is provided on the side wall of the driving chamber 14, and the driving shaft 12 is rotatably arranged in the axial hole 16. The driving chamber 14 is provided with a central cylinder 27, and the central cylinder 27 is coaxially arranged with the driving shaft 12. The central cylinder 27 is fixedly sleeved with a fixing sleeve 24, and a crank 20 is fixedly arranged on the fixing sleeve 24. A driving slide groove 63 is provided on the crank 20, and the sliding shaft 19 slides in the driving slide groove 63. The driving rod 18 reciprocates and drives the central cylinder 27 to swing back and forth through the crank 20. Figure 5-10 As shown, the interior of the drive shaft 12 has a transmission outer cavity 56 and a transmission inner cavity 55 which are interconnected. The transmission outer cavity 56 opens toward the drive cavity 14. The side wall of the transmission outer cavity 56 has an inner tooth portion 57. The transmission inner cavity 55 is embedded with an inner tooth sleeve 34. A transmission groove is opened at the axis of the center tube 27. The transmission shaft 29 is slidably arranged in the transmission groove and the center tube 27 rotates synchronously with the transmission shaft 29. The first gear portion 33 and the second gear portion 31 are fixedly arranged on the transmission shaft 29 at intervals. The first gear portion 33 is meshed with the inner ring teeth of the inner tooth sleeve 34. The rolling teeth 40 are meshed between the second gear portion 31 and the inner tooth portion 57. A telescopic driving device for driving the transmission shaft 29 to slide is also arranged inside the center tube 27. The transmission shaft 29 is extended to allow the second gear portion 31 to mesh with the inner tooth portion 57 through the rolling teeth 40. The transmission shaft 29 is retracted to disengage the second gear portion 31 from the rolling teeth 40 and to allow the first gear portion 33 to mesh with the inner tooth sleeve 34.

[0026] In specific implementation, mounting plates 13 are symmetrically arranged on both sides of the drive box 10, and the mounting plates 13 have a rectangular positioning plane. The positioning surfaces of the two mounting plates 13 are parallel to each other, and a plurality of standard positioning holes are opened on the positioning plane. A through hole is provided at the center of the mounting plate 13, and the through hole is coaxial and connected with the shaft hole 16. The drive shaft 12 passes through the shaft hole 16 and the through hole of the mounting plate 13 from the inside to the outside in turn and extends to the outside of the drive box 10, and the exposed portion of the drive shaft 12 is interconnected with the valve to be operated.

[0027] In this embodiment, the cylinder body 11 is a cylinder with openings at both ends, one end of the cylinder is sealed with a sealing end cover 23, the other end of the cylinder is close to the drive box 10 and has a standard interface 62, a central guide shaft 17 is arranged inside the cylinder body 11, one end of the central guide shaft 17 is fixedly connected to the sealing end cover 23, the other end of the central guide shaft 17 extends into the drive chamber 14 and is fixedly connected to the inner wall of the drive chamber 14, the central guide shaft 17 is located at the axis of the cylinder body 11, the drive rod 18 deviates from the axis of the cylinder body 11, and the drive rod 18 and the central guide shaft 17 are arranged at the axis of the cylinder body 11. The two guide shafts 17 are parallel to each other and form a gap. A protrusion is provided at the end of the driving rod 18 away from the piston 21. A first sliding hole is provided on the protrusion. The center guide shaft 17 passes through the sliding hole and slides therein. A second sliding hole is provided at the axis of the piston 21. The center guide shaft 17 passes through the second sliding hole and slides therein. The piston 21 slides in the cylinder body 11, and the center guide shaft 17 plays a guiding role. Similarly, the protrusion of the driving rod 18 slides on the center guide shaft 17, and the center guide shaft 17 plays a guiding role for the driving rod 18.

[0028] In this embodiment, a pneumatic hole 26 is provided on the sealing end cover 23, and an air leakage hole 25 is provided on the wall of the drive box 10. The pneumatic device is connected to the pneumatic hole 26 through a pipeline to realize the action of inflating or deflating the cylinder body 11, thereby pushing the piston 21 to slide back and forth inside the cylinder body 11, and the reset spring 22 plays a reset role. The inside of the drive chamber 14 maintains a positive pressure to prevent external gas and dust from entering the inside of the drive chamber 14, and the gas inside the cylinder body 11 is leaked to the outside through the air leakage hole 25. In specific implementation, the diameter of the piston 21 is smaller than the inner diameter of the cylinder body 11, so that a movable gap is formed between the piston 21 and the cylinder body 11, and the outer peripheral surface of the piston 21 is concave to form an annular groove, and an elastic sealing ring is arranged in the annular groove, and the elastic sealing ring contacts the inner surface of the cylinder body 11 to seal.

[0029] Preferably, the inner gear sleeve 34 has a cylindrical cavity, the transmission outer cavity 56 is a conical cavity, the first gear portion 33 is a cylindrical gear, the second gear portion 31 is a bevel gear, and the rolling teeth 40 are cylindrical gears and mesh with the inner gear portion 57 and the second gear portion 31 respectively.

[0030] In other embodiments of the present application, the inner gear sleeve 34 and the transmission outer cavity 56 both have conical cavities, and the axes of the two conical cavities coincide, the large openings of the two conical cavities are oriented consistently toward the drive cavity 14, and the first gear portion 33 and the second gear portion 31 are both conical gears.

[0031] Preferably, a spring support plate 36 is provided on the bottom wall of the transmission cavity 55, and an extrusion spring 35 is provided in the spring support plate 36. One end of the transmission shaft 29 extends into the transmission cavity 55 and abuts against the extrusion spring 35. The extrusion spring 35 provides a reset force for the transmission shaft 29 to move away from the bottom wall of the transmission cavity 55.

[0032] Preferably, Fig.11 As shown, a connecting disk 37 is provided at the opening of the transmission inner cavity 55, the bottom wall of the connecting disk 37 is attached to the end of the driving shaft 12, and a circular groove 41 is provided at the center of the bottom wall of the connecting disk 37, and a plurality of elastic sheets 64 extend inwardly from the edge of the circular groove 41, the elastic sheets 64 are inclinedly arranged and elastically connected to the bottom wall of the connecting disk 37, a connecting frame 39 is fixedly arranged on the elastic sheet 64, a guide shaft is provided in the connecting frame 39, and the rolling teeth 40 roll freely on the guide shaft.

[0033] Preferably, one end of the connecting disk 37 is a blind cylindrical end, a circular groove 41 is provided at the center of the blind end, a sealing inner cover 38 is sealed and installed at the cylindrical opening, a sealing hole 58 is provided at the center of the sealing inner cover 38, the transmission shaft 29 passes through the sealing hole 58, and the sealing inner cover 38 isolates the driving chamber 14 and the transmission outer chamber 56.

[0034] Preferably, the telescopic drive device includes an adjusting shaft 60 and a limiting protrusion 44 fixed at the lower end of the adjusting shaft 60, the limiting protrusion 44 is arranged in the transmission groove of the center tube 27, the outer periphery of the limiting protrusion 44 has two rotating disks 42 symmetrically arranged with the radial line of the limiting protrusion 44 as the symmetry center line, the outer peripheral surface of the rotating disk 42 is an arc surface, the drive box 10 is provided with two coaxial axial holes 16, and a driving shaft 12 is arranged in each axial hole 16, and the ends of the two transmission shafts 29 respectively abut the outer periphery of the limiting protrusion 44.

[0035] Specifically, the center of the rotating disk 42 has a center hole 43, the adjusting shaft 60 extends into the center hole 43, the inner wall of the center hole 43 is recessed to form a positioning groove, the outer wall of the adjusting shaft 60 has a positioning key, the positioning key is stuck in the positioning groove, and the adjusting shaft 60 and the rotating disk 42 can rotate synchronously.

[0036] Preferably, Fig.12 As shown, the midline of the limiting protrusion 44 and the symmetric centerline of the rotating disk 42 form an angle β, the angle of the arc surface of the limiting protrusion 44 is α, the angle β is 67°, and the angle α is 60°.

[0037] In this embodiment, as the rotating disk 42 rotates, the rotating disk 42 abuts against the ends of the two transmission shafts 29 respectively. The rotating disk 42 is at different angles and has corresponding functions. It has four working states in total, such as Fig.14 As shown, for the convenience of description, the two symmetrical transmission shafts 29 are respectively named as the left transmission shaft 29 and the right transmission shaft 29 .

[0038] Working status A: Fig.14 As shown in (a), the left transmission shaft 29 and the right transmission shaft 29 are extended at the same time, and the left and right drive shafts 12 rotate in opposite directions relative to the center tube 27; Working status B: Fig.14 As shown in (b), the left transmission shaft 29 extends, the right transmission shaft 29 retracts, the left drive shaft 12 rotates in the opposite direction relative to the center tube 27, and the right transmission shaft 29 rotates synchronously relative to the center tube 27; Working status C: Fig.14 As shown in (c), the left transmission shaft 29 is retracted, the right transmission shaft 29 is extended, the left drive shaft 12 rotates synchronously with respect to the center tube 27, and the right transmission shaft 29 rotates in the opposite direction with respect to the center tube 27; Working status D: Fig.14 As shown in (d), the left transmission shaft 29 and the right transmission shaft 29 are retracted at the same time, and the left and right drive shafts 12 rotate synchronously relative to the central tube 27.

[0039] Preferably, the end of the transmission shaft 29 close to the rotating disk 42 has a threaded head 53, and the external thread of the threaded head 53 is provided with a conical head 52, and the conical head 52 has an installation space. The wall of the conical head 52 is provided with a ball hole facing the rotating disk 42, and the ball 30 is rolledly arranged in the installation space. A locking body 54 is also arranged in the installation space, and one end of the locking body 54 abuts against the ball 30 so that the ball 30 is exposed through the ball hole and abuts against the outer periphery of the rotating disk 42.

[0040] In this embodiment, the first gear portion 33 and the second gear portion 31 are fixedly connected by a connecting shaft 32, and a second shaft is fixedly connected to the axis of the second gear portion 31. The end of the second shaft has a threaded head 53, the inner wall of the conical head 52 has an internal thread, and the outer wall of the locking body 54 has an external thread. The locking body 54 and the conical head 52 are fastened by threads, and the locking body 54 itself is elastic. The surface of the locking body 54 in contact with the ball 30 is a concave arc surface to increase the support surface for the ball 30 and improve the stability of the ball 30.

[0041] Preferably, the center tube 27 has an inner air avoidance groove, the fixed sleeve 24 has an outer air avoidance groove 65, the inner air avoidance groove and the outer air avoidance groove 65 are aligned and connected, the wall of the drive box 10 has an air avoidance hole, the adjustment shaft 60 passes through the inner air avoidance groove, the outer air avoidance groove 65 and the air avoidance hole from the inside to the outside in sequence, and the outer end of the adjustment shaft 60 extends to the outside of the drive box 10 and is fixedly connected to the adjustment disk 28.

[0042] Preferably, Fig.13As shown, the drive box 10 is concave under the positive projection of the adjustment disk 28 to form a locking groove, a locking sleeve 45 is fixedly installed in the locking groove, an angle limit cylinder 46 is arranged inside the locking sleeve 45, the angle limit cylinder 46 is fixedly connected to the adjustment shaft 60, a plurality of angle limit grooves 50 are distributed circumferentially on the outer circumference of the angle limit cylinder 46, an annular sleeve 61 is sleeved on one end of the locking sleeve 45, a mounting strip 49 is axially extended at the inner ring of the annular sleeve 61, the mounting strip 49 extends into the active gap 51 formed between the angle limit cylinder 46 and the locking sleeve 45, a plurality of mounting strips 49 are distributed circumferentially in the active gap 51, an elastic strip 47 is clamped between two adjacent mounting strips 49, the elastic strip 47 itself is elastic and has a protrusion at the center of the elastic strip 47 that is clamped in the angle limit groove 50. Specifically, a connecting hole 48 is provided at the center of the angle limit cylinder 46, and the adjustment shaft 60 extends into the connecting hole 48 and is fixedly connected to the connecting hole 48.

[0043] In this embodiment, the outer wall surface of the standard joint 15 is concave to form a sealing groove for filling the sealing ring, and the outer wall surface of the drive shaft 12 is concave to form a plurality of annular grooves distributed at intervals, and the annular grooves are filled with sealing rings, and the outer edge of the sealing ring abuts against the inner wall of the shaft hole 16 to seal. A sealing ring is arranged between the sealing end cover 23 and the inner wall of the cylinder body 11.

[0044] Working process of the present invention: The pneumatic device is connected to the pneumatic hole 26 through a pipeline, inflates or deflates the inside of the cylinder body 11, and cooperates with the return spring 22 to push the piston 21 to move back and forth in the cylinder body 11. The piston 21 drives the sliding shaft 19 to move through the driving rod 18. The sliding shaft 19 slides in the driving slide groove 63 and pushes the crank 20 to swing back and forth. The crank 20 drives the center tube 27 to swing through the fixed sleeve 24, and the fixed sleeve 24 drives the center tube 27 to swing synchronously.

[0045] In a natural state, the return spring 22 pushes the piston 21 to approach the drive chamber 14 . When air is inflated into the cylinder 11 , the return spring 22 is squeezed, and the piston 21 slides in the cylinder 11 in a direction away from the drive chamber 14 .

[0046] When the outer peripheral surface of the limiting protrusion 44 abuts against the ball 30, the transmission shaft 29 is pushed outward so that the first gear portion 33 disengages from the meshing with the inner gear sleeve 34 and the second gear portion 31 meshes with the rolling teeth 40. The transmission shaft 29 drives the second gear portion 31 to rotate, and the second gear portion 31 drives the rolling teeth 40 to rotate. The rolling teeth 40 mesh with the inner gear portion 57 and drive the drive shaft 12 to rotate, so that the rotation of the drive shaft 12 is opposite to the rotation of the center tube 27.

[0047] When the concave surface of the outer circumference of the rotating disk 42 abuts against the ball 30, the transmission shaft 29 is pushed by the extrusion spring 35 to disengage the second gear portion 31 from the rolling tooth 40, and the first gear portion 33 and the inner gear sleeve 34 engage with each other. At this time, the rotation of the drive shaft 12 is synchronized with the rotation of the center tube 27.

[0048] According to actual needs, the adjusting disk 28 is manually rotated, and the adjusting disk 28 drives the angle limit cylinder 46 to rotate through the adjusting shaft 60. During the rotation process, the outer periphery of the angle limit cylinder 46 squeezes the elastic strip 47 until the elastic strip 47 is stuck in the angle limit groove 50 to limit the angle between the angle limit cylinder 46 and the adjusting shaft 60. The adjusting shaft 60 drives the rotating disk 42 to rotate to reach a preset angle, such as Fig.14 , according to needs, it is adjusted to the required working state to configure the rotation direction of the left and right drive shafts 12, for example: the left drive shaft 12 and the right drive shaft 12 rotate forward synchronously, the left drive shaft 12 and the right drive shaft 12 rotate reversely synchronously, the left drive shaft 12 rotates forward and the right drive shaft 12 rotates reversely, the left drive shaft 12 rotates reversely and the right drive shaft 12 rotates forward; in this way, after the two drive shafts 12 are connected to the two switch valves, the switch states of the two valves can be controlled.

[0049] Taking a common on-off valve as an example, the on-off valve is closed when it rotates forward and opened when it rotates reversely.

[0050] Rotate the adjustment disk 28 to put the device in working state A. When the pneumatic hole 26 is not charged with air, the two drive shafts 12 control the two switch valves to be in a normally closed state. Only when the pneumatic hole 26 is charged with air, the two drive shafts 12 can simultaneously rotate in the opposite direction to open the two switch valves at the same time. Rotate the adjustment disk 28 to put the device in working state B. When no air is charged into the pneumatic hole 26, the left drive shaft 12 controls the left switch valve to be in a normally closed state, and the right drive shaft 12 controls the right switch valve to be in a normally open state; after charging, the left drive shaft 12 rotates in reverse to open the left switch valve, and the right drive shaft 12 rotates forward to close the right switch valve; Rotate the adjustment disk 28 to put the device in working state C. When no air is charged into the pneumatic hole 26, the left drive shaft 12 controls the left switch valve to be in a normally open state, and the right drive shaft 12 controls the right switch valve to be in a normally closed state; after charging, the left drive shaft 12 rotates forward to close the left switch valve, and the right drive shaft 12 rotates reversely to open the right switch valve; Rotate the adjustment disk 28 to put the device in working state D. When the pneumatic hole 26 is not filled with air, the two drive shafts 12 control the two switch valves to be in a normally open state. Only when the pneumatic hole 26 is filled with air can the two drive shafts 12 rotate forward at the same time to close the two switch valves at the same time.

[0051] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A scotch fork pneumatic actuator based on modular design, comprising a drive box and a cylinder body, characterized in that: The drive box has a drive chamber, the drive chamber has a standard joint, one end of the cylinder body has a standard interface, the standard joint and the standard interface are detachably connected to make the drive chamber communicate with the inner chamber of the cylinder body, a piston is slidably arranged in the cylinder body, a return spring is arranged on the side of the piston away from the drive chamber, the two ends of the return spring are respectively connected to the piston and the inner wall of the cylinder body, a pneumatic hole is arranged at the end of the cylinder body away from the drive chamber, a drive rod is fixedly arranged on the side of the piston facing the drive chamber, a sliding shaft is fixedly arranged at the end of the drive rod, an axial hole is arranged on the side wall of the drive chamber, and a drive shaft is rotatably arranged in the axial hole, a center tube is arranged in the drive chamber, the center tube is coaxially arranged with the drive shaft, a fixed sleeve is fixed on the center tube, a crank is fixedly arranged on the fixed sleeve, a drive groove is arranged on the crank, and the sliding shaft slides in the drive groove. The reciprocating motion of the driving rod drives the center tube to swing back and forth through the crank, and the interior of the driving shaft has a transmission outer cavity and a transmission inner cavity that are interconnected, the transmission outer cavity opens toward the driving cavity, the side wall of the transmission outer cavity has an inner tooth portion, and an inner tooth sleeve is embedded in the transmission inner cavity, a transmission groove is provided at the axis center of the center tube, a transmission shaft is slidably arranged in the transmission groove and the center tube rotates synchronously with the transmission shaft, a first gear portion and a second gear portion are fixedly arranged on the transmission shaft at intervals, the first gear portion is meshed with the inner ring teeth of the inner tooth sleeve, and rolling teeth are meshed between the second gear portion and the inner tooth portion, and a telescopic driving device for driving the transmission shaft to slide is also provided inside the center tube, the transmission shaft is extended to make the second gear portion mesh with the rolling teeth, and the transmission shaft is retracted to disengage the second gear portion from the rolling teeth and make the first gear portion mesh with the inner tooth sleeve.

2. The scotch yoke pneumatic actuator based on modular design according to claim 1, characterized in that: The inner gear sleeve has a cylindrical cavity, the transmission outer cavity is a conical cavity, the first gear portion is a cylindrical gear, the second gear portion is a bevel gear, and the rolling teeth are cylindrical gears and mesh with the inner gear portion and the second gear portion respectively; Alternatively, the inner gear sleeve and the transmission outer cavity both have conical cavities, and the axes of the two conical cavities coincide, the large openings of the two conical cavities remain consistent in direction and both face the drive cavity, and the first gear portion and the second gear portion are both conical gears.

3. The scotch fork pneumatic actuator based on modular design according to claim 1, characterized in that: A spring support plate is arranged on the bottom wall of the transmission cavity, and an extrusion spring is arranged in the spring support plate. One end of the transmission shaft extends into the transmission cavity and abuts against the extrusion spring, and the extrusion spring provides a restoring force for the transmission shaft to move away from the bottom wall of the transmission cavity.

4. The scotch yoke pneumatic actuator based on modular design according to claim 1, characterized in that: A connecting disk is arranged at the opening of the transmission inner cavity, the bottom wall of the connecting disk is attached to the end of the driving shaft, and a circular groove is opened in the center of the bottom wall of the connecting disk, and a plurality of elastic sheets extend inwardly at the edge of the circular groove, the elastic sheets are arranged obliquely and are elastically connected to the bottom wall of the connecting disk, a connecting frame is fixedly arranged on the elastic sheet, a guide shaft is provided in the connecting frame, and the rolling teeth roll freely on the guide shaft.

5. The scotch yoke pneumatic actuator based on modular design according to claim 4, characterized in that: One end of the connecting disk is a blind cylindrical end, the circular groove is provided at the center of the blind end, a sealing inner cover is sealed at the cylindrical opening, a sealing hole is provided at the center of the sealing inner cover, the transmission shaft passes through the sealing hole, and the sealing inner cover isolates the driving cavity and the transmission outer cavity.

6. The scotch yoke pneumatic actuator based on modular design according to claim 1, characterized in that: The telescopic driving device includes an adjusting shaft and a limiting protrusion fixed at the lower end of the adjusting shaft, the limiting protrusion is arranged in the transmission groove of the center tube, the outer periphery of the limiting protrusion has two rotating disks symmetrically arranged with the radial line of the limiting protrusion as the symmetry center line, the outer peripheral surface of the rotating disk is an arc surface, the driving box is provided with two coaxial shaft holes, and a driving shaft is arranged in each of the shaft holes, and the ends of the two transmission shafts respectively abut the outer periphery of the limiting protrusion.

7. The scotch yoke pneumatic actuator based on modular design according to claim 6, characterized in that: An angle β is formed between the midline of the limiting protrusion and the symmetric centerline of the rotating disk, the angle of the arc surface of the limiting protrusion is α, the angle β is 67°, and the angle α is 60°.

8. The scotch yoke pneumatic actuator based on modular design according to claim 6, characterized in that: The transmission shaft has a threaded head at the end near the rotating disk, and a conical head is provided on the external thread of the threaded head. An installation space is provided in the conical head. A ball hole is provided on the wall of the conical head facing the rotating disk. A ball is arranged to roll in the installation space. A locking body is also provided in the installation space, and one end of the locking body abuts against the ball so that the ball is exposed through the ball hole and abuts against the outer periphery of the rotating disk.

9. The scotch yoke pneumatic actuator based on modular design according to claim 6, characterized in that: The central tube has an inner air avoidance groove, the fixed sleeve has an outer air avoidance groove, the inner air avoidance groove and the outer air avoidance groove are aligned and connected, the wall of the drive box has an air avoidance hole, the adjustment shaft passes through the inner air avoidance groove, the outer air avoidance groove and the air avoidance hole from the inside to the outside in sequence, and the outer end of the adjustment shaft extends to the outside of the drive box and is fixedly connected with an adjustment disk.

10. The scotch yoke pneumatic actuator based on modular design according to claim 9, characterized in that: The drive box is recessed under the positive projection of the adjusting disk to form a locking groove, a locking sleeve is fixedly installed in the locking groove, an angular limit cylinder is arranged inside the locking sleeve, the angular limit cylinder is fixedly connected to the adjusting shaft, a plurality of angular limit grooves are circumferentially distributed on the outer circumference of the angular limit cylinder, an annular sleeve is sleeved on one end of the locking sleeve, a mounting strip is axially extended at the inner ring of the annular sleeve, the mounting strip extends into the movable gap formed between the angular limit cylinder and the locking sleeve, a plurality of the mounting strips are circumferentially distributed in the movable gap, an elastic strip is clamped between two adjacent mounting strips, the elastic strip itself is elastic and a protrusion clamped in the angular limit groove is provided at the center of the elastic strip.

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