CN211203084U

CN211203084U - Pneumatic film top-mounted positive-acting hand wheel mechanism

Info

Publication number: CN211203084U
Application number: CN201921803338.5U
Authority: CN
Inventors: 梁万顺; 马龙; 闫昊; 姬晓鹏
Original assignee: Ningxia Wuzhong Shenghui Instrument Co ltd
Current assignee: Ningxia Wuzhong Shenghui Instrument Co ltd
Priority date: 2019-10-25
Filing date: 2019-10-25
Publication date: 2020-08-07
Anticipated expiration: 2029-10-25

Abstract

The utility model discloses a pneumatic membrane top-mounting positive-acting hand wheel mechanism, which comprises a frame, a hand wheel, a screw nut, a lead screw and an anti-rotation part, wherein the frame is arranged at the top of an upper membrane cover and is internally provided with a mounting hole which is communicated with the upper end surface and the lower end surface; the bottom end of the lead screw is provided with an insertion hole along the axial direction. The pneumatic film actuator is characterized by further comprising a positive action push rod inserted into the insertion hole, a step surface is arranged on the periphery of the positive action push rod, the step surface is abutted and pressed by the bottom end of the lead screw, and the bottom of the positive action push rod faces towards the pneumatic push rod in the pneumatic film actuator. Through the thread structure pair, the screw rod pushes the positive action push rod and the pneumatic push rod downwards in sequence, so that the pneumatic valve is closed; when the screw rod moves upwards, the pneumatic membrane actuator automatically resets due to the elastic device arranged in the lower membrane chamber, and the pneumatic valve is opened. Has the characteristics of simple structure, safety and reliability.

Description

Pneumatic film top-mounted positive-acting hand wheel mechanism

Technical Field

The utility model belongs to the technical field of pneumatic control valve, especially, relate to a pneumatic control valve's adjustment mechanism specifically is pneumatic film top mounted positive effect hand wheel mechanism.

Background

The pneumatic membrane actuating mechanism is an important component for starting the regulating valve, is simple in structure, reliable in action, convenient to maintain and low in cost, is widely applied and is divided into a positive action execution mode and a reverse action execution mode. Conventional hand wheel mechanism adopts lead screw nut transmission structure, the screw is directly processed on the frame, when rotating the hand wheel dish, drive the rotatory up-and-down motion that realizes of lead screw, thereby realize opening or closing of valve, current hand wheel mechanism and in the environment of locating, often accompany high temperature and corruption, and the transmission lead screw directly exposes in the air, hand wheel mechanism does not move the use for a long time, lead screw surface receives the corruption and the rust of environmental medium easily, hand wheel mechanism's lead screw nut structure when the valve breaks down, the phenomenon of dying often appears stinging, the valve can't be opened or close through manual mode at the key moment, the potential safety hazard is great.

SUMMERY OF THE UTILITY MODEL

The utility model discloses, be exactly in order to solve among the prior art pneumatic film top loading normal effect hand wheel mechanism the phenomenon of dying of stinging that lead screw appears because of the corruption of environment, provide a simple structure, the strong pneumatic film top loading normal effect hand wheel mechanism of maneuverability.

In order to realize the purpose, the utility model discloses a technical scheme is: a pneumatic film top-mounted positive-acting hand wheel mechanism is used for a pneumatic film actuator of a pneumatic valve and comprises a base arranged at the top of an upper film cover, wherein a mounting hole penetrating through the upper end surface and the lower end surface of the base is formed in the base;

the screw rod is axially arranged in the screw nut and is in threaded fit with the screw nut to form a threaded structure pair, and an anti-rotation part is used for preventing the screw rod from rotating around the axial direction; the bottom end of the lead screw is provided with an insertion hole along the axial direction;

the pneumatic film actuator is characterized by further comprising a positive action push rod, the upper portion of the positive action push rod is inserted into the insertion hole, a step surface is arranged on the lower portion of the positive action push rod and is pressed against the bottom end of the lead screw, and the bottom of the positive action push rod is inserted into the pneumatic film actuator through the top of the pneumatic film actuator and faces the pneumatic push rod in the pneumatic film actuator; through the thread structure pair, the screw rod pushes the positive push rod downwards, the positive push rod further pushes the pneumatic push rod downwards, so that the pneumatic valve is closed, and when the screw rod moves upwards, the pneumatic film actuator pushes the positive push rod upwards due to the fact that the elastic device installed in the lower film chamber automatically resets, and the pneumatic valve is opened.

Furthermore, a first annular notch is formed in the inner side of the bottom end of the mounting hole, the anti-rotation part is of a tubular structure, at least the upper portion of an inner hole of the anti-rotation part is a first polygonal hole, the lower portion of the outer wall of the lead screw is located in the first polygonal hole and matched with the inner wall of the first polygonal hole, the anti-rotation part is located in the first annular notch, the top wall of the first annular notch of the anti-rotation part is tightly pressed on the top of the pneumatic film actuator, the anti-rotation part is tightly pressed until the anti-rotation part cannot rotate around the axial direction along with the lead screw, and the radial size of the inner hole of the anti-rotation part is larger than the radial size of the positive.

Furthermore, a through hole penetrating through the upper end face and the lower end face of the hand wheel is axially formed in the hand wheel, the upper portion of the through hole is a second polygonal hole, the upper portion of the nut extends into the second polygonal hole and continues to extend upwards to extend out of the through hole, and the nut is provided with an outer wall matched with the inner wall of the second polygonal hole.

Furthermore, the outer wall of the nut above the through hole is provided with an external thread; the dustproof end cover is buckled at the top of the through hole, an inner thread matched with an outer thread of the nut is arranged on the inner wall of the dustproof end cover, and the bottom end face of the dustproof end cover is located on the top end face of the through hole and is in sealing fit with the top end face of the through hole; a second annular notch is formed in the inner side of the end face of the bottom of the through hole of the hand wheel, the upper portion of the base is inserted into the second annular notch, and a sealing ring is arranged between the outer wall of the base and the inner wall of the second annular notch. In order to reduce the rotating friction resistance, furthermore, a first annular flange is arranged on the inner wall of the mounting hole in the circumferential direction, a first one-way thrust ball bearing is arranged at the top of the first annular flange, and the top end face of the first one-way thrust ball bearing is in contact with the top wall of the annular gap. Still further, the outer wall of the bottom end of the nut is circumferentially provided with a second annular flange, the second annular flange is located below the first annular flange, a second one-way thrust ball bearing is placed between the first annular flange and the second annular flange, and the upper end face of the second one-way thrust ball bearing is in contact with the bottom end face of the first flange.

Further, the outer wall bottom of frame is equipped with third annular flange, evenly be equipped with first internal thread hole around circumference on the third annular flange, pneumatic film actuator's top seted up with first internal thread matched with second internal thread hole, the frame is through wearing to establish the bolt and nut subassembly fixed sealing connection in first internal thread hole and the second internal thread hole simultaneously.

Furthermore, the pneumatic film actuator comprises an upper film cover, a film sheet and a lower film cover which are arranged from top to bottom, the upper film cover and the film sheet enclose an upper film chamber, the film sheet and the lower film cover enclose a lower film chamber, the lower film chamber is internally provided with the elastic device and the pneumatic push rod, the pneumatic push rod is fixedly and hermetically connected with the film sheet, the top of the upper film cover is provided with a through hole penetrating through the upper end surface and the lower end surface of the upper film cover, and two ends of the elastic device are respectively elastically abutted against the film sheet and the lower film cover; the upper membrane cover is provided with an air inlet hole for communicating the air inlet pipe with the upper membrane chamber, and the lower membrane cover is provided with an air outlet hole for communicating the lower membrane chamber with the atmosphere; when the valve is closed, the lower part of the positive action push rod enters the upper membrane chamber through the through hole, and then the pneumatic push rod is pushed downwards. Compared with the prior art, the utility model discloses the technological effect who gains does: the pneumatic control valve has the characteristics of simple structure and strong operability, the transmission screw is arranged inside the screw nut and prevented from being exposed in the air, so that the surface of the screw nut is greatly prevented from being corroded by an environment medium and getting rusted, the phenomenon of seizure between the screw nut and the screw nut is avoided, the normal opening and closing of the pneumatic control valve is ensured, and the production safety is ensured.

Drawings

Fig. 1 is a schematic structural view of a hand wheel mechanism for positive action of pneumatic film top mounting in the embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a hand wheel in the pneumatic membrane top-loading positive-acting hand wheel mechanism in the embodiment of the present invention.

Fig. 3 is a schematic structural diagram (overlooking direction) of a hand wheel in the pneumatic membrane top-loading positive-acting hand wheel mechanism in the embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a nut in a pneumatic membrane top-loading positive-acting hand wheel mechanism in an embodiment of the present invention.

Fig. 5 is a schematic structural diagram (in a top view direction) of a nut in a pneumatic membrane top-loading positive-acting hand wheel mechanism according to an embodiment of the present invention.

Fig. 6 is a schematic structural view of an anti-rotation member in the hand wheel mechanism for pneumatic film top-loading positive action according to the embodiment of the present invention.

Fig. 7 is a schematic structural view (in a top view direction) of an anti-rotation member in a hand wheel mechanism for pneumatic membrane top-loading normal action according to an embodiment of the present invention.

Fig. 8 is a schematic structural view of a screw rod in a pneumatic membrane top-mounted positive-acting handwheel mechanism in an embodiment of the present invention.

Fig. 9 is a schematic structural diagram (in a top view direction) of a lead screw in a pneumatic membrane top-loading positive-acting handwheel mechanism according to an embodiment of the present invention.

Fig. 10 is a schematic structural diagram of a frame in a pneumatic membrane top-loading positive-acting handwheel mechanism according to an embodiment of the present invention.

Fig. 11 is a schematic structural view of a positive action push rod in a pneumatic membrane top-mounted positive action hand wheel mechanism according to an embodiment of the present invention.

FIG. 12 is a schematic structural view of a pneumatic membrane top mounted reaction hand wheel structure.

FIG. 13 is a schematic diagram of a reaction push rod in a pneumatic membrane top-loading reaction hand wheel configuration.

The reference numbers in the figures are: 1. the pneumatic diaphragm actuator comprises a pneumatic diaphragm actuator, 101, a pneumatic push rod, 102, a lower diaphragm chamber, 103, an elastic device, 104, an upper diaphragm cover, 105, a diaphragm, 106, a lower diaphragm cover, 107, an upper diaphragm chamber, 201, a base, 201-1, a first annular notch, 201-2, a first annular flange, 201-3, a third annular flange, 202, a hand wheel, 202-1, a second polygonal hole, 202-2, a second annular notch, 203, a nut, 203-1, a second annular flange, 204, a screw rod, 204-1, an insertion hole, 205, an anti-rotation piece, 205-1, a first polygonal hole, 206, a positive action push rod, 206-1, a step surface, 207, a dust-proof end cover, 208, a sealing ring, 209, a first one-way thrust ball bearing, 2010, a second one-way thrust ball bearing, 2011 and a locking nut.

Detailed Description

The utility model discloses not confine the following embodiment to, general technical personnel in this field can adopt other multiple embodiment to implement according to the utility model discloses a, perhaps all adopt the utility model discloses a design structure and thinking do simple change or change, all fall into the utility model discloses a protection scope. It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "central", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom" and "vertical" are used,

The directional or positional relationships indicated as "inner", "outer", etc. are those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The utility model discloses a concrete embodiment is shown in fig. 1 to the picture, a pneumatic membrane top mounting normal action hand wheel mechanism for pneumatic valve's pneumatic membrane executor. The pneumatic membrane actuator 1 is commonly used by those skilled in the art and is suitable for opening and closing a pneumatic regulating valve and regulating flow. The pneumatic membrane actuator 1 of the embodiment comprises an upper membrane cover 104, a membrane 105 and a lower membrane cover 106 which are arranged from top to bottom, wherein the upper membrane cover 104 and the membrane 105 enclose an upper membrane chamber 107, the membrane 105 and the lower membrane cover 106 enclose a lower membrane chamber 102, the lower membrane chamber 102 is internally provided with the elastic device 103 and the pneumatic push rod 101, the pneumatic push rod 101 is fixedly and hermetically connected with the membrane 105, the top of the upper membrane cover 104 is provided with a through hole penetrating through the upper end surface and the lower end surface of the upper membrane cover, and two ends of the elastic device 103 are respectively and elastically abutted against the membrane 105 and the lower membrane cover 106; the upper membrane cover 104 is provided with an air inlet hole for communicating an air inlet pipe with the upper membrane chamber 107, and the lower membrane cover 106 is provided with an air outlet hole for communicating the lower membrane chamber 102 with the atmosphere; when the valve is closed, the lower portion of the positive push rod 206 passes through the through hole into the upper diaphragm chamber 107, thereby pushing the pneumatic push rod 101 downward.

The positive-acting hand wheel mechanism comprises a base 201 installed at the top of the pneumatic membrane actuator 1 (namely, the top of the upper membrane cover 104), and a mounting hole penetrating through the upper end face and the lower end face of the base 201 is formed in the base 201.

The device also comprises a hand wheel 202 which is rotatably arranged on the top of the base 201 around the axial direction, a nut 203 which is axially arranged in the hand wheel 202 and the mounting hole in a penetrating way and can rotate synchronously with the hand wheel 202, a lead screw 204 which is axially arranged in the nut 203 and is in threaded fit with the nut 203 to form a thread structure pair, and an anti-rotation part 205 which is used for preventing the lead screw 204 from rotating around the axial direction; the screw 204 is axially provided with an insertion hole 204-1 penetrating the upper and lower end faces thereof. The specific nut 203 is matched with the lead screw 204 through T-shaped threads.

The pneumatic film actuator further comprises a positive action push rod 206 with the upper part inserted into the insertion hole, a step surface 206-1 is arranged on the lower part of the positive action push rod 206, the step surface 206-1 is pressed by the bottom end of the lead screw 204, and the bottom of the positive action push rod 206 is inserted through the top of the pneumatic film actuator 1 and faces the pneumatic push rod 101 in the pneumatic film actuator 1. Through the thread structure pair, the screw 204 pushes the positive push rod 206 downwards, the positive push rod 206 further pushes the pneumatic push rod 101 downwards, so that the pneumatic valve is closed, and when the screw 204 moves upwards, the pneumatic film actuator 1 automatically resets due to the elastic device 103 arranged in the lower film chamber 102, and then jacks up the positive push rod 206 and opens the pneumatic valve.

The inner side of the bottom end of the mounting hole of the base 201 is provided with a first annular gap 201-1, the anti-rotation piece 205 is of a tubular structure, the upper portion of an inner hole of the anti-rotation piece is a first polygonal hole 205-1, the lower portion of the outer wall of the lead screw 204 is positioned in the first polygonal hole 205-1 and matched with the inner wall of the first polygonal hole 205-1, the anti-rotation piece 205 is positioned in the first annular gap 201-1, the anti-rotation piece 205 is pressed at the top of the pneumatic film actuator 1 through the top wall of the first annular gap 201-1 and pressed until the anti-rotation piece 205 cannot rotate around the axial direction along with the lead screw 204, and the radial size of the inner hole of the anti-rotation piece 205 is larger than that of the positive push rod 206 so that the positive push rod moves up and down along the axial direction in the anti-. When the hand wheel 202 drives the screw 203 to rotate, the screw 204 moves upwards or downwards through the trapezoidal thread structure pair, in order to prevent the screw from rotating in the movement process, the first polygonal hole 205-1 of the inner hole of the anti-rotation piece 205 is a hexagonal hole and is matched with a hexagonal surface machined on the outer circle of the screw 204 for use, the anti-rotation piece 205 is pressed and fixed through the base 201 and does not rotate, the first polygonal hole 205-1 of the screw has two structural functions, firstly, the screw 204 is prevented from rotating, and the other function is that the screw is properly guided through the matching of the first polygonal hole 205-1 in the up-and-down movement process.

A through hole penetrating through the upper end surface and the lower end surface of the hand wheel 202 is axially formed in the hand wheel 202, the upper portion of the through hole is a second polygonal hole 202-1, the upper portion of the screw 203 extends into the second polygonal hole (a hexagonal hole in the embodiment) 202-1 and continues to extend upwards and extend out of the through hole, and the screw 203 is provided with an outer wall matched with the inner wall of the second polygonal hole 202-1. The handwheel drives the screw nut 203 to rotate through the second polygonal hole 202-1.

The outer wall of the nut 203 above the through hole is provided with external threads; the anti-dust hand wheel is characterized by further comprising a dust-proof end cover 207 buckled at the top of the through hole, an inner thread matched with an outer thread of the nut 203 is arranged on the inner wall of the dust-proof end cover 207, and the bottom end face of the dust-proof end cover 207 is located on the top end face of the through hole of the hand wheel 202 and is in sealing fit with the top end face of the through hole; a second annular notch 202-2 is formed in the inner side of the bottom end face of the through hole of the hand wheel 202, the upper portion of the base is inserted into the second annular notch 202-2, and a sealing ring 208 is arranged between the outer wall of the base 201 and the inner wall of the second annular notch 202-2, so that dust and impurities are prevented from entering the end face bearing, and the internal structure is protected.

The inner wall of the mounting hole of the base 201 is circumferentially provided with a first annular flange 201-2, the top of the first annular flange 201-2 is provided with a first one-way thrust ball bearing 209, and the top end surface of the first one-way thrust ball bearing 209 is in contact with the top wall of the second annular notch 202-2. The outer wall of the bottom end of the nut 203 is circumferentially provided with a second annular flange 203-1, the second annular flange 203-1 is positioned below the first annular flange 201-2, a second one-way thrust ball bearing 2010 is arranged between the first annular flange 201-2 and the second annular flange 203-1, and the upper end face of the second one-way thrust ball bearing 2010 is in contact with the bottom end face of the first annular flange 201-2. In the positive-acting handwheel mechanism, the nut 203 receives the reaction force of the elastic device (spring in the embodiment) 103 and then transmits the reaction force to the first one-way thrust ball bearing 209 and the second one-way thrust ball bearing 2010, and in the rotation process of the nut 204, the end face friction force is eliminated through the first one-way thrust ball bearing 209 and the second one-way thrust ball bearing 2010.

Specifically, a third annular flange 201-3 is arranged at the bottom end of the outer wall of the base 201, first internal thread holes are uniformly formed in the third annular flange 201-3 around the circumferential direction, a second internal thread hole matched with the first internal thread is formed in the top of the pneumatic film actuator 1, and the base 201 and the pneumatic film actuator 1 are fixedly and hermetically connected through a bolt and nut assembly which is simultaneously arranged in the first internal thread hole and the second internal thread hole in a penetrating manner.

The utility model discloses a frame 201, hand wheel 202, lead screw 204, screw 203 among the reaction hand wheel mechanism, prevent that rotation member 204 has certain commonality, for example still be applicable to reaction hand wheel mechanism, solve the unable mutual commonality of the used part of positive action hand wheel mechanism and reaction hand wheel mechanism, cause product part kind a great variety, be unfavorable for organizing the problem of production and assembly. In particular (see fig. 12 and 13): the positive action push rod 206 of the positive action hand wheel mechanism is replaced by a reaction push rod 206, the reaction push rod 206 is inserted into the insertion hole 204-1 along the axial direction, and the upper part of the reaction push rod 206 extends upwards to form a lead screw and is provided with a lock nut. The outer diameter of the lock nut is larger than the diameter of the insertion hole 204-1. During installation and use, the bottom of the reaction push rod 206 is inserted through the lower membrane cover of the pneumatic membrane actuator 1 and is fixedly connected with the pneumatic push rod 101 in the pneumatic membrane actuator 1 through threads (specifically, an internal thread hole is formed in the bottom end of the reaction push rod along the axial direction, and an external thread matched with the internal thread is arranged at one end, close to the reaction push rod 206, of the pneumatic push rod 101). Through the thread structure pair, the screw 204 sequentially drives the reaction push rod 206 and the pneumatic push rod 101 to move upwards synchronously along the axial direction, and compresses the elastic device 103 in the lower diaphragm chamber 102 of the pneumatic diaphragm actuator 1, so that the pneumatic valve is opened. When the screw 204 moves downwards, the pneumatic membrane actuator 1 automatically resets due to the elastic device 103, and then presses the pneumatic push rod 101 downwards, and closes the pneumatic valve.

The above description is only the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can substitute or change the technical solution and the concept of the present invention within the technical scope disclosed in the present invention.

Claims

1. The utility model provides a pneumatic film top-mounted is hand wheel mechanism just acting for pneumatic valve's pneumatic film executor, its characterized in that: the positive-acting hand wheel mechanism comprises a base (201) arranged at the top of the pneumatic thin-film actuator (1), and mounting holes penetrating through the upper end face and the lower end face of the base (201) are formed in the base (201);

the anti-rotation device is characterized by further comprising a hand wheel (202) which is rotatably arranged on the top of the base (201) around the axial direction, a nut (203) which is axially arranged in the hand wheel (202) and the mounting hole in a penetrating manner and can rotate synchronously with the hand wheel (202), a lead screw (204) which is axially arranged in the nut (203) and is in threaded fit with the nut (203) to form a thread structure pair, and an anti-rotation part (205) which is used for preventing the lead screw (204) from rotating around the axial direction; the bottom end of the lead screw (204) is provided with an insertion hole (204-1) along the axial direction;

the pneumatic film actuator is characterized by further comprising a positive action push rod (206) with the upper part inserted into the insertion hole, a step surface (206-1) is arranged on the lower part of the positive action push rod (206), the step surface (206-1) is pressed by the bottom end of the lead screw (204), and the bottom of the positive action push rod (206) is inserted through the top of the pneumatic film actuator (1) and faces towards the pneumatic push rod (101) in the pneumatic film actuator (1); through the thread structure pair, the screw rod (204) pushes the positive action push rod (206) downwards, the positive action push rod (206) further pushes the pneumatic push rod (101) downwards, so that the pneumatic valve is closed, and when the screw rod (204) moves upwards, the pneumatic film actuator (1) automatically resets due to the elastic device (103) installed in the lower film chamber (102), further jacks the positive action push rod (206) upwards, and opens the pneumatic valve.

2. The pneumatic membrane top mounted positive action hand wheel mechanism of claim 1, wherein: the bottom end of the mounting hole of the base (201) is inboard to be equipped with first annular breach (201-1), prevent changeing (205) and be tubular structure, the at least upper portion of its hole is first multilateral hole (205-1), the outer wall lower part of lead screw (204) is arranged in first multilateral hole (205-1), and cooperatees with the inner wall in first multilateral hole (205-1), prevent changeing (205) and be arranged in first annular breach (201-1), and prevent changeing (205) and compress tightly the top at pneumatic film executor (1) by the roof of first annular breach (201-1) to compress tightly to preventing changeing (205) and can not be along with lead screw (204) around the axial rotation, prevent that the radial dimension of the hole of changeing (205) is > the radial dimension of positive action push rod (206).

3. The pneumatic membrane top mounted positive action hand wheel mechanism of claim 1, wherein: a through hole penetrating through the upper end face and the lower end face of the hand wheel (202) is axially formed in the hand wheel, the upper portion of the through hole is a second polygonal hole (202-1), the upper portion of the screw nut (203) extends into the second polygonal hole (202-1) and continues to extend upwards to extend out of the through hole, and the screw nut (203) is provided with an outer wall matched with the inner wall of the second polygonal hole (202-1).

4. The pneumatic membrane top mounted positive action hand wheel mechanism of claim 3, wherein: the outer wall of the nut (203) above the through hole is provided with an external thread; the anti-dust hand wheel is characterized by further comprising a dust-proof end cover (207) buckled at the top of the through hole, an inner thread matched with an outer thread of the nut (203) is arranged on the inner wall of the dust-proof end cover (207), and the bottom end face of the dust-proof end cover (207) is located on the top end face of the through hole of the hand wheel (202) and is in sealing fit with the top end face of the through hole; a second annular notch (202-2) is formed in the inner side of the end face of the bottom of the through hole of the hand wheel (202), the upper portion of the base is inserted into the second annular notch (202-2), and a sealing ring (208) is arranged between the outer wall of the base (201) and the inner wall of the second annular notch (202-2).

5. The pneumatic membrane top mounted positive action hand wheel mechanism of claim 4, wherein: the inner wall circumference of the mounting hole of frame (201) is equipped with first annular flange (201-2), the top of first annular flange (201-2) is equipped with first one-way thrust ball bearing (209), the top terminal surface of first one-way thrust ball bearing (209) with the roof contact of second annular breach (202-2).

6. The pneumatic membrane top loading positive action hand wheel mechanism of claim 5, wherein: the outer wall of the bottom end of the nut (203) is circumferentially provided with a second annular flange (203-1), the second annular flange (203-1) is located below the first annular flange (201-2), a second one-way thrust ball bearing (2010) is placed between the first annular flange (201-2) and the second annular flange (203-1), and the upper end face of the second one-way thrust ball bearing (2010) is in contact with the bottom end face of the first annular flange (201-2).

7. The pneumatic membrane top mounted positive action hand wheel mechanism of claim 1, wherein: the pneumatic membrane actuator is characterized in that a third annular flange (201-3) is arranged at the bottom end of the outer wall of the base (201), first internal thread holes are uniformly formed in the third annular flange (201-3) around the circumferential direction, second internal thread holes matched with the first internal threads are formed in the top of the pneumatic membrane actuator (1), and the base (201) and the pneumatic membrane actuator (1) are fixedly and hermetically connected through bolt and nut assemblies which are simultaneously arranged in the first internal thread holes and the second internal thread holes in a penetrating mode.

8. The pneumatic membrane top loading positive-acting hand wheel mechanism of any one of claims 1 to 7, wherein: the pneumatic film actuator (1) comprises an upper film cover (104), a film sheet (105) and a lower film cover (106) which are arranged from top to bottom, wherein the upper film cover (104) and the film sheet (105) enclose an upper film chamber (107), the film sheet (105) and the lower film cover (106) enclose a lower film chamber (102), the elastic device (103) and the pneumatic push rod (101) are arranged in the lower film chamber (102), the pneumatic push rod (101) is fixedly and hermetically connected with the film sheet (105), a through hole penetrating through the upper end face and the lower end face of the upper film cover (104) is formed in the top of the upper film cover (104), and two ends of the elastic device (103) are elastically abutted against the film sheet (105) and the lower film cover (106) respectively; the upper membrane cover (104) is provided with an air inlet hole for communicating an air inlet pipe with the upper membrane chamber (107), and the lower membrane cover (106) is provided with an air outlet hole for communicating the lower membrane chamber (102) with the atmosphere; when the valve is closed, the lower part of the positive action push rod (206) enters the upper membrane chamber (107) through the through hole, and then pushes the pneumatic push rod (101) downwards.