RU2174628C1 - Pneumatic actuating apparatus - Google Patents

Abstract

FIELD: actuating systems for replacing and tracing motion of locking and regulating fittings of conduits for gas and oil products. SUBSTANCE: apparatus includes electropneumatic control unit; fluid motor; reduction gear; rotary mechanism; output shaft; device for displaying data related to position of output shaft, said device having reed limit switches; limiter of maximum value of transferred angular momentum. Said limiter is in the form of mechanism for reciprocation motion of steel shutter placed between fixed reed switches and fixed permanent magnets. EFFECT: enhanced operational reliability of actuating apparatus. 5 dwg

Description

 The invention relates to the field of pneumatic engineering and relates to a device for moving and following the movement of the shut-off and control valves of gas and oil pipelines.

 Known pneumatic drive with a jet engine, including a distributor, gearbox, link mechanism, screw-nut mechanism and spring-loaded screw support [1].

 The disadvantage of this drive is the likelihood of transmission of excessive torque to the moving parts of the drive. This can happen when the drive stops abruptly in the end positions.

 There is no mechanism in the drive that controls the occurrence of excessive torque. As a result, parts of the drive or pipe fittings may break.

 A known drive containing an electro-pneumatic control device, a jet engine, a gearbox, a rotary mechanism, an output shaft, a device for position information of an output shaft of a drive, including magneto-reed limit switches, as well as a device for limiting the maximum amount of transmitted torque [1].

 The device for limiting the maximum value of the transmitted driving moment contains a mechanism for the rotary movement of permanent magnets. The mechanism for moving permanent magnets contains a leash sitting on the axis and a holder on which two permanent magnets are mounted.

 A disadvantage of the known drive is that the device for limiting the maximum value of the transmitted torque is unreliable in operation. The mechanism for moving permanent magnets is difficult to tune. Once tuned, the mechanism over time does not give a stable response or does not work at all. This is due to the unsuccessful design of this mechanism, as well as the unstable magnetic fields of permanent magnets, which change with time.

 The drive does not exclude damage to parts with an excessive increase in torque.

 The basis of the present invention is the creation of such a pneumatic actuator, which would ensure stable values of the driving moment and would exclude breakage of the drive parts or jamming, i.e. increase the reliability of the drive.

 The problem is achieved in that in a pneumatic actuator containing an electro-pneumatic control device, a jet engine, a gearbox, a rotary mechanism, an output shaft, an information device on the position of the output shaft of the drive, including magnetically reed limit switches, as well as a device for limiting the maximum value of the transmitted torque, according to the invention, the limiter of the maximum value of the transmitted torque is made in the form of a reciprocating mechanism Movement of the steel curtain, which is located between the fixed reed switches and the fixed permanent magnets.

 The invention is illustrated by the accompanying drawings and examples of specific performance of the drive with a limiter of the maximum amount of torque.

 In FIG. 1 shows a general view of the drive.

 In FIG. 2 is a diagram of a pneumatic drive.

 In FIG. 3 - limiter of the maximum magnitude of the driving moment in a section along the pusher with a shutter.

 In FIG. 4 is a section AA in FIG. 3.

 In FIG. 5 is a view B in FIG. 4 with cover removed 50.

 The pneumatic drive contains a jet engine 1 (Fig. 1) on the gearbox 2. The gearbox 2 is connected to the housing 3 of the rotary mechanism. In the housing 3, the bearings 4 are mounted on the bearings (Fig. 2), connected to the gearbox 2.

 In the housing 3, the bearings 5 are mounted on the bearings.

 The lead screw has the ability to axially move when axial loads occur. To quench kinetic energy, one end of the lead screw 4 is equipped with a damper 6. The other end of the lead screw 4 is connected by an end face to the pusher of the torque limiter 7.

 An electropneumatic control device 8 is installed on the housing 3 (Fig. 1).

 The jet engine comprises a turbine 9, which is mounted on bearings in the housing 10 (Fig. 2) of the engine.

 The turbine is made in the form of a "Segner wheel" with nozzles 11 and has the possibility of reverse movement. The turbine shaft is equipped with a gear for transmitting movement by the gear wheel of the gear 2. The helm 12 of the handwheel is mounted on gear 2. Using the lever 13 and the latch 14, the steering wheel 12 is connected to the clutch 15.

 The coupling 15 with the help of a spline connection is located on the shaft 16.

 For acceleration of the engine turbine and gear wheels of the gearbox, an acceleration clutch is located in it, some cams of which are made at the end of the gear wheel 17, and others on the coupling half 18, which is connected to the shaft of the spindle 4 using a hollow spline sleeve.

 The nut 19 is located on the lead screw 4 and with the help of a leash is connected with crackers that are installed in the grooves of the wings 5.

 For accurate positioning of the wings, the associated output shaft 20 and the valve body, adjustable stops 21 and 22 are installed in the housing 3.

 At the time of installation of the scenes on the stop, the gas supply to the engine is stopped, but the lead screw continues to make several revolutions by inertia and compresses the springs 24 of the damper 6.

 The lead screw 4 acts on the stem 25 by the end face.

 In this case, the rod 25 of the torque limiter performs axial movement in one direction or another.

 The rod 25 is rigidly connected to the shutter 26 of the torque limiter. The shutter 26 is located on the slider 27 between the fixedly mounted reed switches 28.1 and 28.2 and the fixedly mounted permanent magnets 29.1 and 29.2.

 Instead of reed switches and permanent magnets, light resistors and LEDs or induction emitters and signal receivers can be used.

 The output shaft 20 of the scenes 5 is connected to the roller 30 of the electro-pneumatic control device.

 This device contains electromagnets 31 and 32, which are connected to pneumatic valves 33 and 34.

 The switches are made in the form of reed switches 35 and 36.

 Permanent magnets may be mounted on the shaft disk 30. A metal shutter can be installed on this disk, which will be located between the fixed-mounted reed switches and the fixed-mounted permanent magnets.

 Instead of reed switches and permanent magnets, light resistors and LEDs or inductive emitters and signal receivers can be used.

 In all cases, the curtain is an obstacle to the impact of emitters on the signal receivers. Only when moving the curtains to the side, the possibility of the action of emitters on the signal receivers opens.

 To supply the working gas mainly from the gas line on the electro-pneumatic device 8 (Fig. 1), a fitting 37 is installed.

 The flow of working gas into the turbine is carried out through gas ducts 38 or 39, depending on the required direction of rotation of the turbine and rotation of the output shaft.

 Reed switches 28.1 and 28.2 are installed on the electrical insulating block 40 (Fig. 3) in the explosion-proof chamber 41 of the housing 42 of the torque limiter.

 Permanent magnets 29.1 and 29.2 are installed in the bracket 43, which is fixed in another cavity of the housing 42, closed by a cover.

 Permanent magnets have the form of cylindrical tablets and are installed in the holes of the bracket 43 between the focus 44 and the shock absorber 45, for example rubber.

 The shutter 26 is made of two thin metal plates 26.1 and 26.2 (Fig. 5) having a L-shaped profile. Both plates are attached to the slider by 27 screws 46. Both halves have the ability to move apart and move. To do this, they are made longitudinal grooves, which include screws 46.

 At the end of the rod 25, an emphasis 47 is made with a ball at the end and a thread for adjustment when interacting with the end of the screw 4.

 The emphasis of the stop 47 with the rod 25 to the end of the screw 4 is carried out by the spring 48.

 The slider 27 is located on the guide plate 49 in the lower cavity of the housing 42. This cavity is closed by a cover 50.

The pneumatic drive operates as follows. When applying to the electro-pneumatic control device 8 of the control signal U _{p is} triggered, for example, the reed switch 35 and the electromagnet 31 includes a pneumatic valve 33.

 Gas enters the turbine through the gas duct 9. As a result of the gas ejection at high speed through the nozzles 11, the turbine rotates and transmits the rotation through the reducer 2 to the lead screw 4. The screw 4 moves the drive nut 19 and moves the link 5 from one position to another through the lead and crackers, e.g. all the way to 21.

 The shaft 20 of the scenes while turning the roller 30 of the control device 8.

 The magnet on the roller disk 30 approaches the reed switch 35 and turns it off. The gas supply to the turbine 9 is stopped.

 At the same time, the magnet 38 moves away from the reed switch 36, the contacts of which switch and prepare the operation of the pneumatic actuator in the opposite direction.

 If the torque exceeds the permissible limit during the operation of the drive for any reason (jamming, ingress of a foreign object, etc.), gas continues to flow into the turbine. The drive can develop a torque that can lead to breakage of drive components and pipeline fittings.

 In this case, the lead screw 4 moves relative to the nut 19 and the end face of the screw 4 acts on the pusher 25. The pusher 25 with the slider 27 moves the shutter 26, blocks the action of the magnetic field on the reed switch, or opens such an action.

 The supply of working gas to the turbine is shut off.

 This embodiment of the pneumatic actuator and torque limiter increases the reliability of the drive, eliminates the breakdown of parts and the occurrence of an emergency.

 The torque limiter is made simpler and more reliable.

 Easy access to adjust the position of the curtain.

 The implementation of the torque limiter using a shielding curtain that overlaps the magnetic field between the reed switches and permanent magnets, allows you to ensure stability of the torque limit by a predetermined value, which is controlled by the position of the curtain, regardless of the change in the magnetic fields of the permanent magnets due to aging or other factors.

 From available sources of information, the authors did not find a device with similar features.

 The proposed device is feasible in mass production of a machine-building enterprise.

 The device uses widely known materials, unique materials or equipment for the manufacture and testing of such a pneumatic actuator is not required.

 Tests of the pneumatic actuator with the proposed torque limiter showed better results compared to the known one.

Sources of information
1. Patent of the Russian Federation N 2050478, Cl. F 15 B 9/03, 1994

 2. Patent of the Russian Federation N 2131065, Cl. F 15 B 9/03, 1998

Claims (1)

 A pneumatic drive comprising an electro-pneumatic control device, a jet engine, a gearbox, a rotary mechanism, an output shaft, a drive output position information device including magnetic reed limit switches, and a device for limiting the maximum amount of transmitted torque, characterized in that the maximum limiter the magnitude of the transmitted torque is made in the form of a mechanism for reciprocating movement of the steel curtain, which is located hedgehog fixedly mounted reed switches and fixedly mounted permanent magnet.

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