RU2320901C1 - Pneumatic straight moving drive with jet engine for valves - Google Patents

Abstract

FIELD: the invention refers to machine building industry.

SUBSTANCE: pneumatic straight moving drive of two side action is assigned for controlling locking-regulating accessories particularly for valves of gas and hydraulic systems. Drive is assigned for working in expanded range of pressure 0,4-10 MPa. Drive has no mobile frictional seals.

EFFECT: drive has increased resource and longevity.

4 cl, 3 dwg

Description

The invention relates to the field of pneumatic engineering, to mechanisms designed to control control valves, in particular pneumatic valves.

State of the art

Known pneumatic diaphragm actuator direct action [1, p. 119], operating on compressed air of low pressure (0.4 ÷ 0.6 MPa). The driving force of the drive is created due to the pressure of compressed air on the fabric or metal membrane, which, bending under the action of compressed air, provides the working stroke of the output element (rod) of the drive. In this case, compression of the return spring occurs. The reverse movement of the actuator rod is due to the action of the return spring. The disadvantages of this drive are the large dimensions of the drive due to the large size of the membrane and spring. In addition, membranes, especially fabric ones, have a significantly limited resource and low reliability.

Known pneumatic piston linear two-way drive [1, p.120]. The drive provides two-way force on the stem. The disadvantage of this drive is also the large size and the presence of moving friction seals, which reduce the durability of the drive. In addition, the first and second of these drives are very sensitive to changes in compressed air pressure. When the pressure of compressed air in the pneumatic network drops, the working forces developed by the drive are proportionally reduced. At the same time, it is almost impossible to increase these efforts.

Known drive with a jet engine for gas shutoff and control valves [2]. The drive contains a jet engine, a mechanical gearbox, a rocker-screw rotary mechanism, an electro-pneumatic control device. The drive runs on natural (transported) compressed gas with a pressure of 1.5 ÷ 3.0 MPa. Due to the force and other requirements imposed on it, the actuator has a complex structure, large mass and dimensions and can hardly be used to control linear valves.

Disclosure of the invention

An object of the invention is the creation of a pneumatic actuator for controlling valves of gas and hydraulic systems, with smaller dimensions and weight, increased reliability and durability and the possibility of application in an extended pressure range of the working fluid (compressed air).

This technical problem is solved due to the fact that in a drive containing a jet engine connected in series, a mechanical gearbox with an output gear, a kinetic energy absorption device for the moving parts of the drive, a spindle nut, a spindle, a spindle nut is connected to the output gear with axial displacement, this nut is associated with a device for absorbing the kinetic energy of the moving parts.

This problem is also solved due to the fact (the second option) that the running nut is connected to the output gear with the possibility of axial movement relative to the gear.

The problem is also solved due to the fact that the rotor of the engine is made with two nozzles, each of which is connected to one of the input channels of the rotor.

This technical problem is also solved due to the fact that adjustable inductors are installed at the entrance to the engine rotor.

The essence of the invention lies in the fact that in a pneumatic drive containing a jet engine connected in series, a mechanical gearbox with an output gear, a kinetic energy absorption device of the moving parts of the drive, a running nut is connected to the output gear with axial movement, and the nut is connected to a kinetic absorption device energy of moving parts.

The essence of the invention also lies in the fact (the second option) that the running nut is connected to the output gear with the possibility of axial movement relative to the gear.

The invention also lies in the fact that the rotor of the engine is made with two nozzles, each of which is connected to one of the input channels of the rotor; and also that adjustable inductors are installed at the rotor inlet.

A causal relationship between the achieved scientific and technical result and the totality of features.

The reduction in size and increased reliability is achieved due to the fact that the running nut is connected to the output gear with the possibility of axial movement, while the nut is connected to a device for absorbing the kinetic energy of the moving parts; and also due to the fact (the second option) that the running nut is connected to the output gear with the possibility of axial movement relative to the gear.

The expansion of the pressure range of the working fluid (compressed air) is achieved due to the fact that adjustable inductors are installed at the engine inlet.

Brief Description of the Drawings

The invention is further illustrated by the description of an example implementation with reference to the drawings, where:

figure 1 shows a diagram of the drive;

figure 2 - diagram of the gearbox with a driving nut connected to the output gear with the possibility of axial movement relative to the gear;

figure 3 - diagram of the rotor of the engine.

An embodiment of the invention

The pneumatic actuator (Fig. 1) contains serially connected: a jet engine 1, a mechanical gearbox 2 with an output gear 3, a lead screw 4, a lead nut 5 connected to the output gear 3 with the possibility of axial movement of the nut, while the nut is connected through thrust bearings 6 , 7 with a device for absorbing kinetic energy of the moving parts of the drive, made in the form of a plate of disk springs 8. The lead screw is protected from rotation around its axis by means of a key 9 and is equipped with a docking element 10 for docking with that control 11.

In the second embodiment (figure 2), the driving nut 5 is connected by splines with the output gear 3 and has the possibility of axial movement relative to the gear.

In the housing of the jet engine 1, the inlet pipes 14, 15 and the rotor 16 with nozzles 17, 18 are installed (Figs. 1, 3). In this case, both nozzles are directed to one side and each nozzle is connected through input channels of the rotor 21, 22 through channels 19, 20 (Fig. 3). The rotor shaft for transmission of rotation is equipped with a gear ring 24. Adjustable chokes are installed at the engine inlet (cranes ) 26, 27. In addition, figure 1 shows the control pneumatic valves 30, 31 (not included in the application), the inputs of which are connected to a power source with compressed air with a pressure R.

The implementation of the engine rotor according to the scheme with two nozzles (instead of the usual four) made it possible to significantly reduce the moment of inertia of the rotor, which, in turn, allows to reduce the kinetic energy of the moving parts of the drive and the energy intensity, mass and dimensions of the device for absorbing the kinetic energy of the drive.

The installation of adjustable throttles 26, 27 at the rotor inlet allows the rotor to be installed in the engine with slightly larger nozzle sections, which practically does not affect the dimensions or mass of the drive. At the same time, an increase in gas consumption and an increase in drive power are eliminated by “covering” the adjustable chokes.

With an unauthorized decrease in pressure P, the magnitude of the required torque is easily restored by simply opening the throttles and increasing the flow rate of compressed air.

Pneumatic actuator operates as follows.

When opening, for example, a pneumatic valve 30, compressed air with a pressure P through an adjustable throttle 26 and a nozzle 14 enters the engine rotor and, emerging, for example, from the nozzle 17, creates a reactive force F (Fig. 3) and a driving moment on the shaft of the engine rotor. The rotor begins to rotate, its rotation through the ring gear 24 and the mechanical gearbox is transmitted to the output gear 3. The gear rotates and rotates the spindle nut 5, which at the same time moves the spindle through the thread (Fig. 1), for example, to the right. The movement of the lead nut along the axis is prevented by its connection with the pre-loaded spring package 8. When the lead screw reaches the extreme right position and stops the docking element 10 in the control object 11, the lead screw stops. However, due to the accumulated kinetic energy, the rotor 16 and the gears of the gearbox, including the output gear 3, will continue to rotate. In this case, the nut will move to the left and compress the spring package 8 through the bearing 6 until all the kinetic energy of the moving parts passes into the potential energy of the compressed springs. After that, all moving parts of the drive stop.

To move the lead screw 4 with the connecting element 10 in the opposite direction, close the valve 30 and open the valve 31. When the screw stops in the left extreme position, the lead nut will move to the right and the spring pack 8 will be compressed through the bearing 7.

Information sources

1. On.N. Shpakov. Alphabet of pipe fittings. Reference manual. St. Petersburg, 2003

2. Patent of Russia No. 2131065.

Claims (4)

1. Pneumatic linear actuator with a jet engine for valves, comprising a series-connected jet engine, a mechanical gearbox with an output gear, a device for absorbing the kinetic energy of the moving parts of the actuator, a spindle nut, a spindle, characterized in that the spindle nut is axially connected to the output gear displacement, while the nut is connected to a device for absorbing kinetic energy of the moving parts of the drive. 2. The drive according to claim 1, characterized in that the running nut is connected to the output gear with the possibility of axial movement relative to the gear. 3. The drive according to claim 1, characterized in that the rotor of the engine is made with two nozzles directed in the same direction, with each of the nozzles connected by channels to one of the output channels of the rotor. 4. The drive according to claim 1, characterized in that at the entrance to the rotor is installed adjustable chokes.

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