RU208762U1 - Axial flow control valve - Google Patents

Abstract

The utility model relates to pipeline fittings designed to control flow or pressure in injection pipelines. The axial flow control valve comprises a body (1) with inlet (2) and outlet pipes (3) and a fairing (4) placed inside the body to form an annular channel. The outlet part of the fairing (4) is blocked by perforated holes (7) separator (6). The separator (6) is rigidly connected to the seat (8) fixed in the outlet pipe (3). Inside the separator (6) is placed with the possibility of axial movement of the piston (10). The piston (10) is fixed on the driven rail (15) of the rack and pinion mechanism. The drive rod (13) of the rack and pinion is connected to the drive. The piston (10) is made with discharge channels at the end. The helical engagement (14) of the rack and pinion mechanism and the free ends of the driving rod (13) and the driven rack (15) are located in the cavities formed for them. The cavities of the helical gearing (14) and the end face of the driving rod (13) are isolated from the pressure of the working medium. The axis of the rod (13) is displaced relative to the axis of the rail (15) by a distance of not less than 2 mm, but not more than 30 mm, respectively, for this, holes are bored in the guide bush (16) and in the housing (1) with the required offset, and the teeth of the rod (13) and racks (15) are displaced from the axis of symmetry. The stable operation of the valve is maintained by increasing the accuracy of valve regulation by the actuator (actuator) by shifting the stem axis relative to the rack axis. 3 ill.

Description

The utility model relates to pipeline fittings, in particular to control valves designed to control the flow rate of the working medium on injection pipelines, and can be used on high-pressure gas and oil pipelines.

An axially symmetrical control valve of axial flow is known, comprising a body with inlet and outlet pipes and a fairing placed inside the body to form an annular channel, the outlet of which is blocked by a perforated separator, rigidly connected to a seat fixed in the outlet pipe, and placed inside it with the possibility of axial movement a piston fixed on the rail of the rack and pinion mechanism, the rod of which is connected to the drive, the piston is made with discharge channels at the end, and the helical gearing of the rack and pinion mechanism and the free ends of the rod and rack are located in the cavities formed for them, the cavities of the helical gearing and the end of the rod are isolated from the pressure of the working environment, (Patent RU No. 191873 U1, IPC F16K 1/12, F16K 1/226, F16K 47/08, priority dated 01/10/2019, published 08/26/2019).

The closest in purpose, technical essence and achieved result to the one claimed as a utility model is an axisymmetric control valve, containing a housing with inlet and outlet nozzles and a fairing placed inside the housing to form an annular channel, the outlet of which is blocked by a perforated separator rigidly connected to saddle, fixed in the outlet pipe, and placed inside it with the possibility of axial movement of the piston, fixed on the rail of the rack and pinion mechanism, the rod of which is connected to the drive, the piston is made with discharge channels at the end, and the helical engagement of the rack and pinion mechanism and the free ends of the rod and rail are located in cavities formed for them, while the cavities of the helical engagement and the end of the rod are isolated from the pressure of the working medium, the guide sleeve with a channel in the form of an annular groove on the outer surface at the junction with the fairing plug with channels in the form of through windows for medium overflow, (Patent RU No. 196436 U1, IPC F16K 1/12, F16K 47/14, priority dated 09/09/2019, publ. February 28, 2020).

The disadvantage of the known designs is that the axes of the rod and rails are in the same plane. During the operation of valves with these designs, wedging may occur when the valve is moved in the direction of opening and closing, due to the presence of a small area of contact between the surface of the stem and rail with holes bored in the guide sleeve, and the presence of an “extra” degree of freedom - the possibility of moving the rail and stem with teeth towards each other, which leads to increased wear of the rod and rack teeth, as well as possible failure of the valve, violation of the algorithm of the actuator (drive), namely, a decrease in the accuracy of valve control.

The technical problem to be solved by the utility model is to maintain stable operation of the valve by increasing the accuracy of valve control by the actuator (actuator) by shifting the stem axis relative to the rail axis.

To solve the technical problem posed, an axial flow regulating valve, comprising a body with inlet and outlet pipes and a fairing placed inside the body with the formation of an annular channel, the outlet of which is blocked by a perforated separator, rigidly connected to a seat fixed in the outlet pipe, and placed inside it with the possibility of axial movement of the piston fixed on the rail of the rack and pinion mechanism, the rod of which is connected to the drive, the piston is made with unloading channels at the end, and the helical engagement of the rack and pinion mechanism and the free ends of the rod and the rack are located in the cavities formed for them, while the cavities of the helical engagement and the end of the rod are isolated from the pressure of the working medium, the guide sleeve with a channel in the form of an annular groove on the outer surface at the junction with the fairing plug with channels in the form of passage windows for the flow of the medium, according to the utility model, in the body and in the guide sleeve Holes are filled with an offset of at least 2 mm, but not more than 30 mm, providing a displacement of the rod axis relative to the axis of the rack by the specified distance, and displacement of the teeth of the rack and rod from the axis of symmetry with the possibility of increasing the area of contact between the surface of the rod and the rail with holes in the guide bushing.

Displacement of the holes in the guide sleeve and the body leads to a displacement of the rod axis relative to the axis of the rail by a distance of at least 2 mm, but not more than 30 mm, and, accordingly, the displacement of the teeth of the rack and rod from the axis of symmetry, thereby increasing the surface contact area rod and rail with holes in the guide bushing, which ensures reliable and stable operation of the valve, wear of the rack and rod teeth is reduced, and the accuracy of valve regulation by the actuator (actuator) is increased. The "extra" degree of freedom is excluded - the possibility of moving the rail and the stem towards each other, which eliminates the likelihood of wedging when the valve is moved to open and close.

When the displacement of the stem relative to the rail is less than 2 mm, there is a possibility of wedging when the valve is moved in the direction of opening and closing, due to the presence of a small area of contact between the surface of the stem and the rail with the holes bored in the guide bushing, which leads to increased wear of the teeth of the rail and stem, and also possible failure of the valve, violation of the algorithm of the actuator (drive), namely, a decrease in the accuracy of valve control.

With an increase in the displacement of the rod relative to the rack by more than 30 mm, there is a possibility of high loads on the helical gearing of the rack and pinion mechanism due to a decrease in the contact area of the rack and rod teeth, which leads to increased wear of the rack and rod teeth, as well as possible failure of the valve.

Axial flow control valve is illustrated by drawings where:

in fig. 1 - shows a general view of the valve regulating axial flow, a longitudinal section;

in fig. 2 - section A-A in Fig. 1, one of the channels is shown, made in the form of passage windows in the fairing;

in fig. 3 - view B in Fig. 2, the displacement of the axis of the rod relative to the axis of the rail is shown at a distance of not less than 2 mm, but not more than 30 mm.

In the drawings, positions are indicated:

1 - body

2 - inlet pipe

3 - outlet pipe

4 - fairing

5 - passing annular channel

6 - separator

7 - radial holes in the separator

8 - saddle

9 - clamping sleeve

10 - piston

11 - piston cavity

12 - holes in the piston end

13 - stock

14 - helical gearing

15 - rail

16 - bushing guide

17 - vertical hole in the guide sleeve

18 - horizontal hole in the guide sleeve

19 - hole in the body

20 - movable seal

21 - stationary seal

22 - helical engagement cavity

23 - sealing element

24 - sealing element

25 - fairing cap

26 - seal

27 - channel in the form of an annular groove

28 - walk-through windows

29 - gland assembly.

The axial flow control valve comprises a body 1 with inlet 2 and outlet 3 nozzles and fairing 4 forming an annular through passage 5 (Fig. 1). At the outlet of the channel 5, a separator 6 with radial holes 7 is installed. The separator 6 is fixed with a seat 8 and a clamping sleeve 9 in the outlet pipe 3. A piston 10 is installed inside the separator 6 with the possibility of axial movement. The cavity 11 of the piston 10 communicates with the cavity of the outlet pipe 3 through holes 12, made in the end face of the piston 10. The mechanism for moving the piston 10 is made in the form of a rack and pinion mechanism and contains a rod 13 interacting by means of a helical engagement 14 with a rack 15. A guide sleeve 16 is installed in the housing 1. Two mutually perpendicular holes are made in the guide sleeve 16: vertical 17 and horizontal 18.

The vertical hole 17 is made coaxially with the hole 19 made in the body 1, they contain the rod 13. In the horizontal hole 18 of the bushing of the guide 16 there is a rail 15. The horizontal hole 18 is made coaxially with the inlet pipe 2, the outlet pipe 3 and the cavity 11 of the piston 10. Hole 18 between the movable seal 20 and the fixed seal 21 and the holes 17 and 19 form a cavity 22 of the helical engagement 14 with the axis of the rod 13 offset relative to the axis of the rack 15.

The hole 19 in the housing and the hole 17 in the bushing of the guide 16 are offset by a distance of not less than 2 mm, but not more than 30 mm. Execution in the housing 1 and in the sleeve of the guide 16 holes 19 and 17 with offset, provides a displacement of the axis of the rod 13 relative to the axis of the rail 15 at the specified distance, and accordingly the displacement of the teeth of the rail 15 and the rod 13 from the axis of symmetry, thereby increasing the contact area of the surface of the rod 13 and rails 15 with holes 17 and 18 bored in the guide bushing 16, and an "extra" degree of freedom is excluded - the possibility of moving the stem 13 and rail 15 towards each other, which eliminates the likelihood of wedging when moving the shutter to open and close.

The cavity 22 is isolated by sealing elements 23 and 24 from the pressure of the working medium. The hole 18 in the bushing of the guide 16 on the side of the free end of the rail 15 is isolated from the cavity of the inlet pipe 2 by a plug 25 installed in the fairing 4 with a seal 26, and is connected to the cavity 11 of the piston 10 by two channels 27 and 28 (Fig. 2). One channel 27 is made in the form of an annular groove on the outer surface of the guide bushing 16 at the junction with the cap 25 of the fairing 4. The other channel is made in the form of passage windows 28 in the fairing 4. The channel 27 and passage windows 28 serve to increase the flow area and flow of the medium in a large volume from the inner space of the guide bushing 16 and the cavity of the plug 25 into the cavity 11 of the piston 10, as well as to reduce the weight of the valve body 1. For the tightness of the cavity 22 of the helical engagement 14 relative to the external environment in the housing 1, a stuffing box assembly 29 is located on top of the hole 19.

The valve works as follows.

The regulated medium enters the inlet pipe 2 and, passing through the annular channel 5 formed by the body 1 and the fairing 4, through the radial holes 7 of the separator 6, enters the outlet pipe 3. If it is necessary to reduce the volume of the regulated medium (when closing the valve), the piston 10 through the rack 15 and stem 13 of helical gearing 14, is shifted by the drive to the right position, blocking the holes 7 of the separator 6. The volume of the passing controlled medium is determined by the number of open holes 7 in the separator 6. When the separator holes are completely blocked, the valve is closed.

The valve is opened by a drive that sets the movement of the rod 13, connected by means of a helical engagement 14 with the rack 15, which moves the piston 10 to the left position. piston 10 communicating these cavities. Piston 10 is completely unloaded.

The pressure of the working medium in the horizontal hole 18 of the guide sleeve 16, formed for the end of the rail 15, is equal to the pressure in the cavity 11 of the piston 10 due to the presence of channels 27 and the channel 5 of the fairing 4 communicating these cavities, and, therefore, the pressure in the cavity of the outlet pipe 3 The rod 13 is completely unloaded.

The cavity 22 of the helical gear 14 is isolated from the pressure of the working medium by means of sealing elements 20, 21, 23, 24, due to which the force from the pressure of the working medium does not act on the end of the drive rod 13 when the piston 10 moves, and relative to the external environment, the tightness of the cavity 22 of the helical gear 14 provided with sealing gland assembly 29.

Thus, the result of improving the design of the axial flow control valve is to increase its reliability, maintain stable operation of the valve, increase the accuracy of valve control by the actuator (actuator) by making holes in the body and in the guide sleeve with a distance of at least 2 mm, but no more than 30 mm, providing displacement of the rod axis relative to the axis of the rack by the specified distance, and displacement of the teeth of the rack and rod from the axis of symmetry with the possibility of increasing the contact area of the rod and rack surfaces with holes in the guide bushing.

Claims (1)

Axial flow regulating valve, comprising a body with inlet and outlet pipes and a fairing placed inside the body to form an annular channel, the outlet of which is blocked by a perforated separator, rigidly connected to a seat fixed in the outlet pipe, and a piston placed inside it with the possibility of axial movement, fixed on the rail of the rack and pinion mechanism, the rod of which is connected to the drive, the piston is made with discharge channels at the end, and the helical gearing of the rack and pinion mechanism and the free ends of the rod and rail are located in the cavities formed for them, while the cavities of the helical gearing and the end of the rod are isolated from the pressure of the working medium, a guide bushing with a channel in the form of an annular groove on the outer surface at the point of its connection with the cap of the fairing with channels in the form of passage windows for the flow of the medium, characterized in that holes are made in the body and in the guide bushing with an offset of not less than it is more than 2 mm, but not more than 30 mm, providing a displacement of the axis of the rod relative to the axis of the rail by a specified distance, and displacement of the teeth of the rack and rod from the axis of symmetry with the possibility of increasing the contact area of the surface of the rod and rail with holes in the guide bushing.

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