RU1789744C - Positive displacement pump - Google Patents

Abstract

Usage: in the coal industry during the hardening of rocks by injection of polyurethane foams. SUMMARY OF THE INVENTION: A discharge valve with an inlet in that wall is installed on the first end wall of the housing with an internal cavity. The working body with emphasis is placed with the formation of the working chamber in a spring loaded relative to the housing and the working body of the sleeve. The sleeve is mounted movably in the axial direction, contacts the first wall of the housing and has means for sealing the outer surface in the area of contact with the housing. The reciprocating drive is made in the form of an elastic deformable sleeve. The pressure source is in the form of a two-position spool valve. The spool is installed in the second wall of the housing and interacts with the working body. In the body cavity there is a transverse partition with an axial hole for the passage of the working body and radial holes for communication of one of the drive chambers with a distributor and an additional sleeve fixed by the ends to the partition and the working body with the formation of one part of the second drive chambers. 1 ill. with C

Description

The invention relates to pump construction and can be used in various sectors of the national economy, for example, in the coal industry, in particular in the hardening of rocks by injection of polyurethane foam compositions.

It can also be used, for example, in chemical installation and special construction works, in particular for the manufacture of heat-insulating half-cylinders and foam slabs FRP-1, as well as heat-insulating pipes used in the conditioning system of the mine atmosphere.

The closest in technical essence of the invention is a volumetric pump containing a housing with an internal cavity and two end walls, the first of which is equipped with a discharge valve with an inlet in this wall, a working body with stops placed to form a working chamber in spring loaded relative to the housing and the working body of the sleeve mounted movably in the axial direction with the possibility of contact with the first wall of the housing and having means of sealing the outer surface in the area of contact with housing, operating reciprocating drive XJ 00

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an organ in the form of an elastically deformable sleeve installed with the formation of two drive chambers, one end of which is attached to the working member, and means for alternately connecting the drive chambers to a pressure source and drain, made in the form of a two-position spool valve, the spool of which is installed in the second the wall of the housing with the ability to interact with the working body (1).

The lime pump has the following disadvantages.

The reliability of the pump on chemical hazardous substances (toxic or explosive liquid components) is reduced, the ingress of which into the drive chambers and mixing, for example, with oil or emulsion is unacceptable. The known pump does not exclude the possibility of such a danger, since when the reciprocating movement of the working body relative to the sleeve, and the last relative to the housing, the corresponding seals wear out, the tightness of the insulation of the drive chamber, in which the elastically deformable sleeve is placed, is broken, and into it from the working chamber and The pumped liquid enters the suction cavity of the pump and mixes with the drive fluid, which may, for example, cause an explosion.

In the prototype pump, the metering accuracy is reduced, since long-term operation results in residual deformation of the elastically deformable sleeve, which for this reason, due to its elastic deformation forces, decreases in diameter and the elongation does not return to the original standing, i.e. it does not restore its original length under the influence of pressure of the drive fluid on its outer side surface. And this, in turn, reduces the stroke length of the working body and violates the dosing of the known pump.

The purpose of the invention is to increase the reliability of operation and the accuracy of dosing.

This goal is achieved by the fact that the known volumetric pump comprising a housing with an internal cavity and two end walls, the first of which is equipped with a discharge valve with an inlet in this wall, a working body with a stop placed to form a working chamber in spring loaded relative to the housing and the working body of the sleeve mounted movably in the axial direction with the possibility of contact with

the first wall of the housing and having means of sealing the outer surface in the interface with the housing, the reciprocating drive of the working body in the form installed with the formation of two is attached to the working body, and means for alternately connecting the drive chambers to the pressure source and discharge, made in the form of a two-position according to the invention is provided with a spool valve, the spool of which is installed in the second wall of the housing with the possibility of interaction with the working body a partition in the inner cavity of the housing with an axial hole for the passage of the working body and radial holes for communication of one of the drive chambers with a spool distributor, and an additional elastically deformable sleeve fixed by the ends on the partition and the working body with the formation of one and part of the second drive chambers, the diameter the additional sleeve is larger than the diameter of the main one and the other end of the latter is fixed on the partition, the working body is loaded with a spring relative to the housing, and the drive measure, formed by the inner walls of the primary and secondary sleeves, mounted to be connected to the injection cycle to a pressure source, for suction stroke - to the sink.

Such a new set of features is unknown from the known similar technical solutions and it leads to the achievement of a new positive effect: the reliability of operation and the dosing accuracy are increased. In this case, the reliability of the pump increases, since due to the fact that it is provided with a partition transversely located in the internal cavity of the housing and an additional elastically deformable sleeve, absolute tightness of the drive chambers and their isolation from the working chamber and the suction cavity of the pump are ensured. Improving the metering accuracy is ensured by the fact that the pump is equipped with a partition transverse to the inner cavity of the housing with an axial hole for passage of the working element and radial holes for communication of one of the drive chambers with a spool distributor, and an additional elastically deformable sleeve fixed with ends to the partition and the working body the formation of one and a part of the second drive chambers, and the diameter of the additional sleeve is larger than the diameter of the main and the second end of the last on the partition, the working body is loaded with a spring relative to the housing, and the drive chamber, formed by the inner walls of the main and additional sleeves, is installed with the possibility of connecting to the pressure source at the pressure stroke, to the drain at the suction stroke, since this ensures a constant length of the working body in the sleeve, irrespective of the permanent deformation of the sleeves, or of the back pressure in the consumer network.

The drawing shows a diagram of a volumetric pump.

The volume pump contains a housing 1 with an internal cavity and two end walls, on the first of which there is a discharge valve 2 with an inlet in this wall, mounted on the supporting surface 3, a working body 4 with a stop 5, placed in the sleeve 6 with the formation of the working chamber 7 , suction and discharge pipes 8 and 9. The working body 4 is equipped with a sealing element 10 in the area of contact with the sleeve 6. The sleeve 6 is mounted movably in the axial direction with the possibility of contact with the supporting surface 3 of the first wall of the housing 1 and spring loaded relative to the working body 4 by the spring 11 by means of a stop 12. Moreover, the sleeve 6 is installed with an annular gap relative to the inner surface of the housing 1 and has a means of sealing 13 of the outer surface in the mating zone of the housing 1. In this case, the sleeve 6 relative to the housing 1 is loaded with a spring 14 by emphasis 15. The working body 4 relative to the housing 1 is spring-loaded with a spring 16. The suction cavity 17 is located on the side of the discharge valve 2 and is in communication with the suction pipe 8. Reciprocating drive movement of the working member 4 is formed as a proxy uprugodeformiru- sleeves 18 and 19 to form two chambers and drive means for alternately connecting the drive chamber to the pressure source and a drain formed as a two-position slide valve distributor.

The pump is equipped with a partition 20 transversely located in the internal cavity of the housing 1 with an axial hole 21 for passage of the working body 4 and radial holes 22 for communicating one of the drive chambers with a spool valve 23, the spool 24 of which is installed in the second wall of the housing 1 with the possibility of interaction with the working body 4. Elastically deformable sleeves 18 and 19 are fixed with ends on the partition and

working body. Moreover, an additional elastically deformable sleeve 18 is installed with the formation of one chamber 24 and part of the second chamber formed by internal

the walls of the main and additional sleeves 19 and 18. The diameter of the additional sleeve 18 is larger than the diameter of the main sleeve 19, and the drive chamber, formed by the inner walls of the main and additional sleeves 19 and 18, is installed with the possibility of connection at the discharge stroke to the pressure source, and at the suction stroke - to the drain. The end part of the sleeve 6 on the side of the valve 2 is equipped with a removable

5 with a glass 26 with a sealing ring 27. Using, for example, a threaded connection with a spool 24, a screw 28 is connected, which is partially located in the internal cavity of the working body 4. Using

0 seals 29 and 30 ensures tightness of placement in the housing 1, respectively, of the distributor 23, the cover 31 and the partition 20. The distributor 23, the cover 31 and the partition 20 are secured in the housing 5 by the nut 32 by means of bushings 33 and 34. The cavity 35 between the distributor 23 and the cover 31 constantly in communication with the drive chamber 25 by a pipe 36. The drive chamber formed by internal

The walls 37 of the main and additional hoses 19 18 are continuously connected by a pipe 37 through the radial holes 22 in the partition 20 with the outlet openings 38 of the distributor 23. On the casing 1, nozzles 39 and 40 are placed for connecting the pump to the pressure source and to the drain. The inlet 8 and 39 outlet 9 and 40 nozzles with the corresponding inlet and outlet pipes (hoses) disconnected from the pump are closed by covers 41. When the reciprocating movement in the extreme positions, the working element 4 switches the spool 24 in the distributor 23, on it with a screw

5 28 with a pusher placed in the internal cavity of the working body 4 and including two axially movable bushings 42 and 43, mounted with a gap using the spring 44 located between them and fixed in the working body 4 using, for example, a special split ring 45.

The pump operates as follows. Pipes 39 and 40 are connected respectively to a pressure source and to a drain, for example, a hydraulic system of a powered roof support of a treatment plant. The nozzles 8 and 9 are respectively connected to the suction and discharge hoses. With reciprocating work

body 4, the volume of the working chamber 7 changes. The movement of the working body 4 to the left begins when the pressure valve 2 is closed and the cup 26 is pressed against the supporting surface 3 by the springs 11 and 14 by means of the sleeve 6. When the working body 4 moves to the left, the volume of the working chamber 7 increases, and when moving to the right decreases. Working body 4 at the suction stroke, i.e. at the beginning of the movement to the left until its abutment 5 contacts with the abutment 12 of the sleeve 6, it moves under the action of the difference of the liquid pressure forces in the drive chamber 25 and in the drive chamber formed by the inner walls of the main and additional sleeves 19 and 18 onto the side surface of the elastically deformable sleeve 18, and under the action of the expanding springs 11 and 16. As the working body 4 moves to the left, the distance between its stop 5 and the stop 12 of the sleeve 6 is reduced, and at the moment of interaction of these stops, the working chamber 7 communicates with the suction pipe 8 through the cavity 17 of the housing 2 and is filled with an injection medium. At the moment of the stops stops 5 and 12, the working body 4 and the sleeve 6 continue to move to the left simultaneously, and the suction cavity 17 of the housing 1 and the working chamber 7 are filled with the pumped (filled) medium coming from the supply tank (not shown conventionally in the drawing) through the suction pipe 8. At the suction stroke, the drive chamber 25 is in communication with the pressure source through the pipe 36, the cavity 35 is the corresponding channels of the distributor 23 and the drive pipe 39, and the drive chamber formed by the inner walls of the main and complement of the sleeve hoses 19 and 18, in communication with the drain through the pipe 37, the spool valve 23 and the outlet pipe 40. In this case, under the action of the overpressure force of the drain liquid, the main sleeve 19 increases in diameter and shortens with the movement of the end attached to the working body 4, along towards the partition 20, in which the second end is fixed. At the same time, under the action of elastic deformation forces and the pressure difference of the pressure fluid in the drive chamber 25 and the drain fluid in the inner cavity of the elastically deformable sleeve 18, the latter decreases in diameter and lengthens with the end attached to the working body 4 moving away from the partition 20 in which its other end is fixed. In this case, under the action of potential energy accumulated at the injection stroke by the compressing spring 16, the latter is unclenched at the suction stroke with the movement of its end interacting with the working body 4, towards the partition

20, through the opening 21 of which the working body 4 is freely passed with an annular gap 4. Moving the working body 4 to the left, i.e. at the suction stroke, the forces from the sealing elastic elements 10 and 13, respectively, against the inner and outer walls of the sleeve 6, from compressing the spring 14, as well as the pressure force of the pressure fluid located in the drive chamber 25, on the cross-sectional area of the working

5 of the organ 4 in the place of fastening in it one of the ends of the additional sleeve 18, the diameter of which is larger than the diameter of the main sleeve 19. However, the indicated forces applied to the working body 4 to the working body 4 on the left are significantly less than the forces applied to it on the right, therefore it on the suction stroke it moves to the left, i.e. to increase the volume of the working chamber 7. The main, determining forces,

5 providing movement of the working member 4 to the left, is the pressure force of the pressure fluid in the drive chamber 25 over the lateral surface area of the elastically deformable sleeve 18 and the unloading force

0 springs 16.

When the slide valve 24 is moved to its extreme left position, it blocks the channels in the distributor 23 with its working slots so that the drive chamber 25 is isolated from the pipe 39, i.e. from a pressure source, and is communicated through a nozzle 40 with a drain. At the same time, the drive chamber formed by the inner walls of the primary and secondary arms 19

0 and 18, is isolated from the drain and connected to a pressure source through radial channels 22 in the baffle 20, pipe 37, spool valve 23 and inlet pipe 39.

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Due to the fact that the diameter of the additional sleeve 18 is larger than the diameter of the main sleeve 19, the total force of the pressure of the pressure fluid in these hands acts on the working body 4 in the direction of the working chamber 7. In this case, the elastically deformable sleeve 18 under the action of the pressure force of the pressure fluid on its inner walls increase in diameter and shorten with the movement of its end, fixed in the working body 4, towards the partition 20, in which its other end is fixed, i.e. towards the discharge valve 2. Therefore, the working body 4 moves

to the right, i.e. pumping cycle is in progress.

When the working body 4 moves to the right, i.e. on the pumping stroke, the sleeve 6 moves at the same time, since it is pressed against the stop 5 of the working body 4 by the springs 11 and 14. At the moment of contact of the cup 26 with the supporting surface 3, the working body 4 continues to move to the right and compresses the spring 11. moves relative to the sleeve 6, reducing the volume of the working chamber 7.

In the injection stroke, the spring 16 is compressed all the time and potential energy is accumulated in it due to the energy of the pressure fluid entering the drive chamber formed by the inner walls of the main and additional arms 19 and 18. After contact with the supporting surface 3 of the cup 26 of the sleeve 6, the spring 14 is stopped .

At the injection stroke, under the influence of the working body 4, moving to the right, the elastically deformable sleeve 19 lengthens and decreases in diameter. At the same time, its end, mounted on the working body 4, simultaneously moves towards the working chamber 7, i.e. in the direction from the partition 20, in which the other end of this sleeve is fixed. When the main sleeve 19 is stretched in it, and more precisely in its special braid net, potential energy accumulates, as in a spring, on the pressure stroke, within the limits of its elastic deformation due to the pressure energy of the pressure fluid on the inner walls of the elastically deformable sleeve 18. As the movement of the working body 4 to the right in the working chamber 7, the pumped (pumped) medium through the discharge valve 2 is displaced into the pipe 9.

Moving the working body 4 to the right, i.e. on the injection stroke the forces hinder:

- friction forces of the sealing elastic elements 10 and 13, respectively, on the inner and outer side walls of the sleeve 6;

- elastic deformation forces under tension (elongation) of an elastically deformable sleeve 19;

- elastic deformation forces during compression of the springs 11 and 16;

- pressure forces of the pressure fluid on the inner walls of the elastically deformable sleeve 19, aimed at increasing it in diameter and decreasing in length;

-the force of the pressure of the liquid on the working body 4 when it is compressed in the working chamber 7;

- the resulting pressure force (on the working member 4) of the pressure fluid in the drive chamber formed by the inner walls of the primary and secondary arms 19 and 18;

- pressure force of the drain fluid in

the drive chamber 25 on the outer side wall of the additional sleeve 18 located therein.

However, the forces preventing the movement of the working body 4 to the right, i.e. on the

the discharge stroke is always less than the driving force, i.e. the pressure force of the pressure fluid on the inner side wall of the additional sleeve 18, which in this case increases in diameter and shortens

in moving its end fixed on the working body 4, towards the working chamber 7, moving the working body 4 to the right.

Upon reaching the right extreme position, the working element 4 moves to the extreme right position the spool 24 in the distributor 23 by pressing the screw 28 with the movable sleeve 43 of the pusher, compressing the spring 44. When moving the spool 24

in the extreme right position, he blocks the corresponding channels and holes in the distributor 23 with his working slots so that the drive chamber 25 communicates with the pressure source through the inlet

a pipe 39, a spool valve 23, a cavity 35, a pipe 36, a radial hole in the housing 1 and slotted holes — grooves in the end part of the sleeve 33 from the side of the valve 23, and the drive chamber formed by the inner walls of the main and additional sleeves 19 and 18 communicates with drain through the holes 22 of the partition 20, the annular grooves on its outer side wall and the inner wall of the housing 1, a radial hole in the latter, a pipe 37, radial channels 38 and other corresponding channels and holes in the distributor 23 and outlet pipe 40. At the moment of communication of the drive chamber 25 with the pressure source, and the drive chamber formed by the inner walls of the primary and secondary arms 19 and 18, with a drain, the working member 4 changes the direction of travel in the opposite direction, i.e. moves to the left and the cycle repeats.

Claims (1)

SUMMARY OF THE INVENTION A displacement pump comprising a housing with an internal cavity and two end walls, the first of which is equipped with a discharge valve with an inlet opening in this wall, a working body with an abutment placed to form a working chamber in the sleeve loaded with springs relative to the housing and working body mounted movably in the axial direction with the possibility of contact with the first wall of the housing and having means of sealing the outer surface in the area of contact with the housing, the reciprocating drive the movement of the working body in the form of an elastically deformable sleeve installed with the formation of two drive chambers, one end of which is attached to the working tool, and means for alternately connecting the drive chambers to a pressure source and drain, made in the form of a two-position spool valve, whose spool installed in the second wall the housing with the ability to interact with the working body, characterized in that, in order to increase the reliability of operation and dosing accuracy, the pump is equipped with a partition transversely located in the internal cavity of the housing with an axial hole for passage of the working body and radial holes for communication of one of the drive chambers with a spool a distributor and an additional elastomeric sleeve, fixed by the ends on the partition and the working body with the formation of one and part of the second drive chambers, with a diameter of up to the filling sleeve is larger than the diameter of the main one, and the second end of the latter is fixed to the partition, while the working element is loaded with a spring relative to the housing, and the drive chamber formed by the inner walls of the main and additional sleeves is installed with the possibility of connection at the suction stroke to the pressure source, and at the discharge stroke - to the drain.