RU2594540C1 - High pressure piston pump with electric drive - Google Patents

Abstract

FIELD: gas industry.

SUBSTANCE: invention relates to pneumatic systems, in particular, to devices for generating high pressure of air or gas in a main pipe, and can be used for metrological purposes for supply of means of controlling and measuring pressure. Pump includes housing 1, working chamber 2 formed by piston 3 of smaller diameter and cylinder 4. Working chamber 5 is formed by piston 6 of larger diameter and cylinder 7. Chambers 2 and 5 are separated by valve unit 8 with intake valve 9 and discharge valve 10, respectively connected with gas supply system and gas pressure consumption system. Pistons 3 and 6 are arranged on opposite ends of rod 11. In valve unit 8 there is longitudinal axial hole 12 for movement of rod 11. In neck of axial hole 12 there is sealing elastic ring 13, sealing chamber 2 and chamber 5 relative to each other. At end of rod 11 on side of piston 3 there is bypass channel 14.

EFFECT: simplified design while providing high output pressure, higher reliability and reduced cost.

3 cl, 5 dwg

Description

The invention relates to structural elements of pneumatic systems, and in particular to devices that create high air or gas pressure in the line and can be used for metrological purposes to power control and pressure measurement devices in high pressure mode with the necessary and sufficient air or gas productivity when carrying them out calibration or verification.

Designs of piston devices that create high pressure incorporate such elements as cylinders, pistons, suction and discharge valves, which form the so-called “dead” or “harmful” space when the piston is in top dead center, composed of over-valve and sub-valve spaces , communication channels, as well as the gap between the piston bottom and the cylinder cover, necessary to compensate for the thermal expansion of the piston, which affects the performance of the devices. "Harmful" space affects the filling of the cylinder with atmospheric air, because first, expansion of compressed air that is not pushed out of the harmful space by the piston occurs, reducing the performance of the piston device. Also, when the piston moves to the top dead center of the device, if the piston is driven by the drive, the pressure of the harmful space acting on the piston is explosive, expanding in the cylinder, having a destructive effect on the kinematics of the piston drive: connecting rod, crank, transmission links, etc. if the speed of the piston does not exceed the speed of expansion of the air.

Known devices are sources of creating pneumatic pressure and vacuum, such as Wika CPP30, Druck LPP30, Crystal PN: 2907 and Crystal PN: 2908, Germany, Druck PV211, Merian M-600KT, Heise TP 1-40 and Fluke 700PTP-1 pneumatic pumps. , USA, Elemer PV-60, Moscow, Russia and H-2,5, Chelyabinsk, Russia, as well as a device for creating pneumatic pressure, patent RU 2488788 C1, designed to create excessive pressure or vacuum during calibration of pressure measuring instruments by direct comparison testimony of the reference and verifiable pressure measuring instruments.

These pneumatic pumps have the same set of basic elements that provide pressure: a cylinder with inlet and outlet valves, a piston, a lever piston drive with a compression return spring to provide piston movement and create pressure or vacuum in the system of standard and calibrated pressure measuring instruments during calibration or verification. When compressing the air in the pump, the piston at the end of the stroke is adjacent to the cylinder cover, thereby reducing the harmful space, and the air pressure remaining after the compression process helps the return spring to move the piston to its original position. As a rule, the sealing of the piston in the pump cylinders is ensured by rubber seals, for which the movement speed is allowed up to 0.5 m / s, and the compression frequency of the lever arm of the pump by the operator manually does not allow reaching such a piston speed. At low cost, the disadvantage of hand pumps is that the compression of the lever handles is carried out manually by the operator.

Compressors are also widely used in the national economy for compressing and supplying air or any gas under pressure. Compressors incorporate an electric motor for driving piston assemblies through a transmission element - a belt drive, which provides a high linear speed of movement of the pistons. In this case, the tightness of the piston in the cylinder is ensured by metal O-rings, the speed of movement of which can be permissible up to 7 m / s. Therefore, the influence of harmful space extends only to the performance of the compressor. In order to eliminate the influence of harmful space in the cylinder walls, grooves are made to transfer compressed gas in the harmful space to the other side of the piston or gas bypass in compressors with spool distribution through special channels in the spool kinematically connected to the piston drive.

The disadvantages of using compressors to power calibrated or verifiable means of monitoring or measuring pressure, containing a small amount of closed working cavities or pressure receivers, are that the compressors are large in size, excess capacity, and correspondingly high cost. In addition, in the process, they create a high level of noise.

The closest in technical essence to the claimed is a piston vacuum pump, presented in A. with. USSR No. 1548510 according to class F04B 37/16 claimed 09/18/1987, publ. 03/07/1990, and selected as a prototype.

Known vacuum pump contains a piston with a rod installed in the cylinder with the formation of the working chambers, sealed with covers. Each of the working chambers has its own suction and discharge channel. On the mirror of the cylinder on the side of the ends of the cylinder bypass channels are made with a length exceeding the height of the piston. In FIG. 1 it can be seen that the pistons are driven from the crankshaft through a crosshead assembly rigidly connected to the piston rod.

The principle of operation of the piston vacuum pump described in the prototype - and.with. USSR No. 1548510, is as follows. When moving the piston from the drive, the gas is sucked into the working chambers one by one and the compressed one is pushed out of them by the piston. When the piston approaches the extreme position, for example, when gas is compressed in the rodless chamber through the channels on the cylinder mirror, the working chambers communicate with each other, and the gas remaining in the harmful space of the rodless chamber flows into the rod chamber. When the piston reaches the opposite extreme position during compression of the gas in the rod chamber through the channels on the cylinder mirror, the working chambers communicate with each other and the gas remaining in the harmful space of the rod chamber flows into the rodless chamber. For the possibility of bypassing, the known piston vacuum pump is double-acting.

This design solves the problem of eliminating the influence of harmful space, thus increasing the pump performance and relieving pump kinematics from the effect of explosive expansion of gas pressure in the harmful space when the piston passes the extreme positions.

A disadvantage of the known device is that the bypass channels for communicating the working chambers are made on the mirror of the cylinder. This is a difficult technological operation that requires special tools and technological equipment, and the internal dimensions of the cylinder should allow this operation to be performed. An expensive part, which is a cylinder with channels, increases the cost of the device. In addition, the presence in each of the chambers of its own suction and discharge channel also complicates the design of the device.

The piston seal in the device is metal rings, since the rubber seals would have increased wear due to their friction on the channels. Metal O-rings are difficult to manufacture and therefore expensive, and this also increases the cost of the device.

The fact that the working chambers in the pump are separated by only one piston and have their own separate inlet and outlet valves excludes the possibility of using the pump in the step compression mode, which is also a disadvantage.

The objective of the proposed technical solution is to simplify the design while ensuring high output pressure, increasing reliability and reducing cost.

The problem is solved in that in a high-pressure piston pump containing a housing in which two cylindrical working chambers are located on one longitudinal axis and arranged to move from the electric drive along their longitudinal axis, the piston is mounted on one end of the rod, while the chambers are equipped with exhaust and inlet valves and are able to communicate with each other by means of bypass elements, according to the invention, the working chambers are made of different diameters and are divided between the valve assembly, in which the inlet and outlet valves are located, has grooves communicating valves with the chambers, in the center of the assembly there is a longitudinal axial hole for the passage of the rod, in which a narrowing is made on the side of the smaller diameter chamber with an elastic sealing ring placed on it, on the other at the end of the rod, a bypass channel is made and a second piston is fixed, while each of the pistons is commensurate with its chamber and has the ability to move only in it, the exhaust valve is in communication with a smaller diameter chamber meter, and the inlet valve with a larger diameter chamber.

At the same time, an overflow valve in communication with both chambers can be placed in the valve assembly.

In addition, an additional bypass channel for communicating the chambers can be made in the rod in front of the larger diameter piston.

The implementation of the working chambers of different sizes in conjunction with their separation by means of a valve assembly in which the exhaust and intake valves are located, respectively connected with a smaller chamber and a larger diameter chamber, makes it possible to reduce the number of discharge and suction channels in comparison with the prototype, and the presence on the other the end of the rod of the second piston of a smaller diameter and the bypass channel and the inclusion in the valve assembly of the bypass valve or bypass channel in the rod in front of the piston of a larger diameter RA eliminates the need to make bypass channels on the cylinder mirror, which also simplifies the manufacturing technology of the pump while eliminating the impact on the operation of harmful space and maintaining high pump performance. At the same time, the execution in the valve assembly along the longitudinal axis of the through hole with a narrowing in which the elastic sealing ring is located on the side of the smaller diameter chamber allows avoiding metal sealing rings, also simplifying the design of the device as a whole.

The technical result is a simplification of the design while maintaining high performance and improving performance.

The inventive high-pressure piston pump with electric drive has a novelty in comparison with the prototype, differing from it by the presence of such essential features as the implementation of the working chambers of different diameters and the separation of the valve assembly, in which the inlet and outlet valves are located, grooves are made, communicating valves with cameras, in the center of the assembly there is a longitudinal axial hole for the passage of the rod with a narrowing from the side of the smaller diameter chamber with an elastic sealing ring placed in it, the presence of ugom end passageway rod and the second piston, the performance of each of the pistons commensurate with his camera and providing the possibility of moving them only therein, the message of the exhaust valve with a camera of smaller diameter, and the inlet valve - with a camera of larger diameter providing a plurality of achieving the desired result.

The applicant is not aware of technical solutions containing the above distinguishing features, which together ensure the achievement of a given result, therefore, he believes that the claimed technical solution meets the criterion of "inventive step".

The inventive piston high-pressure pump with electric drive can be widely used in industry when used for metrological purposes to power control and pressure measuring instruments with high-pressure gas or air with the necessary and sufficient performance during calibration or verification, therefore, meets the criterion of "industrial applicability" .

The invention is illustrated by drawings, which are presented in:

- FIG. 1 is a general view of a high pressure piston pump with an electric drive and with an overflow valve in the valve assembly;

- FIG. 2 is a general view of a high-pressure piston pump with an electric drive and with a bypass channel in the rod from the side of a larger diameter piston;

- FIG. 3 - operation of a piston pump for extruding and sucking gas;

- FIG. 4 - operation of the piston pump to relieve gas pressure;

- FIG. 5 - operation of the piston pump during gas bypass.

Structurally, a high-pressure piston pump with an electric drive (Fig. 1 - Fig. 5) contains a housing 1, a working chamber 2, formed by a piston 3 of a smaller diameter and a cylinder 4, and a working chamber 5, formed by a piston 6 of a larger diameter and a cylinder 7, separated by a valve node 8 with an inlet valve 9 and an exhaust valve 10, respectively associated with the gas supply system and the gas pressure consumption system (not shown). In this case, the pistons 3 and 6 are placed at opposite ends of the rod 11, for the movement of which a longitudinal axial hole 12 is made in the valve assembly 8. In the narrowing of the axial hole 12, a sealing elastic ring 13 is placed, which seals the chamber 2 and the chamber 5 relative to each other. At the end of the rod 11 from the side of the piston 3 of a smaller diameter there is a bypass channel 14 (Fig. 1). Also, the valve assembly 8 may include an additional bypass valve 15, or in the rod 11 in front of the piston 6 can be made bypass channel 16 (Fig. 2). Depending on the location of the actuator 17, it can be kinematically connected to the piston 3 or to the piston 6.

An electric piston high-pressure pump, when supplied to the gas pressure consumption system, operates as follows.

When the actuator 17 is mounted on the housing 1 (Fig. 1), the piston 3 kinematically connected to the electric actuator 17 and the piston 6 connected by the rod 11 to the piston 3 make a reciprocating movement in the cylinders 4 and 7. The inlet valve 9 provides gas is sucked into the working chamber 5, and the exhaust valve 10 passes gas under pressure from the working chamber 2. The bypass valve 15 allows the gas to pass from the chamber 5 to the chamber 2 in a one-way direction. The longitudinal axial hole 12 in the process, communicating between the chambers 2 and 5, serves to dump the remaining in the harmful space gas of the working chamber 2 under pressure into the working chamber 5.

The operation of the piston pump in the direction of increasing the volume of the working chamber 5 (Fig. 3) ensures that gas is sucked into the chamber 5 by the piston 6 in the cylinder 7 through the inlet valve 9. At this time, the piston 3 in the cylinder 4 extrudes gas under pressure through the exhaust valve 10 from the power chamber 2 into the gas consumption system. When this valve 9 and 10 are open, and the valve 15 under the influence of gas pressure in the working chamber 2 is closed.

When the pistons 3 and 6 approach their final position (Fig. 4), the exhaust valve 10 and the intake valve 9 are closed. In the working chamber 2 there is a gas pressure, which remained in the harmful space of the communication channels and channels, and in the working chamber 5, the pressure of the gas supplied through the suction valve 9 from the gas supply system. At the same time, the bypass channel 14 passes through the sealing ring 11 and connects the working chamber 2 to the working chamber 5 through an axial longitudinal hole 12. The gas pressure from the harmful space of the working chamber 2 passes into the working chamber 5 and the pressure in both chambers is balanced, but the pressure in the working chamber 5 becomes higher than the gas pressure present here due to the addition of gas pressure from the harmful space of the working chamber 2. The bypass valve 15 remains closed. The transition of the kinematic connection of the top dead center of the piston 3 occurs smoothly, without the pressure of the harmful space of an explosive nature on the piston 3, without exerting a destructive effect on the details of the kinematics of the piston drive: connecting rod, crank, transmission links, electric drive.

Having smoothly passed through the top dead center of the piston 3, the pistons 3 and 6 in the cylinders 4 and 7 respectively begin to move (Fig. 5) and the gas located in the working chamber 5 under pressure higher than the pressure of the sucked gas by the amount of pressure addition from the harmful space of the working chamber 2 begins to compress and flow through the open bypass valve 15 into the working chamber 2. The bypass channel 14 passes through the o-ring 13 and the communication between the working chambers 5 and 2 through the axial longitudinal hole 12 is interrupted. The inlet valve 9 and the exhaust valve 10 are closed at this time. The working chamber 2 is filled with gas with a pressure greater than the gas pressure in the working chamber 5 due to the fact that the volume of the working chamber 2 is less than the volume of the working chamber 5.

When changing the direction of movement of the pistons 3 and 6, gas under pressure is squeezed out of the working chamber 2 through the exhaust valve 10 into the gas pressure consumption system, the bypass valve 15 is closed, and the working chamber 5 is filled with gas through the suction valve 9 from the gas supply system (Fig. 3) .

In the case of performing in the rod 11 in front of the piston 6 of the bypass channel 16 (Fig. 2), after a smooth transition of the top dead center of the piston 3 and the movement of the pistons 3 and 6 in the cylinders 4 and 7 in the direction of decreasing the volume of the working chamber 5, the gas in the working chamber 5 under pressure above the pressure of the sucked gas by the amount of pressure addition from the harmful space of the working chamber 2, begins to compress. When the pistons approach the final position, the bypass channel 16 passes through the sealing ring 13 and connects the working chamber 2 to the working chamber 5 through the axial hole 12. The gas pressure from the working chamber 5 passes to the working chamber 2 and the pressure in both chambers is balanced.

Thus, the electric drive, reciprocating the pistons 3 and 6 in the cylinders 4 and 7, provides a high pressure output through the exhaust valve 9 to the gas pressure consumption system by the piston 3 in the working chamber 2, releasing pressure from the harmful space of the working chamber 2 into the end of the stroke of the piston 3, thereby unloading the piston 3 from the destructive effect of pressure in the harmful space when the piston 3 passes the top dead center and further increasing the pressure of the gas sucked from the gas supply system in the chamber with the piston it in the cylinder 7 of a larger diameter, which at the next moment is fed into the working chamber 2 of the cylinder 4.

In comparison with the prototype of the inventive piston pump is simpler in design while providing high output pressure, increasing reliability and reducing cost.

Claims (3)

1. A piston high-pressure pump with an electric drive, comprising a housing in which two cylindrical working chambers are located on one longitudinal axis and are arranged to move a piston mounted on one end of the rod from the electric drive along their longitudinal axis, the chambers being equipped with an exhaust and inlet valves and have the ability to communicate with each other through the bypass elements, characterized in that the working chambers are made of different diameters and are separated by a valve assembly in which the inlet and outlet valves are placed and grooves are made, communicating valves with the cameras, in the center of the assembly there is a longitudinal axial hole for the passage of the rod, in which, from the side of the smaller diameter chamber, a narrowing is made with an elastic sealing ring placed in it, at the other end of the rod the bypass channel and the second piston is fixed, while each of the pistons is commensurate with its chamber and has the ability to move only in it, the exhaust valve is in communication with a smaller diameter chamber, and the inlet valve en - with larger diameter chamber. 2. The piston pump according to claim 1, characterized in that an overflow valve in communication with both chambers is additionally located in the valve assembly. 3. The piston pump according to claim 1, characterized in that an additional bypass channel is made in the rod in front of the larger diameter piston.

Images