WO1987002100A1

WO1987002100A1 - Displacement pump

Info

Publication number: WO1987002100A1
Application number: PCT/SE1985/000372
Authority: WO
Inventors: Axel Egnell
Original assignee: Axel Egnell
Priority date: 1984-03-27
Filing date: 1985-09-27
Publication date: 1987-04-09

Abstract

A displacement piston pump incorporating a driving pump (11), which via a conduit hydraulically drives a lifting pump (12) provided with a spring loaded differential piston (23). The pistons (15, 23) of the pumps are designed with through channels (16, 29, 34, 35) equipped with valves (21, 21; 32, 36) which open and close concurrently with the lifting. The purpose of the invention is to provide a simple cooperation between a driving source, e.g. a wind turbine and the driving pump, whereby the power transfer and the government of the valve of the driving pump shall take place in a simple and very reliable manner without any energy losses. This has been achieved thereby that the valve of the driving piston, which is intended to close at the driving stroke of the piston and to open at its lifting stroke, is arranged to be urged to closed and open positions by means of a reciprocating push rod forming part of the driving device of the pump.

Description

DISPLACEMENT PUMP

The present invention refers to a displacement pump of the type incorporating at least two piston pumps, one driving pump which via a conduit hydraulically drives a lifting pump equipped with a spring-loaded differential piston, the pistons of the pumps being designed with through channels provided with valves which open an close concurrently with the lifting operation .

Background of the invention

Piston pumps of the above mentioned type are earlier known in different embo iments and are mainly used where the distance between the driving pump and the lifting pump is comparatively large. Where the pumps are not situated directly above each other and where electric current not always is available for driving a pump.

Particulary in the developing countries, where wind power is awailable, it is a demand that the pump is of the most simple design with a few mobile parts only, which a person who lacks mechanical knowledge must be able to handle and maybe also maintain. The wind power is often available at inconvenient locations in relation to the well, the drilling hole or the like and it is therefore necessary to be able to transfer the energy from the wind turbine to alifting energy in a drilling hole, which can be situated at a considerable distance from the wind turbine.

The purpose and most essential features of the invention

The purpose of the present invention is to provide a development of the known hydraulically working piston pump , whereby the power transfer from e.g. the wind turbine to the driving pump and the governing of the valve of a driving pump shall be effected in a simple and very reliable manner, without any energy losses. This has been obtain thereby that the valve of the driving piston, which is intended to close at the driving stroke of the piston and to open at its lifting stroke, is adapted to be urged to closed and open position by means of a reciprocating push rod forming part of the driving device of the pump, and preferably consituting the transmission member from a wind turbine or the like.

Description of the drawings

Fig. 1 shows a displacement pump consisting of a driving pump and a lifting pump as seen in section with the pistons in one end position.

Fig. 2 shows a section analogons with fig. 1 through the displacement pump according to the invention, with the pistons shown in the opposite end position.

Description of the embodiment.

The displacement pump according to the invention consists of two piston pumps, a driving pump 11 intended to be arranged in the vicinity of the driving source (not shown), which e.g. can be a wind turbine, and a lifting pump 12, situated at a lower lewel, from which the liquid-water-shall be collected. Between the two piston pumps 11 ,12 then is arranged a conduit 13 in the shape of hose a tube or the like, by means of which the two piston pumps are hydraulically interconnected. From the driving source which is not further shown, extends a push rod

14 acting as transmission between the driving source and the driving pump, and which push rod acts directly upon the piston

15 of the driving pump 11 , which is axially displaceable in the pump housing 17 and in one end of which - in the drawing the lower end - is arranged an inlet 18 to which the conduit

13 is connected whereas at the oposite end of the pump housing is arranged a laterally directed outlet 19. The piston 15 is provided with a through channel 16 and the end of the push rod

14 acting upon the piston 15 is designed as a valve body 20, which can be brought to sealing engagement against a seat at the upper end of the through channel 16. The valve body 20 is further provided with a stop face 21 which under cooperation with a yoke 22, fitted to the piston 15 limits the movement of the valve body. The task of the yoke 22 is to interconnect the push rod 14 and its valve body 20 with a piston 15 thus that the piston would be connected to the push rod if the liquid in the system should sink or the system should become entirely emptied .

The lifting pump 12 is provided with a differential piston 23 consisting of two piston sections one of which 24 has a smaller diameter than the other piston section 25. The pump housing 26 is design in a corresponding manner with a housing portion which has an inner diameter corresponding to the diameter of the piston 24 where as the second housing portion 28 has an internal area corresponding to the area of the second piston section 25. The bigger piston portion 25 of the differential piston is provided with a number of through channels 29, which interconnect the space 30 below the bigger piston section 25 with the annular space 31 above the piston section 25. The channels 29 are each one provided with a non-return valve 32 which closes when the differential piston moves in the direction towards the outlet 33 of the lifting pump and opens at movement in the opposite direction. The smaller piston portion 24 is also provided with through channels 34,35 which communicate on one hand with the annular space 31 and via a non-return valve 36 with a pump department 37, which is connected to the outlet 33.

The differential piston 23 is spring-loaded by means of at least one and preferable two pressure springs 38,39 arranged in the pump department 30. The springs shall firstly and support the static pressure in the system and secondly as potential energy, take up and give away the work necesary for each pump stroke. For allowing adjustment of a suitible spring pressure, one end wall 40 of the lifting pump is designed as a nut, which can be screwed in or out in relation to the pump housing 28. In this end wall there is arranged a inlet 41, which preferably is provided with a self cleaning inlet sieve. In both pump housings 17,26 are provided arranged stop faces 42 and 43 resp. which limit the stroke of each piston. The pump according to the invention operates in the following manner.

At the downwards movement of the push rod 14 in the direction of the arrow 44, in figure 1, the liquid present in the pump chamber 45 of the driving pump 11 and in the conduit 13 is pressed into the pump compatement 37 of the lifting pump 12 which hydraulic pressure thus acts upon a small end surface 46 of the differential piston 23. The non-return valve 36 is thereby closed and at the displacement of the differential piston towards the pump chamber 30 in the direction of arrow 47 the non-return valves 32 are opened, thus that liquid can flow into the pump chamber 31 and via the channels 34,35 into the pump compartement 37. The springs 38,39 are compressed at the same time as the differential piston is urged into the pump chamber 30, when the push rod turns and is displaced in the direction of arrow 48 towards the outlet 19 is at the same time the valve body 20 is simutltanpously raised from the seat 21 thus that liquid can flow through the through channel 16 of the piston and further towards the outlet 19. The pack of springs thereby can come into action and press the differential piston in a direction against the outlet 33, whereby the liquid in the pump chamber 31,37 is pressed up through the conduit 13 to the pumproom 45 of the driving pump from where the liquid can flow away through the channel 16 to the pump chamber 49 and the outlet 19. When the push rod 14 has reached its upper position in order to start its driving stroke the above described process is repeated as long as the driving device is running.

The invention is not limited to the embodiment shown but a plurality of variations are possible within the scope of the claims. It is thus possible that the push rod 14 instead of supporting the valve body at one of its ends can be so designed that it in a suitable manner governs the valve function inquestion.

Claims

CLA I MS

1. A displacement pump of the type incorporating at least two piston pumps, one driving pump (11) , which ^'via a conduit hydralically drives a lifting pump (12) equipped with a spring-loaded differential piston 23) , the pistons (15,23) of the pumps being designed with through channels (16,29,34,35) provided with valves ( 21 , 21 ; 32 , 36 ) , which open and close concurrently with the lifting operating, characterized therein, that the valve (20,21) of the driving piston (15), which is intended to close at bhe driving stroke of the piston and to open at its lifting stroke, is adapted to be actuated to closed and open position by means of a reciprocating push rod (14) forming part of the driving device of the pump, and preferably constituting the transmission member from a wind turbine or the like.

2. A displacement pump as claimed in claim 1 , characterized therein, that the end of the push rod (14) acting upon the piston (15) is designed as a valve body (20) , designed to close the valve and thereby the through channel (16) of the piston at dis¬ placement of the push rod in one direction and to open the valve in the opposite displacement direction, and that the valve body of the push rod is provided with a stop face (10) arranged to limit the movement of the push rod (14) relative to the piston (15).