EP0105877B1

EP0105877B1 - Pump for liquids and gases

Info

Publication number: EP0105877B1
Application number: EP83900580A
Authority: EP
Inventors: Ludvig Naess
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-02-15
Filing date: 1983-02-15
Publication date: 1987-09-09
Also published as: EP0105877A1; WO1983002805A1; DK159857B; FI72784C; DK466783A; FI833737A0; NO150371B; JPS59500179A; DK466783D0; NO150371C; NO820431L; FI72784B; JPH0380993B2; AU1159283A; DE3373517D1

Abstract

Pump for liquids and gases, particularly for immersing in a well hole. A pump piston (35) is operated by a double acting operating piston (33) provided with working medium through a supply conduit (13). The supply of working medium to the respective sides of the operating piston (33) is controlled by a reversing valve (34). This has a slide (45) being operated by the operating piston (33).

Description

The invention relates to a pump of the kind described in the introductory part of claim 1, particularly for immersing into a well hole.
From US-A-1 557 116 there is known a pump, wherein the supply of working medium to the operating piston is controlled by a pilot valve arranged in a valve chamber. The pump is arranged remotely from a hydraulic linear motor in a separate cylinder. This decreases the efficiency and increases the number of parts and the time for manufacturing. This known pump thus has a disadvantageous costs-output ratio and can not be used for manual operation.
GB-A-595 223 discloses a liquid pressure operated pump which comprises a casing with a cylinder in which a double acting piston is reciprocally movable. Between the piston and the cylinder are provided two working chambers for movement of the piston. Separated from said cylinder and plunger arrangement there is provided a pump for supplying working fluid into the cylinder and into one of the working chambers in order to move the piston. Interposed in the supplying conduits for the working fluid is arranged a slide valve for selectably supplying said working fluid to one of said working chambers. The slide valve is operable in response to the pressure of the working fluid supplied to the casing of the pump and is changing from one operating position into the other in response of an increase of the pressure of the working fluid. This results that the working fluid is supplied to the other one of said two working chambers and in that the piston is moved in a reciprocal direction. Said arrangement is provided with the drawback that the operation control of the pump is only possible in dependency of the pressure of the working fluid. Variations in said pressure or a decrease of said pressure under a predetermined value would result in a breakdown of the operation of the pump.
GB-A-1 023 444 discloses a control system for a hydraulic operated engine in which an engine and pump unit comprises an engine piston which is reciprocally movable in a housing. The piston is provided with an axial hole through which the fluid to be pumped can be displaced into a tubing arranged axially to the piston. The movement of the piston is controlled by an engine valve unit which is arranged separately to the piston and housing arrangement and which is connected therewith by means of a plurality of conduits for supplying working pressure of a working fluid to the respective working chambers of the piston. The working fluid is strictly separated from the fluid to be pumped by a working fluid circuit. The engine valve unit is provided with an engine valve which is reciprocally movable in a housing and which is movable between a plurality of working positions in dependency of the pressure of the working fluid supplied to the working chambers of the piston and housing arrangement of the engine and pump unit. Therefore said control system requires a plurality of different conduits for the working fluid which are rather complicated and very costly in manufacturing. A further disadvantageous aspect lies in the fact that there is the danger of shutting up one of said conduits due to pollution of the working fluid. This would also lead to a breakdown of the operation of the control system.
The object underlying the present invention is to provide a pump of the above mentioned type which may be used in narrow well holes and on any depth, which is failsafe in operation, which can be manufactured under low costs and in which also a manual operation should be possible.
According to the invention, this may be achieved by the pump constructed according to the characterizing part of claim 1.
According to the invention, the slide valve is reciprocally movable between its operation positions by direct engagement with the plunger piston. This brings the advantage that the control of the pump is independent upon the pressure of the working fluid supplied to the pump. Variations of the pressure of said working fluid do therefore not cause a breakdown of the operation of the pump. A further advantage lies in the fact that the working fluid is of the same kind as the fluid to be pumped so that in general only two movable parts are necessary, namely the plunger piston and the slide valve which leads to lower manufacturing costs and which causes a failsafe operation of the pump.
Further advantageous details are stated in the subclaims.
A pump of this kind may be operated by hand and can be utilised in relatively deep holes, down to 3000-4000 m. This makes it possible to have water accessible at reasonable costs in areas previously without this possibility.
The invention will be further described with reference to the drawings, wherein:

Figure 1 shows schematically a water supply plant with a pump according to the invention immersed in a hole drilled in the ground.
Figure 2 shows an axial section A-A in Figure 4 through an embodiment of a pump according to the invention,
Figure 3 shows an axial section B-B in Figure 4 of a part of the pump in Figure 2, while
Figure 4 shows a section C-C through the pump of Figure 2.

In Figure 1 is shown a pump 11 which is immersed in a hole 12. The pump 11 has connections to the surface through a supply conduit 13 and an outlet conduit 14. These may preferably be integrated and made of a plastic material.
For the supply of working medium, in this example water, it is in the shown embodiment used a hand operated feeding pump 15 with a handle 16 operating a single acting piston 17 in a cylinder 18. The inlet opening for starting up fluid and the valves necessary may be of known kind and are not shown. Integrated with the hand pump 15 is a water reservoir 19, this being emptied through an outlet pipe 20. In the reservoir 19 is arranged a partition wall 21 to ensure water supply through the feeding pump 15.
This plant is adopted for use in areas wherein the technical and/or economical base for a motor driven feeding pump is missing. This may be the case in several economically underdeveloped rural areas in the world. The pump 11 may however well be operated with water supplied from a motor powered feeding pump.
In Figure 2 it is shown an axial section through an embodiment of the pump 11. This is adopted for immersing into a hole with diameter 45-60 mm. The pump in this embodiment has a generally pipe shaped casing 22 provided with an inlet filter 24 being screw fitted into the casing. The inlet filter is provided with holes 25 at the side. With an end wall 26 provided with a one- way-valve 27, an inlet chamber 28 is enclosed inside the inlet filter 24.
At one side of the casing 22 a longitudinal channel or conduit 29 is arranged down from the upper edge. Space for the conduit 29 has been provided by arranging the cylinder bore 23 somewhat excentrical, making a part 30 of the wall with larger thickness. The conduit 29 is substantially narrower than the cylinder bore 23, in the same way as the supply conduit 13 is more narrow than the outlet conduit 14. The area relationship between the two sections may e.g. be 1,6 at shallow holes and 1:1,5 at deeper. The two conduits 13 and 14 are connected to the conduit 29 and the cylinder 23 resp. with two junctions 31, resp. 32.
The main part of the pump 11 in the shown embodiment is a combined operating- and pump- piston, in the following named plunger piston 33, which will be described further. The supply of working medium from the supply conduit 13 to the plunger piston 33 through the conduit 29 is in the embodiment shown controlled by a slide valve 34, which acts as a reversing valve and which will be further described. The plunger piston 33 consists of two separate pistons, an upper 35 and a lower 36 one, being connected through a common, hollow piston rod 37. The piston rod 37 is journalled by a partition wall 38, creating a working chamber on each side of it, respectively a higher one 39 and a lower one 40. The upper chamber 39 is connected to the slide valve 34 through a conduit 41 and the lower chamber 40 over a conduit 42, the conduits 41 and 42 are extending through the casing 22.
On supplying working medium through the conduits 41 and 42 respectively, the plunger piston 33 will move up and down in the cylinder. The control of the supply will be described further. At this movement the plunger piston 33 will act as a pump piston. At the upper end of an axial, concentrical bore 43 through the plunger piston 33 a kickback valve 44 is arranged. The kickback valve 44 will let through water when the piston 33 is moving downwards. The reversing or slide valve 34 comprises a slide 45 with an annular groove which can connect the supply conduit 29 with the conduit 41 in a lower position and the conduit 42 in an upper position. The other of the two conduits 41 and 42 respectively then is opened to the cylinder 23 with connection to the outlet conduit 14. This means that working medium supplied to the chambers 39 and 40 exits together with water pumped by the plunger piston 33.
The slide 45 is moved a short distance upwards at the end of the corresponding movement of the piston 33 and correspondingly downwards at the end of the downwards movement of the piston 33. The movement upwards is effected by a direct thrust between the two parts, a coil spring 49 being arranged in between.
The movement downwards is effected by a pipelike rod 47 attached at the end of a central bore through the slide 45 by threads. The rod 47 extends down to the bore 43 and is provided with a radial flange 51 at the free end. In order to have cooperations between this flange 51 and the piston 33, the bore 43 has a flange 52 at the upper end, extending radially over the flange 51. At the end of the rod 47 there is arranged a coil spring 50 to suppress the shock of a force transferred between the two flanges 51 and 52.
To keep the slide 45 in certain end positions, it is provided with a spring biased ball 53 in a radial bore 54. This is extending sidewards from the slide 45 and is engaging one or another of an upper and a lower annular groove 55 and 56 respectively, with a mutual distance corresponding to the movement of the slide 45. The ball 53 may also have another biasing member, alternatively.
To let water from the conduit 42 into the cylinder 23, the slide 45 is provided with an annular groove 57 with outlets 58 radially to the bore 48 through the slide.
The partition wall 38, which can be prepared of a plastic material, may be inserted between an upper and a lower part of the casing 22, which are connected by threads. The lower piston 36, enclosing the valve 44 is suitably connected to the lower end of the piston rod 37 by threads.
The pump according to the invention may be manufactured of different materials. The most parts may be moulded or otherwise prepared from a plastic material. When manufactured for use on larger depths it may be suitable to use metal e.g., aluminium, for some parts.
The pump in the shown embodiment is also provided with sealings and other sealants of known kind.
Different details in the shown embodiment can be modified. The reversing valve shown as a slide valve 34 can be a pressure operated valve arranged in the wall 30 or at the feeding pump 15. In the last case an additional supply conduit to the piston 33 will be necessary.
The pump may also be provided with a different form of slide valve 34, being provided with three annular grooves, enabling an additional outlet conduit for the operating medium. When using such a valve it will be possible to operate the working piston with a medium different from that to be pumped.
The pump according to the invention can also be arranged with several operating units combined. E.g. two pistons of the shown kind can be arranged in the compound in the casing 22, the conduits 41 and 42 being connected to a lower, respectively an upper operating chamber for such a compound piston.

Claims

1. Pump for liquids and gases for immersing in a well hole or a corresponding opening, comprising a casing (22), a double acting plunger piston (33) arranged in a cylinder bore (23) of said casing (22) and forming two working chambers (39, 40), a slide valve (34) for selectable supplying working pressure to one of said working chambers (39,40) for reciprocally moving said plunger piston (33), characterized in that said slide valve (34) is arranged in said cylinder bore (23) wherein it is movable reciprocally between two operating positions, and in that the plunger piston (33) at the end of its movement into its uppermost or its lowermost position is engagable with said slide valve (34) to move same into the other operating position, respectively.

2. Pump as claimed in claim 1, characterized in that the slide valve (34) comprises a slide (45), which is resiliently held in its operating position by means of at least one member (53) being arranged in said slide (45) and biased into one of two recesses (54) provided in said cylinder bore (23) in relationship to the two operating positions of said slide (45).

3. Pump according to one of claims 1 or 2, characterized in that the operating engagement between the slider (45) and the plunger piston (33) is made by means of interposed coil springs (49, 50), respectively.

4. Pump according to one of claims 1 to 3, characterized in that the plunger piston (33) comprises two pistons (35, 36) joined by a stem (37) guided by an annular bearing (38) to provide, on each side of the bearing, said working chambers (39,40) with connections to the slide valve (34) for supplying of working medium alternatively to one of said chambers (39,40), the annular bearing (38) being one end wall of said two chambers (39, 40).

5. Pump according to one of claim 1 to 4, characterized in that the plunger piston (33) and the slide (45) are provided with an axial bore, respectively, for displacement of working fluid.

6. Pump according to claim 5, characterized in that the slide (45) is provided with an axial hollow rod (47) by which it is engageable with the plunger piston (33), said rod (47) extending into the axial bore of said plunger piston (33).

7. Pump as claimed in claim 6, characterized in that the hollow rod (47) is concentrically attached to the slide (45), its free end being provided with a flange (51) cooperating by means of the interposed helical spring (50), with a flange (52) projecting into the bore in the plunger piston (33) at the end of this being closer to the slide valve (45), the plunger piston (33) being arranged to engage the slide (45) by means of the interposed helical spring (49) when both said members are moved in proximity.