GB2105793A - A pump machine - Google Patents

Abstract

The machine is made up of a driving unit (1) and a piston pump, having pump ports, for fluids and more specially aggressive liquids. The driving unit (1) of the machine is joined up by way of at least one connection part (2) with a magnet (8) designed for running on the outer face of the unmagnetic cylinder material of the pump, [whose two cylinder ends are shut off]. The outer magnet (8) on the cylinder is used for moving a rodless pump piston or body (11), which has at least one magnet, therein and is moved axially by way of a magnetic force. <IMAGE>

Description

SPECIFICATION A pump machine The present invention is with respect to a pump machine and more specially to such a machine having a driving unit, a pump cylinder, a separating body placed within the cylinder and a connection between the driving unit and the body, and more specially to such a machine for pumping gases and liquids such as aggressive liquids.

Machines for pumping liquids and gases are widely used. Dependent on the function, liquid pumps may be classed as piston and centrifugal pumps. In piston pumps a driving body, which is moved from the outside in a limited space by a driving unit is used for pumping a separated-off amount of the material to be pumped recurrently.

Different sorts of piston pumps may furthermore be put in different classes, dependent on the sort of driving body, f.i. into pumps with a reciprocating ram or round plate-like piston, into vane pumps in which a driving body is moved backwards and forwards in a circle, into rotary displacement pumps such as rotary piston pumps, and into pumps in which the fluid itself, vapor or compressed air takes over the pumping function.

Unlike the case of piston pumps, the pumping effect is continuous in the case of centrifugal pumps, the important point being that the bladed impeller, to which the liquid to be pumped makes its way by way of an inlet port, is responsible for an increase in the kinetic energy of flow of the fluid, which is forced out of the pump through an output diffuser or a fixed peeler and is the taken up by the pressure line.

For pumping aggressive liquids use is generally made of diaphragm piston pumps, the displacement effect of the piston acting mechanically or by way of a liquid filling (of water or oil) on a diaphragm fixed in the housing of the pump. The selection of the material for the diaphragm, such as a rubber-like material, will be dependent on the nature of the material to be pumped. Furthermore, the displacement effect on the diaphragm may be produced by compressed air as well. Diaphragm piston pumps have the shortcoming for example that the amount of liquid pumped is dependent on the distance moved by the diaphragm so that if the pumping rate of such a diaphragm piston pump is to be stepped up, there will necessarily be an important increase in the size of the machine.

The use of piston pumps for chemically and mechanically aggressive liquids is responsible for an undesired effect inasfar as leaking will, in all cases, be likely at the point where the driving unit and the pump part moved thereby are joined together. Such a leak is likely to make the machine, and parts near it, dirty so that upkeep work will be necessary.

One purpose of the present invention, for taking care of these shortcomings, is that of designing a machine of the sort noted in which there is no chance of leaks and wear of the machine is cut down to the lowest possible rate. Furthermore, the machine is to be simple in its mechanical design.

For effecting this purpose, a pump machine having a driving unit, a pump cylinder, a separating body movingly placed within said cylinder and a connection between said unit and said body, is characterized in the present invention in that said cylinder is made of unmagnetic material and is shut off at two ends thereof, said body being magnetic and said connection having an outer magnet on the outside of said cylinder for moving said body axially backwards and forwards within said cylinder and forcing fluid through fluid ports of said cylinder under the power produced by said driving unit.

One useful effect produced by the invention is that there is no driving connection running through the wall of end of the pump cylinder so that there are no stuffing box troubles and, more specially, aggressive liquids may be pumped without any chance of their leaking to the outside. Leaks inside the pump, that is to say on one side of the pump piston to the other are only undesired inasfar as the efficiency of the machine is decreased to a certain degree. It will be seen that the liquid pump of the present invention does not have any undesired effects on the environment and keeps itself clean, the outer part of the driving system, from which the inner part is sealed off hermetically, not being touched by any aggressive liquid being pumped.Afurther point is that, because of the design, the number of moving parts is cut down as far as possible so that is may be said that it has, in relation to the useful effects offered, a low price. Furthermore, the machine of the present invention has a low wear rate and needs little upkeep.

As part of a useful development of the invention, the driving unit may be in the form of a doubleacting compressed air-powered cylinder. On using an air-powered driving unit in the machine, it is possible to make certain of a further decrease in the wear rate in the machine generally.

Because, as part of a further development of the invention, the connection part has a rod which is moved in the length direction of the pump cylinder and which is best formed by the piston rod of the air-powered cylinder, the rod being guided outside the cylinder, it is possible to make certain that the machine has a very low number of parts.

As part of a further development of the invention there is a joint in the end of the piston rod nearest to the pump cylinder, such a design stopping the parts from canting.

As a still further part of the design of the invention the connection between the driving unit and the outer magnet system may be undone, this being of great help for upkeep and repair work and furthermore driving units and piston pumps of different sizes may be joined up together.

As part of a further development, the outer magnet system is in the form of a ring-like driving magnet piece and at least one magnet part of the pump piston is in the form of a washer or ring, such a design giving a radial space between the driving unit and the piston pump so that these two parts may be placed next to each other while needing little space.

Further developments of the invention make certain that the magnetic connection function between the two magnet systems (outer and inner magnet systems) has the best possible properties, the inner magnet piece being safeguarded against the aggressive liquid.

Further useful effects and developments of the invention will be seen from the single figure, which is of a lengthways section through a machine of the present invention.

The machine to be seen in the figure, for pumping liquids and gases has as its most important parts a driving unit 1 and an unmagnetic pump cylinder 3, shut off at its two ends and joined up with driving unit 1 by way of a connection part 2, such part 2 being made up of a rod 4 functioning as the piston rod of driving unit 1, that is to say being joined up with its piston 5, and having a joint 6, with the function of joining up the driving unit 1 with the magnet system 8, which is in the form of a round hollow, that is to say ring-like, magnet driving structure. Driving unit 1 is in the present case designed as a double-acting air-powered cylinder.

Pump cylinder 3 is made of stainless steel, brass or synthetic resin with reinforcing fibers if necessary.

Pump cylinders 3 has connection pipes 10 at its two ends.

Piston 11 has a piston body made of aluminum or an other unmagnetic material with a low weight. The piston has permanent plate magnets 13, placed in a train one after the other and having spacer plates 14 placed therebetween. At the two ends of the system of plate magnets 13, which take the form of a cylinder-like body, the piston body has sliding guide plates 15. In place of plates 15 it is possible to have rings with their outer edges running on the face of the cylinder. On the outer sides of guide plates 15 there is, in each case, an elastomeric buffer plate (not to be seen in detail in the figure) so that, by way of such buffer plate, the piston 11 may be braked at a fixed stop, not to be seen in the figure.

The outwardly turned faces of the plate magnets 13 are at a small distance from the inner face of the pump cylinder 3 so that there is a space therebetween whose ends are sealed off by guide plates 15 so that it is not possible for any waste material such as turnings, produced on making the pump cylinder 3, to be taken up between the outer face of the ring magnet system of the piston 11 and the inner face of the cylinder.

The outer magnet system 8, which is formed by a cylinder-like magnetic driving structure, may be said to be of generally the same design as the piston 11 along a tube-like face or plane of symmetry between the outer faces of the pipes. The piston body 11 may, for these reasons, be said to be copies or "mirrored" by a sleeve part 20, which, however, has been specially designed with a view of cutting down stray magnetic fields by making sleeve part 20 of magnetizable material. The sleeve part 20 is placed round the axially stacked permanent ring-like magnets 21 placed one after the other and kept separate by the spacer washers 23 therebetween. The ring-like magnets 21 are locked in place by the end walls 24 screwed on to the sleeve part 20.The end walls 24 have an inwardly open groove 26, in which a stripper ring 16 is seated to keep undesired material from making its way into the small space between the ring-like magnets 21 and the outer face 33 of the pump cylinder.

Pump ports, not to be seen in any great detail, are placed opening into the cylinders spaces 30, 31 of the pump cylinder 3. Such ports are for example joined up with connection pipes 10. By using a system, not to be seen in detail here, of outlet and inlet or suction valves, it becomes possible for the pump to be run with the best possible working properties.

An account will now be given of the function of the machine: The recurrent backward and forward motion of piston 5 in driving unit 1 is transmitted by way of shaft 4, joint 6 and link 32 to magnet system 8.

Because the magnet system 8 is moved along the outer face 33 of pump cylinder 3 and because the piston 11 has the plate magnet parts 13, the piston 11 and the magnet system 8 are joined up magnetically with each other, so that the piston is moved as well. On motion of the magnet driving system 8 in the direction of arrow 34, the liquid, presently in cylinder space 30, is being forced out from pump cylinder 3 and the cylinder space 31 will be seen, on such motion of the pump taking place, to be an inlet port. The frequency of the backward and forward motion of the piston 11 is dependent, in the present system, on the frequency of the piston 5 in the driving unit 1.

Changes may be made in the design of the machine, and, to take an example, the permanent magnets 13 and the guide plates 15 may be of ring-like instead of plate-like form.

Claims (10)

1. A pump machine comprising a driving unit, a pump cylinder formed of a non-magnetic material and being closed at each end, a separating body formed of a magnetic material and movably located within said cylinder, and a connection provided between the driving unit and the body, the connection having an outer magnet on the outside of the pump cylinder for moving the body axially backwards and forwards within the cylinder and forcing fluid through fluid ports of the cylinder by means of the power produced by the driving unit.

2. A machine as claimed in claim 1, wherein the driving unit is pivotally connected with the magnet on the outside of the cylinder.

3. A machine as claimed in claim 1 or 2, wherein the driving unit and the magnet on the outside of the pump cylinder are removably connected with each other.

4. A machine as claimed in any of claims 1 to 3, wherein the driving unit is in the form of a doubleacting air-powered cylinder.

5. A machine as claimed in claim 4, wherein the connection includes a rod designed to be linearly movable in the length direction of the pump cylinder, the rod being in the form of a piston rod of the air-powered cylinder and extending out of the cylinder.

6. A machine as claimed in claim 5, wherein the rod has a joint thereon at an end of the rod nearest to said pump cylinder.

7. A machine as claimed in claim 5 or 6, including a link for joining said magnet on the outside of said cylinder with the rod, the link extending radially in relation to the cylinder.

8. A machine as claimed in any of the preceding claims, wherein the outer magnet is part of a ring-like magnet driving structure, the body in the cylinder having at least one plate-like magnet.

9. A machine as claimed in any of the preceding claims, wherein the body within the cylinder has at least one magnet part and at least one non-magnetic part, the body separating the cylinder into cylinder spaces, and ends of said body being covered with a material which is resistant to aggressive fluids.

10. A pump machine substantially as hereinbefore described with reference to the accompanying drawing.