GB2206157A

GB2206157A - Improvements in and relating to pumps

Info

Publication number: GB2206157A
Application number: GB08813098A
Authority: GB
Inventors: Lutz Lorenz
Original assignee: Uhde GmbH
Current assignee: ThyssenKrupp Industrial Solutions AG
Priority date: 1987-06-03
Filing date: 1988-06-03
Publication date: 1988-12-29
Also published as: GB8813098D0; DE3718560A1; CH676624A5

Description

f 1k I- "Improvements in and relating to pumps The invention relates to a

pump, especially a pump of the sort that is best described by the German term Spaltrohrrmotorpumpem that is driven by magnetic coupling.

Hermetic pumps are distinguished by the'absolute tightness of the housing, that is to say it is not possible either for external media to enter the pump or for the fluid inside the pump, that is to be transported, to reach the outside, except by flowing through the outlet opening of the pump. Such pumps are used for transporting all media that endanger the environment or that are endangered by the environment. Liquidified gases especially are transported using such pumps. Plain bearings have in the past been used for mounting the rotors of these pumps. The slide bearings are lubricated by the fluid that is to be transported itself or by an additional auxiliary. During the start-up or the shutdown phase of the pump and in operating areas that do not correspond to the design point there is direct contact between the bearing bushes and parts of the rotor and the housing. In the long term this direct contact causes bearing damage or, in an extreme case, may lead to destruction of the pump. it has been found that liquefied gases in particular are especially unsuitable for lubricating slide bearings in he start-up and shutdown phases.

It is known to use complicated temperature and bearing monitoring systems are so expensive compared with the pump that their use is scarcely justifiable for economic reasons.

It is an object of the invention to provide satisfactory mounting of the rotors of hermetically encased pumps even under difficult operating conditions.

The invention provides a pump comprising a rotor that is driven by magnetic coupling and is mounted on rolling bearings that can run dry.

The invention also provides a hermetically enclosed pump comprising a rotor that is mounted on rolling bearings that can run dry.

The invention further provides a pump, especially a slot tube motor pump, that is driven by permanentmagnet or electromagnetic coupling through a slit tube, wherein the mounting for the rotor of the pump is formed from rolling bearings that can run dry.

The mounting of the rotor of the pump being formed from rolling bearings that can run dry, the rotor of the pump is held in a defined position,, with the result that the start-up and shutdown phases of operation are omitted completely. For the reason monitoring of the bearings is superfluous or can be done very simply (for example using shock wave analysis).

It is especially advantageous for the rolling bearings to be made of ceramics. Ceramics materials are suitable for use at very high temperatures, so that 1 with ceramics rolling bearings dry running of the bearing is also possible without damage to the bearing being caused.

The invention also provides the use of the pump according to the invention in the f ield of nuclear technology. The use of hermetic pumps is especially suitable in that field.

In addition, the invention provides the use of the pump for transporting liquefied gases. Since liquefied gases are decidedly unsuitable for lubricating plain bearings, the mounting having rolling bearings that can run dry is especially advantageous for transporting such materials.

Also provided is the use of the pump for is transporting liquids that endanger the environment and liquids that are endangered by the environment.

One form of hermetic pump constructed in accordance with the invention will now be described by way of example with reference to the accompanying drawing, in which:

Figure 1 shows a hermetic pump in axial cross-section.

Referring to the drawing, one form of hermetic pump indicated generally by the reference numeral 1 has an inlet opening 2 and an outlet opening 3 which are connected to corresponding pipelines or the like that are not shown in the drawing. A rotor 4 pumps the fluid that is to be conveyed. This rotor 4 is mounted by way of ball bearings 5 and 6. The bearings are lubricated by the fluid that is to be transported itself, which preferably passes through a drilled hole 7 to the bearings 5 and 6. The ball bearings 5 and 6 are preferably made of ceramics material, with the result that even in the start-up and shutdown phases of the pump when there is little lubrication from the fluid that is to be transported there is no damage to the bearings.

The rotor is driven by an electromagnetic or permanent-magnet coupling, preferably through a magnetic gap tube.

Of course the invention is not limited to hermetic pumps having rolling bearings made of ceramics materials; for example other bearing materials that can run dry are also suitable for use.

1 It J2 is

Claims

1. A pump comprising a rotor that is driven by magnetic coupling and is mounted on rolling bearings that can run dry.

2. A hermetically enclosed pump-comprising a rotor that is mounted on rolling bearings that can run dry.

3. A pump as claimed in claim 1 or claim 2. which is a slit tube rotor pump.

4. A pump, especially a split tube motor pump, that is driven by permanent-magnet or electromagnetic coupling through a slotted tube wherein the mounting for the rotor of the pump is formed from rolling bearings that can run dry.

5. A pump as claimed in any one of claims 1 to 4, wherein the rolling bearings are made of ceramics.

6. A method of transporting liquefied gases, and/or - fluids that might adversely affect the environment, and/or fluids that might be adversely affected by the environ20 ment, using a pump as claimed in claim 1 or claim 2.

Published 1985 at The Patent Office, State House. 66.71 High Holborn, London WC1R 4TP. FVrther copies may be obtained from The Patent office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent. Con. 1.187.

6. A pump substantially as hereinbefore described with reference to, and as shown in, the accompanying drawing.

7. Use of a pump as claimed in any one of claims 1 to 6 in the field of nuclear technology.

8. Use of a pump as claimed in any one of claims 1 to 6 for transporting liquefied gases.

9. Use of a pump as claimea in any one of claims 1 to 6 for transporting liquids that endanger the environment and liquids that are endangered by the environment.

10. A method of transporting liquefied gases and/or fluids that might adversely affect the environment and/or fluids that might be adversely affected by the environment, using a pump as claimed in any one of claims 1 to 6.

Amendments to the claims have been filed as follows Claims:

1. A pump, especially a canned motor pump, that is driven by permanent or electromagnetic coupling through a can, having a rotor mounted on rolling bearings made from ceramics materials that can rundry.

2. A canned motor pump substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

3. Use of a pump as claimed in claim 1 or claim 2 10 in the field of nuclear technology.

4. Use of a pump as claimed in claim 1 or claim 2 for transporting liquefied gases.

5. Use of a pump as claimed in claim 1 or claim 2 for transporting liquids that endanger the environment 15 and/or liquids that are endangered by the environment.