Rotary kinetic fluid motors or pumps – Working fluid passage or distributing means associated with... – Casing having multiple parts releasably clamped
Patent
1995-03-16
1996-08-27
Look, Edward K.
Rotary kinetic fluid motors or pumps
Working fluid passage or distributing means associated with...
Casing having multiple parts releasably clamped
4151991, 4151992, F04D 2944
Patent
active
055494501
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
It is widely customary, for the different operating parts of a centrifugal machine, to provide casings having an identical shell diameter which are lined up axially in succession and which are clamped together by means of the end faces of their shells. At the same time, each casing shell includes the inner walls which govern the operation of the particular casing section. These inner walls, which define flow paths and media spaces, form sometimes complicated hollow shapes and undercut contours which can be produced by casting only at a high outlay. This is also true when the casing sections are surrounded by means of a tube absorbing the axial forces and centring the casing shells (U.S. Pat. No. 4,708,589) or stepped casings are arranged within an outer casing, leaving a functional interspace (EP-A-0 248 104). However, because there is then a larger number of casing sections, it would involve an even higher outlay, particularly in terms of stockkeeping, assembly and maintenance, to divide sections of this kind once more in order to make the cavities and undercut regions more readily accessible in the casting technique.
SUMMARY OF THE INVENTION
The invention is intended to simplify the production conditions, without impairing the uniform handling capacity of the casing sections. This is achieved by means of the features of the present invention.
Accordingly, there are individual casing sections, the casing shell of which is composed of an outer shell part continuous over the length of the respective section and of at least two separate inner shell parts having respectively associated inner-wall parts. The outer and inner shell parts are preferably connected firmly to one another. For example, they can be adhesively bonded or secured by heat shrinking one to the other. Adhesive shrinkage is preferred in order to exclude crevice corrosion. The remaining casing sections, the inner-wall parts of which do not have such a complicated construction, can be designed conventionally with only one casing shell. However, in these too, it may be expedient to make the casing shell multi-part in the way specified, in order to produce identical shell properties in all or most of the casing sections, particularly with regard to their strength.
The invention also has the advantage that different materials can be used for the inner and the outer shell part. For example, rolled material of high tensile strength can be used for the outer shell part, whilst the inner shell part consists of cast material. As a result, the wall thickness as a whole, but at least the thickness of the inner shell part, and therefore the cast weight, can be reduced. This advantage is known per se DE-A 28 08 741, FR-A 536 590).
The seals between successive casing sections are expediently provided on the outer shell part. It is also possible, however, to mount them on the inner shell part or so as to engage over both shell parts.
Since the inner shell parts are responsible for the correct axial positioning of the inner-wall parts, it is usually recommended to cause the end faces of the inner shell parts of successive casing sections to be contiguous with one another. High accuracy can be achieved especially when the shell end faces, each composed of an outer and an inner shell part, are machined in a unitary manner (in one operation).
BRIEF DESCRIPTION OF THE DRAWING
The invention is explained in more detail below with reference to the drawing which illustrates an advantageous exemplary embodiment in longitudinal section.
DESCRIPTION OF A PREFERRED EMBODIMENT
This relates to a liquid pump with a suction connection 1, a delivery connection 2, a shaft 3, three fully loaded impellers 4, 5, 6 and one partly loaded impeller 7 guaranteeing the self-priming capacity of the pump.
The fully loaded impellers 4 and 5 are located in stepped casings 8 and 9 which each receive the impeller and which form the distributor chambers 10 and 11. These chambers or closed spaces, are located between axially successive said complementary
REFERENCES:
patent: 3051090 (1962-08-01), Zumbusch
patent: 3927763 (1975-12-01), Strub et al.
patent: 4116583 (1978-09-01), Budris
patent: 4120606 (1978-10-01), Reiss
patent: 4264285 (1981-04-01), Erickson et al.
patent: 4708589 (1987-11-01), Nielsen et al.
patent: 4778334 (1988-10-01), Medgyesy et al.
patent: 4781531 (1988-11-01), James
patent: 5201633 (1993-04-01), Peu
patent: 5385445 (1995-11-01), McKenna
patent: 5407323 (1995-04-01), Gay et al.
Soviet Patents Abstracts, Section PQ, Week 9139, Nov. 13 1991, Derwent Publications Ltd., London, GB; Class Q56, 91-286368/39;SU 1620-682 A; 1/91; F04D-01/06.
Lehmann Wilfried
Mann Ralf
Muller Hermann
Look Edward K.
Sgantzos Mark
SIHI GmbH & Co KG
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