GB2242932A

GB2242932A - Centrifugal pump unit with support cage

Info

Publication number: GB2242932A
Application number: GB9107288A
Authority: GB
Inventors: Wolfgang Mock
Original assignee: KSB AG; Klein Schanzlin and Becker AG
Current assignee: KSB AG; Klein Schanzlin and Becker AG
Priority date: 1990-04-09
Filing date: 1991-04-08
Publication date: 1991-10-16
Anticipated expiration: 2011-04-08
Also published as: NO173406C; GB2242932B; DE4011477A1; NO173406B; NO911007D0; NO911007L; GB9107288D0; DE4011477C2

Abstract

In a centrifugal pump unit of vertical construction, in which a cage (3) provides a connection between a motor casing (7) and the pump casing (1), a horizontal parting line (6) is provided between two parts of the cage or between the cage and a flange (8) of the motor casing, the parting line (6) being between the input and output shaft ends, which ends are connected by a removable shaft coupling. This construction enables the motor to be separated from the pump, in restricted space conditions, by removing the shaft coupling separating the two parts of the structure along said parting line (6) and displacing one of said two parts relative to the other, parallel with said parting line. <IMAGE>

Description

DESCRIPTION OF INVENTION

Title: UCentrifugal Pump Unit with Support Cage" THIS INVENTION relates to a centrifugal pump unit of vertical construction, in which a one-part or multi-part support cage is disposed between the motor and the centrifugal pump, access apertures to a shaft coupling being provided in the cage.

Units of this kind may be equipped with various types of support cages. For example DE-OS 2301961 shows an embodiment in which a bearing casing provided with an intermediate shaft is disposed inside a two-part support cage. The ends of the intermediate shaft are connected to the pump input shaft end by a f ixed coupling and to the motor output shaft end by a flexible coupling. After the fixed coupling has been dismantled, the intermediate shaft can be moved vertically upwards inside the bearing casing. In this way a free space is created inside the support cage to enable the pump shaft seal to be rapidly and easily changed. An alternative solution to this is shown in DE-PS 2261643 in which, instead of moving the shaft, the entire bearing casing with the intermediate shaft is moved. In both solutions work on the pump shaft bearing requires the motor to be lifted and the motor shaft end to be lifted out of the cage.

DE-AS 2262017 shows a one-part support cage on which the motor directly rests and projects into the cage by the end of its output shaft. In this a coupling provides a connection to the input shaft end. The pumps shown in the technical dictionary Europump, 1st Edition, Chapter 2.1, Figures 19 to 22, also have support cages in 2 which, f or access to the bearings disposed inside the cage, the motor together with its output shaft end has to be lifted to a very considerable extent to allow free access to the input shaft end. This already causes considerable difficulties in cases in which the space conditions are inadequate for removal of the motor. This applies particularly to ships and offshore oil rig platforms, in which space conditions are very restricted owing to the deck heights. The pump unit dimensions then make it impossible in some cases for the units to be erected vertically to save space, since space conditions prevent this.

An object of the invention, therefore, is to develop, for vertically disposed pump units, the possibility of an assembly which allows removal of the motor from a cage under restricted space conditions.

According to one aspect of the invention, there is provided a centrifugal ump unit of vertical construction, in which a one-part or multi-part support cage is disposed between the motor and the centrifugal pump, access apertures to a shaft coupling being provided in the cage, in which a horizontal parting line between the motor and the cage is provided between the input shaft end and the output shaft end.

Where a one-part support cage is used, the provision of the horizontal parting line between the input and output shaft ends allows very easy dismantling of the motor. In this way, the motor connection flange is moved into or beneath its output shaft end. After the two shaft ends have been disconnected, e.g. by releasing a shaft coupling through the access apertures in the cage and releasing the connection between the motor and the cage, i 4 1 3 the motor can be removed with minimal lifting. All that is required, therefore, is, as it were, to lift the motor from its support surface and then move it aside.

According to another aspect of the invention, there is provided a centrifugal pump unit in which, in a multipart cage, a horizontal parting line between the cage parts is provided between the input shaft end and the output shaft end.

This solution is advantageous where a conventional motor is used. In one embodiment of the invention in its last-noted aspect, the motor output shaft end projects beyond the motor flange. In this case, for example, if the support cage is split, the projecting motor shaft end can be bridged by a part of the cage. Assembly and dismantling may then be carried out similarly to the case, noted above, in which a one-part support cage is used. After release of a coupling connecting the shaft ends, and release of the connection between the cage parts along the parting line between the input and output shaft ends the motor can be swung aside after it has been slightly lifted. In that case the individual cage parts remain connected to the motor and pump.

Preferably, the horizontal parting line is disposed in the plane of the input shaft end of the pump. This feature offers the advantage that assembly time is reduced for any dismantling of the pump. For example, to reduce the time required for removing a pump from a pot casing, the connection between the support cage and the pump is advantageously left. Bearings or seals accommodated in the cage can thus remain in the assembled state and their settings unchanged. It has been found advantageous for the horizontal parting line to be moved into the area of the 4 pump shaft end. As a result, despite the cage part mounted on the pump, the length of the unit requiring to be moved is not increased as compared with the pump on its own.

Exemplified embodiments of the invention are described in detail below with reference to the drawings wherein:

FIGURE 1 shows a pump unit connected to a motor with the interposition of a two-part cage; FIGURE 2 shows a pump unit with a one-part cage and FIGURE 3 shows a dismantling operation.

Figure 1 shows a pump 1 vertically disposed on a floor 2. A two-part cage 3 connects the pump to a motor 4 flanged on the cage 3. The end 5 of the output shaft of the motor 4 projects conventionally into the cage 3. The provision of a horizontal parting line 6 in the cage 3 enables the motor to be swung away to the side after a short lifting movement, as shown in Figure 3, after a shaft coupling (not shown) has been released or removed and after the connection of the two parts of the cage has been broken along the parting line 6.

Figure 2 shows an embodiment in which a motor 7 is provided with a fixing flange 8 which projects beyond the end 9 of the pump motor output shaft. The input shaft end 10 of the pump 1 - which is in this case situated beneath the horizontal parting line 6 - does not obstruct a movement for swinging the motor aside.

Referring to Figure 3. after the connections, (between the two parts of the two-part cage or between the t Z fixing flange 8 and the cooperating flange of the one-part cage). have been released, all that is required is a short lifting movement of the motor in order to swing it aside. A hoist 11 is used for the lifting movement. - f e, 6

Claims

1. A centrifugal pump unit of vertical construction in which a one-part or multi-part support cage is disposed between the motor and the centrifugal pump, access apertures to a shaft coupling being provided in the cage, in which a horizontal parting line (6) between the motor (4, 7) and the cage (3) is provided between the input shaft end (10) and the output shaft end (5, g).

2. A centrifugal pump unit according to the preamble to claim 1, in which, in a multi-part cage (3), a horizontal parting line (6) between the cage parts is provided between the input shaft end (10) and the outut shaft end (5, 9).

3. A centrifugal pump unit according to claim 1 or 2, in which the horizontal parting line (6) is disposed in the plane of the input shaft end (10) of the pump (1).

4. A centrifugal pump unit substantially as hereinbefore described with reference to and as shown in Figure 1 of the accompanying drawings.

5. A centrifugal pump unit substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.

6. Any novel feature or combination of features described herein.

Published 1991 at The Patent Office. Concept House. Cardiff Road. Newport. Gwent NP9 I RH. Further copies may be obtained from Sales Branch. Unit 6. Nine Mile Point. CAmfelinfach. Cross Keys. Newport. NP1 7HZ. Printed ky Multiplex techniques ltd. St Mary Cray. Kent.