EP0336384B1 - Centrifugal pump - Google Patents

Abstract

The invention, which relates to a centrifugal pump with a bearing housing, solves the object of avoiding an unnecessarily large shaft overhang in the case of the optional installation of an axially short mechanical seal. This is achieved by means of an extension to the bearing housing, which extension projects in the direction of the sealing part, can be removed if required and within which the bearing situated on one side of the sealing part is arranged in a manner which allows it to be displaced axially and locked at any desired point with the aid of known fixing means. <IMAGE>

Description

The invention relates to a centrifugal pump according to the preamble of claim 1.

The service life and the tightness of mechanical seals in centrifugal pumps depend, among other things, on the plane parallelism of the fixed and rotating parts of the mechanical seal. In centrifugal pumps, the shaft deflection and thus the plane parallelism of the two mechanical seal halves is very much determined by the overhang of the impeller. With a larger overhang and thus greater shaft deflection, the misalignment of the mechanical seal is also greater.

A centrifugal pump can be sealed by means of different mechanical seal designs and different mechanical seal arrangements, the different seal designs also having different axial dimensions. The longest installation spaces require double seals in tandem or back-to-back arrangement.

Now, as it is e.g. B. is the case with chemical standard pumps, the requirement that the same centrifugal pump must be equipped with all possible seals and sealing arrangements, so the space to be provided for the mechanical seal is to be dimensioned according to the longest seal. This has the consequence that during installation a short, single-acting seal, a long shaft overhang and thus result in the above-mentioned adverse consequences for the mechanical seal.

The invention has for its object on the one hand to meet the requirement for the possibility of installing all types and arrangements of seals and on the other hand to avoid unnecessary shaft overhang and thus misalignment of the mechanical seal in the case of short seals.

The object is achieved according to the invention by a centrifugal pump characterized in more detail in claim 1.

The approach arranged on the bearing housing of the centrifugal pump allows the bearing on the pump side, ie on the side of the sealing section, to be axially displaced and thus to be adapted to the axial space requirement of the mechanical seal installed in each case.

The part of the attachment that protrudes beyond the pump-side bearing and may not be required can be removed by mechanical processing (sawing, turning, milling). An advantageous embodiment of the approach results if it is detachably connected to the bearing housing according to claim 2. Mechanical processing can thus be avoided. This is particularly advantageous for warehousing in areas where mechanical processing would not be possible or would only be possible with difficulty.

• Fig. 1 eine erfindungsgemäße Kreiselpumpe mit einem Lagergehäuse, dessen Ansatz bei Bedarf durch mechanische Bearbeitung zu verkürzen oder zu entfernen ist, die
• Fig. 2 eine erfindungsgemäße Kreiselpumpe mit einem lösbar am Lagergehäuse befestigten Ansatz.

The invention is explained in more detail with reference to two exemplary embodiments shown schematically in the drawing. It shows the

• Fig. 1 shows a centrifugal pump according to the invention with a bearing housing, the approach of which can be shortened or removed if necessary by mechanical processing
• Fig. 2 shows a centrifugal pump according to the invention with a detachably attached to the bearing housing approach.

The centrifugal pump of the two exemplary embodiments are each equipped with an impeller (2) arranged on a shaft (1). A mechanical seal (4) is also provided on the shaft (1) between the impeller (2) and a bearing housing (3). In both exemplary embodiments, there is a single-acting mechanical seal (4).

In order to also be able to install mechanical seals that have a longer extension than the mechanical seal (4) shown, the bearing housings (3) of the two exemplary embodiments are equipped with basically similar approaches, which are only different in the way they are connected to the bearing housing (3). differentiate:

The approach (5) shown in Fig. 1 is made in one piece with the bearing housing (3). Like the shaft (1), it has a constant one in the area of the possible bearing arrangement Diameter. A roller bearing (6) provided here can thus be moved as desired and locked using known fastening means. If, instead of the single-acting mechanical seal (4) shown, a double-acting mechanical seal were installed, the roller bearing (6) could be moved to the position shown in broken lines. The resulting overhang of the approach (5) could be removed by mechanical processing.

The centrifugal pump shown in FIG. 2 has a shoulder (7) attached to the bearing housing (3) by means of threaded bolts and nuts. If the roller bearing (6) is also shifted into the position shown in dash-dotted lines with a correspondingly long seal, the shoulder (7) only needs to be removed by unscrewing it.

Claims (2)

1. A centrifugal pump with a bearing housing, which is adjacent to a sealing part, which, while being adapted to respective requirements and operational conditions, is to be fitted with elements having different axial dimensions, characterized by a headpiece (5 and 7) on the bearing housing (3) extending towards the sealing part (4) and able to be removed when desired, and within which the bearing (6), which is arranged on the end with the sealing part (4), is arranged in an axially sliding manner and able to be locked at any desired point by the intermediary of known securing means.

2. The centrifugal pump as claimed in claim 1, characterized in that the headpiece (7) is designed in the form of a separate part secured to the bearing housing (3) detachably by known means.

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