DE2051011A1 - Gap seal for centrifugal pumps and the like - Google Patents

Description

Gap seal for centrifugal pumps and the like.

Note: Loewe Pumpenfabrik GmbH, Lüneburg The invention relates to a Gap seal for centrifugal pumps and the like, as well as for all machines with fixed Housing parts and surrounding parts in which rooms with different pressures must be sealed against each other.

Shall rooms with different pressures sealed against each other parts and walls of the rooms are and are movable, e.g. in centrifugal pumps and impellers, then, as is well known, there are sometimes very difficult sealing problems. If seals are used in such cases, as is known, <tie an one part are attached and c n the other part with more or less large Apply pressure, then creates a grinding effect through which this Seals wear out more or less quickly and thus become unusable.

Contact-free seals, such as so-called, are therefore better Split ring seals, in which the best possible sealing of the rooms against each other is known to be achieved in that throttling points are formed by narrow gaps which oppose a high resistance to the passage of the liquid.

These known split ring seals put when they have good effects should show a very high manufacturing accuracy in the manufacture of the parts advance through which the gap is formed. To make matters worse, all Fit tolerances, e.g. between the impeller and the shaft and the seat of the shaft in the housing and the housing parts with each other and then the split ring seal themselves, can lead to the fact that the gaps are one-sided during operation (see Fig. 1, and so only imperfect throttling effects occur.

The conditions are particularly difficult with multistage centrifugal pumps with longer waves, because there is an additional one due to the deflection of the wave radial deflection of the shaft occurs. It is therefore almost only in exceptional cases to expect a functional split ring seal with an evenly narrow gap.

With the invention, the task should be solved, always eggs optim len. i.e. narrow and even sealing gap between the still @ te @ ends and the to ensure rotating parts, especially with centrifugal pumps, with better Sealing effect independent of the manufacturing tolerances of the various composite Parts.

To solve this problem it is proposed according to the invention at the sealing gaps between the fixed housing parts and the circumferential ones Parts of centrifugal pumps, compressors and the like. @N the sealing points between the fixed housing parts and the rotating parts a freely rotating and slidable wear ring @n to be assigned, the opposite of the one sealing point a narrower Has play than compared to the other sealing point. The split ring should be advantageous have a sliding fit with respect to the circumferential parts of the sealing point.

E @ has proven useful in improving the automatic Adjustment of the split ring 4 @ between the fixed and rotating parts to provide this with a special pressure shoulder. The split ring is useful made of a material that has good sliding or running properties the material at the sealing points in the fixed housing parts and at the surrounding ones Has parts.

to better adapt to different media in the other In order to achieve a selection of materials, it is advisable to work at the sealing points in to provide special base rings on the fixed housing parts and on the circumferential Parts races, which are firmly connected to these parts. It it has proven expedient to make the wear ring out of wear material, so that only these rings have to be replaced when the pump is overhauled.

en With reference to the drawing, on which Fig. 1 a gap seal known Design shows schematically, Fig. 2 shows a centrifugal pump with the invention Husführung of the gap seal and Fig. in an enlarged view of the effect This seal should show the invention using the example of a centrifugal pump on which the invention is of course not limited, to be described hereafter.

The known design of a split ring seal, which is shown in Fig.

1 is shown, it can be seen that with unilateral deflection of the Impeller between the split ring 10 and the impeller 11 on one side quite considerable gap widths @ can perform. If, despite the corresponding reduction in the gap on the diametrically opposite area a contact of the rotating with the stationary Parts @ should be excluded.

If there is another radial deflection of the impeller during operation E.g. in the direction of the arrow, @n occurs at the point of contact between St @@ tring and Impeller wear one and the Gap @n the opposite side is no @@ bigger. The sealing effect decreases very rapidly.

Unlike the gap seal according to the invention, which is shown in Figs. 2 and is shown. Here are located between the shaft 15 seated impeller 11 and the fixed housing parts 16 and 17 special split rings 1, preferably with i the housing parts 16 and 17 pressed-in base ring 12 @@@ Waving together on the running ring 1 @, which is free @@ ehb opposite @ Base and race rings 12 @@. 14, where they also ei @ e @ di le and in particular have an i le displaceability. D you an e @@ es @ iel opposite the @ races 1 @ un @ have a larger clearance or a larger space to the base ring 12, they can be used in the event of radial deflections of the impeller shaft or

of the impeller, for example, in that indicated by the arrow in FIG Sufficient direction to the base ring without the gap on the opposite Page gets bigger. The chosen one - and there only two parts pressed against each other must be, - very precisely to be kept narrow gap is thus retained and thus an optimal sealing effect is always guaranteed.

The wear ring 1 @ or 19 should e.g. be slidable and rotatable with a sliding fit @ @en throttle points of the impeller 11 or at the throttle points between the individual Pump @ @ufen (see base ring 18 and liner 20) on the rotating part of the Sealing point sit. When conveying the pump, the split ring 13 or 19 is caused by the differential pressure pressed axially against the fixed base ring and seals there by being firmly is present and stands still. In the narrow gap of the sliding fit between the stationary one Split ring 1; and the rotating impeller 11 or the spacer sleeve 20 on the shaft only a very small pressure loss is possible.

With radial deflection of the shaft as well as with center misalignment due to manufacturing errors can the wear ring 1 the mechanical pressure or push @ the rotating parts in released in the radial direction and in its new position due to the differential pressure stay sealingly on the base ring.

In the event of a dry run, the compressive force on the split ring also fills (1 @) and thus no excessive wear occurs.

It is also conceivable that the materials are selected in such a way that that first the split ring (13) wears and only this when overhauling the Pump needs to be replaced.

Claims (5)

Claims 1. Gap sealing especially for the sealing gaps between the fixed housing parts and the rotating parts of centrifugal pumps, compressors And the like., characterized in that at the sealing points between the fixed Housing parts (16, 17) and the rotating parts (11, 20) freely rotatable and slidable Split rings (13) are arranged opposite the one sealing point (13-14, 19 - 20) show e @ gens play if compared to the other sealing point (12 - 13, 18-19). 2. Gap seal according to claim 1, characterized in that the Split ring (13) is provided with a pressure shoulder (21). 3. Gap seal according to claim 1 and 2, characterized in that @@ the wear ring (13) is made of a material that is good sliding or Running properties compared to the materials of the sealing points in the fixed Have housing parts and the revolving parts. 4. Spaltabdi @ n @ according to claim 1 to, characterized in that at the sealing points in the housing parts (16, 17) @@@@ rings (12, 18) and at the rotating parts (impeller 11, @@ lle 15) race rings (14) and spacer sleeves (20) attached ei @@. 5. Gap seal according to claim 1 to 4, characterized in that S @@@@ i 1 made of @lieblei @ material