Brush-hair seal with a front plate and a bearing plate

Details Brush-hair seal with a front plate and a bearing plate Brush-hair seal with a front plate and a bearing plate

2000-02-17

2001-10-16

Sandy, Robert J. (Department: 3626)

Seal for a joint or juncture

Seal between relatively movable parts

Brush seal

Reexamination Certificate

active

06302400

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is directed to a brush seal having a front panel or plate and a supporting or bearing plate.
2. Description of the Prior Art
Many different brush seals are known that, for example, are utilized in gas turbines in order to seal the interspace, which is between a housing and a rotor rotating at a comparatively high speed, against leakage. Given such seals, the ends of the bristles, which are combined to form a dense bristle packet, project beyond an inside edge of the supporting plate and thus seal the interspace, which is to be kept optimally small, between the inside edge of the supporting plate and the rotor surface. When a high differential pressure is adjacent the seal, then the supporting plate arranged at the low-pressure side supports the bristles to prevent sagging toward the low-pressure side.
For manufacturing a brush seal essentially composed of a front panel, a supporting plate and a bristle packet are arranged therebetween, welding methods were previously utilized with which, in particular, the front panel and supporting plate, which form a seal housing, are welded to one another.
Given a brush seal disclosed by European Patent Application 0 453 315, for example, the front panel, the bristle packet and the supporting plate are connected with a weld that extends over the outer circumference of the brush seal. Since the outer circumferential surface is a fitting surface and must proceed planarly and perpendicularly relative to the two outer lateral surfaces of the front panel and of the supporting plate for an exactly fitting arrangement of the brush seal with reference to the housing and to the rotor, additional processing steps, for example grinding, are necessary due to the weld. This leads to higher manufacturing costs and longer throughput times during manufacture.
It also proves disadvantageous when using the welding processes that the comparatively thin front panel and supporting plates frequently warp due to non-uniform temperature distributions.
German Patent Document No. DE 39 07 614 Al discloses a brush seal having a wire bundle held in a slotted tube, wherein the tube is held together by two supporting rings joined to form a housing by one or more clamp lips that are attached to the one supporting ring and embrace the second supporting ring at the outside to produce a clamping force. The positioning of the clamp lips ensues with a curling or rolling process. The manufacture of the two supporting rings is not disclosed, nor is the provision of a fit surface at the brush seal housing.
SUMMARY OF THE INVENTION
The invention is based on the object of creating a brush seal whose seal housing can be simply manufactured in fabrication-oriented terms, i.e. with optimally few processing procedures.
This yields the advantage that the seal housing is manufactured without the application of heat and no warping occurs as a consequence of different temperature distributions. The additional processing of the outer circumferential or fitting surface that is always required given welding is thus eliminated. The front panel and supporting plate are composed of deep-drawn sheet metal members that are manufactured with exact fit, so that no further processing steps are required at the fit seat.
A free end of the front panel or of the supporting plate is fashioned as a beaded lip. The free end thereby lies at a rectangular section relative to the main propagation plane of the front panel or supporting plate that is inwardly angled off upon respective formation of an outside curved edge with an outside radius R. The beaded lip thereby embraces the outside curved edge of the respectively other plate to such an extent that a rigid and reliable frictional connection of the two plates exists.
The beaded lip includes a thickness s which is reduced compared to the thickness S of the material of the front panel or supporting plate. The thickness s, just like the length l of the beaded lip, is to be selected dependent on the thickness of the material as well as on the shape of the plates, the structural height of the brushes, the bending radii, etc.
Preferably, the thickness s of the beaded lip amounts to approximately
{fraction (2/3+L )} of the thickness S of the material of the front panel or supporting plate.
It is also advantageous that the arc is circular and the corresponding bending radius r is equal to 1.1 through 1.5 times the thickness S of the material of the front panel or supporting plate.
Preferably, the bending radius r is equal to the outside radius R at the outside edge of the front panel or supporting plate.
The front panel and supporting plate can be composed of sheet steel, wherein special steels can also be utilized.
The bristles or the bristle packet are preferably clamped non-positively by the cold joining of the front panel and supporting plate. As a result thereof, the bristles not only seal but a co-rotation of the bristle packet given extreme brushing of the rotor is also avoided. In order to enhance the coefficient of friction, a C-tube serving for the acceptance of the bristles or the inside surfaces of the front panel and supporting plate can, for example, be roughened, knurled or can be provided with notches.


REFERENCES:
patent: 5066024 (1991-11-01), Reisinger et al.
patent: 5688105 (1997-11-01), Hoffelner
patent: 5794938 (1998-08-01), Hofner et al.
patent: 5927721 (1999-07-01), Schulze et al.
patent: 39 07 614 A1 (1990-09-01), None
patent: 0 043 315 (1984-05-01), None

Affiliated with

Also associated with

Rating

Brush-hair seal with a front plate and a bearing plate does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Brush-hair seal with a front plate and a bearing plate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Brush-hair seal with a front plate and a bearing plate will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2603819