Patent Application
20060267291
This invention relates generally to brush seals, and more particularly to cartridge-style brush seal for use in small engines or screw compressors.
Brush seals comprising a plurality of bristles sandwiched between a side plate and a back plate are used to prevent or inhibit fluid flow from a higher pressure region to a lower pressure region. Typically, the brush seal seals the gap between a stationary member and a rotating member such as a shaft where the higher pressure region exists on one side of the members and the low pressure region on the other side. The seal is attached to either the stationary or the rotating member with its bristles extending across the gap therebetween. Brush seals are also designed to provide a controlled leakage flow from a higher pressure region to a lower pressure region through a gap disposed between the stationary member and the rotating member.
The brush seal includes one or more arrays of brushes that are generally radial in orientation and extend between the rotating surface and the stationary surface. The back plate is on the lower pressure side and extends nearly the length of the brushes to prevent the bristles of the brushes from bending away from the high pressure side. Typically, brush seals require special tools for installation. Moreover, brush seals require machining to a high degree of tolerance in order to effectively seal a gap between the stationary member and the rotating member.
Accordingly, it is an object of the present invention to provide an improved brush seal that overcomes the above-mentioned drawbacks and disadvantages.
In one aspect of the present invention, a brush seal assembly comprises a brush seal including a back plate, a side plate and a plurality of bristles disposed between the back plate and the side plate. A resilient mounting ring includes at least one mounting section for coupling to the brush seal. The mounting ring defines a slot for being received over a projection of a housing to prevent the mounting ring and brush seal to rotate relative to the housing.
In another aspect of the present invention, a method of assembling a brush seal assembly comprises providing an annular brush seal including a back plate, a side plate and a plurality of bristles disposed between the back plate and the side plate. A resilient annular mounting ring is provided including a first mounting section, a second mounting section defining a slot, and a curved section extending between the mounting sections. An annular housing is provided including a mounting projection. The side plate of the annular brush seal is engaged with the first mounting section and the curved section of the mounting ring. The brush seal is coupled to the mounting ring. The housing is engaged with the second mounting section and the curved section of the mounting ring such that the mounting projection of the housing is received in the slot defined by the second mounting section of the mounting ring.
Referring to
As shown in
The process for assembling the brush seal assembly 10 in accordance with the present invention will now be explained with reference to
With reference to
The present invention is well suited to be embodied as a small diameter (e.g., 6 inch outer diameter or less) low cost brush seal. Suitable applications of the present invention include, but are not limited to, small axial and centrifugal compressors, screw compressors, and small engines such as, for example, small aircraft engines.
There are several benefits for employing a brush seal assembly in accordance with the present invention. The benefits include:
1) The brush seal assembly can be installed and removed without any special tools (preferably without any tools whatsoever);
2) The brush seal and support “fit diameters” can be machined to tolerances looser than those of current designs; the formed mounting ring, acting as a spring, can take up some of the deviations in size of the two pieces of hardware;
3) Reduced machining of support/housing structure, as there is no need to incorporate a diameter “step” to locate the downstream side of the seal;
4) Welding (or otherwise joining) the seal and mounting ring together eliminates the need for an anti-rotation device between the seal and mounting ring;
5) The anti-rotation device, a pin larger (i.e., head) on the downstream side than the upstream (part mounting) side, fool-proofs installation; and
6) Pressure loading holds the seal in place during operation (mounting ring must locate on upstream side of seal as shown in figures).
As will be recognized by those of ordinary skill in the pertinent art, numerous modifications and substitutions can be made to the above-described embodiment of the present invention without departing from the scope of the invention. Accordingly, the preceding portion of this specification is to be taken in an illustrative, as opposed to a limiting sense.
