JPH0319398B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an air seal structure provided at the inner end of a row of stator vanes, which is formed integrally with an inner shroud and is made of a polishable material as a sealing element. This relates to an air seal structure that supports an air seal structure.

BACKGROUND OF THE INVENTION Many compressor seals located at the inner ends of several rows of compressor vanes include a separate seal ring positioned to engage a seal flange formed on the rotor. It is bolted or welded to the inner loud ring and extends radially inward from the inner loud ring. Conventional compressor seals are therefore two-piece structures, such that the radial dimension between the shroud ring and the rotating seal element is large.

Problems to be Solved by the Invention It is desirable that the air seal have an external shape with a height as small as possible relative to the gas flow path, be small in weight, and have high durability in use. On the other hand, while many seals can only be replaced at the dealer's equipment, it would be desirable to be able to repair or replace the seals at an overhaul facility.

Means for Solving the Problems According to the present invention, in order to solve the above problems, a hole is provided in the annular inner shroud through which the tongue of the vane passes, and the tongue of the vane is inserted into the hole of the inner shroud. The vane and the inner shroud are constructed as an integral structure by welding or brazing to the inner shroud within the vane. Further, according to the present invention, the inner seal is constructed by filling the inner surface of the inner shroud with sealing material to form an annular layer of sealing material. The sealing material is preferably a polishable material and can be sprayed onto the inner surface of the inner shroud.

Function The vane, the inner shroud, and the sealing material filled in the inner shroud constitute an integral structure, and the height of the air seal can be designed to be small with respect to the gas flow path. The polishable seal material can be removed by gritplast to expose the vane tongue. Additionally, the braze or weld between the vane tongue and the inner shroud can be heated away to replace the vane.

EXAMPLES The present invention will now be described in detail by way of examples with reference to the accompanying drawings.

The illustrated compressor is of substantially conventional construction and has a rotor 2 in the form of a drum, having at its periphery several rows of blades 4 spaced apart from each other in the direction of the engine axis. It also carries a plurality of sealing fins 6 extending radially outward between the rows of blades. The rotor 2 is surrounded by a case 8 which supports several rows of stator vanes 10 (only one of which is shown in the figure). The stator vanes 10 extend radially inward from the case 8 or outer shroud and are disposed between the blade rows. The outer ends of the stator vanes 10 may be secured to the outer shroud by brazing.

The inner end of each stator vane 10 has a radially inwardly extending tongue 12 extending through a hole 14 formed in the inner shroud 16. There is. These tongues 12 are brazed or welded to the inner shroud 16. The inner surface of the inner shroud 16 may be in the form of a trough with an end wall or flange 18 extending radially inwardly of the structure as shown. The radially inwardly open trough of the inner shroud 16 is abradable and may be made of any of several materials, such as rubber, nickel aluminide polyester, nickel graphite, and nickel-chrome polyester. It is filled with sealing material 20. Whatever material is used in this case, the sealing material may be sprayed into the trough of the inner shroud 14 to the desired thickness. According to this configuration, the thickness of the sealing material can be made larger than in the case of a normal structure, and when the engine is operated, the fins 6 provided on the rotor form a suitable sealing groove in the polishable sealing material 20. form.

Since this sealing ring forms an integral part of the inner shroud 16, the sealing material filled within the trough of the inner shroud 16 may be substantially the diameter of the inner shroud, and This allows the seal to be placed closer to the gas flow path and reduces the degree of discontinuity in the compressor gas flow path. The blades 4 have an inner shroud substantially aligned with the outer shroud that defines the inner wall of a gas flow path extending through the compressor. Since the seal and shroud are one simple ring structure, weight is also significantly reduced. Costs are also considerably reduced due to the reduced number and weight of parts.

Maintenance costs are also fairly low since the polishable seal material 20 can be replaced at an overhaul facility if necessary, and the seal material 20 can be easily removed by grit blasting if necessary. This is particularly desirable when it becomes necessary to access any one of the tongues 12, for example in the case of replacing the stator vanes 10. The abradable seal material 20 may be removed by grit blasting in a predetermined area proximate the tongue 12. In the inner shroud 16, the shape of the trough-like body may be changed as necessary, and shapes other than the trough-like body may be used. A very effective seal can be obtained by having the seal fin 6 grind a portion of the seal material, thereby forming a groove in the seal material that closely fits the seal fin.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and various modifications and omissions can be made within the scope of the present invention. will be clear to those skilled in the art.

Effects of the Invention In the seal structure according to the present invention, the inner shroud is welded or brazed to the tongue of the vane of the compressor, and the sealing material is attached to the inner surface of the inner shroud by spraying. A fastening means such as a nut is not used, therefore, a certain strength is maintained and the structure is made small as a whole. When replacing a vane, remove the sealing material attached to the inner surface of the inner shroud by grit blasting to expose the vane tongue, and remove any welded or brazed parts on the vane tongue. Since the inner shroud can be removed by heating and thereby removed from the vane, the vane can be easily replaced even in an overhaul facility that does not have predetermined equipment.

[Brief explanation of the drawing]

The attached figure is a partial vertical sectional view showing a stator of a compressor incorporating the present invention. 2... Rotor, 4... Blade, 6... Fin, 8... Case, 10... Stator vane, 1
2...tongue, 14...hole, 16...inner shroud, 18...end wall, 20...sealing material.

Claims (1)

[Scope of Claims] 1. An annular inner shroud 16 mounted on the inner end of the vane 10 of the compressor, the inner shroud having a series of holes 14 protruding from the inner end of the vane. a tongue 12 extends through the hole, the vane tongue being secured to the inner shroud within the hole in the inner shroud by welding or brazing; an annular layer of abrasive sealing material is formed on the inner surface of the inner shroud over the tongue;
A seal structure for a compressor vane, the tongue being configured to be exposed by removing a portion of the annular layer of sealing material proximate the tongue. 2. A sealing structure for a compressor vane according to claim 1, wherein the annular layer of sealing material is formed by spraying a sealing material onto the inner surface of the inner shroud. body. 3. A seal structure for a compressor vane according to claim 1, wherein said annular layer of sealing material is removable by grit blasting.