Claims
- 1. A fluid machine having a rotary shaft, at least one centrifugal impeller which is mounted on the rotary shaft, and a casing which is arranged so as to cover up the centrifugal impeller;wherein at least either of said rotary shaft and said centrifugal impeller is provided with a plurality of first fins, while the casing in an area of said first fins is provided with a plurality of second fins, said casing has an abradable coating at a position opposing the first fins, and a clearance which is defined between said first fins and said casing is set smaller than a clearance which is defined between the second fins and either of said rotary shaft and said centrifugal impeller.
- 2. A fluid machine as defined in claim 1, wherein each of said fins is perpendicular to said rotary shaft and is continuous in a circumferential direction thereof.
- 3. A fluid machine as defined in claim 1, wherein each of said fins is wider at a base than at a distal end.
- 4. A fluid machine as defined in claim 1, wherein said first fins are disposed on both sides of said second fins in an axial direction of said rotary shaft, and said casing is formed with a groove being continuous in a circumferential direction thereof, between said first fins and said second fins.
- 5. A fluid machine as defined in claim 1, wherein the abradable coating is one selected from the group consisting of flame spraying of a nickel-graphite-based coating material, flame spraying of an aluminum-silicon-polyester-based coating material, and coating with white metal.
- 6. A labyrinth sealing device having a rotary shaft and a stationary casing, either of which is provided with a plurality of labyrinth fins;wherein a clearance which at least one of the labyrinth fins defines with respect to a respective opposing part of either of the rotary shaft and the stationary casing is set smaller than a clearance which any other labyrinth fin defines, and said either of said rotary shaft and said stationary casing has an abradable coating at a respective part opposing to the labyrinth fin of the smaller clearance.
- 7. A labyrinth sealing device as defined in claim 6, wherein a plurality of labyrinth fins which oppose to the part subjected to the abradable coating are provided, and heights of the plurality of labyrinth fins are successively changed from a high-pressure side of said labyrinth sealing device toward a low-pressure side thereof.
- 8. A labyrinth sealing device as defined in claim 6, wherein each of said labyrinth fins is perpendicular to said rotary shaft and is continuous in a circumferential direction thereof.
- 9. A labyrinth sealing device as defined in claim 6, wherein each of said labyrinth fins is wider at a base than at a distal end.
- 10. A labyrinth sealing device as defined in claim 6, wherein the abradable coating to-be-bitten is one selected from the group consisting of flame spraying of a nickel-graphite-based coating material, flame spraying of an aluminum-silicon-polyester-based coating material, and coating with white metal.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9-165617 |
Jun 1997 |
JP |
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Parent Case Info
This application is a divisional of application Ser. No. 09/102,562, filed Jun. 23, 1998, now U.S. Pat. No. 6,039,535.
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