Non-lubricated compressor with abradable sealing element and related method for assembling it

Patent metadata

Field	Value
Publication number	US-12345262-B2
Application number	US-202218698478-A
Country	US
Kind code	B2
Filing date	Oct 5, 2022
Priority date	Oct 15, 2021
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

The non-lubricated compressor ( 10 ) for compressing a gas, comprises: a stationary stator ( 12 ) with a housing ( 18 ) comprising a rotor cavity ( 20 ) delimited by a bottom wall ( 22 ), a top wall ( 24 ), and a lateral wall ( 26 ) connecting said bottom wall ( 22 ) and said top wall ( 24 ), a rotor element ( 14 ) arranged for rotation about an axis (z) within the rotor cavity ( 20 ) for compressing a gas therein, a self-supporting sealing element ( 16 ) arranged within the rotor cavity ( 20 ), wherein the sealing element ( 16 ) is made of an abradable carbon material, and comprises a wall portion ( 34 ) arranged on an inner surface of the lateral wall ( 26 ) of the rotor cavity ( 20 ).

First claim

The invention claimed is:

1. A non-lubricated compressor ( 10 ) for compressing a gas, comprising:
a stationary stator ( 12 ) with a housing ( 18 ) comprising a rotor cavity ( 20 ) delimited by a bottom wall ( 22 ), a top wall ( 24 ), and a lateral wall ( 26 ) connecting said bottom wall ( 22 ) and said top wall ( 24 ),
a rotor element ( 14 ) arranged for rotation about an axis (z) within the rotor cavity ( 20 ) for compressing a gas therein,
a self-supporting sealing element ( 16 ) arranged within the rotor cavity ( 20 ), the compressor ( 10 ) being characterized in that
the sealing element ( 16 ) is made of an abradable carbon material, and in that
the sealing element ( 16 ) comprises a wall portion ( 34 ) arranged on an inner surface of the lateral wall ( 26 ) of the rotor cavity ( 20 ),
wherein the sealing element ( 16 ) has a C2 Shore hardness comprised between 60 and 70.

2. The compressor according to claim 1 , wherein the sealing element ( 16 ) further comprises a plate-like portion ( 36 ), connected with or integral with the wall portion ( 34 ) of the sealing element ( 16 ), the plate-like portion ( 36 ) being arranged on an inner surface of the bottom wall ( 22 ) of the rotor cavity ( 20 ).

3. The compressor according to claim 1 , wherein the wall portion ( 34 ) of the sealing element ( 16 ) has an inner surface ( 34 a ) facing inward the rotor cavity ( 20 ) and an outer surface ( 34 b ) on the opposed side, said inner surface ( 34 a ) having an epitrochoidal shape in a cross-section on a plane that is parallel to the bottom wall ( 22 ) of the rotor cavity ( 20 ) or in a plane that is orthogonal to the central axis (z).

4. The compressor according to claim 3 , wherein the outer surface ( 34 b ) of the wall portion ( 34 ) of the sealing element ( 16 ) is entirely in contact with the lateral wall ( 26 ) of the rotor cavity ( 20 ).

5. The compressor according to claim 1 , wherein the sealing element ( 16 ) comprises a further plate-like portion ( 38 ) arranged on an inner surface of the top wall ( 24 ) of the rotor cavity ( 20 ).

6. The compressor according to claim 5 , wherein the plate-like portion ( 36 ) and the wall portion ( 34 ) of the sealing element ( 16 ) are made in one piece, and wherein the further plate-like portion ( 38 ) is provided as a separate cover component.

7. The compressor according to claim 1 , wherein the sealing element ( 16 ) has a minimum thickness of at least 2 mm.

8. The compressor according to claim 1 , wherein the sealing element ( 16 ) comprises a layered structure.

9. The compressor according to claim 1 , wherein the sealing element ( 16 ) is made of a carbon matrix.

10. The compressor according to claim 1 , wherein the rotor cavity ( 20 ) is a Wankel compression chamber and the rotor element ( 14 ) is a Wankel rotor arranged for eccentric motion about the axis (z) substantially orthogonal to said bottom wall ( 22 ) of the rotor cavity ( 20 ).

11. The compressor according to claim 1 , wherein at least one inlet opening ( 30 ) and at least one outlet opening ( 32 ) are provided on the lateral and/or bottom wall ( 22 ) of the rotor cavity ( 20 ) for, respectively, the supply and the exhaust of the gas.

12. A method for assembling a non-lubricated compressor ( 10 ) according to claim 1 , comprising the steps of:
a) manufacturing a semi-finished sealing element ( 16 ) by machining a block of abradable carbon material so that an outer shape of said block copies an inner shape of said rotor cavity ( 20 ), and so that the block has an open, inner cavity delimited by a bottom wall and by a lateral wall that has a constant thickness;
b) heating the housing ( 18 ) of the stator ( 12 ) to a temperature of at least 350° C.;
c) fitting the semi-finished sealing element ( 16 ) inside the rotor cavity ( 20 ) of the housing ( 18 ) as long as the housing ( 18 ) is at a temperature of at least 350° C.;
d) mounting the rotor element ( 14 ) inside the inner cavity of the semi-finished sealing element ( 16 );
e) running the rotor element ( 14 ) so that the inner cavity of the semi-finished sealing element ( 16 ) is further machined by the rotor element ( 14 ).

13. The method according to claim 12 , wherein the rotor element ( 14 ) is a Wankel rotor arranged for eccentric motion about the axis (z), and wherein the step e) is performed to obtain an inner surface ( 34 a ) of the sealing element ( 16 ) having an epitrochoidal shape in a cross-section on a plane that is parallel to the bottom wall ( 22 ) of the rotor cavity ( 20 ) or on a plane that is orthogonal to the axis (z).

14. The method according to claim 12 , further comprising the step of:
f) after step c) and before step d), machining the bottom wall of the semi-finished sealing element ( 16 ) until it has a constant thickness.

15. The method according to claim 12 , further comprising the steps of:
g1) after step c), machining, by means of a single drilling step, at least one inlet opening ( 30 ) through the wall portion ( 34 ) of the sealing element ( 16 ) and through the lateral wall ( 26 ) of the rotor cavity ( 20 ) for the supply of gas to be compressed; and
g2) after step c), machining, by means of a single drilling step, at least one outlet opening ( 32 ) through the wall portion ( 34 ) of the sealing element ( 16 ) and through the lateral wall ( 26 ) of the rotor cavity ( 20 ) for the exhaust of the compressed gas.

16. The method according to claim 12 , wherein step c) further comprises applying an adhesive layer between the semi-finished sealing element ( 16 ) and the rotor cavity ( 20 ).

17. A method for assembling a non-lubricated compressor ( 10 ) comprising:
a stator ( 12 ) with a housing ( 18 ) comprising a rotor cavity ( 20 ) delimited by a bottom wall ( 22 ), a top wall ( 24 ), and a lateral wall ( 26 ) connecting said bottom wall ( 22 ) and said top wall ( 24 ),
a rotor element ( 14 ) arranged for rotation about an axis (z) within the rotor cavity ( 20 ) for compressing a gas therein,
a sealing element ( 16 ) arranged within the rotor cavity ( 20 ),
the compressor ( 10 ) being characterized in that
the sealing element ( 16 ) is made of an abradable carbon material, and in that
the sealing element ( 16 ) comprises a wall portion ( 34 ) arranged on an inner surface of the lateral wall ( 26 ) of the rotor cavity ( 20 ),
the method comprising the steps of:
a) manufacturing the semi-finished sealing element ( 16 ) by machining a block of abradable carbon material so that an outer shape of said block copies an inner shape of said rotor cavity ( 20 ), and so that the block has an open, inner cavity delimited by a bottom wall and by a lateral wall that has a constant thickness;
b) heating the housing ( 18 ) of the stator ( 12 ) to a temperature of at least 350° C.;
c) fitting the semi-finished sealing element ( 16 ) inside the rotor cavity ( 20 ) of the housing ( 18 ) as long as the housing ( 18 ) is at a temperature of at least 350° C.;
d) mounting the rotor element ( 14 ) inside the inner cavity of the semi-finished sealing element ( 16 );
e) running the rotor element ( 14 ) so that the inner cavity of the semi-finished sealing element ( 16 ) is further machined by the rotor element ( 14 ).

Assignees

• Atlas Copco Airpower Nv

Inventors

• Luyckx Pierre-Yves
• Buls Bartel
• Marien Karen

Classifications

• F05C2251/10

  Hardness · CPC title

• F04C2240/802

  Liners · CPC title

• F04C2240/801

  Wear plates · CPC title

• F04C2240/30

  Casings or housings · CPC title

• F04C2240/10

  Stators · CPC title