Non-lubricated system with abradable sealing element, corresponding sealing element and method for assembling the system
View Patent ↗A non-lubricated system for pumping a gas, includes a stationary stator with a housing that includes a rotor cavity and at least one rotatable rotor element incorporated within the rotor cavity. The stator includes at least one self-supporting sealing element, incorporated within the rotor cavity between an end face of at least one of the rotor elements and an interior wall of the housing to form a seal along the corresponding end face. At least one self-supporting sealing element is provided with an abradable coating on at least one side facing the rotor.
1. A non-lubricated system for pumping a gas, comprising a stationary stator with a housing comprising a rotor cavity and at least one rotatable rotor element incorporated within the rotor cavity, where the stator further comprises at least one self-supporting sealing element, incorporated in the rotor cavity between an end face of at least one of the rotor elements and an interior wall of the housing, to form a seal along the end face, wherein an abradable coating is on at least one side facing the corresponding rotor element of the at least one self-supporting sealing element, wherein at least the abarable coating consists of a carbon matrix.
2. The non-lubricated system in accordance with claim 1 , wherein the at least one self-supporting sealing element has a thickness of at least 1.0 mm.
3. The non-lubricated system in accordance with claim 1 , wherein the abradable coating has a thickness of at least 100 μm.
4. The non-lubricated system in accordance with claim 1 , wherein the at least one self-supporting sealing element is mainly plate-like.
5. The non-lubricated system in accordance with claim 1 , wherein the at least one self-supporting sealing element consists of a layered structure.
6. The non-lubricated system in accordance with claim 1 , wherein the carbon matrix has a degree of graphitization P1 of more than 60%, more than 80% or more than 95%.
7. The non-lubricated system in accordance with claim 1 , wherein the abradable coating has a hardness HR 5/100 between 100 and 120.
8. The non-lubricated system in accordance with claim 1 , wherein at least one end face of at least one of the rotor elements has a contact surface with a roughness Ra>1.0 μm.
9. A non-lubricated system for pumping a gas, comprising a stationary stator with a housing comprising a rotor cavity and at least one rotatable rotor element incorporated within the rotor cavity, where the stator further comprises at least one self-supporting sealing element, incorporated in the rotor cavity between an end face of at least one of the rotor elements and an interior wall of the housing, to form a seal along the end face, wherein an abradable coating is on at least one side facing the corresponding rotor element of the at least one self-supporting sealing element, wherein at least one end face of at least one of the rotor elements is notched around a rotor shaft of the rotor element and wherein the abradable coating of the at least one self-supporting sealing element present there comprises a ring extending into the notch.
10. The non-lubricated system in accordance with claim 1 , wherein the at least one self-supporting sealing element comprises one or more openings for the supply and/or exhaust of the gas.
11. The non-lubricated system in accordance with claim 1 , wherein the system is a compressor, expander or vacuum pump.
12. A self-supporting sealing element according to claim 1 , configured for use in a non-lubricated system for pumping the gas.
13. A method for assembling a non-lubricated system in accordance with claim 1 , comprising the following steps:
attaching the at least one self-supporting sealing element to the interior wall of the housing of the stator, wherein the respective abradable coating is turned away from the respective interior wall;
incorporating rotatably the at least one rotor element in the rotor cavity bounded by the housing; and
running-in the system to partially wear down the abradable coating.
14. The method in accordance with claim 13 , further comprising a step of roughening at least one end face of at least one rotor element.
15. The method in accordance with claim 13 , wherein the attaching comprises the application of a sealant and/or adhesive between the at least one self-supporting sealing element and the respective interior wall of the stator housing.
16. The method in accordance with claim 13 , wherein the end face of the at least one of the rotor elements is notched around a rotor shaft of the rotor element and wherein during the running-in, as a result of the run-in, a ring is formed on the abradable coating of the self-supporting sealing element present there, which extends into the notch.
17. The non-lubricated system in accordance with claim 2 , wherein the at least one self-supporting sealing element has a thickness of at least 1.5 mm.
18. The non-lubricated system in accordance with claim 17 , wherein the at least one self-supporting sealing element has a thickness of at least 2.0 mm.
19. The non-lubricated system in accordance with claim 3 , wherein the at least one self-supporting sealing element has a thickness of at least 200 μm.
20. The non-lubricated system in accordance with claim 19 , wherein the at least one self-supporting sealing element has a thickness of at least 300 μm.
21. The non-lubricated system in accordance with claim 1 , wherein the entire at least one self-supporting sealing element consists of a carbon matrix.
22. The non-lubricated system in accordance with claim 21 , wherein the carbon matrix has a degree of graphitization P1 of more than 60%, more than 80% or more than 95%.
23. The non-lubricated system in accordance with claim 8 , wherein at least one end face of at least one of the rotor elements has a contact surface with a roughness Ra>2.5 μm.