Turbomolecular pump having vanes with ceramic and metallic surfaces
AssigneeZaidan Houjin Shinku Kagaku Kenkyujo
InventorHajime Ishimaru
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Abstract
A turbomolecular pump comprises a casing having an inlet port at one end portion and an outlet port at another end portion, a rotor supported rotatably within the casing, and a stator fixed on an inner wall of the casing. The rotor has rotor vanes which coact with stator vanes on the stator to pump gas molecules from the inlet port to the outlet port. The rotor and stator vanes are arranged in multi-steps and have ceramic surfaces at the steps near the outlet port of the casing and have metallic surface at all other steps, so as to promote the baking efficiency and obtain extremely high vacuums.
Claims12
A turbomolecular pump comprising:
- a casing having an inlet port at one end portion and an outlet port at another end portion,
- a rotor having rotor vanes in multi-steps and being supported rotatably within said casing,
- a stator having stator vanes in multi-steps and inserted between said rotor vanes with very small gaps therebetween and being fixed on an inner wall of said casing, and
- a motor extending coaxially with said rotor for rotationally driving said rotor;
- wherein both said rotor vanes and said stator vanes have ceramic surfaces at the steps near said outlet port, and have metallic surfaces at all the other steps.
Dependencies are inferred from the claim text.