초록 ▼

A turbomolecular pump including a casing stationary blades arranged in a plurality of stages in the casing axially thereof, rotating blades arranged between the stationary blades and located on an outer periphery of a rotor located in a central portion of the casing, and a bearing device journaling

A turbomolecular pump including a casing stationary blades arranged in a plurality of stages in the casing axially thereof, rotating blades arranged between the stationary blades and located on an outer periphery of a rotor located in a central portion of the casing, and a bearing device journaling the rotor at its high vacuum and end a low vacuum end. A first permanent magnet of the fixed side having a high Curie point and a second permanent magnet of the rotor side located in juxtaposed relation to the first permanent magnet constitute a magnetic bearing of an attraction type for journaling the rotor at its high vacuum end. A pivot type hydrodynamic bearing or active magnetic bearings journal the rotor at its low vacuum end.

대표청구항 ▼

A turbomolecular pump comprising; a casing; a plurality of stationary blades arranged in a plurality of stages in said casing axially thereof; a plurality of rotating blades alternately located between said stationary blades and arranged at an outer periphery of a rotor located in a central portion

A turbomolecular pump comprising; a casing; a plurality of stationary blades arranged in a plurality of stages in said casing axially thereof; a plurality of rotating blades alternately located between said stationary blades and arranged at an outer periphery of a rotor located in a central portion of said casing; bearing means journalling said rotor on a high vacuum side and low vacuum side thereof, said bearing means comprising a first permanent magnet member located in a fixed position having a characteristic such that the Curie point of its material is high, and a second permanent magnet member on the rotor side located in spaced juxtaposed relationship to said first permanent magnet member, said first and second permanent magnet members constituting a magnetic bearing of an attraction type; and wherein said rotor has at least more than one stage of said rotating blades located at a higher vacuum end of said rotor above said bearing means at the high vacuum end, said at least more than one stage of said rotating blades being located between the sationary blades on the suction side so as to produce at the high vacuum end above said bearing means a pressure corresponding to an unattained pressure so that gas released by the permanent magnet member of the bearing means exerts no influence on the suction side of the pumps.