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AssigneeBOC Edwards Technologies Limited
InventorsHirotaka Namiki, Akira Yamauchi
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To provide a protective device for a turbo molecular pump and a method of protecting a turbo molecular pump that may cope with abnormal phenomenon according to a kind thereof when the abnormal phenomenon occurs. A kind of abnormal phenomenon is inferred from a change rate in rpm of a rotor when the abnormal phenomenon such as an injection of atmospheric air into an intake port is generated in the turbo molecular pump or the like and a magnitude of the damage imparted to the turbo molecular pump by the abnormal phenomenon is inferred from the rpm of the rotor upon the generation of the abnormal phenomenon. Furthermore, a value weighted to the magnitude of the damage is caused to correspond to and the value is accumulated whenever the abnormal phenomenon occurs in the turbo molecular pump. When the accumulated value reaches a certain value, the protective function is effected so that the turbo molecular pump is stopped to disable its re-operation or to display an alarm to the operator or the like.
A protective device for a turbo molecular pump comprising:
A protective device for a turbo molecular pump according to claim 1, wherein a kind of the abnormal phenomenon inferred by the abnormal phenomenon inference means further includes at least one of a touchdown of the rotor to a protective bearing for protecting the rotor in a case where the rotor is held by a magnetic bearing, a mixture of foreign matters to the bearing for holding the rotor, a power outage of a power to be fed to the turbo molecular pump, and an external turbulence of the turbo molecular pump by an external force.
Dependencies are inferred from the claim text.