The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 21, 2011
Filed:
Jul. 26, 2007
Yoshio Tsunazawa, Kyoto, JP;
Akira Arakawa, Kyoto, JP;
Junichiro Kozaki, Kyoto, JP;
Masaki Ohfuji, Kyoto, JP;
Yoshio Tsunazawa, Kyoto, JP;
Akira Arakawa, Kyoto, JP;
Junichiro Kozaki, Kyoto, JP;
Masaki Ohfuji, Kyoto, JP;
Shimadzu Corporation, Kyoto-shi, JP;
Abstract
A vacuum pump capable of accurately detecting a rotor temperature based on a change in permeability of a magnetic material. Two targets are fixed to a nut opposed to a gap sensor. The nut is made of pure iron, and a surface of the nut opposed to the gap sensor serves as a target. The target has a Curie temperature greater than a temperature monitoring range, and each of the targets has a Curie temperature falling within the temperature monitoring range. When the targets become opposed to the gap sensor in turn according to rotation of a rotor, three types of signals are output from the gap sensor. The difference-signal generation means generates a difference signal of each the targets, on the basis of a signal of the target. The difference signal is compared with a reference signal Vfor detecting the Curie temperatures to detect a rotor temperature.