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:
Feb. 24, 2015
Filed:
Apr. 26, 2012
Naohiko Takahashi, Tsuchiura, JP;
Haruo Miura, Kasumigaura, JP;
Kazutoshi Yanagihara, Tsuchiura, JP;
Naohiko Takahashi, Tsuchiura, JP;
Haruo Miura, Kasumigaura, JP;
Kazutoshi Yanagihara, Tsuchiura, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A vibration characteristic measuring apparatus includes a magnetic bearing that generates magnetic force on the rotating body of a multi-stage centrifugal compressor, a displacement sensor that measures the vibration amplitude of the rotating body, a current amplifier that supplies a current to the magnetic bearing, and an excitation controller which outputs an excitation control signal for applying vibration to the rotating body and which measures the response characteristics of the vibration of the rotating body to the excitation control signal. The excitation controller outputs a rotating body control signal obtained by adding a vibration eliminating signal for eliminating unbalance vibration of the rotating body to the excitation control signal when measuring the response characteristics, and the current amplifier supplies a current that generates magnetic force in accordance with the rotating body control signal to the magnetic bearing.