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:
Apr. 25, 2000
Filed:
Mar. 26, 1998
Kyoji Kawaguchi, Yokohama, JP;
Akihiro Ushitora, Yokohama, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A method and an apparatus for controlling a displacement-type fluid machine which handles fluid including gas and/or liquid for increasing or decreasing pressure of the fluid or transporting the fluid including the use of an alternating current motor for driving the displacement-type fluid machine and a frequency converter which is capable of conducting frequency conversion up to a range higher than the power source frequency to adjust the number of revolutions of the motor. Wherein the number of revolutions is adjusted so that input current to the motor is kept constant, regardless of any change in operating pressure of the displacement-type fluid machine, whereby the displacement-type fluid machine is operated maintaining the process values within an allowable limit without effecting repeated actuation and stopping of the machine.