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:
Mar. 27, 1990
Filed:
May. 01, 1989
Tetsuji Yamashita, Shizuoka, JP;
Hideo Takemoto, Tokyo, JP;
Tomio Yoshikawa, Shimizu, JP;
Shizuo Zushi, Hadano, JP;
Kenji Takahashi, Abiko, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A refrigerating apparatus has a refrigerating cycle including an electromotive compressor whose operational speed is variable in accordance with a drive frequency, and a control unit for operating the compressor at a frequency correspondent to a load so as to control the operation of the refrigerating cycle. Control of the operational frequency of the compressor by the control unit is effected on the basis of target super heat amounts of a discharged gas which is predetermined over an operational frequency range of the compressor. The target super heat amounts are set such that within a lower region of the operational frequency range, each target amount is larger than a super heat amount at which the maximum refrigeration capability is obtained at each operational frequency, so as to suppress a suction pressure of the compressor within an allowable limit for the compressor.