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. 02, 1993
Filed:
Jan. 15, 1991
Satoru Fujiwara, Tokyo, JP;
Ebara Corporation, Tokyo, JP;
Abstract
An oil recovery system for a closed type centrifugal refrigerating machine. The refrigerating machine includes a compressor that has an oil sump below the suction side thereof, a condenser that liquefies compressed refrigerant gas by cooling, an evaporator that evaporates the liquefied refrigerant, a suction volume control valve that controls the volumetric flow of refrigerant gas sucked into the compressor from the evaporator, recovery means for recovering oil from the oil sump to an oil tank in a lubricating system, and control means for starting or stopping the compressor in accordance with the magnitude of refrigeration load. The oil recovery system comprises valve opening control means for controlling the opening of the suction volume control valve such that a decrease in the amount of oil recovered to the oil tank is compensated for when the number of times of start or stop of the compressor per unit of time exceeds a set number.