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:
Aug. 25, 1992
Filed:
Jun. 05, 1991
Naomi Hagita, Shimizu, JP;
Takao Mizuno, Shimizu, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Shimizu Engineering Co., Ltd., Shizuoka, JP;
Abstract
A refrigeration cycle apparatus wherein a positive displacement type compressor is used as a cooling medium compressor, and part of a high-pressure liquid cooling medium liquefied in a condenser of a refrigeration cycle is introduced into a compression chamber of the compressor during a compression stroke thereof via first and second connecting pipes connected to the compressor, thereby preventing the overheating of the compressor. The position of connection of the first connecting pipe to the compressor is set to such a position of the compression chamber that when an operating pressure ratio requiring the cooling of the compressor is minimum, the pressure within the compression chamber of the compressor during the compression stroke can be below a condensation pressure at the operating pressure ratio. The position of connection of the second connecting pipe to the compressor is set to such a position of the compression chamber that the pressure within the compression chamber during the compression stroke can be above the pressure within the compression chamber communicated with the first connecting pipe. The second connecting pipe is normally opened, and control means is provided for controlling the opening and closing of the fist connecting pipe so as to keep the temperature of the compressor below a predetermined allowable temperature during the operation of the compressor.