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. 09, 1996
Filed:
Nov. 21, 1994
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
An apparatus is provided for compressing/expanding a refrigerant gas. The pistons 13 and 16 for use in the apparatus each have cavities formed in the pistons 13 and 16, and check valves 40 and 41 mounted on one end of the respective pistons for closing/opening the cavities so that the cavities are filled with the pressurized gas. The pistons also have a multiplicity of bores 42 and 43 communicating with the respective cavities for ejecting the high pressure gas into respective gaps between the pistons and cylinders accommodating the pistons. The ejected gas forms gas bearings for the pistons, keeping the pistons off the cylinders, thereby eliminating any mechanical friction between them and hence wear of the pistons and the cylinders. This helps significantly prolong life time of the apparatus.