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:
Nov. 30, 1999
Filed:
Jun. 23, 1997
Akiyoshi Higashiyama, Sawa-gun, JP;
Sanden Corporation, Gunma, JP;
Abstract
A scroll-type variable displacement compressor for use in an air conditioning system of a vehicle has a fixed scroll and an orbiting scroll with a lowered minimum operating capacity. A cylinder is formed within an end plate of the fixed scroll and accommodates a capacity control mechanism and a plurality of pairs of bypass holes which penetrate the end plate of the fixed scroll and the cylinder perpendicularly. Via one of a pair of bypass holes, the cylinder communicates with a compression chamber enclosed by the orbiting scroll and the fixed scroll, and via the other of the pair of bypass holes, the cylinder communicates with a low pressure chamber provided within rear portions of a compressor housing. One portion of the low pressure chamber is always open to the suction chamber. The communication between the cylinder and the low pressure chamber is controlled by the position of a piston slidably accommodated within the cylinder. When the thermal load for the air conditioning system is low, the piston retreats to the recessed position of the cylinder, opening the pairs of bypass holes. By providing the low pressure chamber, an extra branch path for returning refrigerant gas is formed, in addition to the conventional returning path. Thus, pressure loss from the compression chamber through the suction chamber is effectively reduced. As a result, the capacity control mechanism of the present invention increases the feed back of refrigerant gas from the compression chamber to the suction chamber. Thus, the capacity control mechanism of the present invention lowers the minimum operating capacity more than that of a conventional device, without any undesired increase in the size or weight of the compressor.