Refrigeration – Gas compression – heat regeneration and expansion – e.g.,...
Reexamination Certificate
1999-10-27
2001-03-27
Capossela, Ronald (Department: 3744)
Refrigeration
Gas compression, heat regeneration and expansion, e.g.,...
C062S151000, C062S155000
Reexamination Certificate
active
06205792
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the art of refrigerators and, more particularly, a refrigerator assembly incorporating a Stirling cycle refrigeration system, the operating phase of which can be electronically controlled to effect both cooling and defrosting of a freezer compartment of the refrigerator.
2. Discussion of the Prior Art
The Stirling cycle is a known type of efficient refrigeration cycle. Such a cycle functions by directing a working fluid through four repetitive operations, i.e., a heat addition operation at constant temperature, a constant volume heat rejection operation, a constant temperature heat rejection operation and a heat addition operation at constant volume. It has been previously proposed to utilize a Stirling cycle in a refrigeration system, particularly a heat pump system. However, it has also been proposed in the art to utilize a Stirling cycle for use in a refrigerator. Such a Stirling cycle arrangement would incorporate an expander having an associated expansion space piston and a pulsator which has an associated compression space piston. In a conventional Stirling cycle refrigeration system, the phase relationship between the expansion piston and the compression piston is determined by a mechanical coupling between the pistons. However, particularly in view of the desire to adjust the degree of refrigeration, it has also been proposed to electronically control the time phase relationship between the expansion and compression pistons in order to alter the cooling capacity of the overall system. That is, the phase relationship can be altered, such as by changing the driving frequency for the expander and compressor, in order to actually reduce the maximum cooling capacity.
Despite these advances, the use of Stirling cycle refrigeration systems has not been widely accepted, in part due to the fact that the electronic controls proposed for such Stirling cycle systems do not provide for all of the cycles incorporated in more conventional refrigeration systems. For instance, the prior art dealing with Stirling cycle refrigeration systems have not addressed providing an automatic defrosting operation. For this and other reasons, there exists a need in the art for an improved refrigerator incorporating a Stirling cycle refrigeration system which can be electronically controlled to perform multiple operations, including both cooling and defrost operations, automatically. In addition, there is need in the art for a compact Stirling cycle system for use in a refrigerator.
SUMMARY OF THE INVENTION
The present invention is directed to a refrigerator assembly incorporating a Stirling cycle refrigeration system which is electronically controlled in order to provide for both cooling and defrost cycles. More specifically, the refrigerator assembly includes a refrigerator cabinet within which defines at least a freezer compartment. The Stirling cycle refrigeration system includes a Stirling cycle compressor and a Stirling cycle displacer, with the compressor being mounted within the cabinet but outside of the freezer compartment and with the displacer being mounted within the freezer compartment. The electronic controller can alter the time phase relationship between the compressor and displacer in order to change the refrigerator between cooling and defrost cycles of operation.
In order to provide a compact arrangement, both the compressor and displacer are preferably formed as a housing within which is positioned a movable piston and from which projects various radially extending, spaced fins. The refrigerator is also provided with a fan which is adapted to blow air over the fins of the displacer within a freezer compartment, at least during cooling cycles. In the most preferred embodiment of the invention, a phase relationship between the compressor and displacer is changed by 180° automatically by the controller in order to switch between the cooling and defrost cycles of operation.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of the preferred embodiment thereof when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
REFERENCES:
patent: 3698182 (1972-10-01), Knoos
patent: 3812682 (1974-05-01), Johnson
patent: 4397155 (1983-08-01), Davey
patent: 4475346 (1984-10-01), Young et al.
patent: 4543793 (1985-10-01), Chellis et al.
patent: 4545209 (1985-10-01), Young
patent: 4578956 (1986-04-01), Young
patent: 4664685 (1987-05-01), Young
patent: 4902952 (1990-02-01), Lavery
patent: 4996841 (1991-03-01), Meijer et al.
patent: 5079924 (1992-01-01), Van der Broeck et al.
patent: 5095700 (1992-03-01), Bolger
patent: 5284022 (1994-02-01), Chung
patent: 5333460 (1994-08-01), Lewis et al.
patent: 5460009 (1995-10-01), Wills et al.
patent: 5642622 (1997-07-01), Berchowitz et al.
patent: 5693991 (1997-12-01), Hiterer et al.
patent: 5813235 (1998-09-01), Peterson
patent: 5927079 (1999-07-01), Sekiya et al.
patent: 405126427 (1993-05-01), None
patent: 406050622 (1994-02-01), None
Capossela Ronald
Diederiks, Jr. Everett G.
Maytag Corporation
LandOfFree
Refrigerator incorporating stirling cycle cooling and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refrigerator incorporating stirling cycle cooling and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refrigerator incorporating stirling cycle cooling and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2539444