Prevention of unpowered reverse rotation in compressors

a compressor and reverse rotation technology, applied in the field of compressors, can solve the problems of undesirable unpowered reverse rotation, damage to internal components of the compressor, and undesirable noise of unpowered reverse rotation

US20060222510A1Inactive Publication Date: 2006-10-05CARRIER CORP
11 Cites 6 Cited by

Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
Publication Date
2006-10-05
Estimated Expiration
Not applicable · inactive patent
Patent Text Reader

Abstract

The shutdown of a compressor (10) installed in a refrigerant circuit (2) in air conditioning or refrigeration system is controlled so as to prevent unpowered reverse rotation of the compressor. Prior to terminating electric power to the compressor drive motor (24), the pressure within the system is relieved and substantially equalized across the compressor, thereby eliminating the possibility of unpowered reverse rotation of the compressor at shutdown. Pressure relief and equalization may be achieved by reducing the operating speed of the compressor to a low forward speed for a period of time prior to deenergizing the compressor drive motor. Pressure equalization may also be achieved by driving the compressor in reverse rotation prior to deenergizing the drive motor.
Need to check novelty before this filing date? Find Prior Art

Description

TECHNICAL FIELD

[0001] The present invention relates generally to compressors having a shaft driven in rotation by a drive motor, including for example scroll compressors and screw compressors, and more particularly, to a method of operating such compressors at shutdown to prevent unpowered reverse rotation. BACKGROUND OF THE INVENTION

[0002] In air conditioning and refrigeration systems, a compressor is provided to compress a refrigerant and pass that refrigerant through the refrigerant circuit and system components such as a condenser, an evaporator and an expansion device. Scroll compressors and screw compressors are widely used in such air conditioning and refrigerant systems. In both scroll compressors and screw compressors, the refrigerant is compressed as it passes through compression elements associated with a compressor shaft driven in rotation by a drive motor. As the compressor shaft is driven in rotation, the refrigeration passes through progressively smaller compression...

Examples

Embodiment Construction

[0012] Referring now to FIG. 1, the present invention will be described herein with respect to a compressor installed in a refrigerant circuit 2, such as commonly found in an air conditioning, heat pump or refrigeration systems, having a condenser 4, an evaporator 6, an expansion valve 8 and a compressor 10 connected in the conventional manner in refrigerant flow communication by refrigerant lines so as to form the refrigerant circuit 2. It is to be understood, however, the present invention is not limited in application to compressors installed in air conditioning, heat pumps or refrigeration systems, but may be applied to any compressor subject to unpowered reverse rotation upon shutdown due to the re-expansion of compressed fluid back through the compression mechanism. In particular, although the present invention will be described herein with respect to a scroll compressor, it may be applied to a screw compressor and any other compressor subject to unpowered reverse rotation upo...