Dual slide valve assemblies having volume slide valve members that are self-positioning. The slide valve assemblies include a self-positioning volume slide valve mechanism that automatically slidably adjusts to control compressor volume ratio and power input to the compressor. The slide valve assemblies also include a capacity slide valve mechanism that is slidably movable to control compressor capacity.

Dual slide valve assemblies having volume slide valve members that are self-positioning. The slide valve assemblies include a self-positioning volume slide valve mechanism that automatically slidably adjusts to control compressor volume ratio and power input to the compressor. The slide valve assemblies also include a capacity slide valve mechanism that is slidably movable to control compressor capacity.

A volume ratio control system for a compressor includes a chamber formed within a housing of the compressor, a piston disposed within the chamber, where the piston is configured to separate the chamber into at least a first portion fluidly coupled to a low pressure side of the compressor and a second portion fluidly coupled to a high pressure side of the compressor, and a biasing device disposed within the chamber, where the biasing device is configured to adjust a position of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor falling below a threshold value.

A volume ratio control system for a compressor includes a chamber formed within a housing of the compressor, a piston disposed within the chamber, where the piston is configured to separate the chamber into at least a first portion fluidly coupled to a low pressure side of the compressor and a second portion fluidly coupled to a high pressure side of the compressor, and a biasing device disposed within the chamber, where the biasing device is configured to adjust a position of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor falling below a threshold value.

A volume ratio control system for a compressor includes a chamber formed within a housing of the compressor, where the chamber is in fluid communication with a high pressure side of the compressor, a piston disposed within the chamber, where the piston includes a cavity in fluid communication with a low pressure side of the compressor, and a biasing device disposed within the chamber and configured to enable movement of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor falling below a threshold value.

A volume ratio control system for a compressor includes a chamber formed within a housing of the compressor, where the chamber is in fluid communication with a high pressure side of the compressor, a piston disposed within the chamber, where the piston includes a cavity in fluid communication with a low pressure side of the compressor, and a biasing device disposed within the chamber and configured to enable movement of the piston in response to a pressure differential between the low pressure side of the compressor and the high pressure side of the compressor falling below a threshold value.

A screw compressor has a slide valve movement mechanism having a cylinder provided in a casing body, a piston partitioning an interior of the cylinder into a first chamber and a second chamber, and a communication flow passage through which the second chamber communicates with a low-pressure space. The cylinder is provided with a first inflow hole, a second inflow hole, and a third inflow hole, the first chamber communicating with a high-pressure space through the first inflow hole, the second chamber communicating with the low-pressure space through the second inflow hole and the communication flow passage, the second chamber communicating with the high-pressure space through the third inflow hole. The third inflow hole is located at a position at which the third inflow hole is closed by the piston when the piston lies at a stop position at which the piston moves toward the second chamber and stops.

A system is provided for adjusting the volume ratio of a screw compressor. The system can use a port in a rotor cylinder to bypass vapor from the compression chamber to the discharge passage of the compressor. A valve can be used to open or close the port to obtain different volume ratios in the compressor.

A system is provided for adjusting the volume ratio of a screw compressor. The system can use a port in a rotor cylinder to bypass vapor from the compression chamber to the discharge passage of the compressor. A valve can be used to open or close the port to obtain different volume ratios in the compressor.

A control valve includes: a first valve to control a flow rate of refrigerant flowing from a discharge chamber to a control chamber of a compressor; a second valve to control a flow rate of the refrigerant flowing from the control chamber to a suction chamber; a solenoid to generate a drive force in a first valve closing direction and a second valve opening direction; a biasing member to generate a biasing force in an first valve opening direction and a second valve closing direction; and a pressure sensing part to sense a pressure in the suction chamber or the control chamber, and generate a counterforce against the drive force. A state in which both of the first and second valves are open is present during an increase in the current supplied to the solenoid from zero to an upper limit current value, and an increase rate of an opening degree of the first valve is increased during a decrease in the current supplied to the solenoid, a predetermined lower limit current value being an inflection point of the increase.