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 screw compressor has a slide valve movement mechanism that includes 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 includes a first inflow hole, a second inflow hole, and a third inflow hole. The first chamber communicates with a high-pressure space through the first inflow hole, the second chamber communicates with the low-pressure space through the second inflow hole and the communication flow passage, and the second chamber communicates 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 screw compressor has a slide valve movement mechanism that includes 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 includes a first inflow hole, a second inflow hole, and a third inflow hole. The first chamber communicates with a high-pressure space through the first inflow hole, the second chamber communicates with the low-pressure space through the second inflow hole and the communication flow passage, and the second chamber communicates 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 screw compressor includes a casing, a screw rotor accommodated in the casing to be rotationally driven, and a gate rotor assembly configured to rotate with rotation of the screw rotor. The gate rotor assembly includes a gate rotor including a plurality of flat plate-shaped gates configured to mesh with a helical groove of the screw rotor, and first and second support members. The first support member is made of a metal and includes a plurality of first gate support portions to support corresponding gates from a back surface side. The second support member is made of a metal and includes an annular portion having an annular shape and a plurality of second gate support portions each extending radially toward an outer side from an outer peripheral portion of the annular portion to support corresponding gates from a front surface side.

A compressor includes a compression mechanism, and a muffler structure disposed between a compression-chamber outlet of the compression mechanism and an inflow end of a discharge pipe. The muffler structure includes a first muffler portion and a second muffler portion connected in series such that a refrigerant gas repeats expansion and contraction.

A screw compressor includes a screw rotor having a plurality of helical grooves, a first rotor configured to mesh with the helical grooves of the screw rotor, a second rotor configured to mesh with the helical grooves of the screw rotor, and a casing having a partition wall rotatably retaining the screw rotor and covering an outer peripheral surface of the screw rotor. The partition wall includes first and second envelope portions to form first and second compression chambers. The first compression chamber compresses a fluid introduced into the casing with a suction pressure to an intermediate pressure higher than the suction pressure. The second compression chamber compresses the fluid with the intermediate pressure to a discharge pressure higher than the intermediate pressure.

A screw compressor includes a screw rotor having a plurality of helical grooves, a first rotor configured to mesh with the helical grooves of the screw rotor, a second rotor configured to mesh with the helical grooves of the screw rotor, and a casing having a partition wall rotatably retaining the screw rotor and covering an outer peripheral surface of the screw rotor. The partition wall includes first and second envelope portions to form first and second compression chambers. The first compression chamber compresses a fluid introduced into the casing with a suction pressure to an intermediate pressure higher than the suction pressure. The second compression chamber compresses the fluid with the intermediate pressure to a discharge pressure higher than the intermediate pressure.

A screw compressor includes a screw rotor having a plurality of helical grooves, a first rotor configured to mesh with the helical grooves of the screw rotor, a second rotor configured to mesh with the helical grooves of the screw rotor, and a casing having a partition wall rotatably retaining the screw rotor and covering an outer peripheral surface of the screw rotor. The partition wall includes first and second envelope portions to form first and second compression chambers. The first compression chamber compresses a fluid introduced into the casing with a suction pressure to an intermediate pressure higher than the suction pressure. The second compression chamber compresses the fluid with the intermediate pressure to a discharge pressure higher than the intermediate pressure.

A screw compressor includes a casing, a screw rotor accommodated in the casing to be rotationally driven, and a gate rotor assembly configured to rotate with rotation of the screw rotor. The gate rotor assembly includes a gate rotor including a plurality of flat plate-shaped gates configured to mesh with a helical groove of the screw rotor, and first and second support members. The first support member is made of a metal and includes a plurality of first gate support portions to support corresponding gates from a back surface side. The second support member is made of a metal and includes an annular portion having an annular shape and a plurality of second gate support portions each extending radially toward an outer side from an outer peripheral portion of the annular portion to support corresponding gates from a front surface side.

A screw compressor includes a casing, a screw rotor accommodated in the casing to be rotationally driven, and a gate rotor assembly configured to rotate with rotation of the screw rotor. The gate rotor assembly includes a gate rotor including a plurality of flat plate-shaped gates configured to mesh with a helical groove of the screw rotor, and first and second support members. The first support member is made of a metal and includes a plurality of first gate support portions to support corresponding gates from a back surface side. The second support member is made of a metal and includes an annular portion having an annular shape and a plurality of second gate support portions each extending radially toward an outer side from an outer peripheral portion of the annular portion to support corresponding gates from a front surface side.