A screw compressor includes a screw rotor, a gate rotor, and a speed adjuster. The screw rotor has an outer peripheral surface with a plurality of screw grooves. The screw rotor is configured to be rotated. The gate rotor has a plurality of teeth. A ratio T/S of a number T of the teeth to a total number S of the screw grooves is greater than or equal to 2.5. The gate rotor meshes with the screw rotor. The speed adjuster is configured to adjust a rotational speed of the screw rotor. Rotation of the screw rotor at an angle greater than 180° allows the screw compressor to perform a stroke from start of compression to completion of discharge.

A screw compressor includes a screw rotor, a gate rotor, and a speed adjuster. The screw rotor has an outer peripheral surface with a plurality of screw grooves. The screw rotor is configured to be rotated. The gate rotor has a plurality of teeth. A ratio T/S of a number T of the teeth to a total number S of the screw grooves is greater than or equal to 2.5. The gate rotor meshes with the screw rotor. The speed adjuster is configured to adjust a rotational speed of the screw rotor. Rotation of the screw rotor at an angle greater than 180° allows the screw compressor to perform a stroke from start of compression to completion of discharge.

A screw compressor includes a casing, a screw rotor, a low-pressure-side bearing, and a low-pressure-side bearing holder holding the low-pressure-side bearing. The screw rotor is housed in the casing to form a compression mechanism to compress a refrigerant. The low-pressure-side bearing is arranged in a low-pressure-side region inside the casing and rotatably supports a drive shaft of the screw rotor. The casing has a suction port with an opening facing the low-pressure-side bearing holder as viewed along an axial direction. A filter member is attached to the suction port to filter out contaminants contained in the refrigerant being sucked into the casing. The filter member has a cylindrical shape with a bottom. A peripheral portion of the filter member adjacent to an opening of the filter member is fixed to the suction port. The bottom of the filter member is fixed to the low-pressure-side bearing holder.

A screw compressor includes a casing, a screw rotor, a low-pressure-side bearing, and a low-pressure-side bearing holder holding the low-pressure-side bearing. The screw rotor is housed in the casing to form a compression mechanism to compress a refrigerant. The low-pressure-side bearing is arranged in a low-pressure-side region inside the casing and rotatably supports a drive shaft of the screw rotor. The casing has a suction port with an opening facing the low-pressure-side bearing holder as viewed along an axial direction. A filter member is attached to the suction port to filter out contaminants contained in the refrigerant being sucked into the casing. The filter member has a cylindrical shape with a bottom. A peripheral portion of the filter member adjacent to an opening of the filter member is fixed to the suction port. The bottom of the filter member is fixed to the low-pressure-side bearing holder.

A freezing device including a compressor that compresses sucked refrigerant using a compression mechanism and discharges compressed refrigerant includes a compressor, an inverter, and a controller. The compressor includes a motor, a low pressure unit, a compression space, a high pressure unit, a communication flow path, and a flow control valve. The inverter drives or stops the motor. The controller controls the inverter and the flow control valve. The controller performs, in stop control in which an operation of the compressor is stopped, braking control in which driving of the compression mechanism is prevented or suppressed, and pressure equalization control in which pressure in the high pressure unit is equalized with pressure in the low pressure unit.

A high suction pressure thrust load balance assembly configured for use with a single screw compressor includes comprises a sealing baffle that is keyed to, so as to be rotatable along with, a main rotor drive shaft of the single screw compressor. The sealing baffle is configured to create a force or load to counteract the axial force of the main rotor drive shaft created during rotation of the main rotor drive shaft using the pressurized oil used to lubricate the mechanical shaft seal of the compressor.

A high suction pressure thrust load balance assembly configured for use with a single screw compressor includes comprises a sealing baffle that is keyed to, so as to be rotatable along with, a main rotor drive shaft of the single screw compressor. The sealing baffle is configured to create a force or load to counteract the axial force of the main rotor drive shaft created during rotation of the main rotor drive shaft using the pressurized oil used to lubricate the mechanical shaft seal of the compressor.

A screw compressor includes a screw rotor having a plurality of screw grooves, a plurality of gate rotors each including gates that mesh with the screw rotor, and a casing. The screw rotor is rotatably inserted in the casing. The casing has a cylindrical wall through which the gates pass. The screw compressor has a plurality of compression chambers inside the cylindrical wall. The plurality of compression chambers are defined by the screw rotor and the gates. The compression chambers include a first compression chamber and a second compression chamber. A fluid introduced into the casing at a suction pressure is compressed to an intermediate pressure higher than the suction pressure in the first compression chamber. The fluid at the intermediate pressure is compressed to a discharge pressure higher than the intermediate pressure in the second compression chamber.

A single screw compressor comprises a main rotor and at least one gate rotor, a casing for the main rotor having a discharge port at a discharge end of the casing, and a slide slidable within a bore in the casing adjacent the main rotor. The slide has a cut-out (6) between first (2) and second (4) sealing parts of the slide, the slide is slidable between a high volume ratio position where the cut-out (6) is within the casing and provides a path to the discharge port, and a low volume ratio position where the slide is beyond the discharge end of the casing to provide a fixed discharge path in the bore of the casing.

A single screw compressor comprises a main rotor and at least one gate rotor, a casing for the main rotor having a discharge port at a discharge end of the casing, and a slide slidable within a bore in the casing adjacent the main rotor. The slide has a cut-out (6) between first (2) and second (4) sealing parts of the slide, the slide is slidable between a high volume ratio position where the cut-out (6) is within the casing and provides a path to the discharge port, and a low volume ratio position where the slide is beyond the discharge end of the casing to provide a fixed discharge path in the bore of the casing.