Screw compressor and refrigeration apparatus

A screw compressor comprising:

• a casing;
• a screw rotor accommodated in the casing, the screw rotor being configured to be rotationally driven;
• and
• a gate rotor assembly configured to rotate with rotation of the screw rotor, the gate rotor assembly including
• a gate rotor including a plurality of flat plate-shaped gates each configured to mesh with a helical groove of the screw rotor,
• a first support member made of a metal and including a plurality of first gate support portions each configured to support a corresponding one of the gates from a back surface side of the corresponding one of the gates, the first support member being configured to support the gate rotor such that the gate rotor is rotatable, and
• a second support member made of a metal and including a plurality of second gate support portions each configured to support a corresponding one of the gates from a front surface side of the corresponding one of the gates,
• the gate rotor being sandwiched between the first support member and the second support member, and
• the gates being each held by the first support member and the second support member such that the gates are movable slightly in a radial direction and a circumferential direction of the first support member,
• each of the second gate support portions of the second support member including a protruding portion protruding toward a corresponding one of the gates,
• a concave portion with which the protruding portion of a corresponding one of the second gate support portions engages being formed on each of the plurality of gates, and
• a gap being formed between an inner peripheral surface of the concave portion and an outer peripheral surface of the protruding portion so as to surround an entire circumference of the protruding portion.