Rotor type is a kind of rotary type, which is mainly used for household air conditioning at present. Compressors can be divided into positive displacement type and speed type. Positive displacement type includes reciprocating type and rotary type. Reciprocating type is mainly piston type; Rotary type includes rolling rotor type, sliding type, screw type (single screw type, double screw type) and scroll type; The speed type is mainly centrifugal, but also axial flow and mixed flow.