Compressor and refrigeration cycle device

A compressor, comprising:

• a housing;
• a drive assembly, provided in the housing;
• a compression assembly, provided in the housing, and connected to and driven by the drive assembly, wherein the compression assembly is configured to perform a multi-stage compression on a refrigerant under drive of the drive assembly an expansion assembly, provided in the housing and connected to the drive assembly, wherein the expansion assembly is configured to expand the refrigerant compressed by the compression assembly;
• a variable-volume assembly, the variable-volume assembly being configured to control loading or unloading of at least one of the compression assembly and the expansion assembly;
• wherein the compression assembly comprises:
• a first-stage compression structure, configured to perform a first-stage compression on a refrigerant discharged from an evaporator;
• a second-stage compression structure, configured to perform a second-stage compression on a first-stage refrigerant, wherein the first-stage refrigerant comprises the refrigerant compressed through the first-stage compression of the first-stage compression structure;
• wherein the variable-volume assembly is configured to control loading or unloading of the second-stage compression structure;
• the second-stage compression structure comprises:
• a second-stage cylinder, provided with a second gas inlet and a second gas outlet, wherein the second gas inlet draws the first-stage refrigerant into the second-stage cylinder;
• a second-stage roller, arranged in the second-stage cylinder and configured to cooperate with the second-stage cylinder to perform the second-stage compression on the first-stage refrigerant under drive of the drive assembly;
• a second-stage cavity, being in communication with the second gas outlet to discharge the refrigerant compressed through the second-stage compression into the second-stage cavity;
• wherein a second sliding groove is provided in the second-stage cylinder, a second sliding vane is slidably provided in the second sliding groove, the variable-volume assembly controls loading or unloading of the second-stage compression structure by controlling a working state of the second sliding vane.