Rotary compressor having vane that has diamond-like carbon layer

A rotary compressor comprising:

• a vertically-positioned airtight compressor housing having an upper section in which a discharge portion of a refrigerant is provided and a lower section in which an inlet unit of the refrigerant is provided on a side surface thereof;
• a compressing unit that is disposed in the lower section of the compressor housing, that includes an annular cylinder, an end plate which has a bearing unit and a discharge valve unit and closes an end portion of the cylinder, an annular piston which is fit in an eccentric portion of a rotation shaft supported in the bearing unit, performs an orbital motion inside the cylinder along a cylinder inner wall of the cylinder, and forms an operation chamber together with the cylinder inner wall, and a vane which protrudes from the inside of
• a vane groove of the cylinder to the inside of the operation chamber, comes into contact with the annular piston, and partitions the operation chamber into an inlet chamber and a compression chamber, and that performs suction of the refrigerant via the inlet unit and discharges the refrigerant from the discharge portion via the inside of the compressor housing;
• and
• a motor that is disposed in the upper section of the compressor housing and drives the compressing unit via the rotation shaft,
• wherein the vane is formed of steel and has a diamond-like carbon layer having HmV of 1500 or higher which is formed as an under layer on a sliding surf ace with respect to the annular piston and a diamond-like carbon layer having HmV of 1200 or lower which is formed as a fitness layer on an outer side of the diamond-like carbon layer having HmV of 1500 or higher, and
• wherein the annular piston is formed of Ni—Cr—Mo cast iron or Ni—Cr—Mo cast iron to which 0.15 wt % to 0.45 wt % of phosphorus is added, or is formed of cast iron or steel and has an iron nitride layer formed only on an outer circumferential surface thereof, and a nitriding treatment is not performed on an inner circumferential surface thereof.