Swing compressor, Lubrication, Oil film thickness, Visualization
A swing compressor is mainly used for residential air conditioning. Compared with a rotary compressor, the swing compressor has the features that a piston is integrated with a vane and a roller, and that the piston is supported with a pair of bushes. The bushes of the swing compressor is important sliding parts which influence the performance and reliability of the compressor and it is required to clarify the behavior during the actual operation for higher performance and reliability. The pair of bushes has four sliding surfaces that are a suction cylinder side, a suction blade side, a discharge cylinder side and a discharge blade side. In the past research, the clearance at the suction blade side where is in a sever lubrication condition due to pressure difference between a suction and a discharge chamber was measured by using displacement sensors in order to clarify the behavior of the clearance. However, the other clearances have not been measured yet. This research shows the behavior of the clearance at the four sliding surfaces of bushes in an actual operation under the refrigerant atmosphere. The behavior of the bush during the actual operation was visualized by using a high speed camera, and clearance measurement was performed on the four sliding surfaces. In order to quantify the clearance, markings were applied to the parts (bush and piston blade, cylinder) and image processing of high speed camera images was performed to quantify the clearance during the actual operation from the positional relationship of the markings, and the difference of the those behavior at the suction side and the discharge side respectively was clarified.