Ensuring High Reliability of Reciprocating Compressor with Ball Joint

Some reciprocating compressors have connecting rods with ball joints to join the crankshaft and the piston. The load of the pressurized gas inside the cylinder directly loads the joint of the piston and the connecting rod. For this reason, it needs to be highly reliable, so it needs to be made of hard material, high-precision spherical surfaces, and a complicated assembling line. Accordingly, the present study estimated an easily assembled ball joint, which ensures reliability. To ensure the reliability of the reciprocating compressor, the ball joint, which connects the piston to the connecting rod, was optimized by life tests. The tests showed that the ball joint needs an oil path, whose edge does not contact the piston. The oil path is set inside the connecting rod and the face of the outer ball. It also shows that the material of the connecting rod must be harder than that of the piston. That is, the fresh oil is always fed to the ball joint, and this ensures the high reliability of the reciprocating compressor.