PISTON BEARING STRUCTURE FOR FLUID PRESSURE CYLINDER

摘要

This piston bearing structure for a fluid pressure cylinder is provided with one seal ring contained in an accommodating groove of a piston so as to be in sliding contact with a cylinder tube, and two backup wear rings that sandwich the seal ring and are contained in the accommodating groove so as to be in sliding contact with the cylinder tube. Each backup wear ring has a pressure-relief groove that is opposite the accommodating groove and extends over a backup ring part and a wear ring part. The pressure-relief groove links both sides of the backup wear ring in between the piston and the cylinder tube.