| 摘要 |
A rotary piston ring unit is provided to prevent sticking of a piston ring due to carbon accumulation in a ring groove by forcibly rotating the piston ring with upper and lower protrusions of the ring groove according to vertical movement of a piston. A rotary piston ring unit includes a plurality of upper and lower protrusions(5,7) and a piston ring(9). The upper and lower protrusions are formed at regular intervals on upper and lower surfaces of a ring groove(3) formed along an outer peripheral surface of a piston(1). The piston ring is inserted into the ring groove and has a plurality of holes(11) at regular intervals along a cross section to insert the upper and lower protrusions. The upper and lower protrusions are formed in a hemispheric shape to crossly correspond to each other. A diameter(d1) of the upper protrusion is equal to a diameter(d2) of the lower protrusion. |
