Kabushiki Kaisha Riken

Other

Masaaki Fujita

Hiroshi Shimizu

Hiroyuki Yabune

Takayuki Yoguchi

Takayuki Kondo

Hiroyuki Sugihara

A piston ring which is resinous includes an annular main body portion having an inner peripheral surface and an outer peripheral surface facing each other and a pair of side surfaces interconnecting the inner peripheral surface and the outer peripheral surface and a joint portionformed in the main body portion. The joint portion has a step shape when viewed from at least one of the pair of side surfaces and the outer peripheral surface. The outer peripheral surface has a tapered surface having an outer diameter increasing from a side of one side surface of the pair of side surfaces of the main body portion toward a side of the other side surface.

Piston ring

A piston ring includes an annular main bodyhaving a side surfaceand a side surface, and an inner peripheral surfaceand an outer peripheral surface, wherein in the main body, a cutout sectionis provided in a corner sectionformed by the side surfaceand the outer peripheral surface. The cutout sectionhas a first surfaceand a second surface. An angle &#x3b8;formed by the first surfaceand the side surfaceis an obtuse angle, and a corner sectionformed by the second surfaceand the outer peripheral surfaceis located between the side surfaceand the side surfacein a width direction of the main body

A piston ring includes an annular body having: an inner circumferential surface and an outer circumferential surface; one side surface and the other side surface substantially orthogonal to the inner circumferential surface; and a pair of joint ends. The outer circumferential surface includes an inclined surface and an abutment surface. In a direction connecting the one side surface and the other side surface, a maximum width Wof the abutment surface at the joint end is 80% to 150% of a maximum width Wof the abutment surface in a portion other than the joint end. In the body, a two-axis difference (d&#x2212;d) between a diameter din a first axis direction passing through a central position of the joint and a diameter din a second axis direction orthogonal to the first axis direction is greater than &#x2212;0.25 mm and less than +0.36 mm.

A combined oil control ring comprising a pair of circular side rails each having a gap, and a waved spacer expander longitudinally sandwiched by the side rails, which has seating tabs for pushing inner surfaces of the side rails on the inner side, (a) the radial thickness aof the side rail being 50-90% of the height aof the spacer expander, or (b) the height aof the seating tab being 23-60% of the height aof the spacer expander.

Growing community of inventors

Kashiwazaki, Japan

Masaaki Fujita