Daido Metal Company Ltd.

Motohiko Koushima

Yuki Kawashima

Osamu Ishigo

Shiho Tanaka

There is provided a half thrust bearing having a semicircular-ring shape for a crankshaft of an internal combustion engine, including a back metal layer and a bearing alloy layer having a slide surface on which thrust reliefs are formed adjacently to both circumferential end surfaces so that a wall thickness of the half thrust bearing becomes thinner from the slide surface toward the circumferential end surfaces. A thrust relief length Lof each thrust relief extends over a circumferential anglefrom the circumferential end surface toward a circumferential central portion, and is constant between an inside end portion and an outside end portion in a radial direction of the half thrust bearing. A flat surface of each thrust relief includes a first region on the circumferential end surface side and a second region on the circumferential central portion side.

Half thrust bearing and bearing device for crankshaft of internal combustion engine

A main bearing for a crankshaft of an internal combustion engine has first and second half bearings forming an axial groove on an inner circumferential surface of a butting portion. Each half bearing has a main cylinder portion including a central portion, and crush relief portions each extending toward the central portion from an end surface of the half bearing with a center angle of 3&#xb0; to 15&#xb0;. A plurality of crush relief grooves are formed in each crush relief portion in the circumferential direction to communicate with the axial groove. An oil groove is formed in the circumferential direction on an inner circumferential surface of the first half bearing. The second half bearing has a transition region having an inward protruding curved surface a wall thickness of which becomes thinner toward the crush relief portion from the main cylinder portion.

Main bearing for crankshaft of internal combustion engine

A half bearing for supporting a crank shaft of an internal combustion engine is provided. The half bearing having a main semi-cylindrical part, two crush reliefs, and two transition regions. Each crush relief has a depth from a imaginary plane at a circumferential end surface of the half bearing greater than a depth from the imaginary plane at a connecting position between each crush relief and the transition region. A plurality of circumferential grooves extend in a circumferential direction in the main semi-cylindrical part along their entire length in the circumferential direction, and the plurality of circumferential grooves extend also in the transition region continuously.

Half bearing and plain bearing

A main bearing for a crankshaft of an internal combustion engine has first and second half bearings forming an axial groove on an inner circumferential side of a butting portion. Each half bearing has a main cylinder portion including a central portion in a circumferential direction, and crush relief portions each extending toward the central portion from an end surface of the half bearing in the circumferential direction with a center angle of 3&#xb0; to 15&#xb0;. A plurality of crush relief grooves are formed in each crush relief portion to extend in the circumferential direction and communicate with the axial groove. The first half bearing has an oil groove extending in the circumferential direction and a transition region having an inward protruding curved surface with a wall thickness becoming thinner toward the crush relief portion from the main cylinder portion.

A connecting rod bearing fort supporting a crankpin of an internal combustion engine is provided. The crankpin has a discharge port on its surface for supplying lubrication oil to a gap between the crankpin and the connecting rod bearing constituted by a pair of half bearings. The half bearing includes a main cylindrical portion, crush reliefs and transitional regions. A plurality of crush relief grooves are formed in the crush relief to continuously extend in a circumferential direction, and an axial groove is formed at an inner side end edge of the half bearing in the circumferential direction to continuously extend in an axial direction so that the crush relief grooves communicate with the axial groove.

Connecting rod bearing

According to the invention, there is provided a connecting rod bearing constituted by a half bearing, which has a main cylindrical portion, crush reliefs and a transitional region. The crush relief is formed so that a depth from a virtual inner circumferential surface at a position of an end surface of the half bearing in a circumferential direction is larger than a depth from the virtual inner circumferential surface at a position where the crush relief connects with the transitional region. Further, a plurality of circumferential grooves are provided in the main cylindrical portion to continuously extend in the circumferential direction throughout an entire length of the main cylindrical portion in the circumferential direction, and are continuously provided also in the transitional region.

A plain bearing for supporting a crank shaft of an internal combustion engine is provided. The plain bearing is constituted by a pair of semicylindrical members. A crush relief is formed in an inner circumferential surface of the semicylindrical member, and a main cylindrical surface is formed in a region aside from the crush relief. The crush relief includes an outwardly convex curved surface and an inwardly convex curved surface.

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Inuyama, Japan

Motohiko Koushima