Bearing apparatus

Abstract

To provide a bearing device for a rotary shaft which can further restrain the damage to a sliding bearing, by determining the position of a parting surface of the sliding bearing taking into account the position of the maximum pressure of an oil film. A bearing device includes a pair of sliding bearings for rotatably bearing a crankshaft of an internal combustion engine, and an oil supply passage for supplying a lubricating oil into clearances between the crankshaft and the sliding bearings. The sliding bearings are each composed of bearing halves bisected at a parting surface located on a flat plane, substantially orthogonal to the direction of the maximum pressure of the oil films, formed of the lubricating oil in the clearances. The bearing device is applicable to an internal combustion engine including a cylinder having an inclined cylinder axis, which reduces the vibration and noise of the internal combustion engine arising from vibration of a crankshaft, without depending on the angle of inclination of the cylinder axis, and which restrains abrasion and damage of end portion main bearings.

Description

[0001] The patent application of the present invention claims the priority of the Japanese patent applications No. 2002-030129 and 2002-030128 filed on February 6, 2002, and the contents of these two patents are incorporated in this patent application. technical field [0002] The present invention relates to a bearing device comprising a main bearing as a sliding bearing for rotatably supporting a rotating shaft such as a crankshaft of an internal combustion engine. More particularly, the present invention relates to a bearing unit for an internal combustion engine comprising a plurality of main bearings for rotatably supporting a crankshaft of a single-cylinder or multi-cylinder internal combustion engine. In particular, it relates to a bearing arrangement in which each of the ends of the main bearings for supporting the ends of the crankshaft comprises a sliding bearing. Background technique [0003] Usually the main bearing is a sliding bearing used to rotatably support ...

AI Technical Summary

Problems solved by technology

However, in this bearing device, high machining accuracy is required for setting the eccentricity of the main bearing, which causes a problem of high manufacturing cost.

[0013] In addition, when the angle between the cylinder axis and the vertical line is close to 90°, in the direction of the cylinder axis passing through the crankshaft rotation axis, the gap between the crankshaft and the main bearing is enlarged, resulting in easy vibration and noise, and the main bearing is easily damaged. wear and tear

In addition, when the minimum load acts on the collision gap near the separation surface of the main bearing, in some cases, lubricating oil flows out through the gap between the separation surfaces, making it difficult to form a suitable oil film, and in extreme cases, the crankshaft and the main bearing are mutually contact, fearing that the main bearing will be damaged

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