Bearing device for crankshaft of internal combustion engine

Patent metadata

Field	Value
Publication number	US-9909614-B2
Application number	US-201615246672-A
Country	US
Kind code	B2
Filing date	Aug 25, 2016
Priority date	Aug 26, 2015
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The invention provides a bearing device, including a crankshaft, a pair of half bearings each having crush reliefs adjacent to both circumferential ends thereof, a bearing housing having a retaining hole, and one half thrust bearing arranged adjacent to the retaining hole. Each half thrust bearing is configured at least by a bearing alloy layer and a resin slide layer which constitutes a slide surface receiving an axial force of the crankshaft, and thrust reliefs adjacent to both circumferential end portions of the sliding surface so that its wall thickness is made thinner toward the circumferential end surface. A thrust relief length at an inner end portion of the thrust relief positioned on a rear side in the crankshaft rotational direction is formed to be larger than a thrust relief length at an inner end portion of the thrust relief positioned on a front side.

First claim

The invention claimed is:

1. A bearing device for a crankshaft of an internal combustion engine, comprising:
a crankshaft;
a pair of half bearings for supporting a journal portion of the crankshaft, crush reliefs being formed on an inner circumferential surface of each half bearing and adjacent to both circumferential ends of the half bearing;
a bearing housing having a retaining hole for retaining the pair of half bearings, the retaining hole being formed to penetrate through the bearing housing; and
two half thrust bearings each having a semi-annular shape that is arranged adjacent to the retaining hole on each axial end surface of the bearing housing, each half thrust bearing being configured by a bearing alloy layer and a resin slide layer, or by a back metal layer, a bearing alloy layer and a resin slide layer, the resin slide layer constituting a slide surface receiving an axial force of the crankshaft, wherein
at least one of the half thrust bearings comprises a first thrust relief on a front side and a second thrust relief on a rear side in a crankshaft rotational direction, the sliding surface receiving the axial force is arranged between the first and second thrust reliefs, and the first and second thrust reliefs being formed so that a wall thickness of the half thrust bearing is made thinner toward both circumferential ends of the thrust bearing, and
a thrust relief length at an inner end portion of the second thrust relief positioned on the rear side in the crankshaft rotational direction is larger than a thrust relief length at an inner end portion of the first thrust relief positioned on the front side in the crankshaft rotational direction.

2. The bearing device according to claim 1 , wherein both of the half thrust bearings comprise the a first thrust relief on a front side and a second thrust relief on a rear side in the crankshaft rotational direction.

3. The bearing device according to claim 1 , wherein the second thrust relief on the rear side in the crankshaft rotational direction is formed so that the thrust relief length at an inner end portion of the half thrust bearing is longer than a crush relief length at an axial end portion of a crush relief of the half bearing that is correspondingly arranged to the second thrust relief.

4. The bearing device according to claim 3 , wherein a formula: L 2 ≧CL×1.5 is satisfied, where the thrust relief length at the inner end portion of the second thrust relief on the rear side in the crankshaft rotational direction is L 2 , and the crush relief length at the axial end portion of the crush relief of the half bearing that is correspondingly arranged to the second thrust relief is CL.

5. The bearing device according to claim 1 , wherein the first thrust relief on the front side of the half thrust relief in the crankshaft rotational direction is formed so that the thrust relief length at an inner end portion is shorter than a crush relief length at an axial end portion of a crush relief of the half bearing that is correspondingly arranged to the first thrust relief.

6. The bearing device according to claim 5 , wherein a formula: L 1 ×1.5≦CL is satisfied, where the thrust relief length at the inner end portion of the second thrust relief on the front side of the half thrust bearing in the crankshaft rotational direction is L 1 , and a crush relief length at an axial end portion of a crush relief of the half bearing that is correspondingly arranged to the first thrust relief is CL.

7. The bearing device according to claim 1 , wherein a thrust relief depth of each one of the first and second thrust reliefs at both circumferential ends is constant over the entire length in the radial direction of the first and second thrust reliefs.

8. The bearing device according to claim 1 , wherein a thrust relief depth of each one of the first and second thrust reliefs at both circumferential ends is maximum at the inner end portion of the thrust relief and is made shallower toward an outer end portion of the first and second thrust reliefs.

9. The bearing device according to claim 1 , wherein the thrust relief length of the second thrust relief positioned on the rear side of each half thrust bearing in the crankshaft rotational direction is minimum at the inner end portion of the second thrust relief and is made longer toward an outer end portion, and the first thrust relief length of the thrust relief positioned on the front side of each half thrust bearing in the crankshaft rotational direction is constant from the inner end portion to the outer end portion of the first thrust relief.

Assignees

• Daido Metal Co

Inventors

• Tanaka Shiho
• Ozawa Yoshihiro

Classifications

• F16C33/205

  with two layers · CPC title

• F16C2208/44

  Polybenzimidazole [PBI] (F16C2208/58 takes precedence) · CPC title

• F16C2202/50

  Lubricating properties · CPC title

• F16C17/04

  for axial load only · CPC title

• F16C33/206

  with three layers · CPC title