Bearing device for crankshaft of internal combustion engine

• US 9,797,435 B2
• Filed: 12/10/2015
• Issued: 10/24/2017
• Est. Priority Date: 12/15/2014
• Status: Active Grant

• Current Assignee: Daido Metal Company Limited
• Original Assignee: Daido Metal Company Limited
• Inventors: Tanaka, Shiho, Ozawa, Yoshihiro
• Primary Examiner(s): Pilkington, James
• Application Number:
  US14/964,912
• Publication Number:
  US 20160169271A1
• Time in Patent Office: 684 Days
• CPC Class Codes: F16C 17/04 for axial load only
• CPC Class Codes: F16C 17/10 for both radial and axial load
• CPC Class Codes: F16C 2240/30 Angles, e.g. inclinations
• CPC Class Codes: F16C 2240/40 Linear dimensions, e.g. length, radius, thickness, gap
• CPC Class Codes: F16C 2360/22 Internal combustion engines
• CPC Class Codes: F16C 33/046 divided or split, e.g. half-bearings or rolled sleeves
• CPC Class Codes: F16C 33/1065 Grooves on a bearing surface for distributing or collecting the liquid
• CPC Class Codes: F16C 33/1075 Wedges, e.g. ramps or lobes, for generating pressure
• CPC Class Codes: F16C 9/02 Crankshaft bearings

Abstract

A bearing device, including a crankshaft, a pair of half bearings each having crush reliefs formed adjacent to both circumferential ends thereof, a bearing housing in which a retaining hole is formed for retaining the pair of half bearings, and one half thrust bearing having a semi-annular shape arranged adjacent to the retaining hole. The half thrust bearing includes thrust reliefs formed adjacent to both circumferential end portions of a sliding surface receiving an axial force of the crankshaft so that its wall thickness is made thinner toward the circumferential end surface, and 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 in the crankshaft rotational direction.

Claims

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 are arranged so that one half thrust bearing is adjacent to the retaining hole on each axial end surface of the bearing housing, wherein

at least one of the half thrust bearings comprises a first thrust relief on a front side in a crankshaft rotational direction, a second thrust relief on a rear side in the crankshaft rotational direction, and a sliding surface arranged between the first and second thrust reliefs for receiving an axial force of the crankshaft, 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 second thrust relief length of the second thrust relief positioned on the rear side in the crankshaft rotational direction is larger than a first thrust relief length of the first thrust relief positioned on the front side in the crankshaft rotational direction;

wherein the first thrust relief length extends from a first one of the circumferential ends to where the first thrust relief meets the sliding surface; and

wherein the second thrust relief length extends from a second one of the circumferential ends to where the second thrust relief meets the sliding surface.

2. The bearing device according to claim 1, wherein both of the half thrust bearings comprise the first and second thrust reliefs on the front side and the rear side respectively 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 second thrust relief length at a radially inner end 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:

L2≧

CL×

1.5 is satisfied, where the second thrust relief length at the radially inner end of the second thrust relief on the rear side in the crankshaft rotational direction is L2, and the crush relief length at the axial end portion of the crush relief of the half bearing that is correspondingly arranged to the thrust relief is CL.

5. The bearing device according to claim 1, wherein the first thrust relief on the front side in the crankshaft rotational direction is formed so that the first thrust relief length at a radially inner end 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 thrust relief.

6. The bearing device according to claim 5, wherein a formula:

L1≦

CL×

1.5 is satisfied, where the first thrust relief length at a radially inner end of the first thrust relief on the front side of the half thrust bearing in the crankshaft rotational direction is L1, and a crush relief length at an axial end portion of a crush relief of the half bearing that is correspondingly arranged to the 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 a radially inner end of the thrust reliefs and is made shallower towards a radially outer end of the thrust reliefs.

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