Half thrust bearing

Patent metadata

Field	Value
Publication number	US-10408256-B2
Application number	US-201815986962-A
Country	US
Kind code	B2
Filing date	May 23, 2018
Priority date	Jun 12, 2017
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A half thrust bearing includes a sliding surface for receiving an axial force of a crankshaft of an engine, and a rear surface on an opposite side thereto. The sliding surface includes a flat surface portion near a circumferentially central portion, and two inclined flat surface portions on both circumferential sides of the flat surface portion. The axial distance between the rear surface and the sliding surface is maximum at the flat surface portion. At any radial positions, the axial distance in each inclined flat surface portion is maximum on a circumferentially central portion side and is reduced toward a circumferential end portion of the half thrust bearing. Each inclined flat surface portion is arranged to form one constant thickness portion extending linearly from a radially inner end to a radially outer end at a circumferential angle of 45°.

First claim

The invention claimed is:

1. A half thrust bearing for receiving an axial force of a crankshaft of an internal combustion engine, the half thrust bearing having a semi-annular shape and comprising;
a sliding surface for receiving the axial force; and
a rear surface on an opposite side of the sliding surface, and the half thrust bearing defining a reference plane on a rear surface side that is perpendicular to an axial direction, wherein
the sliding surface includes a flat surface portion extending in parallel with the reference plane from a radially inner end of the half thrust bearing to a radially outer end thereof, and two inclined flat surface portions formed on both sides in a circumferential direction of the flat surface portion,
an axial distance between the reference plane and the sliding surface is maximum in the flat surface portion,
at each of radial positions, the axial distance in each inclined flat surface portion is maximum at a circumferential end of the inclined flat surface portion on a circumferentially central portion side of the half thrust bearing and is reduced toward a circumferential end portion of the half thrust bearing,
each inclined flat surface portion is arranged to form one constant thickness portion which extends linearly from the radially inner end to the radially outer end of the half thrust bearing in an area between central angles of 35° and 55° from the circumferential end portion toward the circumferentially central portion side of the half thrust bearing, the axial distance being constant in the constant thickness portion,
in the circumferential direction, the axial distance is maximum at the radially inner end and is reduced toward the radially outer end in a region of each inclined flat surface portion between the constant thickness portion and the circumferential end portion of the half thrust bearing, and is minimum at the radially inner end and increases toward the radially outer end in a region of the inclined flat surface portion between the circumferentially central portion and the constant thickness portion, and
the flat surface portion has a circumferential length extending over a central angle of 5° or more and 35° or less, at any radial positions of the half thrust bearing.

2. The half thrust bearing according to claim 1 , wherein the rear surface is flat, and is positioned within the reference plane.

3. The half thrust bearing according to claim 1 , wherein the flat surface portion includes the circumferentially central portion of the half thrust bearing.

4. The half thrust bearing according to claim 1 , wherein the circumferential length of the flat surface portion is minimum at the radially inner end of the half thrust bearing and is gradually increased toward the radially outer end thereof, or is minimum at the radially outer end of the half thrust bearing and is gradually increased toward the radially inner end thereof.

5. The half thrust bearing according to claim 1 , wherein when the half thrust bearing is viewed from a direction perpendicular to both circumferential end surfaces of the half thrust bearing, an outline of each inclined flat surface portion of the sliding surface is configured by a curved line.

6. The half thrust bearing according to claim 1 , wherein a difference between the axial distance in the flat surface portion and the axial distance in both circumferential end portions at the radially outer ends of the half thrust bearing is 50 to 800 μm.

7. A half thrust bearing having a semi-annular shape including a first circumferential end portion and a second circumferential end portion, the half thrust bearing comprising:
a sliding surface configured to receive an axial force of a crankshaft; and
a rear surface on an opposite side of the sliding surface, wherein the rear surface is parallel to a reference plane on a rear surface side, wherein the reference plane is perpendicular to an axial direction of the half thrust bearing, wherein
the sliding surface includes:
a flat surface portion extending, in parallel to the reference plane, from an inner circumference of the half thrust bearing to an outer circumference of the half thrust bearing,
a first inclined flat surface portion formed at a first side of the flat surface portion in a circumferential direction of the half thrust bearing, and
a second inclined flat surface portion formed at a second side of the flat surface portion in the circumferential direction of the half thrust bearing,

an axial distance between the rear surface and the sliding surface is maximum in the flat surface portion,
in the first inclined flat surface portion, the axial distance is maximum at a third circumferential end of the first inclined flat surface portion and decreases toward the first circumferential end portion of the half thrust bearing, wherein the third circumferential end is adjacent to the flat surface portion,
in the second inclined flat surface portion, the axial distance is maximum at a fourth circumferential end of the second inclined flat surface portion, and decreases toward the second circumferential end portion of the half thrust bearing, wherein the fourth circumferential end is adjacent to the flat surface portion,
the first inclined flat surface portion includes a first constant thickness portion which extends linearly from the inner circumference to the outer circumference, wherein the first constant thickness portion is located at a central angle in a range of 35° to 55° from the first circumferential end portion toward a circumferentially central portion of the half thrust bearing,
the second inclined flat surface portion includes a second constant thickness portion which extends linearly from the inner circumference to the outer circumference, wherein the second constant thickness portion is located at a central angle in a range of 35° to 55° from the second circumferential end portion toward the circumferentially central portion of the half thrust bearing,
in the circumferential direction, the axial distance is maximum at the inner circumference and decreases toward the outer circumference in a region between the first constant thickness portion and the first circumferential end portion of the half thrust bearing, and is minimum at the inner circumference and increases toward the outer circumference in a region between the first constant thickness portion and the first side of the flat surface portion,
in the circumferential direction, the axial distance is maximum at the inner circumference and decreases toward the outer circumference in a region between the second constant thickness portion and the second circumferential end portion of the half thrust bearing, and is minimum at the inner circumference and increases toward the outer circumference in a region between the second constant thickness portion and the second side of the flat surface portion, and
the flat surface portion has a circumferential length extending over a central angle of 5° or more and 35° or less, at any radial positions of the half thrust bearing.

Assignees

• Daido Metal Co

Inventors

• Sakurai Shinichi

Classifications

• F16C33/04

  Brasses; Bushes; Linings · CPC title

• F16C33/046

  divided or split, e.g. half-bearings or rolled sleeves · CPC title

• F16C17/102

  with grooves in the bearing surface to generate hydrodynamic pressure · CPC title

• F16C9/02 Primary

  Crankshaft bearings · CPC title

• F16C33/103

  retained in or near the bearing · CPC title