Half Bearing Groove Layout for Seizure-Resistant Sliding Contact

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Half bearings in internal combustion engines are prone to seizure due to direct contact between the end portion of the sliding surface and the shaft member caused by deflection or whirling, leading to high temperatures and mechanical issues.

Innovation Solution

A half bearing design with a cylindrical shape featuring circumferential-direction grooves on the sliding surface, including curved recessed surfaces and inclined surface portions that progressively incline towards the back surface, reducing direct contact and enhancing lubrication efficiency through turbulence of the oil flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a crowning (inclined surface) is formed at the end portion of the sliding surface to alleviate collision, then the collision between the bearing and shaft member is reduced, but direct contact still occurs causing high temperature and seizure

Engineering Contradiction:

Improvecollision impactVSAvoidseizure resistance

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The sliding surface is segmented into multiple functional zones: a large-area plane portion for primary load support, inclined surface portions at the ends for collision mitigation, and circumferential grooves for lubrication management. This segmentation allows each zone to perform its specific function optimally without compromising overall reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the sliding surface are given different geometries and properties: the plane portion provides stable load support, while the inclined surface portions specifically address collision issues at the ends. The circumferential grooves are strategically positioned to control lubricant flow exactly where needed for heat dissipation and seizure prevention.

Inventive Principle:

Principle #3Local quality

2Weight of moving object

If the shaft member rigidity is reduced for weight reduction, then the engine weight is decreased, but the amounts of deflection and shaking increase causing more direct contact

Engineering Contradiction:

Improveshaft member weightVSAvoiddeflection and shaking

Core Design Contradiction:

Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The design accepts the increased deflection and shaking as inevitable consequences of weight reduction, but converts these potentially harmful effects into beneficial lubrication opportunities. The inclined surface portions and circumferential grooves work together to channel lubricant into the contact zones created by deflection, transforming the harmful contact into a controlled lubrication scenario that prevents seizure.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If circumferential-direction grooves are formed on the sliding surface, then lubrication efficiency is enhanced through oil flow turbulence, but the structural complexity of the bearing increases

Engineering Contradiction:

Improvelubrication efficiencyVSAvoidbearing structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The circumferential grooves are designed with curved recessed surfaces rather than straight channels, creating turbulence in the oil flow as it passes through. This curvature enhances mixing and distribution of lubricant across the sliding surface, improving lubrication efficiency while the grooves remain relatively simple circular features that are easy to manufacture.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design effectively reduces the risk of seizure by efficiently managing oil flow and heat dissipation, preventing temperature rises and mechanical losses during engine operation.

Implementation Method 1

enhancing lubrication efficiency through turbulence of the oil flow

Methodology Applied

Scientific EffectTurbulence: Turbulence

Implementation Method 2

efficiently managing oil flow and heat dissipation, preventing temperature rises and mechanical losses

Methodology Applied

Scientific EffectHydrodynamic lubrication: Lubrication

Data Source

PatentUS11761475B2Half bearing and sliding bearing

Publication Date: 2023.09.19 DAIDO METAL CO LTD

AI summary

Provided is a half bearing constituting a sliding bearing for a shaft member of an internal combustion engine that is unlikely to cause seizure in a sliding surface even if deflection or whirling of the shaft member occurs during an operation of the internal combustion engine. In a half bearing that constitutes a sliding bearing, a plurality of circumferential-direction grooves are formed to be adjacent to each other in a sliding surface, the sliding surface includes a plane portion that is parallel to an axial line direction and an inclined surface portion that is adjacent to the plane portion, the inclined surface portion is displaced from the plane portion toward an end portion of the sliding surface in the axial line direction such that the sliding surface successively comes close to a back surface, positions of maximum groove depths of the circumferential-direction grooves are located on groove center lines, the groove center lines in the inclined surface portion of the sliding surface are inclined relative to a vertical line toward the end portion of the sliding surface in the axial line direction, a groove inclination angle of the circumferential-direction groove that is the closest to the plane portion is a minimum angle, and the groove inclination angle successively increases toward the end portion of the sliding surface in the axial line direction.