Slide Bearing With Localized Grooves for Friction and Oil Control
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Solution Overview
Problem
Conventional slide bearings with grooves around the circumference reduce frictional area, leading to decreased load-carrying capacity and oil film thickness, while also increasing the total volume of effluent oil.
Innovation Solution
A slide bearing design with halved members arranged in a cylindrical structure, featuring narrow grooves only at the lower halved member's edge in the circumferential direction from a specified bearing angle of 45 to 90 degrees, optimizing groove length based on engine speed, radius, oil viscosity, crankshaft angle, and load to maintain oil film thickness and pressure without preventing oil film generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If narrow grooves are provided all over the circumference at both ends of the bearing, then frictional area is reduced and friction-reducing effect is achieved, but load carrying capacity decreases and oil film thickness becomes insufficient
Solution Approach 1:
The patent applies local quality by providing narrow grooves only in specific circumferential regions (from downstream mating surface to 45-90 degrees rotated position) rather than all around the circumference. This localized groove placement reduces friction in areas where it is most beneficial while preserving load carrying capacity in critical regions where the oil film must remain thick and stable.
2Loss of energy
If narrow grooves are provided all over the circumference at both ends of the bearing, then frictional area is reduced, but total volume of effluent oil increases significantly
Solution Approach 1:
The patent reduces effluent oil volume by applying local quality - grooves are provided only in specific circumferential zones rather than uniformly around the entire bearing circumference. This selective groove placement minimizes the total surface area from which oil can escape, thereby reducing the total volume of effluent oil while still achieving friction reduction in the necessary regions.
3Loss of energy
If bearing width is reduced to decrease frictional area, then friction-reducing effect is achieved, but volume of effluent oil increases
Solution Approach 1:
Instead of reducing the overall bearing width, the patent uses local quality by providing grooves only in specific circumferential regions. This approach reduces frictional area locally where grooves are present while maintaining the full bearing width in other regions, thereby preventing the increase in effluent oil volume that would result from a uniform width reduction.
4Loss of energy
If narrow grooves are provided all over the circumference, then frictional area is reduced, but oil film thickness decreases and good lubrication cannot be maintained
Solution Approach 1:
The patent maintains good lubrication by applying local quality - grooves are positioned only in circumferential regions where friction reduction is prioritized, while leaving other regions without grooves to maintain sufficient oil film thickness. This selective placement ensures that lubrication quality is preserved in critical areas while still achieving friction reduction benefits.
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
This design achieves a friction-reducing effect while minimizing the total volume of effluent oil by maintaining necessary oil film thickness and pressure gradients, ensuring effective lubrication and reduced oil consumption.
Implementation Method 1
narrow grooves are only provided at an end of the lower halved member in a circumferential direction from a mating surface on a downstream side of a rotation direction of the crankshaft to a specified bearing angle... a length of the narrow grooves is from the mating surface on the downstream side of the rotation direction of the crankshaft to a place of an upstream side where oil film thickness which is calculated based on a relation between an engine speed, a radius of the slide bearing, a width of the slide bearing, a viscosity of an oil used in the slide bearing
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3
AI summary
Provided is a slide bearing with which friction-reducing effects can be obtained and the total volume of effluent oil can be limited. A slide bearing (1) in which halved members (2, 2) made by dividing a cylinder in two in a direction parallel to the axial are disposed vertically, wherein narrow grooves (3) are provided at the ends of the slide bearing (1) in the axial direction, the narrow grooves extending in the circumferential direction from the mating surface on the downstream side of the rotation direction to a specified bearing angle (ω) is an angle rotated in the range of ≥0 degree to ≤90 degrees from the mating surface on the downstream side in the rotation direction (bearing angle (ω) of 180 degrees) towards the upstream side in the rotation direction. In other words, the bearing angle (ω) is the range of 180 degrees to 270 degrees.