Bearing Lubrication Structure Using an Inclined Inner Ring

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Solution Overview

Problem

Existing bearing apparatuses lack an efficient structure for lubricating oil supply to the contact points between rolling elements and rings, which affects long-term stable operation and lubrication.

Innovation Solution

A bearing apparatus with a lubricating oil supply unit positioned between the outer and inner ring spacers, featuring a nozzle member with an inclined surface and recess to facilitate lubricating oil flow to the contact points via centrifugal force and capillarity, ensuring effective lubrication between the rolling elements and rings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If lubricating oil is supplied to the inside of the bearing apparatus, then the bearing can operate for a long time, but the lubricating oil may not efficiently reach the contact portion between rolling elements and rings

Engineering Contradiction:
Improveoperation timeVSAvoidlubrication effectiveness
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The nozzle member is positioned to supply lubricating oil to the inclination portion before the oil reaches the rolling element contact area. The oil is delivered in advance to a location where it can be naturally guided by the inclined surface and centrifugal force toward the contact portions, ensuring lubrication is already present when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The inner ring is designed with an inclination portion that has a specific slope angle (5-45 degrees) different from other portions. This localized geometric modification creates a flow path that directs lubricating oil specifically toward the rolling element contact areas, ensuring oil is delivered precisely where needed rather than uniformly across the entire surface.

Inventive Principle:
Principle #3Local quality

2Device complexity

If a simple lubricating oil supply structure is used, then the device complexity is reduced, but the lubricating oil cannot be efficiently introduced to the contact portion

Engineering Contradiction:
Improvesupply structure complexityVSAvoidlubrication effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The inclination portion of the inner ring serves multiple functions: it acts as a structural component of the bearing, provides a flow guide surface for lubricating oil, and creates centrifugal force effects during rotation. By combining these functions into a single structural feature, the design avoids adding separate complex lubrication delivery mechanisms while still achieving effective oil distribution.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 apparatus ensures stable and prolonged operation by securely supplying lubricating oil to the contact points, maintaining lubricity and extending the lubricating life of the bearing.

Implementation Method 1

the lubricating oil supplied to the inside of the bearing flows along the inclination portion toward the rolling element contact area due to centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

featuring a nozzle member with an inclined surface and recess to facilitate lubricating oil flow to the contact points via centrifugal force and capillarity

Methodology Applied
Scientific EffectCapillarity: Capillary Action

Data Source

PatentEP3273076B1Bearing apparatus and mechanical apparatus
Publication Date: 2022.11.02 NTN CORP
  • EP3273076B1 patent drawingFigure 1
  • EP3273076B1 patent drawingFigure 2~3
  • EP3273076B1 patent drawingFigure 4

AI summary

A bearing apparatus (10) includes: a bearing (11); and a lubricating oil supply unit (20) connected to the bearing (11). The bearing (11) includes: an outer ring (13); an inner ring (14) having an inner ring raceway surface at an outer circumferential surface of the inner ring (14), the inner ring (14) being disposed inwardly of the outer ring (13); and a plurality of rolling elements (15) in contact with the inner ring raceway surface, the plurality of rolling elements (15) being arranged side by side on an annular raceway. The lubricating oil supply unit (20) includes: a supplier (a drive circuit, a pump, and a nozzle member (37)) configured to supply the lubricating oil to the inside of the bearing (11); and a power generator configured to generate power. The supplier is operated using the power generated by the power generator. The outer circumferential surface of the inner ring (14) includes an inclination portion (14a) that becomes closer to the outer ring (13) as the inclination portion (14a) extends toward the inner ring raceway surface from an end portion of the outer circumferential surface of the inner ring (14) in an axial direction of the bearing (11). The supplier supplies the lubricating oil toward the inclination portion (14a) of the inner ring (14).