Grease Retaining Device for Rolling Bearing Units

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Solution Overview

Problem

Existing grease metering devices for rolling bearing units suffer from uncontrolled grease migration between conical rollers during transportation and operation, leading to uneven lubrication, premature wear, and increased leakage due to friction.

Innovation Solution

A grease retaining and oil metering device with a radially outer ring, radially inner projection, and radial vanes is housed inside the bearing's groove, featuring through-openings that prevent grease migration while allowing controlled oil distribution, utilizing frustoconical surfaces and radial vanes to retain grease and direct oil to the conical rollers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a continuous vertical wall is used in the grease metering device to prevent grease migration during transportation, then grease retention is improved, but uncontrolled grease migration still occurs during operation leading to uneven lubrication

Engineering Contradiction:

Improvegrease retentionVSAvoidgrease distribution uniformity

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The continuous vertical wall is segmented by introducing radial vanes that extend from the top surface to the bottom surface of the outer ring. These vanes divide the internal space into multiple compartments while maintaining the barrier function against grease migration. The segmentation allows controlled grease distribution during operation while preventing uncontrolled migration during transportation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The solution transitions from a two-dimensional continuous wall barrier to a three-dimensional structured system with radial vanes creating multiple compartments. This dimensional enhancement allows the device to simultaneously achieve grease retention during transportation and controlled distribution during operation, resolving the contradiction between reliability and manufacturing precision.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If grease is retained in the central zone between conical rollers, then lubrication is improved, but grease accumulates in zones requiring less lubrication causing increased friction and leakage

Engineering Contradiction:

Improvelubrication effectivenessVSAvoidfriction and leakage

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The radial vanes create compartments with different local characteristics. Some compartments are positioned to supply grease to zones requiring more lubrication, while others control grease flow to zones requiring less lubrication. This local differentiation ensures appropriate grease distribution throughout the bearing unit, preventing both insufficient lubrication and harmful accumulations.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The segmented structure provides automatic feedback control for grease distribution. During operation, the centrifugal force and mechanical movement cause grease to naturally redistribute from compartments near the grease injection point to other compartments, creating a self-regulating system that maintains balanced lubrication without manual intervention.

Inventive Principle:

Principle #23Feedback

3Device complexity

If a simple vertical wall structure is used for grease metering, then device complexity is reduced, but the device cannot provide controlled oil distribution during operation

Engineering Contradiction:

Improvestructure simplicityVSAvoidcontrolled grease distribution

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The outer ring is segmented by radial vanes into multiple compartments, creating a structured yet relatively simple design. This segmentation enables controlled grease distribution during operation while maintaining ease of manufacturing and installation. The modular compartment structure provides functional complexity without proportionally increasing overall device complexity.

Inventive Principle:

Principle #1Segmentation

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

Ensures controlled grease distribution and retention within the bearing unit, preventing uncontrolled grease migration and ensuring consistent lubrication, thereby enhancing durability and extending maintenance intervals by maintaining efficient lubrication and reducing wear.

Implementation Method 1

releasing the oil therefrom in a controlled manner even in the absence of centrifugal force

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentUS10330155B2Grease retaining and oil metering device for a rolling bearing unit

Publication Date: 2019.06.25 AB SKF SKF PATENT DEPARTMENT

AI summary

A bearing unit provided with a rolling bearing having a radially outer race, two radially inner races, a ring of conical rollers arranged between the radially outer race and the two radially inner races, and a device for retaining grease and metering oil housed inside a groove of the radially outer race and having an annular wall arranged transversely with respect to the rolling bearing and acting as barrier for the flow of grease and provided with a plurality of through-openings for retaining the grease and allowing the oil to pass between the two rings of conical rollers in any operating condition, and also with a plurality of radial vanes engaged with the annular wall for retaining the grease.