Tapered Retaining Ring Isolates Thrust Loads in Shaft Assemblies

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Shaft assemblies in transmissions face issues with axial endplay, which can lead to unwanted movement of components and reduced bearing life due to excessive loads and heat, as existing solutions fail to effectively isolate and manage thrust loads induced by helical gear components.

Innovation Solution

A shaft assembly with a tapered groove and a tapered retaining ring isolator that transfers thrust forces directly to the shaft, isolating them from other components and maintaining optimal spacing between bearing races, thereby preventing endplay and reducing load on bearings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional retaining rings are used to control axial endplay, then component positioning is improved, but bearing life deteriorates due to excessive loads and heat from unisolated thrust forces

Engineering Contradiction:
Improveaxial endplay controlVSAvoidbearing life
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The tapered retaining ring acts as an intermediary component between the helical gear and the bearing. It intercepts the axial thrust force generated by the helical gear and transfers it directly to the shaft through the tapered groove, preventing the force from reaching the bearing. This mediator function isolates the bearing from harmful thrust loads while maintaining precise axial positioning of components.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If axial loads are allowed to transfer through components, then force distribution is improved, but component movement deteriorates due to endplay

Engineering Contradiction:
Improveaxial load distributionVSAvoidcomponent axial stability
Core Design Contradiction:
ForceVSStability of the object's composition

Solution Approach 1:

The retaining ring design applies local quality by creating a specific interaction zone between the tapered retaining ring and the tapered groove. The tapered surfaces engage locally to intercept axial forces, while the bearing remains isolated from these forces. This localized force interception mechanism maintains overall force distribution while ensuring axial stability of individual components.

Inventive Principle:
Principle #3Local quality

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 solution effectively isolates thrust loads from bearings, maintaining designed spacing and reducing friction and heat, thus enhancing the life and efficiency of the assembly by directly transferring forces to the shaft, thereby improving reliability and reducing component costs.

Implementation Method 1

a tapered retaining ring isolator that transfers thrust forces directly to the shaft

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

the isolator comprises a tapered retaining ring fully seated in the tapered groove

Methodology Applied
Scientific EffectNormal force: Force

Data Source

PatentEP2376796B1Tapered retaining ring to reduce bearing race movement
Publication Date: 2017.09.20 ALLISON TRANSMISSION INC
  • EP2376796B1 patent drawingFigure 1
  • EP2376796B1 patent drawingFigure 2
  • EP2376796B1 patent drawingFigure 3

AI summary

An assembly comprises a shaft defining a longitudinal axis, a first component supported on the shaft, a second component supported on the shaft, and an isolator positioned between the first component and the second component. The second component configured such that the second component induces a force having a component parallel to the axis of the shaft. The force component parallel to the axis of the shaft induced by the second component is transferred directly to the shaft by the isolator and is isolated from the first component.