Steering Fitting Structure with Load-Bearing Restricting Portions

Solution Overview

Problem

In existing steering systems, the seal member is prone to excessive compression and deterioration due to external forces, such as road surface reactions, leading to compromised sealing effectiveness.

Innovation Solution

A fitting structure with a seal member and two tubular fitting members, where the first restricting portion and second restricting portion support axial loads, preventing excessive compression of the seal member, and the second fitting member is loosely fitted to reduce stress and maintain sealing even in inclined positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the seal member is compressed between the tubular portion and the hole cover to prevent rainwater intrusion, then sealing performance is improved, but the seal member is excessively compressed and deteriorates faster

Engineering Contradiction:

Improvesealing performanceVSAvoidservice life of seal member

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The support function is segmented between two distinct structures: the first supporting structure in the rack housing and the second supporting structure in the hole cover. This segmentation allows the seal member to be supported at both ends independently, preventing excessive compression while maintaining sealing performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second supporting structures act as intermediaries between the external forces and the seal member. These structures receive and distribute the axial loads, preventing direct transmission of excessive compressive forces to the seal member while maintaining the necessary sealing contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the seal member is compressed to restrict displacement and prevent water intrusion, then sealing effectiveness is improved, but the seal member is subjected to excessive axial load and deteriorates

Engineering Contradiction:

Improvesealing effectivenessVSAvoiddeterioration of seal member

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The support function is segmented between two distinct structures: the first supporting structure in the rack housing and the second supporting structure in the hole cover. This segmentation allows the seal member to be supported at both ends independently, preventing excessive compression while maintaining sealing performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second supporting structures act as intermediaries between the external forces and the seal member. These structures receive and distribute the axial loads, preventing direct transmission of excessive compressive forces to the seal member while maintaining the necessary sealing contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the axial load is directly transmitted to the seal member to restrict rack housing displacement, then positioning stability is improved, but the seal member is excessively compressed and deteriorates faster

Engineering Contradiction:

Improvepositioning stabilityVSAvoidservice life of seal member

Core Design Contradiction:

Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The support function is segmented between two distinct structures: the first supporting structure in the rack housing and the second supporting structure in the hole cover. This segmentation allows the seal member to be supported at both ends independently, preventing excessive compression while maintaining sealing performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first and second supporting structures act as intermediaries between the external forces and the seal member. These structures receive and distribute the axial loads, preventing direct transmission of excessive compressive forces to the seal member while maintaining the necessary sealing contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS10641340B2Fitting structure and steering system including the same

Publication Date: 2020.05.05 JTEKT CORP

AI summary

A fitting structure includes an annular seal member; a first fitting member including a first tubular fitting portion having a tubular shape, a first holding portion that contacts the seal member from a first axial end side, and a first restricting portion provided at a position different from a position of the first holding portion; and a second fitting member including a second tubular fitting portion having a tubular shape that is fitted to the first tubular fitting portion from a second axial end side, a second holding portion that contacts the seal member from the second axial end side, and a second restricting portion that contacts the first restricting portion from the second axial end side in a state where the seal member is compressed by a prescribed amount between the first holding portion and the second holding portion.