Power Steering Lid Sealing With Progressive O-Ring Compression

Solution Overview

Problem

Existing methods for attaching lids to power steering system cases are cumbersome, require additional parts, and lack assurance of proper sealing, leading to increased manufacturing costs and potential breakage risks.

Innovation Solution

A method involving an O-ring seal and frustoconical shaped portions in the lid and case grooves ensures secure attachment by elastic deformation, eliminating the need for clips or screws, and maintaining tightness through progressive seal compression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If clips are used to attach the lid to the case, then the lid can be visually controlled for correct insertion, but additional parts are required and manufacturing cost increases

Engineering Contradiction:

Improvecorrect insertion of lidVSAvoidnumber of parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The sealing function and attachment function are merged into a single O-ring seal element. The O-ring seal simultaneously provides sealing against liquid/foreign body intrusion and mechanical attachment through elastic deformation over the frustoconical portion, eliminating the need for separate clips or screws.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The O-ring seal acts as an intermediary element between the lid and case. It mediates both the sealing requirement and the attachment requirement by deforming over the frustoconical portion, creating a reliable connection without requiring direct mechanical fastening elements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Strength

If screws and lugs are used to attach the lid, then secure attachment is achieved, but additional parts and manufacturing operations are required

Engineering Contradiction:

Improveattachment strengthVSAvoidmanufacturing operations

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The sealing function and attachment function are merged into a single O-ring seal element. The O-ring seal simultaneously provides sealing against liquid/foreign body intrusion and mechanical attachment through elastic deformation over the frustoconical portion, eliminating the need for separate clips or screws.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The traditional mechanical fastening system (screws, lugs, threaded barrels) is replaced by an elastic deformation mechanism. The O-ring seal uses its elasticity to deform over the frustoconical portion and maintain attachment, substituting complex mechanical threading with a simpler elastic engagement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If the lid is made from low cost plastic material, then manufacturing cost is reduced, but additional parts are needed to ensure secure attachment

Engineering Contradiction:

Improvematerial costVSAvoidnumber of parts

Core Design Contradiction:

Ease of manufactureVSDevice complexity

Solution Approach 1:

The sealing function and attachment function are merged into a single O-ring seal element. The O-ring seal simultaneously provides sealing against liquid/foreign body intrusion and mechanical attachment through elastic deformation over the frustoconical portion, eliminating the need for separate clips or screws.

Inventive Principle:

Principle #5Merging (Combining)

4Reliability

If the lid is closed tightly to ensure sealing, then prevention of liquid intrusion is improved, but the seal may deform permanently

Engineering Contradiction:

Improvesealing effectivenessVSAvoidseal shape

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The frustoconical portion is designed to gradually compress the O-ring seal during the closing operation, cushioning the transition and preventing sudden excessive deformation. The conical geometry distributes the compression force progressively, allowing the seal to deform controllably while maintaining its ability to return to its original shape.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The frustoconical portion changes the geometric parameters of the sealing interface. By using a conical shape instead of a cylindrical or flat surface, the seal compression is distributed over a gradual slope, changing the deformation profile from abrupt to progressive, which prevents permanent deformation while ensuring effective sealing.

Inventive Principle:

Principle #35Parameter changes

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 method simplifies manufacturing, reduces parts, and ensures reliable sealing and resistance to pressure differentials, enhancing the lid's retention without additional elements.

Implementation Method 1

exerting a pressure on the lid to pass the seal over the frustoconical shaped portion where it is gradually compressed, until reaching a closed position of the lid on the opening of the case, where the seal tends to regain a less deformed shape

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12565257B2Method for attaching a lid to an orifice of a power steering system and such a lid

Publication Date: 2026.03.03 JTEKT EUROPE SAS

AI summary

A power steering case, including an opening, a lid configured to close the opening of the case, and an O-ring seal disposed in a first annular groove formed in a first inner wall of the lid or of the case, a second inner wall, respectively of the case or of the lid, having a frustoconical shaped portion for progressively compressing the seal before reaching the closed position of the lid where the seal tends to regain a less deformed initial shape in a second annular groove facing the first annular groove and formed in the second inner wall.