Steering Gear Sealing and Bellows Venting for Moisture Protection

Solution Overview

Problem

The existing power-assisted steering systems, particularly motor-driven power steering (MDPS) devices, face issues with gear deformation due to moisture ingress, leading to operating noise, vibration, and reduced reliability, which can compromise steering stability and safety, while separate clearance compensators increase manufacturing costs and complexity.

Innovation Solution

A steering system design that incorporates a gear assembly with oil seals and a sealing member on the input and output shafts to prevent moisture ingress, combined with a rack bar housing featuring stretchable bellows and vent holes to manage air flow and reduce load on components, enhancing durability and operational reliability without additional clearance compensators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a separate clearance compensator is applied to prevent clearance caused by gear deformation, then the reliability is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

ImprovereliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the sealing function and clearance compensation function into a single integrated sealing member structure. The sealing member includes a sealing portion that prevents moisture ingress and a compensation portion that compensates for gear clearance, eliminating the need for separate clearance compensators and reducing device complexity while maintaining reliability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sealing member is designed to perform multiple functions simultaneously: it seals against moisture ingress, compensates for gear element deformation and clearance, and maintains proper gear engagement. This multi-functional design eliminates the need for additional separate components, reducing overall device complexity while improving reliability

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a separate clearance compensator is applied to prevent clearance caused by gear deformation, then the reliability is improved, but the manufacturing cost increases

Engineering Contradiction:

ImprovereliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines the sealing function and clearance compensation function into a single integrated sealing member structure. The sealing member includes a sealing portion that prevents moisture ingress and a compensation portion that compensates for gear clearance, eliminating the need for separate clearance compensators and reducing device complexity while maintaining reliability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sealing member is designed to perform multiple functions simultaneously: it seals against moisture ingress, compensates for gear element deformation and clearance, and maintains proper gear engagement. This multi-functional design eliminates the need for additional separate components, reducing overall device complexity while improving reliability

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If moisture enters the gear elements, then the gear deformation occurs, but the operating noise and vibration increase

Engineering Contradiction:

Improvemoisture ingressVSAvoidoperating noise and vibration

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by providing a sealing member that prevents moisture from entering the gear elements in the first place. The sealing member creates a protective barrier between the gear assembly and the external environment, eliminating the root cause of moisture ingress before it can cause gear deformation, operating noise, or vibration

Inventive Principle:

Principle #9Preliminary anti-action

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 prevents gear deformation, reduces operating noise and vibrations, improves manufacturing efficiency, and maintains product competitiveness by enhancing the durability and reliability of the steering system while minimizing manufacturing costs.

Implementation Method 1

a sealing member provided on an outer circumferential surface of at least one of the input shaft and the output shaft

Methodology Applied

Scientific EffectSealing:

Implementation Method 2

a rack bar housing featuring stretchable bellows and vent holes to manage air flow and reduce load on components

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20230399047A1Steering system for vehicle

Publication Date: 2023.12.14 HL MANDO CORP

AI summary

A steering system for a vehicle includes a rack bar of which both end portions are connected to vehicle wheels and which extends in a width direction of a vehicle body, a motor configured to provide a force, and a gear assembly provided between the rack bar and the motor to transmit the force provided by the motor to the rack bar, wherein the gear assembly includes an input shaft configured to receive the force from the motor, an output shaft configured to transmit the force received through the input shaft to the rack bar, and a seal member provided on an outer circumferential surface of at least one of the input shaft and the output shaft.