Rack Guide Elastic Member for Steering Noise and Wear
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rack-and-pinion type steering apparatuses experience runout and noise due to reaction forces from road surfaces, leading to collision noise and adhesive wear when components are made of aluminum or aluminum alloys, and existing solutions like O-rings or elongated elastic members hinder smooth movement.
Innovation Solution
A rack-and-pinion type steering apparatus with a rack guide body featuring a wide annular recessed portion, narrow annular grooves, and a cylindrical bush with a split groove, utilizing an endless annular elastic member and a self-lubricating synthetic resin bush to reduce friction and prevent collision noise, allowing smooth movement without adhesive wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the annular clearance between the rack guide body and housing is large, then the rack guide can move smoothly to accommodate runout, but collision noise increases
Solution Approach 1:
The patent introduces an annular elastic member as an intermediary between the rack guide body and housing. This elastic member fills the annular clearance while maintaining smooth movement capability, preventing direct collision between metal surfaces and thereby eliminating collision noise.
2Object-generated harmful factors
If the rack guide body is strongly pressed against the housing to reduce clearance, then collision noise is reduced, but adhesive wear occurs between aluminum components
Solution Approach 1:
The annular elastic member serves as a mediator that maintains appropriate clearance without requiring strong pressing forces. This prevents direct metal-to-metal contact between aluminum components, eliminating adhesive wear while still controlling clearance to reduce collision noise.
Solution Approach 2:
The patent uses a composite structure combining the aluminum rack guide body with the elastic material member. This composite approach allows the elastic member to provide both noise reduction and wear prevention functions that cannot be achieved with aluminum alone.
3Object-generated harmful factors
If an O-ring or elongated elastic member is used to restrict radial movement, then collision noise is reduced, but smooth axial movement is hampered by friction
Solution Approach 1:
The annular elastic member is designed as a flexible ring structure that can deform radially to reduce clearance and prevent collision noise, while maintaining smooth axial movement capability. The flexible nature of this elastic shell allows it to accommodate radial movements without creating excessive friction against axial motion.
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 collision noise and adhesive wear, ensuring smooth movement of the rack guide towards the rack bar while reducing sliding frictional resistance, thus addressing the issues of runout and noise in rack-and-pinion steering systems made from aluminum or aluminum alloys.
Implementation Method 1
an endless annular elastic member fitted and secured in the narrow annular groove of the rack guide body in such a manner as to project from an opening of the narrow annular groove
Implementation Method 2
a cylindrical bush which has a split groove and is fitted and secured in the wide annular recessed portion, such that the cylindrical bush on an outer peripheral surface side thereof projects from an opening of the wide annular recessed portion of the rack guide body, while an inner peripheral surface of the cylindrical bush abuts against an outer surface of the endless annular elastic member
Data Source
AI summary
A rack-and-pinion type steering apparatus 1 includes a housing 3 having a cylindrical holding hole 2 in its interior; a pinion 6 which is disposed in the housing 3 rotatably in a direction R about an axis O by means of bearings 4 and 5; a rack bar 8 which has rack teeth 7 meshing with the pinion 6 and is movable in a direction A; a rack guide 9 which is disposed in the holding hole 2 within the housing 3 movably in a direction C, and which guides and supports the rack bar 8 movably in the direction A; and a coil spring 10 for resiliently pressing the rack teeth 7 of the rack bar 8 against the pinion 6 by means of the rack guide 9.