Segmented Radial Rack Bearing for Quiet Steering Mesh Fit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rack and pinion steering systems in the automotive industry often suffer from undesirable noise, suboptimal steering feel, and increased maintenance complexity due to the meshed connection between the pinion gear and the rack.
Innovation Solution
A radially preloaded rack bearing is introduced, supported by a housing and preloaded to the rack, featuring semi-cylindrical segments with a hinge portion and resilient members to facilitate radial expansion and contraction, ensuring a secure and adaptable fit that compensates for thermal expansion differences and reduces system noise and maintenance needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a traditional rack bearing is used in the meshed connection, then the structure is simple, but undesirable noise and suboptimal steering feel occur
Solution Approach 1:
The rack bearing is divided into first and second semi-cylindrical segments that can independently expand and contract radially. This segmentation allows each segment to adapt to thermal expansion differences between materials while maintaining the meshed connection, thereby reducing noise and improving steering feel without requiring an overly complex single-piece structure
Solution Approach 2:
The rack bearing is designed with dynamic capability through resilient members that enable radial expansion and contraction of the semi-cylindrical segments. This dynamic adjustment allows the bearing to compensate for thermal effects and maintain optimal contact under varying operational conditions, reducing noise while preserving structural adaptability
2Adaptability or versatility
If rigid connection components are used, then manufacturing precision is maintained, but thermal expansion differences cause fit issues
Solution Approach 1:
The rack bearing utilizes parameter changes through thermal expansion and contraction of its components. The semi-cylindrical segments are designed to expand and contract radially in response to temperature changes, allowing the bearing to maintain precise line-to-line fit between the rack and housing despite thermal expansion differences between dissimilar materials
Solution Approach 2:
The invention explicitly employs thermal expansion principles by designing the rack bearing with semi-cylindrical segments that can expand and contract radially. This allows the bearing to compensate for differential thermal expansion between the rack, housing, and other components, maintaining fit precision across varying temperature conditions
3Ease of repair
If conventional rack bearing designs are used, then ease of manufacture is maintained, but maintenance complexity increases
Solution Approach 1:
By segmenting the rack bearing into two semi-cylindrical halves connected by resilient members, the design maintains relative manufacturing simplicity while enabling easier maintenance. The segmented structure allows for easier assembly and disassembly during maintenance operations compared to a solid rigid bearing, reducing maintenance complexity without significantly complicating the manufacturing process
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 radially preloaded rack bearing minimizes noise, enhances steering feel, and optimizes robustness by maintaining a line-to-line fit under varying temperatures and operational conditions, reducing manufacturing costs and complexity while providing damping and stability.
Implementation Method 1
ensuring a secure and adaptable fit that compensates for thermal expansion differences
Implementation Method 2
providing damping and stability
Data Source
AI summary
A rack and pinion steering system includes a housing, a rack, a pinion gear, and a radially preloaded rack bearing. The rack is supported by the housing, and the pinion gear is meshed to the rack. The radially preloaded rack bearing is supported and preloaded to the housing and is preloaded to the rack.