Steering Column Assist Worm Gear Clearance Adjustment
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Solution Overview
Problem
Current methods for assembling worm and worm gear combinations in power-assisted steering systems are costly, labor-intensive, and unreliable due to variations in critical dimensions, leading to undesirable clearance between gear teeth, which affects responsiveness and feel of the steering system.
Innovation Solution
The implementation of an eccentric bearing assembly system that allows for adjustable positioning of the worm and worm gear, using a configuration with nested eccentric rings to achieve precise alignment and desired clearance, facilitated by a motor cone housing and intermediate housing design for easy adjustment and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional sizing and matching techniques are used to assemble worm and worm gear combinations, then manufacturing precision of individual components can be achieved, but the assembly process becomes costly, labor-intensive, and time-consuming
Solution Approach 1:
The bearing assembly is made adjustable rather than fixed, allowing the worm and worm gear clearance to be modified after assembly. This dynamic adjustment capability eliminates the need for precise pre-matching of components, thereby reducing assembly time and labor while maintaining the desired clearance specifications.
Solution Approach 2:
The invention allows changing the clearance parameter between worm and worm gear teeth after assembly by adjusting the bearing assembly. This post-assembly parameter adjustment replaces the traditional approach of achieving precise parameters during component manufacturing and matching, significantly improving productivity.
2Manufacturing precision
If traditional sizing and matching techniques are used to assemble worm and worm gear combinations, then manufacturing precision of individual components can be achieved, but the assembly process becomes complex and labor-intensive
Solution Approach 1:
The adjustable bearing assembly provides a simple mechanical means to modify clearance after assembly, replacing complex pre-assembly matching procedures. This reduces both the complexity of the assembly process and the labor required, while maintaining precise clearance control.
3Device complexity
If fixed bearing assemblies are used, then the structure is simple, but the fit between worm and worm gear cannot be adjusted, leading to undesirable clearance variations
Solution Approach 1:
The bearing assembly incorporates adjustability without significantly increasing structural complexity. The adjustment mechanism allows clearance modification while maintaining a relatively simple overall structure, thus improving manufacturing precision without proportionally increasing device complexity.
Solution Approach 2:
The bearing assembly enables post-assembly parameter changes in the clearance between worm and worm gear teeth. This capability allows precise fit adjustment without requiring complex pre-assembly matching procedures, resolving the contradiction between structural simplicity and precision control.
4Manufacturing precision
If adjustable bearing assemblies are implemented, then the fit between worm and worm gear can be optimized, but the device complexity increases
Solution Approach 1:
The bearing assembly provides necessary adjustability for optimizing worm and worm gear fit while maintaining a relatively simple structure. The adjustment capability is integrated into the bearing assembly design without requiring additional complex mechanisms, thus minimizing the increase in device complexity.
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
This approach enables a conveniently adjustable fit between the worm and worm gear, improving the responsiveness and reliability of the power-assisted steering system by reducing hysteresis and play, while simplifying the assembly process and reducing costs.
Implementation Method 1
The first bearing assembly is configured as an eccentric bearing assembly. A position of an axis of rotation of the bearing assembly relative to an external surface depends upon an angular orientation of one or more components of the bearing assembly.
Data Source
AI summary
A power-assisted steering system includes an intermediate housing, a motor cone housing coupled to the intermediate housing, and a control shaft arranged along a control shaft axis for rotation about the control shaft axis. The system further includes an assist drive shaft arranged in a plane that is substantially transverse to the control shaft axis, the assist drive shaft being supported relative to the vehicle structure by a first bearing assembly and a second bearing assembly and defining a drive shaft axis, a worm disposed about the assist drive shaft, and a worm gear coupled to the control shaft. The worm gear and control shaft are configured for rotation about the control shaft axis.