Telescoping Steering Shaft Roller Assembly Clearance Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional telescoping shafts in steering columns face challenges in assembly and manufacturing due to small clearances caused by manufacturing tolerances, requiring complex and costly wear plates to preload rollers for smooth movement.
Innovation Solution
A telescoping shaft design featuring an outer shaft with a bore and an inner shaft rotationally fixed relative to the outer shaft, utilizing roller assemblies with springs and rollers that are easily assembled and installed to accommodate relative movement and take up clearances, ensuring smooth operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wear plates are used to preload rollers against tubular shaft interfaces, then smooth relative movement and clearance elimination are achieved, but assembly and manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the preload function from complex wear plates and transfers it to simple spring elements. The springs are installed individually on the inner shaft, eliminating the need for complex wear plate assemblies and reducing overall system complexity while maintaining the preload function.
Solution Approach 2:
The wear plate assembly is segmented into multiple independent spring elements that can be installed separately on the inner shaft. This segmentation simplifies the assembly process, as each spring can be installed independently rather than assembling a complex wear plate structure.
2Manufacturing precision
If wear plates are used to preload rollers, then clearance between components is eliminated, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive wear plates with inexpensive spring elements. The springs are simple, low-cost components that can be easily manufactured and replaced if needed, significantly reducing manufacturing costs while achieving the same clearance elimination function.
Solution Approach 2:
The patent changes the approach from rigid wear plates to elastic springs, utilizing the spring's ability to deform and apply continuous preload force. This parameter change from rigid to elastic allows for effective clearance elimination using simpler, cheaper components.
3Reliability
If linear bearings with hardened steel rollers are used, then low friction is achieved, but small clearances require complex delashing mechanisms
Solution Approach 1:
The spring elements automatically apply preload force to the rollers, eliminating the need for external delashing mechanisms. The system is self-regulating, with the springs continuously pushing the rollers against the shaft interfaces to maintain zero clearance and low friction operation.
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 allows for easy assembly and smooth relative movement between shaft components, effectively addressing the assembly challenges and reducing manufacturing costs while maintaining low friction and accommodating length adjustments.
Implementation Method 1
Each roller assembly of the at least one the roller assembly includes a spring having a first end and a second end spaced apart from the first end
Implementation Method 2
roller bearings may be provided between the tubular shaft and solid shaft
Data Source
AI summary
A telescoping shaft in a steering column in a steering column is provided. The telescoping shaft includes an outer shaft having a bore extending in a longitudinal direction, an inner shaft telescopically received in the bore, the inner shaft rotationally fixed relative to the outer shaft and moveable relative to the outer shaft in the longitudinal direction, and at least one roller assembly positioned between the inner shaft and outer shaft. Each roller assembly of the at least one the roller assembly includes a spring having a first end and a second end spaced apart from the first end, a first roller positioned on the first end of the spring, and a second roller positioned on the second end of the spring, the spring urging the first roller and the second roller into contact with the outer shaft.