Steering Column Roller Guide Layout for Higher Rigidity
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Solution Overview
Problem
Existing steering column designs with roller-mounted casing units face challenges in achieving high rigidity and a compact overall design while maintaining smooth operation and low manufacturing costs.
Innovation Solution
The proposed solution involves optimizing the configuration and arrangement of rolling body guides on polygonal casing tubes, specifically by arranging the center points of rolling bodies within a circularly annular region and utilizing a method for producing steering columns where rolling bodies deform raceways to achieve a predefined adjusting force reference value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If rolling body guides are arranged on the side faces of polygonal casing tubes, then the structure is simple, but the rigidity of the casing unit is limited and installation space requirement is relatively great
Solution Approach 1:
The patent transitions the arrangement of rolling body guides from the 2D side faces of polygonal casing tubes to the 3D corner regions where side faces meet. This dimensional change allows the guides to be positioned at the extremities of the casing tube cross-section, maximizing the distance from the central axis and thereby optimizing the moment of inertia and rigidity of the casing unit.
2Strength
If narrow tolerances are maintained for bearing play, then rigidity is high, but manufacturing and assembly outlay is high
Solution Approach 1:
The patent employs a self-adjusting mechanism where the rolling bodies automatically adapt to minor variations in raceway dimensions through their elastic deformation and redistribution under load. This self-service capability allows the system to maintain low bearing play and high rigidity without requiring extremely narrow manufacturing tolerances, thereby reducing manufacturing and assembly costs.
3Ease of manufacture
If great bearing play is allowed, then manufacturing is easier, but rigidity is reduced
Solution Approach 1:
The patent changes the physical state and distribution parameters of the rolling bodies under operational conditions. Through controlled elastic deformation and load redistribution, the rolling bodies effectively reduce the functional bearing play during operation, maintaining high rigidity despite more generous manufacturing tolerances.
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 results in increased rigidity, improved utilization of installation space, and reduced manufacturing outlay, while ensuring smooth operation and maintaining the advantages of high rigidity in the steering column design.
Implementation Method 1
a method for producing steering columns with rolling bodies which deform the raceways so that the adjusting force which acts during the adjusting corresponds to an adjusting force reference value
Implementation Method 2
A smooth-running and low-play adjusting capability can be realized by virtue of the fact that the rolling cross section which denotes the rolling body cross section in the rolling direction transversely with respect to the longitudinal axis is adapted to the raceway cross section with low tolerances
Data Source
AI summary
A steering column for a motor vehicle may include a casing unit in which a steering spindle is mounted rotatably about a longitudinal axis that extends in a longitudinal direction. The casing unit has at least two casing tubes that have a polygonal cross section and are guided such that they can be adjusted relative to one another in the longitudinal direction. Rolling bodies that have a rolling body radius are arranged between the casing tubes such that the rolling bodies can roll in the longitudinal direction in at least three raceways that are distributed circumferentially. To increase rigidity and improve compactness, center points of the rolling bodies are at a radial spacing that is less than or equal to the rolling body radius from an envelope circle that circumscribes the casing tube, on which the rolling bodies can roll on the outside.