Telescopic Steering Column Bearing Positioning Without Axial Slippage

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Solution Overview

Problem

Existing steering column designs face issues with slippage and increased adjustment force due to the movement of rolling elements, leading to inconsistent rigidity and complex, costly manufacturing and assembly processes.

Innovation Solution

A positioning device with elastic holding elements, such as spring elements, is used to suspend the rolling bearing unit between casing tubes, ensuring synchronized movement and maintaining the rolling bearing unit's position relative to the casing tubes, thereby eliminating slippage and reducing manufacturing and assembly complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If rolling elements are held between casing tubes by rolling and sliding friction, then the rolling element unit can move along in the adjustment direction, but slippage occurs in the axial direction between the rolling elements and the casing tubes, causing the rolling element unit to move in an undefined manner

Engineering Contradiction:
Improveadjustment smoothnessVSAvoidpositioning accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

A positioning device with elastic holding elements is introduced as an intermediary mechanism between the rolling element unit and the casing tubes. This positioning device prevents slippage by providing positive engagement while allowing the rolling elements to move smoothly during adjustment, thus resolving the contradiction between adjustment smoothness and positioning accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic holding elements in the positioning device change their engagement parameters dynamically - allowing movement during adjustment while preventing slippage in the final positioned state. This parameter change enables the system to achieve both smooth adjustment and reliable positioning

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a gear and toothing are used to ensure positive positioning of the rolling bearing unit, then positioning accuracy is improved, but manufacturing and assembly costs increase

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces expensive, complex gear and toothing mechanisms with simpler, cheaper elastic holding elements that achieve the same positioning function. These elastic elements are more cost-effective to manufacture and assemble while providing sufficient positioning accuracy for the application

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The elastic holding elements use material elasticity and geometric design rather than complex mechanical gearing to achieve positioning. This parameter change from mechanical engagement to elastic engagement simplifies manufacturing and reduces costs while maintaining positioning accuracy

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the rolling element unit moves relative to the casing tubes during adjustment, then the adjustment range is increased, but the steering column unit has different stiffness in the same adjustment position depending on the position of the rolling elements

Engineering Contradiction:
Improveadjustment rangeVSAvoidstiffness consistency
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The positioning device acts as an intermediary that controls the relationship between the rolling element unit and casing tubes. It allows the rolling elements to move for adjustment range while ensuring they return to a consistent, defined position, thereby maintaining stiffness consistency in the same adjustment position

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The elastic holding elements provide feedback through their elastic deformation, guiding the rolling element unit to return to a precise, repeatable position after adjustment. This feedback mechanism ensures that the same adjustment position always results in the same stiffness characteristics

Inventive Principle:
Principle #23Feedback

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 provides a cost-effective, slip-free rolling mechanism with consistent rigidity and reduced operational noise, enhancing the adjustment process and manufacturing efficiency of the steering column.

Implementation Method 1

the holding device has at least one elastic tensioning element which is connected to the rolling bearing unit and at least one of the casing tubes in the direction of the longitudinal axis

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3947107B1Steering column for a motor vehicle
Publication Date: 2024.02.21 THYSSENKRUPP PRESTA AG
  • EP3947107B1 patent drawingFigure 1~2
  • EP3947107B1 patent drawingFigure 3~4
  • EP3947107B1 patent drawingFigure 5

AI summary

The present invention relates to a steering column (1) for a motor vehicle, comprising a casing unit (3), in which a steering spindle (4) is mounted rotatably about a longitudinal axis (L) and which has at least two casing tubes (31, 32, 33) which are adjustable relative to one other in the direction of the longitudinal axis (L) and are guided telescopically in one another, wherein a rolling bearing unit (7) having at least one rollable rolling body (72) is arranged between the casing tubes (31, 32, 33), and which has a positioning means for positioning the rolling bearing unit (7) relative to the casing tubes (31, 32, 33) in the direction of the longitudinal axis (L). In order for the outlay on manufacturing and installation to be lower, the invention proposes that the positioning means has an elastic holding device (8) which acts on at least one of the casing tubes (31, 32) in the direction of the longitudinal axis (L) and is connected to the rolling bearing unit (7).