Steering Column Adjustment Drive With Elastic Clamping Joint

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Solution Overview

Problem

Existing adjustment drives for motor-adjustable steering columns in vehicles require high manufacturing effort due to the need for precise dimensional alignment and welding of drive and gear assemblies to ensure smooth operation and low wear, which increases production complexity and costs.

Innovation Solution

The use of elastic clamping elements to securely join the drive and gear assemblies, allowing for precise alignment and connection without the need for precise machining, thereby reducing manufacturing effort and enabling a reliable, play-free joint that can withstand crashes and thermal variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If precise dimensional alignment and welding are used to join drive and gear assemblies, then operational reliability and smooth operation are improved, but manufacturing complexity and production costs increase

Engineering Contradiction:
Improveoperational reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The transmission is divided into separate drive assembly and gear assembly modules that can be manufactured independently with standard tolerances, then joined together using elastic tensioning elements. This segmentation allows each module to be produced separately without requiring high-precision machining at the joining interface, reducing manufacturing complexity while maintaining operational reliability through the compliant connection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The joining method transitions from rigid welding with precise dimensional requirements to elastic mechanical tensioning with standard tolerances. By changing the joining parameter from permanent weld bonds to reversible elastic tension, the system accepts larger dimensional variations while maintaining functional reliability, thereby reducing manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

2Strength

If precise machining and welding are used to join assemblies, then joint strength and stability are improved, but production time and manufacturing effort increase

Engineering Contradiction:
Improvejoint strengthVSAvoidproduction time
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The elastic tensioning elements are pre-loaded during assembly to automatically compensate for dimensional tolerances and create a pre-stressed joint. This preliminary action of pre-tensioning ensures joint strength is achieved during the assembly process itself, eliminating the need for subsequent welding operations and reducing production time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The welding process is replaced with a mechanical elastic tensioning system. Instead of using thermal welding to create strong joints, the patent uses elastic elements that generate clamping forces through mechanical tension, achieving equivalent or superior joint strength without the time-consuming welding process.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Manufacturing precision

If rigid joining methods are used, then alignment precision is maintained, but adaptability to thermal variations and dimensional tolerances decreases

Engineering Contradiction:
Improvealignment precisionVSAvoidadaptability to thermal variations
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The joining system transitions from a static rigid weld to a dynamic elastic connection that can adapt to changing conditions. The elastic tensioning elements can deform elastically in response to thermal expansion, contraction, and manufacturing tolerances, maintaining alignment precision while adapting to environmental variations that rigid joints cannot accommodate.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The elastic tensioning elements are designed to accommodate thermal expansion and contraction of the joined assemblies. As temperature varies, the elastic elements can stretch or compress within their elastic range, maintaining the joint integrity and alignment precision that rigid welded joints would lose due to thermal stress.

Inventive Principle:
Principle #37Thermal expansion

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 solution simplifies the manufacturing process, reduces production costs, and ensures a reliable, low-wear, and crash-resistant connection between the drive and gear assemblies, maintaining optimal engagement and quiet operation over the vehicle's lifespan.

Implementation Method 1

the drive assembly and/or the transmission assembly have at least one elastic tensioning element for tensioning the drive assembly and the transmission assembly in the region of the joining connection

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3921561B1Adjustment drive for a steering column, drive unit for an adjustment drive, motor-adjustable steering column for a motor vehicle, and method for producing an adjustment drive for a steering column
Publication Date: 2024.04.03 THYSSENKRUPP PRESTA AG
  • EP3921561B1 patent drawingFigure 1~2
  • EP3921561B1 patent drawingFigure 3~4
  • EP3921561B1 patent drawingFigure 5~6

AI summary

The invention relates to an adjustment drive (5, 6) for a motor-adjustable steering column (1) for a motor vehicle, comprising a transmission (8, 9) having a drive module (82, 92), in which a drive wheel (922) rotatably driveable about a drive axis (A) is mounted, which drive wheel is operatively engaged with a gear wheel (912) which is mounted roatably about a transmission axis (G) in a transmission module (81, 91) and which is connected to a threaded spindle (52) or a spindle nut (61) of a spindle drive, the drive module (82, 92) and the transmission module (81, 91) being connected to one another by at least one joint (93). In order to be able to produce the joint (93) reproducibly with a relatively low processing and assembly effort, it is proposed according to the invention that the drive module (82, 92) and/or the transmission module (81, 91) have/has at least one resilient clamping element (94) for clamping the drive module (82, 92) and the transmission module (81, 91) in the region of the joint (93).