Steer-By-Wire Steering Column With Integrated Rotation Limiter

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Solution Overview

Problem

Steer-by-wire steering systems lack a compact and structurally efficient mechanism to limit steering wheel rotation and provide mechanical feedback, leading to impaired driving experience and safety due to the absence of haptic feedback and unrestricted steering wheel rotation.

Innovation Solution

A rotation limiter is integrated into the gearbox of a steer-by-wire steering column, utilizing a flexible band element wound onto a rotatable winding core, which limits the steering shaft's rotation and is operatively connected to a feedback actuator for torque transmission, allowing for a compact design with reduced installation space and weight.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical rotation limiter is integrated into the steering column, then the steering shaft rotation can be limited, but the structural complexity and installation space requirements increase significantly

Engineering Contradiction:
Improvesteering shaft rotation limitationVSAvoidgearbox structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The rotation limiter is merged with the existing gearbox structure by integrating the winding core into a gearbox element and the band element into the gear engagement mechanism. This combines two functions (rotation limiting and gear transmission) into a single integrated component, avoiding the need for separate rotation limiting mechanisms and reducing overall structural complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The band element serves multiple functions: it transmits torque between gearbox elements and simultaneously limits rotation when wound onto the winding core. This multi-functional design eliminates the need for dedicated rotation limiting components, reducing device complexity while maintaining reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If a feedback actuator with torque generating device is added to provide haptic feedback, then driving experience improves, but the device complexity and weight increase

Engineering Contradiction:
Improvehaptic feedback qualityVSAvoidsteering column structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The feedback actuator is integrated with the gearbox structure, where the torque generating device shares mounting space and structural elements with the gear transmission system. This merging approach provides haptic feedback functionality while minimizing additional complexity compared to separate actuator installations

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If the rotation limiter uses a winding core with flexible band element, then the installation space is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improverotation limiter space requirementsVSAvoidband element winding precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The winding core is positioned within the existing gearbox element structure, nesting the rotation limiting mechanism inside the gear housing. This nested arrangement utilizes existing structural space, minimizing additional volume requirements while the band element is routed through predefined paths to reduce winding precision requirements

Inventive Principle:
Principle #7Nested doll (Nesting)

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 integrated rotation limiter effectively limits steering wheel rotation, simulating mechanical feedback while reducing design complexity and space requirements, enhancing driving safety and handling by providing intuitive steering feedback.

Implementation Method 1

a flexible band element can be wound onto the winding core

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the band element is fixed between the winding core and the housing or gearbox element

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4238853B1Steer-by-wire steering column for a motor vehicle
Publication Date: 2026.02.18 THYSSENKRUPP PRESTA AG
  • EP4238853B1 patent drawingFigure 1
  • EP4238853B1 patent drawingFigure 2
  • EP4238853B1 patent drawingFigure 3~4

AI summary

The present invention relates to a steer-by-wire steering column for a motor vehicle, comprising a steering shaft (2) rotatably mounted about a longitudinal axis (L) relative to a housing (11), which is operatively connected to a transmission (1), wherein the transmission (1) has at least two transmission elements (3, 4) that interact in the transmission engagement. In order to enable a rotation limiter of the steering shaft in a compact design with minimal construction effort, the invention proposes that a rotation limiter (6) for limiting the rotation of the steering shaft (2) relative to the housing (11) be integrated with the transmission (1).