Steer-by-Wire Column with Integrated Rack Motor for Compact Pivoting

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Solution Overview

Problem

Conventional electrically adjustable steer-by-wire steering columns for motor vehicles require significant space and weight, limiting pivotability, ease of installation, and increasing fuel consumption due to large electric motors and complex components.

Innovation Solution

A compact electrically adjustable steer-by-wire steering column design featuring a telescopic steering tube arrangement with a rack section and combing device driven by an electric motor, allowing for pivoting and adjustment of the steering wheel within limited space, utilizing a modular structure with a hollow shaft motor and helical gearing for efficient torque transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional electric motors and complex components are used for steering wheel adjustment, then the steering column can achieve adjustment functionality, but the installation space requirement increases and dead weight increases

Engineering Contradiction:
Improvesteering wheel adjustment functionalityVSAvoidinstallation space
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The steering tube assembly is nested within the steering column housing, with the telescopic steering tube containing the adjustment mechanism. The rack section and combing device are integrated within the compact motor assembly, allowing components to be nested within each other to minimize overall volume while maintaining full adjustment functionality.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent combines the electric motor, rack section, combing device, and steering tube assembly into a single integrated compact motor assembly. This merging of previously separate components reduces the overall installation space requirement while preserving the steering wheel's ability to perform telescopic and angular adjustments.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If conventional electric motors and complex components are used for steering wheel adjustment, then the steering column can achieve adjustment functionality, but the dead weight increases

Engineering Contradiction:
Improvesteering wheel adjustment functionalityVSAvoiddead weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of stationary object

Solution Approach 1:

The patent merges the electric motor, rack section, combing device, and steering tube assembly into a single integrated compact motor assembly. This consolidation eliminates the need for multiple separate heavy components and their associated mounting structures, reducing the overall dead weight of the steering column while maintaining full adjustment functionality.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If the steering wheel is completely retracted into the cockpit, then driver freedom of movement is improved in autonomous mode, but the pivotability and retraction mechanism becomes more complex

Engineering Contradiction:
Improvedriver freedom of movementVSAvoidretraction mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The steering tube assembly performs self-adjustment through the integrated compact motor assembly. The electric motor automatically controls the telescopic extension and angular pivoting of the steering tube, eliminating the need for complex manual adjustment mechanisms and enabling complete retraction into the cockpit without requiring complex external mechanisms.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The steering tube assembly is designed with dynamic adjustment capabilities, allowing it to automatically extend and retract, and pivot angularly, based on driving mode requirements. This dynamic behavior enables complete retraction in autonomous mode while maintaining optimal positioning during manual driving, achieved through the integrated motor control system.

Inventive Principle:
Principle #15Dynamics

4Volume of moving object

If rack section and combing device are used for pivoting, then pivotability is improved within limited space, but manufacturing complexity increases

Engineering Contradiction:
Improveinstallation spaceVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The compact motor assembly is segmented into distinct functional modules: the electric motor, the rack section, and the combing device. Each module can be manufactured and tested independently, then assembled into the final compact unit. This segmentation reduces manufacturing complexity despite the space-efficient design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The rack section acts as an intermediary mechanism between the electric motor and the combing device, translating motor rotation into linear motion that pivots the steering tube assembly. This intermediary component enables the space-efficient pivoting mechanism while allowing each component to be manufactured using standard processes.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables improved pivotability and automatic adjustment of the steering wheel within minimal space, reducing weight and installation complexity while maintaining effective force feedback and sensor functionality, allowing for complete retraction of the steering wheel into the cockpit.

Implementation Method 1

an electric motor (13) with a meshing device (14) for meshing with the rack section (12)

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a meshing device (14) for meshing with the rack section (12), wherein the rack section (12) and the meshing device (14) are arranged on the steering column in such a way that, by driving the meshing device (14) by means of the electric motor (13), the steering tube arrangement (3) can be pivoted

Methodology Applied
Scientific EffectMechanical advantage through gear meshing: Gear

Data Source

PatentEP3844046B1Electrically adjustable steer-by-wire steering column and motor vehicle
Publication Date: 2024.10.16 VOLKSWAGEN AG
  • EP3844046B1 patent drawingFigure 1
  • EP3844046B1 patent drawingFigure 2
  • EP3844046B1 patent drawingFigure 3

AI summary

The invention relates to an electrically adjustable steer-by-wire steering column (1) for a motor vehicle (2), having a telescopic steering tube assembly (3) with a steering wheel attachment interface (4) for attaching a steering wheel (5), a force feedback actuator (6) for simulating the transmission of mechanical forces and/or mechanical momentum from a driving surface via wheels (7) of the motor vehicle (2) to the steering wheel attachment interface (4), and a steering tube retaining device (8) with a cockpit attachment interface (9) for attaching the steering tube retaining device (8) to a cockpit carrier (10) of the motor vehicle (2), and a steering tube bearing (11). The steering tube assembly (3) is pivotably mounted about a horizontal pivot axis (S) relative to the cockpit attachment interface (9) via the steering tube bearing (11). The steering column (1) has a rack section (12) and an electric motor (13) with a meshing device (14) for meshing with the rack section (12), wherein the rack section (12) and the meshing device (14) are situated on the steering column (1) such that the steering tube assembly (3) can be pivoted about the pivot axis (S) relative to the cockpit attachment interface (9) by driving the meshing device (14) by means of the electric motor (13). The invention also relates to a motor vehicle (2).