Steering Angle Sensor Bearing Element for Compact Radial Guidance

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Solution Overview

Problem

Existing steering angle sensors are sensitive to manufacturing tolerances and require complex positioning of components, leading to a non-compact design and potential wear due to friction.

Innovation Solution

A compact bearing element with a ring-shaped web and annular groove arrangement allows for precise guidance of the gear wheel without a central axis of rotation, enabling a simple and backlash-free bearing that reduces installation space and friction, using self-lubricating materials like PTFE and an arc-shaped bridge part for additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the gear wheel is fixed between the housing and circuit board with annular bearing surfaces, then the gear wheel is positioned in the axial direction, but the available manufacturing tolerances are relatively small requiring exact positioning

Engineering Contradiction:
Improvepositioning precisionVSAvoidpositioning complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

A bearing element is introduced as an intermediary component between the gear wheel and the carrier. This bearing element assumes the positioning function, allowing the gear wheel to be mounted without requiring exact positioning relative to the circuit board or housing. The bearing element bridges the tolerance gaps that would otherwise require precise manufacturing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The positioning function is extracted from the carrier and housing structure and transferred to a dedicated bearing element. This separation allows the bearing element to specialize in providing precise radial guidance while the carrier and housing focus on their primary functions, reducing overall positioning complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If the magnetic sensor is arranged decentrally to achieve high resolution, then the magnet must extend annularly around the pin, but this increases device complexity and is not desirable for all applications

Engineering Contradiction:
Improveangular position resolutionVSAvoidmagnet arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The bearing element acts as a mediator that enables the magnetic sensor to be positioned at the center of the gear wheel without requiring complex annular magnet arrangements. By providing stable radial support through the bearing element, the system achieves high measurement precision with a simpler centralized magnet configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the gear wheel is mounted with tight tolerances to ensure exact positioning, then positioning precision is improved, but the design becomes less compact and more sensitive to manufacturing variations

Engineering Contradiction:
Improvecomponent positioningVSAvoidinstallation space
Core Design Contradiction:
Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The bearing element serves as a mediator that decouples the relationship between component positioning precision and installation space. It provides the necessary radial guidance in a compact configuration, allowing the gear wheel to be precisely positioned without requiring excessive clearance or complex positioning mechanisms that would increase the overall volume.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If bearing surfaces are extended over 360° to ensure complete guidance, then radial guidance is improved, but installation space and device complexity increase

Engineering Contradiction:
Improveradial guidanceVSAvoidaxial space
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The bearing element provides radial guidance through a bearing section that does not need to extend over the full 360° circumference. The bearing section extends over a sufficient angular range to ensure the gear wheel runs without play in the radial direction, while leaving the remaining angular space available for other components, thus optimizing space utilization while maintaining reliable guidance.

Inventive Principle:
Principle #16Partial or excessive action

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 creates a tolerant chain that eliminates the need for exact positioning of components, resulting in a compact, low-friction, and wear-resistant steering angle sensor design with improved resolution and space efficiency.

Implementation Method 1

the bearing section and/or the bearing surface and/or the annular groove and/or the annular web and/or the shoulder and/or the step are made of a self-lubricating material, in particular polytetrafluoroethylene (PTFE)

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP1792806B1Steering angle sensor
Publication Date: 2009.02.18 VALEO SCHALTER & SENSOREN GMBH
  • EP1792806B1 patent drawingFigure 1~2
  • EP1792806B1 patent drawingFigure 3
  • EP1792806B1 patent drawingFigure 4

AI summary

The sensor has a carrier (4) for arranging magnetic sensors that are arranged adjacent to a gear (14), where the gear exhibits multipolar magnets. A bearing unit (18) is arranged at the carrier, where the bearing unit bridges the gear in sections. The bearing unit has a bearing section (32) that forms a stop for the gear, where the stop works in an axial direction. The bearing unit has a bearing surface (34) for guiding the gear in radial direction.