Magnetic-Coupled Vehicle Gauge Pointer for High-Speed Indication

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing digital and analogue instruments for vehicles are limited by slow movement speeds and accelerations of pointers due to contactless magnetic couplings, restricting their use to indicating slowly changing physical quantities.

Innovation Solution

A digital and analogue instrument for vehicles utilizing a magnetic coupling between two rotors, where a front rotor supports a pointer and is synchronized with a rear rotor driven by an electric motor, allowing high-speed and high-acceleration movement of the pointer via a magnetic field transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If contactless magnetic coupling is used to move the pointer, then the pointer movement is smooth and contactless, but the pointer can only move with relatively limited speeds and accelerations

Engineering Contradiction:
Improvepointer movement speedVSAvoidmagnetic connection stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The magnetic coupling system is segmented into multiple independent magnet pairs arranged circumferentially around the rotation axis. Each magnet pair consists of a first magnet on the drive shaft and a corresponding second magnet on the pointer. This segmentation allows the total magnetic force to be distributed across multiple pairs, providing sufficient total attraction force to maintain reliable magnetic connection even at high speeds and accelerations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnets are strategically positioned at specific locations around the circumference to optimize local magnetic field strength and distribution. Each magnet pair is positioned to provide localized magnetic attraction that collectively ensures stable pointer attachment during high-speed rotation, addressing the local quality of magnetic field distribution to prevent connection loss.

Inventive Principle:
Principle #3Local quality

2Speed

If traditional magnetic coupling is used, then the structure is simple, but the pointer cannot indicate rapidly changing physical quantities

Engineering Contradiction:
Improvepointer response speedVSAvoidrange of measurable physical quantities
Core Design Contradiction:
SpeedVSAdaptability or versatility

Solution Approach 1:

By segmenting the magnetic coupling into multiple magnet pairs, the system achieves both high-speed capability and adaptability. The distributed magnetic forces from multiple pairs provide the necessary total attraction to maintain connection during rapid movements, enabling the pointer to accurately indicate rapidly changing physical quantities while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The multi-magnet pair configuration provides universal applicability for measuring various physical quantities regardless of their rate of change. The system can handle both slowly changing quantities (maintaining simplicity) and rapidly changing quantities (through enhanced magnetic holding force), making it versatile for different measurement scenarios in vehicle instrumentation.

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

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 safe and high-speed indication of rapidly changing physical quantities while maintaining a compact design and low production costs, suitable for integration into vehicle dashboards.

Implementation Method 1

the actuator device is configured to move the pointer by transmitting motion to the pointer via a contactless magnetic coupling

Methodology Applied
Scientific EffectMagnetic coupling: Magnetism

Implementation Method 2

a magnetic coupling between two rotors, where a front rotor supports a pointer and is synchronized with a rear rotor driven by an electric motor, allowing high-speed and high-acceleration movement of the pointer via a magnetic field transmission

Methodology Applied
Scientific EffectMagnetic field transmission: Magnetic Field

Data Source

PatentEP4671697A1Digital and analogue instrument for a vehicle with magnetic coupling
Publication Date: 2025.12.31 FERRARI SPA
  • EP4671697A1 patent drawingFigure 1
  • EP4671697A1 patent drawingFigure 2
  • EP4671697A1 patent drawingFigure 3

AI summary

A digital and analogue instrument (1) for a vehicle, comprising: a digital screen (3); a pointer (2) which is movably mounted so as to move in front of the digital screen (3); and an actuator device (4) configured to move the pointer (2). The actuator device (4) comprises: a front rotor (5) which has a centrally holed ring shape, is arranged in front of the digital screen (3), is rotatably mounted about a central rotation axis (6), and supports the pointer (2); a plurality of front permanent magnets (13) that are supported by the front rotor (5); a rear rotor (9) that is rotatably mounted about the central rotation axis (6); a plurality of rear permanent magnets (14) which are supported by the rear rotor (9) and are configured to be magnetically attracted by the respective front permanent magnets (13); and an electric motor (10) configured to rotate the rear rotor (9).