Display Device with Wobble Gear Ring and Ferromagnetic Ring

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Solution Overview

Problem

Display devices with circular arc scales and integrated electromagnetic drive systems face high manufacturing costs due to complex ferromagnetic circuits and non-uniform movement issues.

Innovation Solution

A cost-effective design featuring a rotatably mounted gear wheel or internal/external gear ring with spring-impinged tumbling mechanisms, driven by a ferromagnetic ring with independently energizable pole shoes, reduces component count and assembly complexity, enabling uniform indicator movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If meter movements with integrated electromagnetic drive systems and complex ferromagnetic circuits are used, then the display device achieves reliable electromagnetic actuation, but manufacturing costs increase and device complexity increases

Engineering Contradiction:
Improveelectromagnetic actuation reliabilityVSAvoidferromagnetic circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex ferromagnetic circuit from the electromagnetic drive system. Instead of using a traditional complex ferromagnetic circuit with multiple components, the invention uses a simplified permanent magnet directly positioned on the drive shaft, which generates the necessary magnetic field without requiring additional ferromagnetic circuit elements. This extraction of unnecessary components reduces device complexity while maintaining electromagnetic actuation reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the permanent magnet directly with the drive shaft, eliminating the need for separate ferromagnetic circuit components. The permanent magnet is positioned directly on the drive shaft in alternating polarity arrangement, combining the magnetic field generation function with the mechanical rotation function into a single integrated structure. This merging reduces the number of components and simplifies the overall device construction.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of operation

If traditional gearboxes with multiple stages are used to convert rotation movement, then the indicator movement can be controlled, but manufacturing costs increase and the number of components increases

Engineering Contradiction:
Improveindicator movement controlVSAvoidgearbox component count
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces the traditional multi-stage mechanical gearbox with a direct electromagnetic actuation system. The permanent magnet on the drive shaft interacts directly with wound coils to generate rotational movement, eliminating the need for intermediate mechanical gear stages. This substitution of the mechanical transmission system with a direct electromagnetic drive system reduces the number of components while maintaining precise indicator movement control through electrical control of the coil currents.

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

3Manufacturing precision

If corrective actuation curves are implemented to ensure uniform indicator movement, then measurement accuracy improves, but device complexity and manufacturing costs increase

Engineering Contradiction:
Improveindicator movement uniformityVSAvoidactuation curve complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements dynamic control of the electromagnetic actuation system by independently controlling the current in multiple wound coils positioned around the permanent magnet. By dynamically adjusting the current distribution among the coils, the system achieves uniform indicator movement without requiring complex mechanical corrective mechanisms. The alternating polarity arrangement of permanent magnets combined with selective coil energization creates a balanced magnetic field that naturally produces uniform rotational movement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the control parameters from mechanical corrections to electrical parameter adjustments. By varying the current magnitude and timing in different wound coils, the system achieves precise control over the magnetic field distribution, which in turn controls the rotational movement characteristics. This parameter-based control approach replaces complex mechanical actuation curves with simpler electrical control, reducing device complexity while maintaining movement uniformity.

Inventive Principle:
Principle #35Parameter changes

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 solution achieves a cost-effective, simplified construction with fewer components and uniform movement of the indicator, while reducing assembly effort and construction space, and enhances ruggedness through encapsulation in a housing.

Implementation Method 1

a ferromagnetic ring that extends in the circumferential direction of the tumbling gear ring, having at least two pole shoes that protrude through coils, which are capable of being energized in a mutually independent manner

Methodology Applied
Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Implementation Method 2

the tumbling gear ring being impinged by spring forces distributed across the circumference of the former and act in the engagement direction of the toothing of the tumbling gear ring with the teeth of the gear wheel

Methodology Applied
Scientific EffectElastic force: Spring

Data Source

PatentUS10043589B2Display device
Publication Date: 2018.08.07 CONTINENTAL AUTOMOTIVE GMBH

AI summary

A display device has a scale in the shape of a circular arc. On an axis driving an indicator axis, a rotatably mounted gear wheel is arranged in a rotatably fixed manner, in the teeth of which the toothing of a wobble gear ring partially engages. The wobble gear ring is mounted about the axis of the rotatably mounted gear wheel such that the wobble gear ring can wobble, is acted upon by spring forces distributed around the periphery of the wobble gear ring in the direction of engagement of the toothing of the wobble gear ring in the teeth of the rotatably mounted gear wheel, and is fixedly connected to a ferromagnetic ring extending in the direction of rotation of the wobble gear ring. At least two pole shoes project through independently energizable coils to the outer circumferential surface of the ferromagnetic ring.