Magnetic Detent Rotary Input Control Eliminates Friction

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Solution Overview

Problem

Conventional rotary input controls employ mechanical detent mechanisms, resulting in undesirable noise and friction, which reduces the uniformity of rotation and decreases the product life cycle.

Innovation Solution

A rotary input control with a rotor assembly that utilizes a magnetic detent mechanism, featuring a rotor with magnetic elements and a permanent magnet arranged radially outward, providing non-contact uniform rotational resistance and eliminating friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical detent mechanisms are used in rotary input controls, then discrete rotational increments are achieved, but noise is produced and friction causes component wear

Engineering Contradiction:

Improvediscrete rotational incrementsVSAvoidnoise and friction

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical detent mechanism with a magnetic field-based system. A permanent magnet arranged radially outward from the rotor axis creates magnetic detent effects that provide discrete rotational increments without mechanical contact, thereby eliminating friction and noise while maintaining the indexing function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the rotor and stator components. The permanent magnet generates a magnetic field that interacts with magnetic elements on the rotor to produce detent effects, serving as a non-contact mediator that eliminates direct mechanical engagement and its associated friction and noise.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Force

If mechanical detent mechanisms are used, then rotational resistance is provided, but friction reduces uniformity of rotation

Engineering Contradiction:

Improverotational resistanceVSAvoiduniformity of rotation

Core Design Contradiction:

ForceVSStability of the object's composition

Solution Approach 1:

The patent substitutes mechanical friction-based rotational resistance with magnetic field-based rotational resistance. The permanent magnet creates consistent magnetic forces that provide uniform rotational resistance throughout the rotation, eliminating the variability caused by mechanical friction and wear.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If mechanical components are mechanically engaged, then detent effect is produced, but component wear decreases product life cycle

Engineering Contradiction:

Improvedetent effectVSAvoidproduct life cycle

Core Design Contradiction:

ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces mechanically engaged components with a non-contact magnetic field system. The permanent magnet and magnetic elements interact through magnetic fields without physical contact, eliminating wear and tear on components while maintaining the detent effect, thereby extending product life cycle.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The magnetic field system requires no maintenance or lubrication like mechanical systems. The permanent magnet continuously generates the magnetic field without degradation, and the magnetic elements on the rotor are wear-free, making the system self-sustaining with no service requirements.

Inventive Principle:

Principle #25Self-service

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 magnetic detent mechanism enhances the consistency of torque for discrete increments, improves input accuracy, reduces noise, and extends the product life cycle by eliminating mechanical friction.

Implementation Method 1

At least one permanent magnet is arranged radially outward from the axis of rotation and configured to apply a magnetic field to the magnetic elements

Methodology Applied

Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

This creates a magnetic detent effect when the rotor is rotated due to changes in rotational resistance produced as the magnetic elements rotate through the magnetic field

Methodology Applied

Scientific EffectMagnetic detent effect: Magnetism

Data Source

PatentEP3427128B1Magnetic detent for input controls

Publication Date: 2021.04.21 MICROSOFT TECHNOLOGY LICENSING LLC

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Figure 3A~3B

AI summary

Magnetic detents for input controls are described herein. In one or more implementations, a rotary input control (e.g., a scroll wheel or dial) includes a rotor assembly configured to employ a magnetic detent mechanism. The rotary input control may be integrated with an input device such as a computer mouse, keyboard, or, stylus. The rotor assembly includes a rotor that rotates around an axis of rotation and includes multiple magnetic elements disposed around the rotor, such as teeth of a gear, spokes, metallic regions, and so forth. At least one permanent magnet is arranged radially outward from the axis of rotation and configured to apply a magnetic field to the magnetic elements. This creates a magnetic detent effect when the rotor is rotated due to changes in rotational resistance produced as the magnetic elements rotate through the magnetic field.