Magnetic Rotary Control Knob for Low-Wear Axial Return

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Solution Overview

Problem

Rotary operating elements used in harsh environments, such as agricultural or construction vehicles, experience increased wear and potential malfunctions due to debris and mechanical issues, leading to reduced lifetime and reliability.

Innovation Solution

A compact and robust rotary operating element is designed with a magnetic restoring assembly that provides a contactless interaction to reduce wear and enhance reliability. The assembly includes a first component mounted to the housing and a second component on the shaft, both interacting magnetically to generate a restoring force that returns the shaft to its default position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical restoring assembly is used to return the shaft to the default position, then the restoring force is provided, but wear occurs on the mechanical components leading to reduced lifetime

Engineering Contradiction:

Improvelifetime of operating elementVSAvoidwear on mechanical components

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical restoring assembly with a magnetic restoring assembly. The magnetic assembly includes a first component with a magnet mounted to the housing and a second component with a magnet provided on the shaft. These components interact magnetically to generate the restoring force without mechanical contact, thereby eliminating wear on mechanical components while maintaining the shaft's ability to return to its default position.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the shaft is rotated while being pushed or pulled in axial direction, then both rotary control function and axial control function are provided, but friction on mechanical components increases wear

Engineering Contradiction:

Improvecombined rotary and axial control functionVSAvoidfriction on mechanical components

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The magnetic restoring assembly eliminates mechanical contact between the restoring force components, allowing the shaft to be rotated during axial movement without generating friction-based wear. The magnetic interaction provides the restoring force in the axial direction without impeding rotation, enabling versatile control functions while minimizing harmful friction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If optical means are used for detecting actuation, then mechanical wear is avoided, but dust particles can enter the operating element and degrade the optical detection

Engineering Contradiction:

Improvewear on mechanical componentsVSAvoidoptical detection functionality

Core Design Contradiction:

Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent employs a magnetic restoring assembly that provides contactless interaction through magnetic fields. This approach avoids both the mechanical wear associated with traditional restoring assemblies and the vulnerability of optical systems to dust particle interference. The magnetic field-based restoration maintains reliability in harsh environments by eliminating both mechanical contact and optical pathways that could be blocked by debris.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 restoring assembly significantly reduces wear on the operating element, enhances its reliability in harsh environments, and provides intuitive operation by minimizing friction and debris impact, thus extending the lifetime of the element.

Implementation Method 1

The first component and the second component are configured to interact magnetically to generate the restoring force when the shaft is moved in axial direction out of the default position

Methodology Applied

Scientific EffectMagnetic interaction: Magnetism

Data Source

PatentEP4553606A1Rotary operating element

Publication Date: 2025.05.14 ELOBAU GMBH & CO KG

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AI summary

A rotary operating element for controlling a function of a machine is provided. The rotary operating element (10) comprises a shaft (12), wherein the shaft (12) is rotatable to provide a rotary control function and wherein the shaft is actuatable in an axial direction of the shaft to provide an axial control function. The shaft (12) has a default position in the axial direction. The rotary operating element (10) further comprises a restoring assembly (15) configured to apply a restoring force in the axial direction to the shaft (12) to return the shaft into the default position. The restoring assembly (15) is a magnetic restoring assembly that comprises a first component (20) coupled to a housing (11) of the rotary operating element (10) and a second component (30) provided on the shaft (12). The first component (20) and/or the second component (30) comprises a magnet (40). The first component (20) and the second component (30) are configured to interact magnetically to generate the restoring force when the shaft (12) is moved in axial direction out of the default position.