Spindle Linear Drive Belt Coupling for Overload Protection

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Solution Overview

Problem

Existing linear drives face challenges in achieving a long service life due to the transmission of overloads, which can lead to premature wear and failure.

Innovation Solution

A compact linear drive design featuring a spindle nut and spindle mounted in a bearing plate, with a belt drive system where the spindle nut is non-positively connected to a belt pulley, allowing the electric motor to be positioned transversely to the spindle axis, thereby preventing overload transmission and enhancing service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a direct drive connection between motor and spindle is used, then power transmission efficiency is improved, but overload transmission causes reduced service life

Engineering Contradiction:
Improvepower transmission efficiencyVSAvoidservice life
Core Design Contradiction:
PowerVSDuration of action of moving object

Solution Approach 1:

A belt drive system is introduced as an intermediary between the motor and spindle. The belt provides frictional engagement that transmits power while allowing slip under overload conditions, protecting the spindle and nut from damage while maintaining efficient power transmission during normal operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the motor is positioned coaxially with the spindle, then structural simplicity is improved, but compactness in axial direction is reduced

Engineering Contradiction:
Improvestructural simplicityVSAvoidaxial length
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The motor is repositioned from a coaxial arrangement to a transverse arrangement relative to the spindle axis. This dimensional change allows the motor to be mounted perpendicular to the spindle, significantly reducing the axial length of the linear drive while maintaining power transmission through the belt drive system

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If a positive connection between belt and pulleys is used, then power transmission reliability is improved, but overload protection is lost

Engineering Contradiction:
Improvepower transmission reliabilityVSAvoidservice life
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The belt is designed as a sacrificial element that can wear or slip under overload conditions. This disposable component protects the more expensive and critical spindle and nut assembly, extending their service life while maintaining reliable power transmission during normal operation

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 design achieves a longer service life by preventing overload transmission through a non-positive connection between the belt and pulleys, ensuring the linear drive operates efficiently with reduced wear and tear.

Implementation Method 1

wherein the spindle nut is frictionally engaged or connected to a first pulley of a belt drive, which is frictionally engaged or connected to a belt of the belt drive

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3464945B1Linear drive having a spindle and spindle nut rotatably mounted in a bearing plate
Publication Date: 2022.05.18 SEW EURODRIVE GMBH & CO KG
  • EP3464945B1 patent drawingFigure 1
  • EP3464945B1 patent drawingFigure 2
  • EP3464945B1 patent drawingFigure 3

AI summary

The invention relates to a linear drive having a spindle nut and spindle, as well as a bearing plate, in which a bearing is accommodated for rotatably mounting the spindle nut or spindle, in particular wherein the spindle is operatively connected to the spindle nut, in particular wherein same is screwed into the spindle nut, wherein first elevations protruding transverse to the axis of the spindle are formed on the bearing plate for connecting to a device to be drive by means of a cardan joint, wherein two connected joint parts have second elevations protruding transverse to the axis of the spindle, in particular wherein a respective elevation is formed on each of the joint parts, wherein each of the joint parts has a recess into which a respective first elevation is introduced, in particular via a clearance fitting, i.e. in particular by via a respective fitting with a clearance, wherein the second elevations are oriented perpendicular to the first elevations.