Magnetic Brake Cogging Torque for Silent Drive Positioning

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Solution Overview

Problem

Existing drive devices for sun protection systems, such as blinds and awnings, face challenges with noise generation in flat brakes and increased power requirements in hysteresis brakes, while seeking a solution that balances functionality with minimal structural effort.

Innovation Solution

A drive device with a magnetic brake system featuring a rotating receptacle with a magnetizable ring and a stationary nest of discrete magnetized regions, generating a cogging torque only when the motor is at a standstill, ensuring silent operation and increased braking force, thus reducing energy consumption and enhancing reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If flat brakes with magnetic elements are used to provide braking force, then the braking effect is achieved, but noise is generated due to contact between braking elements

Engineering Contradiction:
Improvebraking effectVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical contact-based braking system with a magnetic field-based braking system. Instead of using mechanical friction between brake elements, the invention uses magnetic forces generated by magnets arranged on the rotor and stator to create eddy currents in a conductive ring, which produces the braking effect without physical contact, thereby eliminating noise.

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

Solution Approach 2:

The patent changes the physical state and interaction mode of the braking system from mechanical contact to magnetic field interaction. By using magnetic fields to induce eddy currents in a conductive ring, the system achieves braking through electromagnetic forces rather than mechanical friction, fundamentally changing the operating parameters from contact-based to field-based interaction.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If hysteresis brakes are used to achieve silent operation, then noise is eliminated, but power consumption increases due to constant magnetic reversal

Engineering Contradiction:
ImprovenoiseVSAvoidpower consumption
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic action through the rotational movement of the rotor, which periodically brings the conductive ring past the magnets. This periodic motion induces eddy currents only during the braking phase rather than requiring continuous magnetic reversal, thereby achieving silent operation while minimizing power consumption by activating the braking mechanism only when needed.

Inventive Principle:
Principle #19Periodic action

3Reliability

If conventional brakes with contact elements are used, then braking force is provided, but structural complexity increases due to multiple brake elements and spring mechanisms

Engineering Contradiction:
Improvebraking forceVSAvoidbrake structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates unnecessary mechanical components from the braking system. By using magnets mounted directly on the rotor and stator with a conductive ring, the invention removes complex spring mechanisms, multiple brake elements, and mechanical actuation systems, achieving braking force with a simplified structure that consists essentially of magnetic components and a conductive ring.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a silent, energy-efficient, and reliable braking mechanism with a significantly higher braking force at standstill, ensuring secure motor positioning and low manufacturing complexity, allowing for efficient operation and easy integration into sun protection systems.

Implementation Method 1

When the electric motor is at a standstill, magnetized areas of the first and second arrangement are arranged opposite one another at a distance and thus generate a cogging torque for the electric motor

Methodology Applied
Scientific EffectCogging torque: Magnetic Field

Implementation Method 2

A brake associated with the electric motor has a first receptacle which rotates with the rotor of the electric motor and has a first ring made of magnetizable material, this ring having a first arrangement of discrete magnetized regions

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3203615B1Drive device
Publication Date: 2021.05.26 ELERO GMBH
  • EP3203615B1 patent drawingFigure 1
  • EP3203615B1 patent drawingFigure 2
  • EP3203615B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a drive device (1) for an positioning system, comprising an electric motor (4), wherein a rotary movement of its rotor extends or retracts an actuating element. A brake (12) associated with the electric motor (4) has a first receptacle rotating with the rotor of the electric motor (4), comprising a first discrete arrangement of magnets (14.1-14.12) or a first ring (14) made of magnetizable material, wherein this ring (14) has a first arrangement of discrete magnetized regions (14.a-14.1) spaced apart in its circumferential direction. A stationary second receptacle has a second discrete arrangement of magnets (16.1-16.12) or a second ring (16) made of magnetized material, wherein this ring (16) has a second arrangement of discrete magnetized regions (16.1-16.12) spaced apart in its circumferential direction. When the electric motor (4) is at a standstill, magnets (14.1-14.12 and 16.1-16.12) or magnetized areas (14.a-14.1 and 16.a-16.1) of the first and second arrangements are arranged opposite each other at a distance and thus generate a cogging torque for the electric motor (4).