Electromagnetic Brake Hub Magnetic Circuit Design

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Solution Overview

Problem

Conventional electromagnetic brakes have limited magnetic attraction due to high magnetic reluctance in the electromagnetic circuit, resulting in restricted braking torque.

Innovation Solution

The electromagnetic brake incorporates a hub configured to form part of the electromagnetic circuit, reducing magnetic reluctance and increasing the magnetic attraction between the armature and brake plate by allowing magnetic flux to travel through radial air gaps, thereby enhancing braking torque.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the electromagnetic circuit is configured with conventional components (housing, conductor, brake plate, armature), then the brake structure is simple and easy to manufacture, but the magnetic reluctance is high which limits the magnetic attraction and braking torque

Engineering Contradiction:
Improvemagnetic attractionVSAvoidelectromagnetic circuit configuration
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The hub is integrated into the electromagnetic circuit as a magnetic circuit component, merging the rotational support function with the magnetic flux conduction function. This reduces magnetic reluctance and enhances magnetic attraction between the armature and brake plate, thereby increasing braking torque without adding separate components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hub serves multiple functions: it supports the rotating shaft, provides a mounting surface for bearings, and acts as a magnetic circuit component to reduce magnetic reluctance. This multi-functionality increases magnetic attraction and braking torque without increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Power

If the magnetic reluctance in the electromagnetic circuit is high, then the brake structure is simpler, but the braking torque is limited due to reduced magnetic attraction between armature and brake plate

Engineering Contradiction:
Improvebraking torqueVSAvoidmagnetic circuit performance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The magnetic circuit parameters are optimized by incorporating the hub with appropriate magnetic properties and geometric configuration. This reduces magnetic reluctance in the circuit, enhances magnetic flux density, and increases the magnetic attraction force between the armature and brake plate, thereby improving braking torque.

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

This configuration effectively increases the braking torque by reducing magnetic reluctance and enhancing the magnetic attraction between the armature and brake plate, improving the braking performance of the electromagnetic brake.

Implementation Method 1

When current is supplied to the conductor an electromagnetic circuit is created between the housing of the electromagnet assembly and an armature

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the magnetic attraction between the brake plate and armature may be limited by a relatively high magnetic reluctance in the electromagnetic circuit

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3408554B1Electromagnetic brake for a power transmission assembly
Publication Date: 2019.12.04 WARNER ELECTRIC TECHNOLOGY LLC
  • EP3408554B1 patent drawingFigure 1
  • EP3408554B1 patent drawingFigure 2
  • EP3408554B1 patent drawingFigure 3

AI summary

An electromagnetic brake (34) includes a hub (48) disposed about a shaft and configured for rotation with the shaft about a rotational axis (38). An electromagnet assembly is fixed against rotation about the axis (38) and includes a housing (64) defining axially extending, radially spaced inner (74) and outer (78) poles and a brake plate (80) extending radially therebetween. A conductor (66) is disposed between the poles on one side of the brake plate (80). An armature (96) is disposed on the other side of the brake plate (80) and coupled to a body driven by the shaft. The electromagnet assembly, armature (96) and hub (48) form an electromagnetic circuit when the conductor (66) is energized urging the armature (96) towards the brake plate (80). A portion of the magnetic flux in the circuit travels radially inwardly across a first radial air gap from the inner pole (74) to the hub (48) and then radially outwardly across a second radial air gap from the hub (48) to the brake plate (80).