Rotary Cam Brake Release in Non-Excitation Electromagnetic Brakes

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Solution Overview

Problem

Existing non-excitation operable electromagnetic brakes face challenges in clearly indicating the release state through operational reaction force and maintaining the rotary cam in its acting position due to gradual force changes and susceptibility to external vibrations.

Innovation Solution

A non-excitation operable electromagnetic brake design featuring a spring for braking, an electromagnet for releasing, and a rotary cam with a linear acting portion on its circumferential cam, allowing distinct operation reaction force changes and line contact for stable positioning, along with a rotation restriction and positioning mechanism to ensure reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an arcuate acting portion of the circumferential cam is used, then the rotary cam can be operated manually, but the change in operation reaction force is gradual and difficult to recognize

Engineering Contradiction:
Improvemanual operation capabilityVSAvoidrecognition of brake release state
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The acting portion of the circumferential cam is changed from an arcuate shape to a linear shape extending along the tangent at the center of the acting portion. This parameter change in the geometric form creates a sharp, distinct change in operation reaction force when the rotary cam is rotated, enabling clear recognition of the brake release state through tactile feedback.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the rotary cam is set to its acting position, then the brake can be kept released, but external forces like vibration can cause the rotary cam to slip off the acting position

Engineering Contradiction:
Improvebrake release maintenanceVSAvoidrotary cam position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The linear shape of the acting portion creates a line contact between the circumferential cam and the rotor when the rotary cam is at the acting position. This line contact provides greater stability and resistance to external forces such as vibration, preventing the rotary cam from slipping off the acting position and ensuring reliable maintenance of the brake release state.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If a linear acting portion is used, then the operation reaction force changes sharply for easy recognition, but the contact area with the rotor decreases

Engineering Contradiction:
Improverecognition of brake release stateVSAvoidcontact force distribution
Core Design Contradiction:
Measurement precisionVSForce

Solution Approach 1:

The linear acting portion is designed to extend along the tangent at the center of the acting portion, creating a line contact with the rotor. This geometric parameter change concentrates the contact force along a linear path, producing a sharp change in operation reaction force that is easily recognizable, while the line contact geometry distributes the force effectively to maintain sufficient contact force for reliable operation.

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

Enables easy recognition of brake release state and maintains the rotary cam in its position, preventing unintended switching due to vibrations, thus ensuring reliable operation and compact design.

Implementation Method 1

a spring for operating a rotor into a braking state

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an electromagnet configured, under an excited state thereof, to operate the rotor into a brake releasing state against the spring

Methodology Applied
Scientific EffectElectromagnetism: Electromagnet

Data Source

PatentEP3643943B1Non-excitation operable electromagnetic brake
Publication Date: 2023.11.08 KUBOTA CORP
  • EP3643943B1 patent drawingFigure 1
  • EP3643943B1 patent drawingFigure 2
  • EP3643943B1 patent drawingFigure 3~4

AI summary

Provided is a non-excitation operable electromagnetic brake that includes a manually operable rotary cam for switching over a rotor to a brake releasing state, but that allows easy recognition of switchover to the brake released state via an operation reaction force and that also allows reliable keeping of the rotary cam under its acting state. Even when an electromagnet 22 is under a non-excited state, when a rotary cam 31 is rotatably operated to an acting position (a), an acting portion 38a of the rotary cam 31 slidably operates a rotor 24 via a releasing plate 32 to a brake releasing state against springs 27. The acting portion 38a of the rotary cam 31 is formed linear along a tangent at a center of the acting portion 38a with respect to a rotary cam rotational direction.