Self-Amplifying Brake Cage Clutch for Low-Force Shaft Locking

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Solution Overview

Problem

Existing braking and clutch assemblies for rotating shafts require high actuation forces to effectively engage or disengage, and they often face challenges in providing a low activation/deactivation power while maintaining high torque capacity and efficiency, especially in lubricated and hydraulic environments.

Innovation Solution

A selective shaft engaging assembly that incorporates a braking mechanism with an earth ring and engagement members, where the engagement members are urged towards the earth ring to inhibit or enable rotation, utilizing a biasing mechanism and an electromagnet to apply a controlled braking or coupling force, allowing for low activation power and self-amplification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional braking or clutch assemblies are used to inhibit or enable rotation of shafts, then torque capacity can be achieved, but high actuation forces are required

Engineering Contradiction:
Improveactuation forceVSAvoidactivation power
Core Design Contradiction:
ForceVSPower

Solution Approach 1:

The engagement members are designed to self-engage and self-disengage based on the rotational direction of the shaft. When the shaft rotates in the braking direction, the engagement members automatically engage with the earth ring to provide braking torque. When rotation reverses, they automatically disengage. This self-service mechanism eliminates the need for external actuation forces, resolving the contradiction between achieving torque capacity and requiring high actuation forces.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces conventional mechanical actuation systems (which require high forces) with a mechanism that utilizes the rotational motion itself to activate the braking or clutch function. The engagement members are positioned on ramped surfaces that convert shaft rotation directly into engagement or disengagement, substituting complex mechanical actuation with a simpler motion-based activation system.

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

2Power

If engagement members are designed to self-engage and disengage based on rotation direction, then low activation power is achieved, but the mechanism complexity increases

Engineering Contradiction:
Improveactivation powerVSAvoidmechanism complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent merges the braking/clutch function with the rotational motion control into a single integrated mechanism. The engagement members serve dual purposes: they are both the braking elements and the actuation elements. The same rotational motion that drives the shaft also activates the engagement members, combining what would traditionally be separate systems into one unified device, thereby reducing overall complexity despite the sophisticated engagement mechanism.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The engagement members are designed with multi-functionality, serving as both the actuating elements and the braking/clutch elements. A single component performs multiple functions: it is driven by rotation, converts that rotation into engagement/disengagement action, and provides the braking or clutching force. This multi-functionality reduces the number of separate components needed, offsetting the complexity of the self-engaging mechanism.

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

3Speed

If a braking mechanism is applied to the brake cage, then rotational movement is inhibited, but the torque capacity must be maintained

Engineering Contradiction:
Improverotational speedVSAvoidtorque capacity
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The engagement members act as intermediaries between the brake cage and the shaft. Instead of directly applying braking force to the shaft, the braking mechanism applies force to the brake cage, which then transmits this force through the engagement members to the shaft. This intermediary mechanism allows the braking force to be amplified and transmitted effectively, maintaining torque capacity while controlling rotational speed.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The engagement members utilize curved or ramped surfaces to convert the braking force applied to the brake cage into tangential forces on the shaft. The curved geometry of the engagement member surfaces allows for efficient force transmission and amplification, ensuring that the braking torque is effectively transferred from the brake cage to the shaft, maintaining torque capacity during speed control.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 high-capacity, low-activation power braking or clutch system that effectively inhibits or enables rotation with a small actuation force, suitable for applications like aircraft flight controls, and eliminates complex rotary sealing issues by using a frictionally restricted earth ring and biasing members.

Implementation Method 1

The present disclosure provides a high capacity, low activation/deactivation power, self-amplifying brake.

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Implementation Method 2

utilizing a biasing mechanism and an electromagnet to apply a controlled braking or coupling force

Methodology Applied
Scientific EffectElectromagnetism: Electromagnet

Implementation Method 3

The earth ring may be moveably connected or coupled to the housing such that it can move in a frictionally restricted manner relative thereto

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3447324B1Braking or clutch assembly for rotating shafts
Publication Date: 2021.07.07 GOODRICH ACTUATION SYST
  • EP3447324B1 patent drawingFigure 1
  • EP3447324B1 patent drawingFigure 2
  • EP3447324B1 patent drawingFigure 3A~3B

AI summary

A braking assembly is disclosed comprising a shaft (12), a brake cage (14) being rotatable with the shaft (12), an earth ring (16) extending circumferentially around the brake cage (14), at least one engagement member (28) coupled to the shaft (12), and a braking mechanism configured for selectively applying a force to the brake cage (14) for slowing or preventing rotational movement of the brake cage (14) such that the shaft (12) rotates relative to the brake cage (14), and wherein the braking assembly is configured such that when the shaft (12) rotates relative to the brake cage (14), said at least one engagement member (28) is urged to engage the earth ring (16) such that rotation of the shaft (12) is inhibited or prevented. The earth ring (16) may be replaced with an output shaft such that the assembly operates as a clutch assembly.