Roller Positive Clutch With Integrated Torque Limiter

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Solution Overview

Problem

Conventional clutches face issues such as low rigidity due to windup, large size, bulkiness, wear, and instability in torque load control, particularly in ratchet-type clutches and torque limiter mechanisms, which affect durability and performance.

Innovation Solution

A positive clutch design featuring coaxial outer and inner races with rollers biased by a resilient member, incorporating a torque limiter mechanism with a piston member and a resilient member to adjust torque limit load, allowing for high rigidity, size reduction, and improved durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ratchet-type clutch is used, then mechanical engagement is achieved, but the overall length increases and bulkiness increases

Engineering Contradiction:

Improvemechanical engagementVSAvoidoverall length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent combines the clutch mechanism and torque limiter mechanism into a single integrated structure. The clutch shoes and torque limiter weights share the same radial arrangement within the clutch assembly, eliminating the need for separate mechanisms and reducing overall length.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The clutch shoes serve dual functions: they provide mechanical engagement through friction contact and simultaneously act as torque limiter weights. This multi-functionality reduces the number of components needed and compact the overall design.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a tolerance ring torque limiter mechanism is used, then excessive torque is limited, but friction loss increases and torque limit load becomes unstable

Engineering Contradiction:

Improvetorque limitationVSAvoidfriction loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the traditional friction-based torque limiter mechanism with a mechanical overload release system. The torque limiter weights engage with release ramps to mechanically limit torque, eliminating the need for friction plates and reducing friction loss.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If a separate torque limiter mechanism is used in combination with clutch mechanism, then torque limitation is achieved, but the number of components increases and space requirement increases

Engineering Contradiction:

Improvetorque limitationVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the torque limiter mechanism within the clutch assembly structure. The torque limiter weights, springs, and release ramps are housed within the same radial space as the clutch shoes, eliminating the need for separate mechanisms and reducing component count.

Inventive Principle:

Principle #5Merging (Combining)

4Power

If friction clutch is used, then torque transmission is achieved, but rigidity decreases due to windup

Engineering Contradiction:

Improvetorque transmissionVSAvoidrigidity

Core Design Contradiction:

PowerVSStability of the object's composition

Solution Approach 1:

The patent uses multiple clutch shoes (typically 3-4) distributed around the circumference to transmit torque. This segmentation allows the load to be distributed across multiple contact points, reducing windup of individual components and improving overall rigidity.

Inventive Principle:

Principle #1Segmentation

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 high rigidity, reduces size, enhances durability, and allows for easy adjustment of torque limit load, minimizing friction loss and noise, while improving performance stability and extending service life.

Implementation Method 1

a resilient member that applies a constant load on the piston member

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

to transmit torque, the relative rotation between the inner race and the outer race is stopped by frictional engagement between the torque transmission members and the inner and outer races

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS12104663B2Positive clutch

Publication Date: 2024.10.01 TSUBAKIMOTO CHAIN CO

AI summary

An object of the invention is to provide a positive clutch that has a high rigidity and simple structure, and offers potential to allow easy adjustment of torque limit load, suppress friction loss and noise generation, realize a size reduction, and extend the service life. This positive clutch is configured to prohibit relative rotation of an outer and inner races by circumferentially holding each of a plurality of rollers between an outer race slope portion and an inner race slope portion. The clutch includes a torque limiter mechanism, which includes a piston member having a flat portion that forms the outer or inner race slope portion, and a resilient member that applies a constant load on the piston member. The piston member is slidably accommodated in a piston member accommodating hole formed in the outer race or the inner race.