Reverse Input Blocking Clutch With Integrated Locking Element

Solution Overview

Problem

The existing reverse input blocking clutch designs, such as those described in WO 2021/054481, have a large number of parts, leading to increased manufacturing costs and complexity due to the configuration of the engagement element and link member, which complicates the switching between locked and unlocked states.

Innovation Solution

A reverse input blocking clutch design that includes a pressed member, an input member, an output member, and an engagement element with a pair of pressing surfaces that are circumferentially separated and movable, allowing for efficient torque transmission and blocking by adjusting the distance between contact points and using a single engagement element to handle both torque transmission and locking/semi-locking functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the engagement element is configured to include the engagement element body and the link member, then the reverse input blocking clutch can transmit torque and block reverse torque, but the number of parts increases, leading to increased manufacturing costs and parts management complexity

Engineering Contradiction:

Improvetorque transmission and blocking functionVSAvoidnumber of parts

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the engagement element body and link member into a single integrated engagement element. The engagement element includes a pressing surface that directly contacts the pressed surface, eliminating the need for a separate link member. This integration maintains the torque transmission and blocking functions while reducing the total number of parts, thereby lowering manufacturing costs and simplifying parts management.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If the engagement element is configured to include the engagement element body and the link member, then the reverse input blocking clutch can transmit torque and block reverse torque, but the manufacturing costs increase due to more parts

Engineering Contradiction:

Improvetorque transmission and blocking functionVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the engagement element body and link member into a single integrated engagement element. The engagement element includes a pressing surface that directly contacts the pressed surface, eliminating the need for a separate link member. This integration maintains the torque transmission and blocking functions while reducing the total number of parts, thereby lowering manufacturing costs and simplifying parts management.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If the pressing surface is pressed against the pressed surface to block reverse torque, then the reverse input is blocked, but the switching between locked and unlocked states may not be smooth with complex mechanisms

Engineering Contradiction:

Improvereverse torque blockingVSAvoidswitching smoothness

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent merges the engagement element body and link member into a single integrated engagement element. The engagement element includes a pressing surface that directly contacts the pressed surface, eliminating the need for a separate link member. This integration maintains the torque transmission and blocking functions while reducing the total number of parts, thereby lowering manufacturing costs and simplifying parts management.

Inventive Principle:

Principle #5Merging (Combining)

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 design allows for smooth switching between locked and unlocked states while reducing manufacturing costs by minimizing the number of parts and stabilizing the operation, preventing unnecessary peak torque and size increases in the input mechanism.

Implementation Method 1

the engagement element is configured to press the pressing surface against the pressed surface so that the pressing surface frictionally engages with the pressed surface

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11982325B2Reverse input blocking clutch

Publication Date: 2024.05.14 NSK LTD

AI summary

A distance between a rotation center of an input member and a contact portion between an input side engaging portion and an input side engaged portion in a second direction is set to be shorter than a distance between a rotation center of an output member and a contact portion between an output side engaging portion and an output side engaged portion in the second direction. In a locked or semi-locked state, a contact portion between the output side engaging portion and the output side engaged portion is located on the side closer to the rotation center of the output member in a first direction in relation to a virtual line connecting the rotation center of the output member and a contact portion between one pressing surface of the pair of pressing surfaces and the pressed surface.