One-Way Clutch Assembly for Electric 4WD Systems

Solution Overview

Problem

The existing electric 4-wheel drive systems with complex clutch mechanisms suffer from reduced driving performance due to tooth combination impacts, spline abrasion, and delayed response times, which can lead to motor damage and decreased durability.

Innovation Solution

A clutch assembly featuring a one-way clutch with a ratchet mechanism and a fork member, actuated by an electrical signal, allows for rapid and smooth coupling and decoupling of the drive and driven elements based on torque conditions, eliminating the need for a toothed sleeve and reducing mechanical stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex clutch mechanism with toothed sleeve is used to selectively connect and block power delivery, then the clutch can achieve selective coupling and decoupling functions, but it causes tooth combination impacts, spline abrasion, and delayed response time

Engineering Contradiction:

Improveselective coupling functionVSAvoidtooth combination impact

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the toothed sleeve component from the clutch mechanism. By eliminating the teeth structure, the invention avoids tooth combination impacts and spline abrasion while maintaining the selective coupling function through a simplified structure consisting of a clutch body, clutch drum, and clutch plate

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the complex mechanical toothed engagement system with a friction-based mechanical system. The clutch plate engages with the clutch drum through friction contact rather than toothed meshing, eliminating impacts and wear associated with toothed mechanisms while achieving the same power transmission control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a complex clutch mechanism with toothed sleeve is used to selectively connect and block power delivery, then the clutch can achieve selective coupling and decoupling functions, but it increases device complexity

Engineering Contradiction:

Improveselective coupling functionVSAvoidclutch mechanism complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the toothed sleeve component from the clutch mechanism. By eliminating the teeth structure, the invention avoids tooth combination impacts and spline abrasion while maintaining the selective coupling function through a simplified structure consisting of a clutch body, clutch drum, and clutch plate

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the toothed sleeve, fork, and actuator into a unified clutch assembly with integrated components. The clutch plate directly engages the clutch drum without requiring separate toothed engagement components, reducing the number of parts and simplifying the overall mechanism

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If synchronization control is performed before clutch engagement to reduce impacts, then the durability of drive and driven elements is improved, but the response time is delayed and driving performance is deteriorated

Engineering Contradiction:

Improveelement durabilityVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the complex mechanical toothed engagement system with a friction-based mechanical system. The clutch plate engages with the clutch drum through friction contact rather than toothed meshing, eliminating impacts and wear associated with toothed mechanisms while achieving the same power transmission control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The clutch plate is pre-positioned within the clutch drum, ready for immediate engagement. When actuation is required, the clutch plate can engage instantly without requiring preliminary synchronization operations, achieving both rapid response and impact-free engagement through the friction-based mechanism

Inventive Principle:

Principle #10Preliminary action

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 solution enhances driving performance by minimizing impacts and delays, improving the durability of the drive and driven elements, and eliminating the need for synchronization control, thereby reducing power loss and enhancing vehicle stability.

Implementation Method 1

a one-way clutch which allows power to pass from the drive element to the driven element in one direction

Methodology Applied

Scientific EffectOne-way clutch mechanism: Ratchet

Implementation Method 2

a clutch plate having a friction material formed on an inner surface of the clutch plate, which is brought into frictional contact with an inner surface of the clutch drum

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8880312B2Clutch assembly for electric 4-wheel drive system

Publication Date: 2014.11.04 HYUNDAI MOTOR CO LTD

AI summary

A clutch assembly is provided for an electric 4-wheel drive system. The clutch assembly selectively blocks power delivered from a drive element of a motor to a driven element of a rear wheel and includes a one-way clutch movably installed between the drive element and the driven element, a fork member movably installed in a clutch housing and brought into sliding contact with the external circumference of the one-way clutch, and an actuator installed in the clutch housing and configured to provide forward working force and backward working force to the fork member.