Moveable Axle Shaft Actuator for Torque Disconnection

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Solution Overview

Problem

Existing drive axle assemblies lack an efficient mechanism to disconnect the axle shaft from the wheel hub assembly, leading to unnecessary torque transmission and potential tire wear during turns, which can affect vehicle handling and efficiency.

Innovation Solution

A drive axle assembly with a moveable axle shaft and an actuator mechanism that can position the axle shaft between a torque-transmitting and a disconnected state, allowing the differential assembly to selectively engage or disengage with the wheel hub assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the axle shaft is permanently connected to the wheel hub assembly, then torque transmission is continuous and reliable, but tire wear increases and vehicle handling deteriorates during turns

Engineering Contradiction:

Improvetorque transmission reliabilityVSAvoidtire wear

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The axle shaft is designed to be moveable along its axis rather than fixed, allowing it to dynamically change position between engaged and disengaged states. The actuator mechanism enables the axle shaft to move axially relative to the wheel hub assembly, transitioning torque transmission from a static continuous state to a dynamic controllable state, resolving the contradiction between continuous torque reliability and tire wear prevention

Inventive Principle:

Principle #15Dynamics

2Power

If the axle shaft is permanently connected to the wheel hub assembly, then torque transmission is maintained, but energy loss increases during non-traction conditions

Engineering Contradiction:

Improvetorque transmissionVSAvoidenergy loss

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The system transitions from static permanent connection to dynamic selective engagement. The actuator mechanism controls axial movement of the axle shaft to engage only when torque transmission is needed, eliminating continuous energy loss during coasting or non-traction conditions while maintaining power transmission capability when required

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If an actuator mechanism is added to move the axle shaft, then torque transmission can be selectively controlled, but device complexity increases

Engineering Contradiction:

Improvetorque transmission controlVSAvoidactuator mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The actuator mechanism serves as an intermediary device that enables controlled axial movement of the axle shaft. This intermediary component provides the necessary adaptability for selective torque transmission while isolating the complexity of the control system from the main drivetrain components, achieving a balance between versatility and manageable complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3527416B1Drive axle assembly with moveable axle shaft and method of operation

Publication Date: 2020.03.25 ARVINMERITOR TECHNOLOGY LLC

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AI summary

A drive axle assembly includes a differential assembly, a wheel hub assembly, an axle shaft, and an actuator mechanism. The actuator mechanism is adapted to move the axle shaft between a first axial position in which the axle shaft is engaged with the wheel hub assembly, and a second axial position in which the axle shaft is disengaged from the wheel hub assembly.