Selectable One-Way Clutch Torque Limiting Mechanism

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Solution Overview

Problem

Vehicles without a neutral mode and without a friction clutch to limit torque transfer are prone to damage from torque spikes, as components must handle excessive torque, leading to increased size and cost.

Innovation Solution

Incorporating a selectable one way clutch with a ball-detent torque limiting mechanism that prevents rotation in one direction and limits torque transfer above a pre-defined value, reducing the need for oversized components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the transmission is configured without a neutral mode and without a friction clutch, then the device complexity is reduced, but the transmission components must handle excessive torque spikes, leading to increased component size and cost

Engineering Contradiction:

Improvetransmission structureVSAvoidcomponent torque handling capacity

Core Design Contradiction:

Device complexityVSStrength

Solution Approach 1:

A selectable one-way clutch is introduced as an intermediary device between the transmission input shaft and the driveline. This clutch selectively engages to block torque transmission in the forward direction while allowing free rotation in reverse, serving as a mediator that protects transmission components from torque spikes without requiring a neutral mode or friction clutch

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The one-way clutch provides dynamic torque management by automatically engaging and disengaging based on rotation direction. The clutch transitions between locked and free states depending on whether the driveline attempts to rotate forward or backward, enabling adaptive protection against torque spikes during vehicle operation

Inventive Principle:

Principle #15Dynamics

2Ease of operation

If the transmission is configured without a neutral mode, then the ease of operation is improved, but torque spikes are communicated through the transmission, requiring components to be sized for maximum torque, increasing cost

Engineering Contradiction:

Improvetransmission operationVSAvoidtorque spike damage

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The one-way clutch converts the potentially harmful effect of torque spikes into a beneficial protective mechanism. By allowing reverse rotation freedom while blocking forward torque transmission, the clutch transforms what would be damaging torque spikes into controlled mechanical action, protecting the transmission while maintaining operational simplicity

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 effectively prevents damage from torque spikes by limiting torque transfer, reducing component size and cost, and ensuring the transmission can operate within a safer torque range.

Implementation Method 1

A ball-detent torque limiting mechanism, which is operable to prevent torque transfer greater than a pre-defined value, between the housing and the shaft

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

The selectable one way clutch is selectively operable to prevent rotation of the shaft about the axis in at least one rotational direction

Methodology Applied

Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentUS9546703B2Transmission brake and torque limiting system

Publication Date: 2017.01.17 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A vehicle includes a transmission, which is characterized by the absence of a friction clutch that is operable to limit torque transfer between the drive wheels and a shaft of the transmission, to prevent torque communication between the drive wheel and the shaft. The transmission includes a selectable one way clutch, which interconnects a housing of the transmission and the shaft. The selectable one way clutch is selectively operable to prevent rotation of the shaft in at least one rotational direction. The selectable one way clutch includes a torque limiting system, such as a ball-detent torque limiting mechanism, which is operable to prevent torque transfer greater than a pre-defined value, between the housing and the shaft.