Controllable Overrunning Coupling Assembly Reducing Fluidic Drag

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Solution Overview

Problem

Prior art selectable or controllable one-way clutches require a large quantity of lubricating fluid to dampen struts during overrun, leading to increased oil consumption and potential fluidic drag.

Innovation Solution

A controllable overrunning coupling assembly with a hybrid design combining rocker and MD (mechanical diode) elements, where forward rockers are placed in the rotating member and include spring-biased locking formations and ramped surfaces, reducing the need for lubricating fluid by utilizing centrifugal forces and hydrodynamic effects to stabilize rockers during overrun.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a large quantity of lubricating fluid is used to dampen struts during overrun, then stability during overrun is improved, but oil consumption increases and fluidic drag increases

Engineering Contradiction:

Improvestability during overrunVSAvoidoil consumption

Core Design Contradiction:

Stability of the object's compositionVSLoss of substance

Solution Approach 1:

The patent replaces the traditional mechanical damping system (which relies on lubricating fluid) with a hydrodynamic bearing system. The forward rockers are supported by hydrodynamic bearings that utilize fluid dynamics principles to provide stability during overrun without requiring large quantities of lubricating fluid. This substitution reduces both oil consumption and fluidic drag while maintaining stability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of the lubricating fluid system by transitioning from a high-fluid-consumption damping mechanism to a low-fluid-consumption hydrodynamic bearing system. The hydrodynamic bearings operate with minimal fluid, changing the quantity and flow characteristics of the lubricating fluid required for stable operation during overrun.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If a large quantity of lubricating fluid is used to dampen struts during overrun, then stability during overrun is improved, but fluidic drag increases

Engineering Contradiction:

Improvestability during overrunVSAvoidfluidic drag

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the traditional mechanical damping system with hydrodynamic bearings that minimize fluidic drag. The hydrodynamic bearing design allows the forward rockers to be supported with minimal fluid contact, reducing the harmful fluidic drag forces while maintaining the necessary stability during overrun operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If traditional one-way clutch design is used, then simplicity of structure is maintained, but wear increases due to fluidic drag

Engineering Contradiction:

Improvestructural simplicityVSAvoidoverrun life

Core Design Contradiction:

Device complexityVSDuration of action of moving object

Solution Approach 1:

The patent replaces traditional damping mechanisms with hydrodynamic bearings, reducing wear caused by fluidic drag. This substitution extends the duration of action (overrun life) of the moving parts while maintaining relatively simple structural integration into the one-way clutch design.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 hybrid design minimizes lubricating fluid requirements, reducing fluidic drag and wear, while maintaining robustness and stability during clutch overrun, thus improving overrun life and reducing oil consumption.

Implementation Method 1

spring-biased locking formations

Methodology Applied

Scientific EffectElastic force: Elasticity

Implementation Method 2

ramped surfaces

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 3

utilizing centrifugal forces and hydrodynamic effects to stabilize rockers during overrun

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

utilizing centrifugal forces and hydrodynamic effects to stabilize rockers during overrun

Methodology Applied

Scientific EffectHydrodynamic effects:

Data Source

PatentUS8079453B2Controllable overrunning coupling assembly

Publication Date: 2011.12.20 MEANS IND INC

AI summary

A controllable overrunning coupling assembly includes a control member mounted for controlled shifting movement between a first pair of coupling faces of first and second coupling members relative to reverse pockets formed in one of the coupling faces. The first pair of coupling faces oppose each other and are oriented to face axially along a common rotational axis. The control member is operable for controlling position of only reverse struts in the reverse pockets without controlling the position of forward rockers in forward pockets formed in a coupling face of a second pair of coupling faces of the coupling members that oppose each other and are oriented to face radially with respect to the rotational axis.