Freewheel Rotating Connection With Forced Lubricant Circulation

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Solution Overview

Problem

Existing rotational connection systems with freewheels face challenges in effectively lubricating contact zones during both engaged and disengaged operating modes, with traditional methods either causing overheating or inadequate lubrication.

Innovation Solution

A rotational connection system with a freewheel incorporating a fluidic circulation device that generates forced lubricant circulation during disengaged mode to prevent bubbling and retains fluid during engaged mode for optimal lubrication, using a pump or endless screw to manage lubricant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the contact zones are immersed in an oil bath during disengaged mode, then the lubrication is effective, but the oil causes heating by a bubbling effect

Engineering Contradiction:
Improvelubrication effectivenessVSAvoidcontact zone temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent applies a dynamic lubrication system where the lubrication method changes based on the operational mode. During disengaged mode, the system uses spray lubrication instead of oil bath to avoid bubbling and heating. During engaged mode, the system transitions to oil bath immersion for effective lubrication. This dynamic adaptation resolves the contradiction by selecting the appropriate lubrication method for each operational state.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lubrication system operates periodically, switching between spray lubrication during disengaged mode and oil bath lubrication during engaged mode. This periodic action ensures that the contact zones receive appropriate lubrication for each operational phase without suffering from the adverse effects of the wrong lubrication method.

Inventive Principle:
Principle #19Periodic action

2Temperature

If a small quantity of oil is sprayed during disengaged mode, then the heating is limited, but the contact zones are not sufficiently lubricated during engaged mode

Engineering Contradiction:
Improvecontact zone temperatureVSAvoidlubrication effectiveness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The system dynamically adjusts the lubrication quantity and method based on operational mode. During disengaged mode, spray lubrication with small oil quantity is applied to limit heating. During engaged mode, the system transitions to oil bath immersion with sufficient oil quantity to ensure effective lubrication. This dynamic adjustment resolves the contradiction between temperature control and lubrication effectiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The lubrication system changes key parameters (oil quantity, delivery method, pressure) based on the operational mode. The transition from spray lubrication to oil bath immersion involves significant parameter changes that optimize both temperature control during disengaged mode and lubrication effectiveness during engaged mode.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If grease is used to lubricate contact zones, then wear is limited, but the speed of rotation of the driven part is reduced

Engineering Contradiction:
Improvewear resistanceVSAvoiddriven part rotation speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent replaces grease lubrication with a fluid-based spray lubrication system during disengaged mode. This hydraulic/pneumatic approach delivers lubricant in a controlled manner that does not impede the rotation speed of the driven part, while still providing wear protection at the contact zones.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The system changes the lubrication medium from grease to liquid lubricant delivered by spray during disengaged mode. This parameter change maintains wear resistance while preserving rotation speed, as the liquid spray does not create the same frictional resistance as grease would during high-speed rotation.

Inventive Principle:
Principle #35Parameter changes

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

Ensures consistent lubrication of contact zones in both operating modes, preventing overheating and wear while maintaining efficient fluid circulation and retention.

Implementation Method 1

said fluid circulation device being rotated with respect to the leading pumping section in the presence of a speed of rotation driving around the axis of rotation of said leading pumping section lower than a speed of rotation driven around the axis of rotation of said driven pumping section to generate a forced circulation of said lubricating fluid within said connecting space

Methodology Applied
Scientific EffectForced circulation:

Implementation Method 2

The grease may tend to limit the overheating of the freewheel components at the contact zones between the various elements

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 3

a rotational connection system provided with a freewheel and a lubricating device aimed at performing well both during the engaged operating mode and during the disengaged operating mode

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3978793B1System for connection in rotation provided with a free wheel and a lubrication device
Publication Date: 2023.04.26 EUROCOPTER FRANCE SA
  • EP3978793B1 patent drawingFigure 1
  • EP3978793B1 patent drawingFigure 2
  • EP3978793B1 patent drawingFigure 3~4

AI summary

The present invention relates to a lubricated rotating connection system (10) equipped with a freewheel (20) having a driving portion (30) and a driven portion (40), and at least one rotating connecting member (50) arranged in a connecting space (55), said connecting space (55) being located radially between a driving connecting section (31) and a driven connecting section (41). A lubrication device (60) includes a fluid circulation device (65) rotationally fixed to a driven pumping section (42) of the driven portion (40). The said fluid circulation device (65) is rotated relative to a leading pumping section (32) in the presence of a leading rotation speed of said leading pumping section (32) less than a driven rotation speed around the axis of rotation (AX) of said driven pumping section (42) to generate a forced circulation of said lubricating fluid within said connecting space (55).