Wind Turbine Drivetrain Lubrication Using Gravity-Fed Oil Reservoirs

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Solution Overview

Problem

Wind turbines in remote locations face challenges in maintaining adequate lubrication of drive train components, especially during idling or when disconnected from the grid, as excessive lubrication liquid increases friction losses, and existing systems lack efficient solutions for lubrication without auxiliary power.

Innovation Solution

A lubrication system with a main oil tank and separate reservoirs for lubrication liquid, utilizing gravity-driven oil flow and geodetic positioning to supply lubrication to drive train components, including a gearbox, main shaft, and generator, with valves and sensors to manage oil distribution and level control, ensuring continuous lubrication without active pumping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a high amount of lubrication liquid is used to ensure adequate lubrication during grid disconnection, then reliability is improved, but friction losses increase and performance decreases

Engineering Contradiction:

Improvelubrication reliability during grid disconnectionVSAvoidfriction losses

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The lubrication system is divided into multiple separate reservoirs (first reservoir for main shaft and generator, second reservoir for gearbox) instead of a single common reservoir. This segmentation allows independent control of lubrication liquid distribution to different drive train components, enabling the system to provide adequate lubrication during grid disconnection while minimizing friction losses during grid connection by preventing excessive oil accumulation in the gearbox.

Inventive Principle:

Principle #1Segmentation

2Reliability

If lubrication liquid is supplied without auxiliary power during grid disconnection, then reliability is improved, but device complexity increases due to gravity-driven flow requirements

Engineering Contradiction:

Improvelubrication capability without auxiliary powerVSAvoidsystem complexity for gravity-driven flow

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The reservoirs are positioned at a higher elevation than the drive train components, creating a gravitational potential difference that drives oil flow without requiring auxiliary power. The system utilizes the natural gravitational field to maintain lubrication during grid disconnection, transforming the potential energy of elevated oil into kinetic energy for flow, thereby achieving reliable lubrication without additional power-consuming pumping equipment.

Inventive Principle:

Principle #12Equipotentiality

Solution Approach 2:

The lubrication system is designed to be self-regulating through gravity-driven flow and atmospheric pressure, automatically supplying lubrication liquid to drive train components without requiring external control systems or auxiliary power during grid disconnection. The system uses its own structural configuration (elevated reservoirs) to generate the necessary flow pressure.

Inventive Principle:

Principle #25Self-service

3Loss of energy

If the gearbox has no oil sump during grid connection, then friction losses are reduced, but lubrication reliability may be compromised during transition to grid disconnection

Engineering Contradiction:

Improvefriction losses in gearboxVSAvoidlubrication reliability during grid transition

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system dynamically adjusts the lubrication liquid distribution between reservoirs and drive train components based on operational mode (grid connection or disconnection). During grid connection, the gearbox operates without an oil sump to minimize friction losses. During grid disconnection, the system automatically redirects lubrication liquid from the elevated reservoirs to create an oil sump in the gearbox, ensuring continuous reliable lubrication throughout transitions.

Inventive Principle:

Principle #15Dynamics

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 system ensures reliable lubrication of wind turbine drive trains during grid connection and disconnection, minimizing friction losses and maintaining performance by using gravity-driven oil flow and controlled valve operations, thus enhancing operational efficiency and reliability.

Implementation Method 1

the oil drains primarily by gravity from the first reservoir and/or the second reservoir to the respective component of the drive train

Methodology Applied

Scientific EffectGravity: Gravitation

Data Source

PatentUS11512681B2Lubrication system for a drive train of a wind turbine, wind turbine and method of lubricating

Publication Date: 2022.11.29 ADWEN

AI summary

Provided is a lubrication system for a drive train of a wind turbine including a main oil tank including a lubrication liquid, for lubricating the drive train when the wind turbine has connection to a grid and a main reservoir which is separate from the main oil tank and contains lubrication liquid for the drive train when the wind turbine has no connection to the grid. The main reservoir includes a first reservoir containing a first amount of lubrication liquid for at least a first component of the drive train and a second reservoir including a second amount of lubrication liquid for at least a second component of the drive train. The lubrication system is configured to supply the oil from the main reservoir to the drive train when the wind turbine has no grid connection for creating an oil sump in at least the second component of the drive train.