Wind Turbine Generator Rotor Axial Seal for Controlled Lubricant Leakage

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Solution Overview

Problem

Existing single-lip rubber seals in wind turbines fail to effectively seal against high axial and radial loads, leading to significant lubricant leakage, especially in large, grease-lubricated applications, necessitating frequent maintenance and power loss.

Innovation Solution

A sealing arrangement featuring an axial seal with multiple lips, including a first lip that allows controlled leakage for lubrication and a second lip that minimizes further leakage, utilizing elastomeric materials and optional spring members for compensation, along with a channel for lubricant flow between chambers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard single-lip rubber seals are used in large size grease lubricated applications, then the seal structure is simple and easy to manufacture, but the seal cannot maintain integrity under high axial and radial loads, leading to significant lubricant leakage

Engineering Contradiction:
Improveseal integrity under loadVSAvoidseal structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The seal is divided into multiple lips (first lip, second lip, and optionally third lip) arranged in series, where each lip segment handles a portion of the sealing task. This segmentation allows the seal to better distribute and withstand high axial and radial loads while maintaining integrity, directly resolving the contradiction between reliability under load and structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single-lip radial seal to a multi-lip axial seal configuration. The lips are arranged axially rather than radially, creating a new dimensional approach to sealing that effectively handles high loads while maintaining structural feasibility.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the sealing lip is lubricated to allow sliding on the rotating surface, then the seal can operate smoothly, but lubricant leakage increases

Engineering Contradiction:
Improveseal sliding operationVSAvoidlubricant leakage
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The invention converts the harmful effect of lubricant leakage into a beneficial lubrication mechanism. The first lip is designed to allow controlled leakage that provides necessary lubrication to the seal lips, while subsequent lips capture and contain this leaked lubricant, preventing it from escaping to the air chamber. This transforms the harmful leakage into a useful lubrication source.

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

Solution Approach 2:

The multi-lip structure acts as an intermediary system between the lubricant chamber and air chamber. The lips create intermediate zones that control lubricant flow, allowing necessary lubrication while preventing excessive leakage, thus mediating between the need for lubrication and the need to contain lubricant.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If more lubricant is provided to ensure proper bearing lubrication and establish a thin lubricant film layer, then the bearing operation is improved, but the volume of lubricant in closed chambers increases, requiring larger and more complex sealing

Engineering Contradiction:
Improvebearing lubrication qualityVSAvoidlubricant chamber volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The multi-lip seal creates flexible sealing zones that can accommodate the lubricant film layer without requiring excessive chamber volume. The lips form thin film sealing zones that efficiently contain the necessary lubricant volume while allowing proper bearing lubrication, resolving the contradiction between lubrication quality and chamber volume.

Inventive Principle:
Principle #30Flexible shells and thin films

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 significantly reduces lubricant leakage, maintains seal integrity under load conditions, and ensures efficient lubrication of the seal components, reducing maintenance needs and power loss.

Implementation Method 1

The first lip (5) is configured to allow a leakage of lubricant at the contact between the first lip (5) and the generator rotor (13)

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

The seal (10) comprises a first lip (5) configured to contact the generator rotor (13)... utilizing elastomeric materials and optional spring members for compensation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

utilizing elastomeric materials and optional spring members for compensation

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP4379209B1Axial seal for a generator rotor of a wind turbine
Publication Date: 2025.12.31 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP4379209B1 patent drawingFigure 1
  • EP4379209B1 patent drawingFigure 2~3
  • EP4379209B1 patent drawingFigure 4~5

AI summary

The present invention relates to a sealing arrangement of a wind turbine comprising an axial seal (10), a stationary member (16) and a generator rotor (13) for sealing a gap between the stationary member (16) and the generator rotor (13). According to the invention, the stationary member (16) is arranged between a lubricant chamber (12) and an air chamber (11) and the generator rotor (13) is configured to rotate about a rotational axis (15), wherein the seal (10) is arranged at an end of the stationary member (16). The seal (10) comprises a first lip (5) configured to contact the generator rotor (13) and the first lip (5) is configured to allow a leakage of lubricant at the contact between the first lip (5) and the generator rotor (13). The seal (10) further comprises a second lip (6) arranged radially outwards with respect of the first lip (5) and the rotational axis (15).