Wind Turbine Slide Bearing Sealing for Lubricant Recirculation

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Solution Overview

Problem

Existing wind turbines face challenges with lubrication leakage and maintenance in slide bearings, particularly in large multi-Megawatt systems, due to the need for effective sealing and fluid collection in main bearings.

Innovation Solution

A main bearing design with a tilted rotation axis and dual sealing means, where the outer ring rotates and the inner ring is stationary, incorporates a leakage collection system using axial bores and a collector ring to recirculate lubrication fluid, ensuring continuous lubrication and minimizing leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a slide bearing is used with liquid lubrication, then lubrication effectiveness is improved, but leakage occurs and requires complex sealing and collection systems

Engineering Contradiction:
Improvelubrication effectivenessVSAvoidlubrication fluid leakage
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent converts the harmful leakage into a beneficial recirculation system. The leakage collection means captures lubrication fluid that escapes through the sealing means, and the return channel guides it back to the lubrication circuit, transforming waste fluid into reusable lubrication medium, thus eliminating the negative effect of leakage while maintaining the benefits of liquid lubrication

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

Solution Approach 2:

The return channel acts as an intermediary element between the leakage collection means and the lubrication circuit. This intermediary structure provides a controlled pathway for fluid return, mediating between the bearing clearance where leakage occurs and the lubrication system that needs replenishment, thereby resolving the contradiction between effective lubrication and fluid loss

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If dual sealing means are added to reduce leakage, then sealing effectiveness is improved, but device complexity increases

Engineering Contradiction:
Improvelubrication fluid leakageVSAvoidsealing system complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The leakage collection means serves multiple functions simultaneously: it acts as a sealing support structure, a fluid collection reservoir, and a guide for the return channel. By combining these functions into a single integrated component rather than separate elements, the design achieves effective leakage prevention without proportionally increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The return channel is nested within or integrated with the leakage collection means structure. The channel is positioned to utilize the space created by the collection means, allowing the fluid return pathway to be housed within the existing sealing architecture rather than requiring additional external structures, thus minimizing complexity increase

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the outer ring rotates and inner ring is stationary, then bearing function is maintained, but leakage collection becomes more difficult due to rotation

Engineering Contradiction:
Improvebearing functionVSAvoidleakage collection
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The bearing system is segmented into distinct functional zones: the rotating outer ring with sealing means, the stationary leakage collection means, and the return channel connecting them. This segmentation allows the collection means to remain stationary and simple while the sealing elements handle the rotation, making leakage collection easier without compromising bearing function

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The return channel serves as a mediator that bridges the rotating and stationary parts. It is designed to rotate with the outer ring at its inlet end while connecting to the stationary collection means at its outlet end, thus mediating between the rotating bearing components and the stationary collection system, enabling effective leakage collection despite rotation

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design effectively collects and recirculates lubrication fluid, maintaining consistent lubrication, reducing maintenance needs, and preventing fluid loss, while providing corrosion protection and efficient lubrication distribution.

Implementation Method 1

the main bearing being lubricated with a lubrication fluid

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

the first sealing means is due to the tilt of the main bearing lower than the second sealing means

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP4118320B1Wind turbine
Publication Date: 2025.07.23 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP4118320B1 patent drawingFigure 1
  • EP4118320B1 patent drawingFigure 2
  • EP4118320B1 patent drawingFigure 3

AI summary

Wind turbine comprising a nacelle (3) with at least one main bearing (11) tilted with its rotation axis (18) towards the horizontal axis (19) and comprising an inner ring (14) and an outer ring (13), whereby the main bearing (11) is a slide bearing (12) and the inner ring (14) is stationary while the outer ring (13) rotates around the inner ring (14), with the main bearing (11) being lubricated with a lubrication fluid (22), and with the outer ring (13) comprising a first and a second sealing means (25, 26) arranged at both sides of the outer ring (13) for sealing to the inner ring (14) and extending around the outer ring (13), whereby the first sealing means (25) is due to the tilt of the main bearing (11) lower than the second sealing means (26), whereby a stationary leakage lubrication fluid collection means (39) is provided adjacent to the first sealing means (25) adapted for collecting lubrication fluid leaking from the first and the second sealing means (25, 26), whereby the outer ring (13) is provided with one or more axial bores (42) connecting a leakage lubrication fluid collection area (37) adjacent to the second sealing means (26) to the leakage lubrication fluid collection means (39) and wherein each sealing means (25, 26) comprises a groove (35, 36) accommodating a sealing element (27, 28) and a sealing element carrier ring (29, 30) having a fold (31, 32) and a clamp ring (33, 34) attached to the carrier ring (29, 30) closing the fold (31, 32) to build the groove (35, 36) and clamping the sealing means (27, 28) in the groove (35, 36).