Wind Turbine Hub Fluid Film Bearing With Backside Tilting Pads

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Solution Overview

Problem

Conventional roller or ball bearings used in wind turbines are costly and difficult to service due to their complex design and the need for precise alignment, which increases maintenance complexity and weight.

Innovation Solution

A fluid film bearing with pads mounted to a support structure on the backside, allowing for tilting and easy access, formed as one piece to reduce complexity and cost, and using a lubricant like oil for hydrodynamic or hydrostatic support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If roller or ball bearings are used for the hub, then radial support and rotation are provided, but the bearing requires high precision production (increasing cost) and is difficult to service

Engineering Contradiction:
Improveradial support capabilityVSAvoidserviceability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The bearing is divided into two separable parts: a stationary support structure with pads and a rotating first part with sliding surface. This segmentation allows the stationary part to remain in place while the rotating part can be independently serviced, improving serviceability while maintaining radial support capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of mounting pads between the two rings as in conventional bearings, the pads are mounted on the backside of the stationary support structure. This inversion allows access to pads from the exterior of the bearing assembly, making maintenance and replacement significantly easier without requiring disassembly of the entire bearing.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If pads are mounted between the two rings to provide radial support, then the bearing functions correctly, but access to pads is difficult requiring dedicated crawl space

Engineering Contradiction:
Improveradial support functionVSAvoidaccess structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pads are mounted on the backside of the stationary support structure rather than between the rings. This inversion allows maintenance personnel to access and service the pads from the exterior of the bearing assembly, eliminating the need for complex crawl spaces or disassembly procedures.

Inventive Principle:
Principle #13The other way round (Inversion)

3Adaptability or versatility

If pads are designed with pivot joints to allow tilting, then misalignments and tolerances are compensated, but the pad complexity and cost increase

Engineering Contradiction:
Improvetilting capabilityVSAvoidpad structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting section is designed with controlled flexibility to allow the contact section to tilt dynamically in response to misalignments and load variations. This dynamic adaptation compensates for tolerances and misalignments without requiring complex pivot joints, maintaining simplicity while achieving the necessary adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connecting section's geometric parameters (length, cross-section, material properties) are optimized to provide the appropriate degree of flexibility. By carefully selecting these parameters, the pad achieves the necessary tilting capability to compensate for misalignments while maintaining structural integrity and avoiding excessive complexity.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If the connecting section is made long to allow tilting, then pad adaptability improves, but the risk of damaging the connection section increases

Engineering Contradiction:
Improvetilting rangeVSAvoidconnecting section durability
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The connecting section's geometric parameters (length, cross-sectional area, wall thickness, material properties) are carefully optimized to achieve the desired balance between flexibility and strength. The section is designed with controlled flexibility to allow necessary tilting while maintaining sufficient strength to prevent damage under operational loads.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The pad assembly uses different materials for different sections: the mounting and contact sections use rigid materials for structural integrity, while the connecting section uses a more flexible material or optimized geometry to allow tilting. This composite approach enables the long connecting section to provide adequate tilting range without compromising strength and durability.

Inventive Principle:
Principle #40Composite materials

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 simplifies maintenance, reduces weight and cost, and allows for efficient rotation support with minimal additional mechanisms, enhancing serviceability and reducing the complexity of pad replacement.

Implementation Method 1

The bearing is a fluid film bearing, wherein a lubricant is present between the first annular sliding surface and the pad sliding surfaces

Methodology Applied
Scientific EffectHydrodynamic lubrication: Lubrication

Implementation Method 2

using a lubricant like oil for hydrodynamic or hydrostatic support

Methodology Applied
Scientific EffectHydrostatic support: Lubrication

Data Source

PatentEP3904677B1Fluid film bearing and wind turbine
Publication Date: 2023.09.06 SIEMENS GAMESA RENEWABLE ENERGY AS
  • EP3904677B1 patent drawingFigure 1
  • EP3904677B1 patent drawingFigure 2~3
  • EP3904677B1 patent drawingFigure 4~5

AI summary

Fluid film bearing, especially for a rotor hub (3) in a wind turbine (1), comprising a first and second part (6, 7) rotatably connected to each other, wherein the first part (7) forms an first annular sliding surface (14, 16, 17, 32, 33) that extends in the circumferential direction of the bearing (2) along the first part (7), wherein the second part (6) comprises a support structure (11) and first pads (8, 9, 20, 22, 28, 29) distributed along the circumference of the support structure (11), wherein a respective pad sliding surface (10, 18, 19, 30, 31) of each of the first pads (8, 9, 20, 22, 28, 29) or of a first subgroup of the first pads (8, 9, 20, 22, 28, 29) supports the first annular sliding surface (14, 16, 17, 32, 33), wherein each first pad (8, 9, 20, 22, 28, 29) comprises a mounting section (13) that is mounted to a backside (42) of the support structure (11) that is facing away from the first part (7), a contact section (34) that is either forming the respective pad sliding surface (10, 18, 19, 30, 31) or carrying a coating (36) that forms the respective pad sliding surface (10, 30, 31) and a connecting section (35) that connects the contact section (34) with the mounting section (13) and that preferably allows for a tilting of the contact section (34) with respect to the mounting section (13), wherein the mounting section (13), the connecting section (35) and the contact section (34) are formed as one piece.