Wind Turbine Rotor Blade Adjustment via Pull-Belt Drive

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Solution Overview

Problem

Existing rotor blade adjustment systems in wind turbines face limitations in transmitting large actuating forces while maintaining a high belt lifetime, often requiring oversized toothed belts and complex designs that increase maintenance needs and tensile forces.

Innovation Solution

A traction drive system using an endless toothed belt with a pulley block design, where the belt wraps around pulley rollers and is guided by deflection rollers, allowing for double the tensile force transmission and reducing the belt width, eliminating the need for extensive pretension and additional tensioning rollers, and incorporating a slidable fabric layer for reduced friction and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a toothed belt drive is used for rotor blade adjustment, then the adjustment mechanism can transmit actuating forces, but the high tooth/tooth root load and tensile load require excessively wide toothed belts

Engineering Contradiction:
Improveactuating force transmissionVSAvoidbelt width
Core Design Contradiction:
ForceVSArea of moving object

Solution Approach 1:

The belt drive system is segmented into multiple parallel belts that work together to transmit the total actuating force. Each individual belt carries a portion of the total load, allowing the use of narrower belts while maintaining the required force transmission capability. This segmentation reduces the width requirement of each belt while achieving the same total force transmission.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Tensioning rollers are introduced to apply a counteracting force that balances the tensile load on the belts. The rollers provide a counterweight effect by distributing the tension forces and reducing the peak tensile loads that the belts must withstand, thereby allowing for narrower belt designs.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

2Reliability

If tensioning rollers are added to the belt drive system, then the belts can be tensioned, but the counter-bending of the toothed belts increases their load

Engineering Contradiction:
Improvebelt tensioningVSAvoidbelt load
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The design parameters of the tensioning rollers are optimized to minimize counter-bending effects. The rollers are positioned and dimensioned such that they apply tension while causing minimal bending moments on the belts. This parameter optimization allows effective tensioning while keeping the additional load on the belts within acceptable limits.

Inventive Principle:
Principle #35Parameter changes

3Power

If the power output of wind turbines is increased, then more energy can be generated, but the high tensile load on toothed belts requires excessively wide belts

Engineering Contradiction:
Improvepower outputVSAvoidbelt width
Core Design Contradiction:
PowerVSArea of moving object

Solution Approach 1:

The belt drive system is divided into multiple parallel belts that collectively transmit the high forces required for high-power wind turbines. Each belt carries a fraction of the total load, enabling the system to handle high power outputs without requiring excessively wide individual belts. This segmentation scales the force transmission capability with power output while maintaining reasonable belt dimensions.

Inventive Principle:
Principle #1Segmentation

4Ease of operation

If spur gear drives are used for rotor blade adjustment, then adjustment can be achieved, but a relatively high level of maintenance is required

Engineering Contradiction:
Improveadjustment functionalityVSAvoidmaintenance requirement
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

The spur gear drive system is replaced with a belt drive system that eliminates the complex meshing gears and their associated lubrication requirements. The belt drive uses flexible belts and pulleys, which have fewer moving parts, no tooth meshing to lubricate, and simpler maintenance needs, while still providing the required adjustment functionality for rotor blades.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This design effectively transmits high torques with reduced tensile forces, extending belt life and allowing for compact installation, while minimizing maintenance requirements and maintaining precise power control across varying wind speeds.

Implementation Method 1

a one-piece pull belt encircles at least one drive pulley connected to a drive motor and is in operative connection with the foot or shaft of the rotor blade in such a way that a torque required for adjusting the rotor blade can be transmitted from the drive motor to the shaft and thus to the rotor blade

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3324040B1Rotor blade adjustment
Publication Date: 2021.06.23 CONTITECH ANTRIEBSSYSTEME GMBH
  • EP3324040B1 patent drawingFigure 1
  • EP3324040B1 patent drawingFigure 2
  • EP3324040B1 patent drawingFigure 3

AI summary

Device for rotor blade adjustment on a wind turbine, in which the adjustment of a rotatably mounted rotor blade is effected via a pull-belt drive, wherein a one-piece pull-belt wraps around at least one drive pulley connected to a drive motor and is in operative connection with the base or shaft of the rotor blade in such a way that a torque required for adjusting the rotor blade can be transmitted from the drive motor to the shaft and thus to the rotor blade, wherein the pull-belt between the wrapping area on the drive pulley and its operative connection with the base or shaft of the rotor blade is guided in the form of a block and tackle over pulley rollers and is attached at both ends to a fixed part of the rotor blade bearing or rotor hub that is not rotatable with the rotor blade or the shaft.