Wind Turbine Drive Train With Bottom-Mounted Generator

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Solution Overview

Problem

Current wind turbine designs face high construction and maintenance costs due to the large and heavy generators being placed at the top of tall towers, making access and maintenance difficult and expensive, especially for offshore installations, and indirect drive turbines have reliability issues with gear sets located at the top of the tower.

Innovation Solution

A device using eccentric mechanisms, cam-follower mechanisms, and swashplate mechanisms to transmit rotational energy from the turbine rotor at the top of the tower to a generator located at the bottom, eliminating the need for a gearbox at the top and allowing for easier maintenance by relocating the generator closer to the ground, utilizing tensile links and yaw mechanisms for efficient energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the generator is placed at the top of the tower close to the rotor, then the rotational energy can be directly transmitted to the generator, but the construction cost increases due to the need for large and expensive cranes to lift the heavy generator

Engineering Contradiction:

Improveelectrical energy productionVSAvoidconstruction cost

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional wind turbine configuration by placing the generator at the bottom of the tower instead of at the top. This inversion allows the heavy generator to remain on the ground where it can be easily serviced and where smaller, less expensive equipment is needed for installation and maintenance, while still capturing the rotational energy from the rotor at the top through the drive train mechanism.

Inventive Principle:

Principle #13The other way round (Inversion)

2Power

If the generator is placed at the top of the tower, then the rotational energy transmission is direct, but the maintenance cost and difficulty increase due to limited access and dangerous working conditions

Engineering Contradiction:

Improveelectrical energy productionVSAvoidmaintenance cost

Core Design Contradiction:

PowerVSEase of repair

Solution Approach 1:

By inverting the generator location from the top to the bottom of the tower, the patent places the heavy maintenance equipment and personnel on the ground where access is easy and conditions are safe, rather than requiring workers to service equipment at heights of hundreds of feet where special safety equipment and procedures are needed.

Inventive Principle:

Principle #13The other way round (Inversion)

3Speed

If indirect drive turbines use gear sets at the top of the tower, then the rotational speed can be increased for the generator, but the reliability decreases due to the gear sets being inaccessible and difficult to service

Engineering Contradiction:

Improverotational speedVSAvoidgear set reliability

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The patent inverts the location of the gear set from the top of the tower to the bottom, where it can be easily accessed for maintenance and replacement. This improves reliability by allowing prompt servicing of the gear set, which is critical for maintaining the rotational speed increase needed for generator operation.

Inventive Principle:

Principle #13The other way round (Inversion)

4Power

If direct drive wind turbines use additional poles in the generator, then the generator can produce sufficient electrical energy at low rotor speed, but the weight and cost of the generator substantially increase

Engineering Contradiction:

Improveelectrical energy productionVSAvoidgenerator weight

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

The patent replaces the direct-drive generator design with additional poles with an indirect drive system using a drive train that includes a gear set or belt drive. This mechanical substitution allows the use of a smaller, lighter generator with fewer poles, as the gear set or belt drive provides the necessary rotational speed increase, thereby reducing generator weight while maintaining electrical energy production capability.

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

Reduces overall weight and maintenance costs by moving the generator closer to the ground, simplifying maintenance, and allowing for flexible gear ratios without the need for a gearbox at the top of the tower, enhancing reliability and reducing weight, particularly beneficial for offshore installations.

Implementation Method 1

The wind turbine has a first eccentric mechanism connected to a turbine rotor... a cam-follower mechanism has a cam shaft with at least one cam profile, having a plurality of cam lobes driven by the turbine rotor

Methodology Applied

Scientific EffectCam mechanism: Cam

Implementation Method 2

a plurality of tensile links connecting the first and second eccentric mechanisms

Methodology Applied

Scientific EffectMechanical force transmission: Mechanical Force

Implementation Method 3

a second eccentric mechanism connected to an electric generator... the second eccentric mechanism is a swashplate mechanism

Methodology Applied

Scientific EffectSwashplate mechanism: Swashplate

Data Source

PatentUS11306703B2Wind turbine drive train

Publication Date: 2022.04.19 TOLLI WILLIAM

AI summary

A wind turbine having a tower having a top end and a bottom end; a first eccentric mechanism connected to a turbine rotor, the turbine rotor at the top end of the tower; a second eccentric mechanism connected to an electric generator, the electric generator being at the bottom end of the tower; and a plurality of tensile links connecting the first and second eccentric mechanisms.