Wind Turbine Lifting Cable Bushing Aperture Design

Solution Overview

Problem

Current wind turbine assembly devices experience large stress concentrations in lifting cables due to the inability of bushings to rotate relative to the mounting block, leading to potential cable failure during tower section orientation changes from horizontal to vertical.

Innovation Solution

The design features bushings with a trumpet-shaped aperture wall that allows the lifting cable to move circumferentially, accommodating orientation changes without the need for bushing rotation, ensuring continuous operation even if bushings cannot rotate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If bushings are designed to rotate relative to the mounting block to accommodate orientation changes, then the lifting cable stress is reduced, but the device complexity increases and reliability decreases due to potential bushing seizure

Engineering Contradiction:

Improvelifting cable stress resistanceVSAvoidbushing rotation reliability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The invention extracts the rotation function from the bushing and transfers it to the lifting cable itself. The lifting cable is designed with a flexible section that can bend and rotate, allowing the cable to accommodate orientation changes independently of the bushing rotation mechanism. This eliminates the harmful effect of bushing seizure while maintaining the benefit of reduced cable stress.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical state of the lifting cable by introducing a flexible section with different mechanical properties. This flexible section allows the cable to bend and rotate, changing the cable's orientation parameters without requiring the bushing to rotate. This parameter change resolves the contradiction by providing rotation capability without the reliability issues of rotating bushings.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If bushings are made fixed relative to the mounting block to simplify the device, then manufacturing and maintenance are easier, but large stress concentrations develop in the lifting cable during orientation changes

Engineering Contradiction:

Improvemounting block manufacturing simplicityVSAvoidlifting cable stress resistance

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The invention extracts the rotation function from the bushing and transfers it to the lifting cable. The lifting cable is designed with a flexible section that can bend and rotate, allowing the cable to accommodate orientation changes independently of the bushing rotation mechanism. This eliminates the harmful effect of bushing seizure while maintaining the benefit of reduced cable stress.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical state of the lifting cable by introducing a flexible section with different mechanical properties. This flexible section allows the cable to bend and rotate, changing the cable's orientation parameters without requiring the bushing to rotate. This parameter change resolves the contradiction by providing rotation capability without the reliability issues of rotating bushings.

Inventive Principle:

Principle #35Parameter changes

3Strength

If bushings rotate relative to the mounting block to accommodate orientation changes, then cable stress is minimized, but the device complexity and maintenance difficulty increase

Engineering Contradiction:

Improvelifting cable stress resistanceVSAvoidbushing maintenance ease

Core Design Contradiction:

StrengthVSEase of repair

Solution Approach 1:

The invention extracts the rotation function from the bushing and transfers it to the lifting cable itself. The lifting cable is designed with a flexible section that can bend and rotate, allowing the cable to accommodate orientation changes independently of the bushing rotation mechanism. This eliminates the harmful effect of bushing seizure while maintaining the benefit of reduced cable stress.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the physical state of the lifting cable by introducing a flexible section with different mechanical properties. This flexible section allows the cable to bend and rotate, changing the cable's orientation parameters without requiring the bushing to rotate. This parameter change resolves the contradiction by providing rotation capability without the reliability issues of rotating bushings.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11098697B2Equipment for handling a wind turbine component and method of assembling such equipment and handling a wind turbine component using such equipment

Publication Date: 2021.08.24 VESTAS WIND SYSTEMS AS

AI summary

Equipment for handling a wind turbine component includes a lifting cable and a mounting block having a block main body with a cable passage and a pair of bushings coupled to the mounting block. Each bushing has an aperture defined by an aperture wall and the lifting cable extends through the aperture of each of the bushings. At least an outer region of the aperture wall forms a closed loop about the lifting cable and is substantially circumferentially continuous. This allows the lifting cable extending the bushings to move in a circumferential direction along the aperture wall relative to the bushings during use. A method of assembling such handling equipment and a method of using such equipment for handling a wind turbine component is also disclosed.