Wind Turbine Slip Ring Cooling Projections

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Solution Overview

Problem

Compact wind power generator slip ring arrangements experience increased current loads and temperature issues due to reduced air volume and poor convection, leading to potential damage from overheating, while larger designs incur higher material costs and dimensions.

Innovation Solution

The implementation of projections on the rotary body's lateral surface to generate a cooling air flow, which directly cools the slip rings and brush holders, allowing for efficient ambient air utilization and reduced temperatures, enabling smaller, cost-effective designs with higher output capabilities without external ventilation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the slip ring arrangement is made compact to reduce material costs and generator size, then the generator becomes more cost-effective and smaller, but the temperature of the slip ring components rises significantly due to increased current loads and poor convection

Engineering Contradiction:
Improvegenerator sizeVSAvoidslip ring component temperature
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The rotary body is segmented with multiple projections (ridges) that divide the cooling air flow into multiple paths, directing cool air to different areas of the slip rings simultaneously. This segmentation allows effective cooling of multiple slip ring components without increasing the overall size of the slip ring arrangement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Projections are strategically positioned at specific locations on the rotary body to create localized cooling zones. The projections generate eddy currents that direct cooling air precisely to the slip ring areas that require it most, providing targeted cooling where needed rather than uniform cooling throughout the entire assembly.

Inventive Principle:
Principle #3Local quality

2Temperature

If the slip ring surface is enlarged to handle higher current loads, then the temperature of the slip ring body is reduced, but the external dimensions and material costs of the generator increase significantly

Engineering Contradiction:
Improveslip ring body temperatureVSAvoidslip ring outside diameter
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

The invention uses pneumatic cooling by introducing cool ambient air into the slip ring arrangement and utilizing the projections to generate eddy currents that distribute this air flow. The pneumatic cooling system effectively removes heat from the slip ring body without requiring an increase in the slip ring surface area or outside diameter.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The projections on the rotary body automatically generate eddy currents that draw in and distribute cooling air without requiring external fans or complex mechanical cooling systems. The rotating motion of the slip rings themselves creates the cooling air flow, making the system self-cooling and eliminating the need for additional cooling components.

Inventive Principle:
Principle #25Self-service

3Temperature

If external ventilation is added to generate cooling air flow, then the temperature of the slip ring arrangement is reduced, but the device complexity and additional components increase

Engineering Contradiction:
Improveslip ring arrangement temperatureVSAvoidcooling system complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The projections on the rotary body automatically generate eddy currents that draw in and distribute cooling air without requiring external fans or complex mechanical cooling systems. The rotating motion of the slip rings themselves creates the cooling air flow, making the system self-cooling and eliminating the need for additional cooling components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention extracts the cooling function from separate external ventilation systems and integrates it directly into the rotary body structure through the projections. This integration eliminates the need for external fans, ducts, and control systems, simplifying the overall device while maintaining effective cooling.

Inventive Principle:
Principle #2Taking out (Extraction)

4Power

If the slip ring arrangement operates at higher output levels, then the power generation capability is improved, but the temperature of the components rises to or above critical values causing damage

Engineering Contradiction:
Improveoutput powerVSAvoidcomponent reliability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The pneumatic cooling system effectively removes heat from the slip ring body without requiring an increase in the slip ring surface area or outside diameter.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

Instead of increasing the radial size of the slip rings to handle higher power, the invention introduces cooling in the axial dimension by directing cool air through the projections onto the slip ring surfaces. This allows higher power operation without increasing the critical radial dimensions of the slip ring components.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution effectively reduces slip ring temperatures, enables smaller component sizes, and allows for higher output levels without additional components or costs, ensuring reliable operation and compatibility with existing systems.

Implementation Method 1

the at least one rotary body has projections protruding from the lateral surface for generating a cooling air flow... Thanks to the projections, the directly stressed components of the slip ring arrangement, such as the at least two slip rings, can be cooled, in particular by utilizing the ambient air

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

compact slip ring units have a smaller air volume and poorer free convection inside the slip ring

Methodology Applied
Scientific EffectFree convection: Free Convection

Data Source

PatentEP2961009B1Wind power generator with a slip ring assembly
Publication Date: 2017.09.27 SIEMENS AG
  • EP2961009B1 patent drawingFigure 1~2
  • EP2961009B1 patent drawingFigure 3~4
  • EP2961009B1 patent drawingFigure 5~6

AI summary

The invention relates to a slip ring arrangement, in particular for a wind turbine generator, comprising at least one rotating body (1) rotatably mounted about an axis of rotation (2), and at least two slip rings (3), each arranged on a lateral surface (4) of the at least one rotating body (1). The invention further relates to an electrical machine, in particular a generator or a wind turbine generator, with such a slip ring arrangement. To improve the cooling of slip ring arrangements, it is proposed that the at least one rotating body (1) has projections (5) extending from the lateral surface (4) to generate a cooling airflow.