Lubrication Filter Bypass Control for Wind Turbine Gearboxes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems for supplying lubricants to wind turbine gearboxes face issues with unacceptably high pressure build-up and contamination, leading to potential system inefficiencies and the need for larger, less compact filter designs.

Innovation Solution

A system with a main filter stage integrated between the conveying device and consumer, controlled by a valve device that bypasses fluid to a storage tank based on differential pressure, using sensors and valves to manage fluid flow and prevent excessive pressure, incorporating a heat exchanger and pre-filter to protect components from contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a main filter stage is integrated between the conveying device and consumer in the main flow, then filtration effectiveness is improved, but differential pressure builds up excessively

Engineering Contradiction:
Improvefiltration effectivenessVSAvoiddifferential pressure
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The filter device is divided into multiple filter stages (pre-filter stage and main filter stage) arranged in series. The pre-filter stage handles coarse filtration with lower differential pressure, while the main filter stage provides fine filtration. This segmentation allows the main filter to operate at acceptable pressure differentials by pre-cleaning the fluid upstream.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A bypass line with a bypass valve is introduced as an intermediary path between the conveying device and the main filter stage. When differential pressure across the main filter exceeds a threshold, the bypass valve opens to divert fluid through the bypass line, relieving pressure on the main filter while maintaining system operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If a bypass line is introduced to relieve differential pressure, then pressure control is improved, but system complexity increases

Engineering Contradiction:
Improvedifferential pressure controlVSAvoidsystem complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The bypass valve is designed to automatically respond to differential pressure conditions without external control. When pressure differential across the main filter stage exceeds a preset threshold, the bypass valve self-activates to open the bypass path, and closes automatically when pressure normalizes, eliminating the need for complex external control systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The bypass valve incorporates a feedback mechanism where the differential pressure across the main filter stage directly influences valve operation. The valve senses the pressure differential and adjusts its opening accordingly, creating a self-regulating system that maintains pressure within acceptable ranges while simplifying overall control architecture.

Inventive Principle:
Principle #23Feedback

3Temperature

If cooling volume flow is diverted through bypass into storage tank, then cooling efficiency is improved, but filter loading is reduced

Engineering Contradiction:
Improvecooling efficiencyVSAvoidfilter loading
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The system dynamically adjusts flow distribution between the main filter path and bypass line based on operating conditions. During high-temperature operation, more flow is directed through the bypass for cooling, while during normal operation, flow is directed through the main filter for lubrication and filtration, optimizing both cooling and filtration functions as needed.

Inventive Principle:
Principle #15Dynamics

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 prevents high differential pressures, allows for compact filter designs, and ensures efficient lubrication by managing fluid flow and temperature, reducing particle ingress and pressure spikes, thereby enhancing system efficiency and reliability.

Implementation Method 1

a heat exchange device for heat transfer between the lubrication circuit of the gearbox and the lubrication circuit of the bearing

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

a main filter stage of the filter device is integrated between the conveying device and the respective consumer in the main flow of a fluid guide

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP4707552A1System for supplying fluid
Publication Date: 2026.03.11 HYDAC FILTERTECHNIK GMBH
  • EP4707552A1 patent drawingFigure 1
  • EP4707552A1 patent drawingFigure 2~3
  • EP4707552A1 patent drawing

AI summary

2. System for supplying fluid to at least one consumer (V), in particular for supplying lubricant to consumers (V), such as bearings in gearboxes of wind turbines including plain bearings, comprising at least a conveying device (14), a filter device (16), and a heat exchanger (18), which are connected to each other via fluid-carrying lines (20, 22) and can be permeated with fluid along a flow direction within a fluid guide (24), characterized in that a main filter stage (42) of the filter device (16) is connected between the conveying device (14) and the respective consumer (V) in the main flow (40) of a fluid guide (24), that at least one valve device (46) is provided for controlling a secondary flow (44) of the fluid guide (24), and that the respective valve device (46) is actuated with increasing differential pressure with respect to the main filter stage (42).a predefinable subset of the fluid is removed from the fluid guide (24) to the consumer (V).