Planetary Gear Lubricant Transfer Between Stages With Low Leakage

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Solution Overview

Problem

Existing planetary gears face challenges in reliable and low-loss lubricant transport, requiring complex designs and additional features like lubricant channels and external feeds, which complicate manufacturing and increase costs.

Innovation Solution

A planetary gear design featuring a lubricant transfer device between two stages, eliminating the need for external lubricant feeds and channels by using a delivery and receiving component that rotate with the stages, allowing for compact and low-leakage lubricant transfer, and a lubricant channel that extends radially through the sun gear's tooth engagement area for efficient lubrication across multiple stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lubricant channel is formed between a sliding bushing and a flange of a planetary carrier, then lubricant can be supplied to the planetary stage, but the housing wall requires additional bores and the design becomes more complex

Engineering Contradiction:
Improvelubricant supply reliabilityVSAvoidhousing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lubricant transfer device merges the delivery component and receiving component into a single integrated mechanism that transfers lubricant between planetary stages without requiring separate housing bores. The output component of the delivery device and input component of the receiving device are designed to complement each other, creating a unified lubricant transfer path that eliminates the need for additional housing wall penetrations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The lubricant transfer device acts as an intermediary mechanism between the first and second planetary stages. The delivery component with output component and receiving component with input component serve as intermediate elements that bridge the lubricant supply between stages, eliminating the need for direct housing wall bores and complex external lubricant channels.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If external lubricant feeds and additional lubricant channels are added to ensure reliable lubrication, then lubrication reliability improves, but manufacturing complexity and costs increase

Engineering Contradiction:
Improvelubrication reliabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The lubricant transfer device enables the planetary gear system to serve itself by transferring lubricant from the second planetary stage back to the first planetary stage. The delivery component and receiving component work together to create a self-contained lubricant circulation system that eliminates the need for external lubricant feeds and complex manufacturing procedures.

Inventive Principle:
Principle #25Self-service

3Productivity

If a lubricant transfer device with rotating components is used to transfer lubricant between stages, then lubrication efficiency improves, but leakage losses may increase

Engineering Contradiction:
Improvelubrication efficiencyVSAvoidlubricant leakage loss
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The delivery component and receiving component are designed with complementary local geometries that create precise mating surfaces. The output component of the delivery device and input component of the receiving device have specifically shaped features that work together to minimize clearance and prevent lubricant leakage while maintaining efficient lubricant transfer to the rotating components of the first planetary stage.

Inventive Principle:
Principle #3Local quality

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 simplifies manufacturing, reduces leakage losses, and allows for cost-effective, reliable lubrication of all planet gears, enabling a more compact and weight-efficient gear with increased mass-specific power density and design flexibility.

Implementation Method 1

The output component is arranged so as to rotate with a component of the second planetary stage... The output component and the receiving component are designed to complement one another... allows a low-leakage transfer of lubricant from the second to the first planetary stage

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

a lubricant channel that extends radially through the sun gear's tooth engagement area for efficient lubrication across multiple stages

Methodology Applied
Scientific EffectFluid flow through channels:

Data Source

PatentEP4200543B1Planetary transmission with improved lubricant transfer, drive train, wind turbine and industrial installation
Publication Date: 2024.05.08 FLENDER GMBH
  • EP4200543B1 patent drawingFigure 1
  • EP4200543B1 patent drawingFigure 2~3

AI summary

A planetary gearbox (10) is provided, comprising: - a lubricant transfer device (50) between a first and a second planetary stage (20, 30), the lubricant transfer device (50) comprising a discharging component (52), which is disposed on a component (13) of the second planetary stage (30) for conjoint rotation, and the lubricant transfer device comprising a receiving component (54) for lubricant (55), which receiving component is disposed on a component (13) of the first planetary stage (20) for conjoint rotation; and - a lubricant channel (58), which communicates with the lubricant transfer device (50); wherein the lubricant channel (58) runs over the entire axial extent of a tooth engagement region (56) of a sun gear (21) of the first planetary stage (21), radially within a set of teeth (29) of the sun gear (21), with at least one planet gear (26) of the first planetary stage (21). Economical and improved lubricant supply is thereby achieved.