Planetary Gear Labyrinth Seal for Grease Retention
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Solution Overview
Problem
Existing transmission systems face challenges in effectively lubricating the tooth engagement area without using excessive lubricating grease, which can impede heat dissipation and lead to grease sagging due to poor conductivity and transport away from the engagement zone.
Innovation Solution
A planetary gear stage equipped with a labyrinth seal that non-rotatably connects a labyrinth disk to the planet carrier, ensuring lubricating grease is retained within the tooth engagement area, utilizing a conveying slope to efficiently direct grease to the engagement zone while preventing escape, thus minimizing grease usage and maintaining heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lubricating grease is used to lubricate the tooth engagement area, then lubrication effectiveness is improved, but heat dissipation deteriorates due to poor thermal conductivity of grease
Solution Approach 1:
The patent applies local quality by providing grease only in the specific engagement area between teeth through the labyrinth seal structure, rather than filling the entire gearbox. The seal creates a localized grease reservoir at the tooth flanks where lubrication is needed, while other areas remain grease-free for better heat dissipation.
2Reliability
If a large amount of lubricating grease is used to ensure continuous lubrication, then lubrication reliability is improved, but heat dissipation deteriorates and grease sagging occurs
Solution Approach 1:
The labyrinth seal structure creates a localized grease retention zone specifically at the tooth engagement area. This ensures continuous lubrication where needed while avoiding excessive grease in other areas, preventing both heat dissipation issues and grease sagging.
Solution Approach 2:
The patent segments the gearbox internal space using the labyrinth seal, creating a distinct grease-containing zone separated from the rest of the gearbox volume. This segmentation allows grease to be confined to where it is functionally necessary.
3Reliability
If grease is retained in the engagement area to improve lubrication, then lubrication effectiveness is improved, but grease may sag and be carried away from the engagement zone
Solution Approach 1:
The labyrinth seal structure provides localized grease retention with a specific geometry designed to hold grease in the engagement area. The seal's structure creates a physical barrier that prevents grease from sagging away while maintaining it where lubrication is needed.
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 enables economical lubrication of the engagement area, preventing grease sagging and ensuring continuous lubrication while maintaining efficient heat dissipation by using minimal lubricant, as the labyrinth seal effectively confines the grease within the tooth meshing area.
Implementation Method 1
The labyrinth disc 4 has a conveying ramp 5 designed such that its axial distance to the planet 11 decreases with increasing radial distance... When the driving shaft 6 rotates, lubricating grease that has penetrated the labyrinth disc 4 is conveyed, and in particular flung, into the engagement area 3
Implementation Method 2
The labyrinth gap is so narrow that even when the gearbox is at rest, any lubricating grease present cannot pass through the labyrinth seal
Data Source
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AI summary
The invention relates to a transmission having a planetary gear stage which comprises a housing part and a rotationally mounted part. Said planetary gear stage comprises a labyrinth seal which comprises a labyrinth disk and a labyrinth stator part interacting with the labyrinth seal, in particular for forming a seal. The labyrinth disk is rotationally connected to the part and the labyrinth stator part is connected to the housing part.