Double-Walled Planetary Gear Lubrication for Leakage Control
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Solution Overview
Problem
Existing planetary gearings in wind turbines face challenges with lubricant efficiency and leakage, leading to reduced performance and increased maintenance needs, particularly in high-load operational conditions.
Innovation Solution
A double-walled pipe system with a bushing configuration that minimizes lubricant leakage by creating a small gap between the outer pipe and the bushing, allowing for efficient lubricant throughput and distribution to gearing components, while preventing direct contact and wear, and incorporating a guide bearing to manage radial displacement and maintain alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional single-walled pipe is used for lubricant supply, then the structure is simple, but lubricant leakage increases and lubrication efficiency decreases
Solution Approach 1:
The pipe is divided into two concentric walls forming a double-walled structure with an annular channel between them. This segmentation allows the lubricant to be supplied through a controlled pathway while preventing direct leakage, as the annular channel acts as a containment barrier between the lubricant supply line and the external environment.
Solution Approach 2:
The inner pipe is nested within the outer pipe, creating a concentric double-walled structure. The annular channel between the nested pipes provides a controlled pathway for lubricant flow, enabling the system to maintain reliable lubricant supply while minimizing leakage through the hierarchical nesting arrangement.
2Loss of substance
If the bushing outer diameter is increased to reduce leakage, then lubricant loss decreases, but material cost increases and manufacturing complexity increases
Solution Approach 1:
Instead of increasing the overall bushing dimensions, the patent applies a selective coating (such as PTFE/Teflon) to specific local areas of the bushing surface that contact the lubricant or experience wear. This localized treatment provides effective leakage prevention and wear resistance while minimizing material usage and manufacturing cost, as only critical zones are treated rather than the entire component.
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 configuration enhances lubricant efficiency, reduces maintenance requirements, and allows for increased operational loads by minimizing lubricant loss and wear, thereby improving the performance and reliability of planetary gearings.
Implementation Method 1
The inner pipe and the outer pipe form an annular channel for passage of a lubricant
Implementation Method 2
the bushing and the double-walled pipe can be arranged to define a gap in fluid communication with the outlet point to allow leakage of lubricant. During operation, lubricant enters the gap so that there is no direct contact between the outer pipe of the double-walled pipe and the bushing
Implementation Method 3
The gap has a minimized gap height, i.e. radial dimension. The gap height can be 0.1 mm to 0.5 mm, in particular 0.25 mm to 0.35 mm. Herein, the gap height is the gap height obtained during operation as intended of the planetary gearing taking into account the thermal expansion of the bushing. The minimized gap height reduces lubricant loss at the gap.
Implementation Method 4
The gap height is the gap height obtained during operation as intended of the planetary gearing taking into account the thermal expansion of the bushing
Data Source
AI summary
A planetary gearing includes at least a first planetary stage and a second planetary stage and a double-walled pipe. The double-walled pipe has an inner pipe and an outer pipe and is provided with an outlet point in a central section. A bushing is arranged on the outlet point.