Gearbox Oil Return Channels for Non-Contacting Isolator Leakage
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Solution Overview
Problem
Existing gearboxes using non-contacting bearing isolators experience oil leakage, particularly in horizontal orientations, leading to environmental contamination and lubricant waste, with existing solutions like radial lip seals and external tubing systems being inefficient or impractical.
Innovation Solution
A gearbox design incorporating a carrier with an oil collection well and return channel, combined with an isolator plate featuring an oil passage and projection, redirects leaked oil back into the main housing, minimizing leakage through shaft penetrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-contacting bearing isolators are used to prevent oil leakage through shaft penetrations, then wear is eliminated and seal longevity is improved, but oil leakage still occurs especially in horizontal orientations
Solution Approach 1:
The patent converts the harmful effect of oil leakage into a beneficial system by providing oil collection wells and return channels that capture leaked oil and redirect it back to the main reservoir. This transforms the leakage problem into a controlled oil management system that prevents environmental contamination while maintaining lubrication.
Solution Approach 2:
The patent introduces intermediary components (oil collection wells, return channels, and scavenge pumps) between the isolator and the external environment. These intermediaries capture oil that escapes through the isolator and redirect it back, preventing direct leakage to the environment while maintaining the benefits of non-contacting isolators.
2Reliability
If radial lip seals or mechanical seals are used at shaft penetrations, then direct contact sealing is achieved, but wear occurs and frequent replacement is required
Solution Approach 1:
The patent extracts the sealing function from the shaft penetration interface by using non-contacting bearing isolators that create a magnetic or electrostatic barrier without physical contact. This separates the sealing function from mechanical contact, eliminating wear while maintaining sealing effectiveness.
3Object-generated harmful factors
If external tubing systems are used to collect and redirect leaked oil, then oil recovery is achieved, but system complexity increases
Solution Approach 1:
The patent merges the oil collection and return functions directly into the gearbox housing structure. The oil collection wells, return channels, and scavenge pumps are integrated with the existing housing and lubrication system, eliminating the need for separate external tubing systems while achieving the same oil recovery goal.
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
The system effectively reduces oil leakage and contamination by passively diverting oil back into the gearbox reservoir, enhancing lubrication efficiency and reducing waste.
Implementation Method 1
The carrier includes an oil collection well spaced from the shaft bore and an oil return channel in fluid communication with the oil collection well and extending through the carrier to the main housing
Implementation Method 2
Fluid at the interior surface of the isolation dam is drawn into the main housing via the primary oil passage, the oil collection well and the oil return channel
Data Source
Figure 1A~1B
Figure 2~3
Figure 4~5
AI summary
A gearbox includes a main housing carrying input and output shafts, a carrier mounted to the housing having a bore, an isolator plate mounted to the carrier having a bore aligned with the carrier bore, and an isolator mounted to the isolator plate having a bore aligned with the isolator plate and carrier bores. The carrier includes an oil collection well, spaced from the bore, and an oil return channel in fluid communication with the oil collection well that extends through the carrier to the main housing. The isolator plate includes an interior surface and an oil passage formed therein that extends from the interior surface to the oil collection well, such that the interior surface is in fluid communication with the main housing via the oil passage, the oil collection well and the oil return channel, and fluid at the interior surface is drawn into the main housing via the oil passage, the oil collection well and the oil return channel.