Planetary Gear Lubrication Structure Using a Helical Groove
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Solution Overview
Problem
Existing planetary gear mechanisms for aircraft are large and complex due to multiple pumps required for lubrication, which complicates the structure and size.
Innovation Solution
A compact lubrication structure is achieved in the planetary gear mechanism by using a helical groove and lubricating oil passages between the sun gear, planetary gears, and shafts, forming a screw pump effect to distribute lubricating oil to sliding contact parts, eliminating the need for external pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple internal pumps are provided in the planetary carrier to feed lubricating oil to various parts, then the lubrication function is improved, but the device size increases and the structure becomes complicated
Solution Approach 1:
The patent combines multiple pump functions into a single integrated pump structure located in the planetary carrier. Instead of providing separate pumps for different lubrication points, one pump with multiple oil passages integrates the lubrication of planetary gears, sun gear, ring gear, and bearing areas, thereby reducing structural complexity while maintaining comprehensive lubrication coverage
Solution Approach 2:
The single pump in the planetary carrier serves multiple functions by supplying lubricating oil to various components through dedicated passages. The pump simultaneously lubricates planetary gears, sun gear, ring gear, and bearing areas, making one component perform multiple lubrication tasks that would otherwise require separate pumps
2Reliability
If multiple pumps are provided in the planetary carrier to feed lubricating oil to various parts, then the lubrication function is improved, but the device size increases
Solution Approach 1:
The patent combines multiple pump functions into a single integrated pump structure located in the planetary carrier. Instead of providing separate pumps for different lubrication points, one pump with multiple oil passages integrates the lubrication of planetary gears, sun gear, ring gear, and bearing areas, thereby reducing structural complexity while maintaining comprehensive lubrication coverage
Solution Approach 2:
The pump is nested within the planetary carrier structure, and multiple oil passages are nested within the pump body. The passages are arranged concentrically or radially within the pump housing, allowing multiple lubrication pathways to occupy the same spatial envelope, thus minimizing the overall volume required for the lubrication system
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 reduces the size and complexity of the lubrication system while ensuring effective lubrication of critical components, enhancing the mechanism's efficiency and compactness.
Implementation Method 1
one of the connecting shaft and the receiving hole is formed with a helical groove (105) that extends vertically in a helical manner about the connecting shaft and is connected to the gap, the second shaft is formed with a first lubricating oil passage (108) that connects the helical groove to sliding contact parts of the second shaft and the case, lubricating oil (110) is stored in the case, and at least a part of each of the multiple planetary gears is immersed in the lubricating oil when the first shaft is rotating
Implementation Method 2
when the first shaft rotates, the multiple planetary gears engaged with the sun gear rotate, and the lubricating oil adhering to the planetary gears is scattered radially outward of each planetary gear
Data Source
AI summary
A planetary gear mechanism includes: a case; a first shaft having a connecting shaft; a second shaft having a receiving hole to rotatably receive the connecting shaft; a sun gear joined to the first shaft; a planetary carrier joined to the second shaft; planetary gears rotatably supported by the planetary carrier; and a ring gear provided on an inner surface of the case. The connecting shaft or the receiving hole is formed with a helical groove extending vertically and connected to a gap formed between an upper surface of the sun gear and a lower end surface of the second shaft. The second shaft is formed with a first lubricating oil passage connecting the helical groove to sliding contact parts of the second shaft and the case. When the first shaft is rotating, at least a part of each planetary gear is immersed in lubricating oil stored in the case.