Planetary Gearset Lubrication Cup Layout to Prevent Oil Buildup
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Solution Overview
Problem
In epicycloidal gear trains, especially when the outer crown is fixed in rotation, lubrication of the satellite pinion shafts is inefficient due to complex networks of pressurized oil routing pipes with dynamic seals that wear out and require frequent maintenance, and at low rotation speeds, oil accumulates and spills, leading to excessive heating.
Innovation Solution
An epicycloidal gear train design with a central pinion, outer crown, and satellite pinions mounted freely on a satellite carrier, featuring a first lubrication oil circuit for contact areas and a second for satellite pinion axes, with an annular cup divided into fluidly separated basins, where the second basins have openings in the annular wall to allow excess oil to escape, preventing accumulation and spills.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex networks of pressurized oil routing pipes with dynamic seals are used for lubrication, then lubrication of satellite pinion shafts can be achieved, but the system becomes complex and requires frequent maintenance due to wear
Solution Approach 1:
The annular cup is divided into multiple separate basins (first basins for gear contact areas, second basins for satellite pinion axes) that are fluidly separated. Each basin independently manages lubrication for its specific function, eliminating the need for complex routing pipes and dynamic seals while maintaining reliable lubrication delivery to each lubrication point
Solution Approach 2:
The invention extracts and eliminates the complex network of pressurized oil routing pipes with dynamic seals from the system. Instead, it uses a simplified gravity-based oil distribution system where oil flows naturally into the annular cup and is distributed to different basins, removing the problematic components that caused wear and maintenance issues
2Device complexity
If a single annular cup is used for oil collection, then structure is simple, but oil accumulates and spills at low rotation speeds, causing excessive heating
Solution Approach 1:
The single annular cup is segmented into multiple functionally separate basins (first basins for gear contact, second basins for pinion axes). This segmentation allows oil to be distributed to specific areas and prevents accumulation in any single location, eliminating oil spills and excessive heating while maintaining the simple cup structure
Solution Approach 2:
Different basins within the cup are designed with different characteristics - first basins for receiving oil from gear contact areas and second basins for satellite pinion lubrication. Each basin is optimized for its specific function, with openings in second basins to allow excess oil escape, preventing localized oil accumulation and heating
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 lubrication by eliminating dynamic seals, reduces oil spills and heating issues, and ensures effective lubrication by directing excess oil away from critical areas, enhancing the reliability and maintenance efficiency of the gear train.
Implementation Method 1
the lubrication and cooling of the gears and axes of the satellite pinions is then not a problem and is ensured by nozzles that are fixed in rotation and can project oil permanently on the meshing areas of the satellite pinions with the central pinion and with the crown and on the satellite pinion axes
Data Source
AI summary
The invention concerns an epicycloidal gear train (10) comprising a central pinion (26), an outer crown (28) and satellite pinions (32) in engagement with the central pinion (26) and the outer crown (28) and each mounted freely rotatable on a satellite carrier (36), the gear train (10) comprising an annular cup (56) being integral with the satellite carrier (36) and open radially inward. According to the invention, the cup (56) is divided into a circumferential succession of first basins (60) of the first oil circuit and second basins (62) of the second oil circuit, the first basins (60) being fluidly separated from the second cells (62) and characterised in that the cup (56) comprises two annular walls (56a, 56b) axially facing, the annular wall (56b) of which is furthest from a median transverse plane (74) of the gear train (10) has openings (76) opening into the second basins (62).