Lubrication of windmilling journal bearings
AssigneeUnited Technologies Corporation
InventorMichael E. McCune
Life of this patent
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Abstract
A support shaft provides lubrication to a journal bearing during windmilling operation of a gear set. A primary oil pump provides oil from an oil supply during driven operation of the fan, and a secondary oil pump provides oil from an internal sump during windmilling operation of the fan. During driven operation of the fan, oil is pumped with the primary oil pump through a primary oil flow path to an outer surface of the support shaft. During windmilling fan operation, oil is pumped from an internal sump with a secondary oil pump through the secondary oil flow path. The secondary oil flow path has a smaller flow capacity, and the secondary oil pump is a smaller capacity pump.
Claims22
An epicyclic gear set comprising:
- a sun gear;
- a plurality of planet gears arranged around and driven by the sun gear;
- and
- a plurality of support shafts each associated with one of the plurality of planet gears, wherein each of the plurality of support shafts has a primary oil flow path for supplying oil during driven gear operation and a secondary oil flow path for supplying oil when the sun gear is not driving the plurality of planet gears,
- wherein, during driven gear operation, the oil flows through the primary oil flow path and does not flow though the secondary oil flow path, and
- wherein, when the sun gear is not driving the plurality of planet gears, the oil flows through the secondary oil flow path and does not flow through the primary oil flow path.
A turbine engine comprising:
- a turbofan;
- an epicyclic gear system for driving the fan, the epicyclic gear system including a sun gear and a plurality of planet gears arranged around and driven by the sun gear;
- a plurality of support shafts each associated with one of the plurality of planet gears, wherein each of the plurality of support shafts includes a primary oil flow path for supplying oil during driven gear operation and a secondary oil flow path for supplying the oil when the sun gear is not driving the plurality of planet gears;
- and
- an oil supply system to supply the oil to the primary oil flow path and the secondary oil flow path,
- wherein, during driven gear operation, the oil flows through the primary oil flow path and does not flow though the secondary oil flow path, and
- wherein, when the sun gear is not driving the plurality of planet gears, the oil flows through the secondary oil flow path and does not flow through the primary oil flow path.
Dependencies are inferred from the claim text.