Variable speed transmission and related methods
AssigneeThe Boeing Company
InventorsGregory Forrest Heath, Stephen C. Slaughter, Robert J. Atmur, William Patrick Sargent, Tse-hua Shen, Bryant Scott Owen, Alice A. Murphy
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Abstract
A variable speed transmission is disclosed, with a transmission apparatus which includes a planetary gear set having a ring gear and a sun gear. The variable speed transmission further includes a primary engine for powering the sun gear, a braking device engaging the ring gear, and a controller configured to alter the rotational speed of the ring gear by adjusting the braking device.
Claims20
A variable speed transmission system, comprising:
- a first transmission apparatus including a planetary gear set having a ring gear and a sun gear,
- a primary engine for powering the sun gear,
- a braking device engaging the ring gear, and
- a controller configured to alter the rotational speed of the ring gear by adjusting the braking device,
- wherein the braking device includes a virtual elliptical drive and a positive engagement brake, the positive engagement brake preventing rotation of the ring gear when engaged.
A rotorcraft, comprising:
- a main body portion,
- an engine contained in the main body portion,
- a first transmission assembly connected to the engine, including a planetary gear set having a planetary ring structure engaging a set of planet gears that orbit a sun gear in a first rotational direction, and
- a first virtual elliptical drive engaging teeth on an outer circumferential side of the planetary ring structure, and configured to adjust a rotational speed of the planetary ring structure,
- wherein the engine and first transmission assembly are configured to drive an aft propulsor.
A method of varying speed of a planetary gear system, comprising:
- driving planet gears to orbit a sun gear in a first rotational direction, the planet gears engaging a stationary ring gear, and
- varying the orbital speed of the planet gears by driving the ring gear in a second rotational direction, opposite from the first rotational direction,
- engaging a brake to mechanically lock the ring gear, wherein the ring gear is driven by one or more virtual elliptical drives.
Dependencies are inferred from the claim text.