Epicyclic gear train for turbo fan engine
AssigneeUnited Technologies Corporation
InventorWilliam G. Sheridan
Life of this patent
Estimating the term…
Abstract
A two-stage turbofan system for use in a gas turbine engine comprises a first-stage fan shaft, a second-stage fan shaft, a stationary torque tube and a gear system. The second-stage fan shaft connects with a drive shaft in the gas turbine engine such that the second-stage fan shaft is driven at the speed of the drive shaft. The stationary torque tube is connected with a fan case in the gas turbine engine. The gear system is connected to the second-stage fan shaft and the torque tube. The first-stage fan shaft extends from the gear system such that the first-stage fan shaft is driven at a speed reduced from that of the drive shaft.
Claims18
A two-stage turbofan system for use in a gas turbine engine through which inlet air travels from an upstream direction to a downstream direction, the two-stage turbofan system comprising:
- a second-stage fan shaft for connection with a drive shaft in the gas turbine engine such that the second-stage fan shaft is driven at a speed of the drive shaft;
- a stationary torque tube having a fixed upstream portion for connection with a fan case in the gas turbine engine;
- a gear system comprising:
- a ring gear connected to the second-stage fan shaft;
- a stationary sun gear connected to a downstream portion of the torque tube concentric with the ring gear;
- and
- a gear carrier positioned concentrically between the ring gear and the sun gear, the gear carrier having a plurality of planet gears positioned in the gear carrier to interface with the sun gear and the ring gear;
- and
- a first-stage fan shaft having a downstream portion extending from the gear carrier such that the first-stage fan shaft is driven at a speed reduced from that of the drive shaft.
A drive system for a two-stage turbofan gas turbine engine, the drive system comprising:
- a first shaft system connected to a turbine within the gas turbine engine for driving a high speed fan stage section;
- a static torque tube disposed coaxially with the first shaft system, the static torque tube being anchored to the gas turbine engine in a non-rotating fashion;
- a planetary gear system coupled between the first shaft system and the static torque tube, the planetary gear system comprising:
- a static sun gear positioned around the static torque tube;
- a gear carrier positioned concentrically around the sun gear;
- a plurality of planet gears positioned in the gear carrier such that the planet gears interface with the sun gear;
- and
- a ring gear positioned concentrically around the gear carrier such that the ring gear interfaces with the plurality of planet gears and the first shaft system;
- and
- a second shaft system connected to the gear carrier of the planetary gear system for driving a low speed fan stage section.
A gear system for use in a two-stage turbofan engine, the gear system comprising:
- a static shaft for connection to a non-rotating member of the turbofan engine;
- a sun gear affixed to the static shaft such that it is non-rotating about the static shaft;
- a gear carrier positioned concentrically around the sun gear, the gear carrier comprising:
- a plurality of gear slots circumferentially disposed about a circumference of the gear carrier;
- a plurality of journal pins extending through the plurality of gear slots;
- a plurality of planet gears disposed about the journal pins within the gear slots such that the planet gears interface with the sun gear;
- and
- a plurality of torque slots extending through the gear carrier between the plurality of gear slots;
- a ring gear positioned concentrically around the gear carrier such that the ring gear interfaces with the plurality of planet gears;
- a first-stage drive shaft connected to the torque slots and extending axially from the gear carrier for connection to a first-stage fan;
- a first conical drive shaft connected to the ring gear and extending axially from the ring gear in a first direction for connection to a second-stage fan;
- and
- a second conical drive shaft connected to the ring gear and extending axially from the ring gear in a second direction for connection to an input turbine shaft.
Dependencies are inferred from the claim text.