Asymmetric gear teeth
AssigneeSikorsky Aircraft Corporation
InventorsDavid A. Binney, Yuriy Gmirya, Joseph A. Mucci, Jonathan Frost, Adam Taylor
Life of this patent
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Abstract
A gear train includes a first gear having teeth meshed with teeth of a second gear. Each tooth of the first gear includes a coast side and a drive side opposed to the coast side. The drive side has a pressure angle that is greater than that of the coast side. The gear train can be part of a powertrain system for a rotorcraft, and can replace a traditional gear train in a retrofit or new build. The first gear is a planet gear and the second gear is a ring gear wherein the planet gear and ring gear are in a planetary gear train configuration.
Claims16
A gear train comprising:
- a first gear having teeth meshed with teeth of a second gear, wherein each tooth of the first gear includes a coast side and a drive side opposed to the coast side, wherein the drive side has a pressure angle that is greater than that of the coast side, and wherein the first gear is a planet gear and the second gear is a ring gear wherein the planet gear and ring gear are in a planetary gear train configuration.
A powertrain system for a rotorcraft comprising:
- an input module for receiving power from a powerplant system, the input module including first stage reduction gearing;
- a main transmission assembly including second stage reduction gearing mechanically coupled to the first stage reduction gearing for receiving power therefrom and a drive shaft mechanically coupled to the second stage reduction for providing power therefrom;
- a sun gear mechanically coupled to the drive shaft to be driven thereby;
- a set of N primary planetary pinions meshed with the sun gear, wherein N/2 of the primary planetary pinions are upper primary planetary pinions and N/2 of the primary planetary pinions are lower primary planetary pinions, wherein the upper and lower primary planetary pinions are disposed in a staggered, biplanar relationship;
- a plurality of N secondary planetary pinions;
- a compound drive shaft supporting each respective primary planetary pinion and a respective secondary planetary pinion;
- a fixed ring gear meshed with the plurality of secondary planetary pinions;
- and
- a planetary carrier assembly disposed in rotatable combination with the compound drive shafts and operative to provide output power to a main rotor shaft of the rotorcraft,
- wherein each tooth of each of the secondary pinions includes a coast side and a drive side opposed to the coast side, wherein the drive side has a pressure angle that is greater than that of the coast side.
A method of retrofitting a rotorcraft power train comprising:
- removing a first planetary gear from a rotorcraft powertrain, wherein each tooth of the first planetary gear includes a coast side and a drive side opposed to the coast side, wherein the drive side has a pressure angle that is equal to that of coast side;
- and
- installing a replacement planetary gear into the rotorcraft powertrain, wherein each tooth of the replacement planetary gear includes a coast side and a drive side opposed to the coast side, wherein the drive side has a pressure angle that is greater than that of the coast side.
Dependencies are inferred from the claim text.