GEARED GAS TURBINE ENGINE
First Claim
1. A gas turbine engine comprising a gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, each planet gear being rotatably mounted in the carrier by at least one bearing, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the sun gear, the planet gears and the annulus gear comprising helical gear teeth, the annulus gear being secured to a surrounding structure by a radially extending member, a face of the radially extending member nearest the middle of the annulus gear being axially spaced from the middle of the annulus gear by a first distance, the reference diameter of the annulus gear being radially spaced from a point at which the radially extending member is secured to the surrounding structure by a second distance, wherein the ratio of first distance to second distance is between and including 0.5 and 1.2.
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Accused Products
Abstract
A gas turbine engine includes gearbox including sun gear, annulus gear, plurality of planet gears and carrier. Each planet gear is rotatably mounted in carrier by bearing. The sun gear meshes with planet gears and planet gears mesh with annulus gear. The sun gear, planet gears and annulus gear comprise helical gear teeth. The annulus gear secured to surrounding structure by a radially extending member. A face of the flange nearest the middle of the annulus gear axially spaced from middle of annulus gear by first distance. The reference diameter of the annulus gear is radially spaced from a point which the radially extending member is secured to the surrounding structure by second distance. The ratio of first distance to second distance is between and including 0.5 and 1.2 such that misalignment between annulus gear and planet gears are reduced to minimize vibrations, noise, stress and wear of gearbox.
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Citations
20 Claims
- 1. A gas turbine engine comprising a gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, each planet gear being rotatably mounted in the carrier by at least one bearing, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the sun gear, the planet gears and the annulus gear comprising helical gear teeth, the annulus gear being secured to a surrounding structure by a radially extending member, a face of the radially extending member nearest the middle of the annulus gear being axially spaced from the middle of the annulus gear by a first distance, the reference diameter of the annulus gear being radially spaced from a point at which the radially extending member is secured to the surrounding structure by a second distance, wherein the ratio of first distance to second distance is between and including 0.5 and 1.2.
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19. A gas turbine engine comprising a gearbox, the gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, each planet gear being rotatably mounted in the carrier by at least one bearing, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the sun gear, the planet gears and the annulus gear comprising helical gear teeth, the helical gear teeth having a pressure angle and a helix angle, the annulus gear being secured to a surrounding structure by a radially extending member, a face of the radially extending member nearest the middle of the annulus gear being axially spaced from the middle of the annulus gear by a first distance, the reference diameter of the annulus gear being radially spaced from a point at which the radially extending member is secured to the surrounding structure by a second distance, wherein the first distance=(the second distance×
- sin (helix angle of the helical gear teeth))/tan (pressure angle of the helical gear teeth).
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20. A gearbox comprising a sun gear, an annulus gear, a plurality of planet gears and a carrier, each planet gear being rotatably mounted in the carrier by at least one bearing, the sun gear meshing with the planet gears and the planet gears meshing with the annulus gear, the sun gear, the planet gears and the annulus gear comprising helical gear teeth, the annulus gear being secured to a surrounding structure by a radially extending member, a face of the radially extending member nearest the middle of the annulus gear being axially spaced from the middle of the annulus gear by a first distance, the reference diameter of the annulus gear being radially spaced from a point at which the radially extending member is secured to the surrounding structure by a second distance, wherein the ratio of first distance to second distance is between and including 0.5 and 1.2.
Specification