Transmission device for splitting torque between two coaxial gears, in particular for a planetary gearing for aeronautic applications, and method for manufacturing and assembling said transmission device

Patent metadata

Field	Value
Publication number	US-10823260-B2
Application number	US-201816020064-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Jul 21, 2017
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A transmission device for splitting torque between two coaxial gears, in particular for a planetary gearing for aeronautic applications, has a motion input member and two transmission members, which are coaxial and have respective shafts provided with gears at an axial end and respective external flanges, at the opposite axial end; the two flanges are axially facing and placed abutting against each other, and are fixed to the motion input member so as to split the torque transmitted from the motion input member between the two flanges; one of the two shafts is axially hollow and houses, with radial clearance, an intermediate portion of the other shaft; the latter is formed by at least two pieces which are coaxial and fixed to each other.

First claim

What we claim is:

1. A transmission device for splitting torque between two coaxial gears of a planetary gearing for aeronautic applications, the device comprising:
a motion input member;
a first and a second transmission member, which are coaxial to each other and to said motion input member along a longitudinal axis and comprise:
a first shaft having a first gear at an axial end, and a first intermediate portion, wherein said first shaft is formed by at least two pieces which are coaxial and fixed to each other;
a second shaft having a second gear at an axial end, wherein said second shaft is axially hollow and defines an inside diameter, wherein said first intermediate portion has an outside diameter smaller than said inside diameter of said second shaft and is housed in said second shaft with radial clearance;
a first flange radially protruding outwards from said first shaft at an axial end opposite to said first gear;
a second flange radially protruding outwards from said second shaft at an axial and opposite to said second gear, wherein the first and second flanges are axially facing and placed abutting against each other and are fixed to said motion input member so as to split the torque transmitted from said motion input member between said first and second flanges; and
a centering ring coupled around the first shaft and having an inside diameter equal to an outside diameter of the first shaft, the centering ring comprising a conical surface which is complementary to a corresponding conical surface of said second shaft.

2. The device according to claim 1 , wherein said at least two pieces are coupled to each other in a rotationally fixed manner; the first shaft further comprising a tightening ring nut screwed onto one of the said at least two pieces so as to axially lock said at least two pieces to each other.

3. The device according to claim 2 , wherein said at least two pieces are coupled to each other in an angularly fixed manner by means of a splined coupling or by means of a front dog coupling.

4. The device according to claim 3 , wherein said splined coupling or said front dog coupling is arranged radially inside said second shaft.

5. The device according to claim 3 , wherein said splined coupling is arranged at said first gear.

6. The device according to claim 3 , wherein said at least two pieces are coupled to each other in an angularly fixed manner by means of a front dog coupling, and said ring nut is screwed onto a collar which extends as an axial extension of a tubular portion; at least one of said at least two pieces being fitted onto said tubular portion.

7. The device according to claim 2 , wherein said ring nut is screwed onto a collar forming part of one of said at least two pieces.

8. The device according to claim 2 , wherein said second shaft has, at its opposite axial ends, respective conical surfaces facing towards said first shaft.

9. A method for manufacturing and assembling a transmission device for splitting torque between two coaxial gears of a planetary gearing for aeronautic applications, the transmission device comprising a motion input member, a first transmission member, and a second transmission member, the first and second transmission members being coaxial to each other and to said motion input member along a longitudinal axis and comprise:
a first shaft having a first gear at an axial end, and a first intermediate portion, wherein said first shaft is formed by at least two pieces which are coaxial, the first shaft further comprising a tightening ring nut screwed onto one of the said at least two pieces so as to axially lock said at least two pieces to each other,
a second shaft having a second gear at an axial end, wherein said second shaft is axially hollow and defines an inside diameter, wherein said first intermediate portion has an outside diameter smaller than said inside diameter of said second shaft and is housed in said second shaft with radial clearance,
a first flange radially protruding outwards from said first shaft at an axial end opposite to said first gear;
a second flange radially protruding outwards from said second shaft at an axial and opposite to said second gear, wherein the first and second flanges are axially facing and placed abutting against each other and are fixed to said motion input member so as to split the torque transmitted from said motion input member between said first and second flanges; and
a centering ring coupled around the first shaft and having an inside diameter equal to an outside diameter of the first shaft, the centering ring comprising a conical surface which is complementary to a corresponding conical surface of said second shaft
the method comprising the steps of:
axially inserting at least one of said pieces in said second shaft;
coupling said pieces to each other in an angularly fixed manner, after the axial insertion step;
screwing said ring nut onto a corresponding collar, without screwing it tightly;
positioning said first and second transmission members so as to axially align the teeth of said first and second gears;
tightening said ring nut after the positioning step; and
after the tightening step, fixing said first and second flanges to said motion input member.

Assignees

• Ge Avio Srl

Inventors

• Gravina Michele
• Facchini Marco

Classifications

• F02C7/36 Primary

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• F16H57/08

  of gearings with members having orbital motion · CPC title

• F16H2001/289

  comprising two or more coaxial and identical sets of orbital gears, e.g. for distributing torque between the coaxial sets · CPC title

• F16H1/2845

  by allowing limited movement of the sun gear · CPC title

• F16H57/023

  Mounting or installation of gears or shafts in the gearboxes, e.g. methods or means for assembly · CPC title