CN-121986223-A - Planet carrier for a mechanical reduction gear of an aircraft turbine engine, reduction gear and aircraft turbine engine comprising a reduction gear

CN121986223ACN 121986223 ACN121986223 ACN 121986223ACN-121986223-A

Abstract

A planet carrier (213) for a mechanical reduction gear (10, 110) of an aircraft turbine engine (1) is disclosed, the planet carrier comprising-a first disc (236) centred on and extending perpendicularly to a first axis (X), the first disc (236) comprising a first aperture (292) centred on and extending parallel to a second axis (Y) parallel to the first axis (X), respectively, -a second disc (238) centred on and extending parallel to and at a distance from the first disc (236), the second disc (238) comprising a second aperture (294) centred on and extending parallel to a second axis (Y), respectively, the number of second apertures (294) being equal to the number of first apertures (292), -a bridge connector (296) extending between and connecting the first and second discs (236, 238) together, the bridge connector (296) being formed in one piece with the first and second discs (236, 238).

Inventors

Patrick Julian Putashnsky
Claremont Jialu
Jordan Amir Andre Pertier
Pierre Damian Tuna

Assignees

赛峰传动系统公司

Dates

Publication Date: 20260505
Application Date: 20241002
Priority Date: 20231010

Claims (12)

1. A planet carrier (213,313) for a mechanical reduction gear (10, 110) of an aircraft turbine engine (1), the planet carrier (213,313) comprising: A first disc (236, 336) centred on and extending perpendicularly to a central axis (X), the first disc (236, 336) comprising first bearing apertures (292,392) centred on a bearing axis (Y) respectively, said bearing axes being distributed circumferentially around and parallel to the central axis (X), -A second disc (238, 338) centred on said central axis (X), parallel to said first disc (236, 336) and extending axially away from said first disc, the second disc (238, 338) comprising second bearing apertures (294,394) centred on said bearing axis (Y), respectively, the number of said second bearing apertures (294,394) being equal to the number of said first bearing apertures (292,392), Bridge connectors (296, 396) extending between and connecting the first and second disks (236,238,336,338) together, The planet carrier is characterized in that: -at least one of said discs (236,238,336,338) comprising alternating concave and convex curved sections (298 a,299a, and convex curved sections (298 b,299 b) on each of the inner and outer peripheral edges (298,299) of said disc (236,238,336,338), the concave and convex curved sections (298 b,299 a) of said inner and outer peripheral edges (298, 298b,299 a) being radially aligned with respect to said central axis (X) and extending radially inwardly and radially outwardly of bearing apertures (292, 294) of said disc (236, 238), respectively, the concave and convex curved sections (298 a,299 b) of said inner and outer peripheral edges (298, 299) being radially aligned with respect to said central axis (X), and the number of concave and convex curved sections (298 a, 8b,299 b) of said inner and outer peripheral edges (298,299) of said disc (236, 238) being equal to the number of bearing apertures (292, 294) of the disc (236, 238), And/or: -the bearing apertures (392, 394) of at least one of the discs (336, 338) are distributed in pairs, each pair of bearing apertures (392, 394) comprising two bearing apertures (392, 394) circumferentially adjacent, the or each disc (336, 338) comprising a pair of bearing apertures (392, 394) comprising a first through hole (400) located between the bearing apertures (392, 394) of each pair of bearing apertures (392, 394), the first through hole intersecting a first plane (P1) extending radially with respect to the central axis (X) and located at an equal distance from the bearing axes (Y) of the pair of bearing apertures (392, 394), and intersecting a second plane (P2) passing through the bearing axes (Y) of the pair of bearing apertures (392, 394), the first plane (P1) being a first plane of symmetry of the hole (400).
2. The planet carrier (213) according to claim 1, wherein the convex curved section (298 b) of the inner peripheral edge (298) extends around a bearing axis (Y) of the bearing aperture (292, 294) of the disc (236, 238).
3. The planet carrier (213) according to claim 1 or 2, wherein the convex curved section (298 b) of the inner peripheral edge (298) has an angular extent (a) around the central axis (X) that is smaller than an angular extent (β) of the concave curved section (299 a) of the inner peripheral edge (299) around the central axis, And/or: -the concave curved section (299 a) of the peripheral edge (299) has an angular extent (y) around the central axis (X) that is smaller than or equal to the angular extent (d) of the convex curved section (299 b) of the peripheral edge (299) around the central axis.
4. A planet carrier (213) according to any of claims 1 to 3, wherein the convex curved section (298 b) of the inner peripheral edge (298) has an angular extent (a) around the central axis (X) equal to +/-10% of the angular extent (ψ) of the concave curved section (299 a) of the outer peripheral edge (299) around the central axis (X) and/or the concave curved section (298 a) of the inner peripheral edge (298) has an angular extent (β) around the central axis (X) equal to +/-10% of the angular extent (δ) of the convex curved section (299 b) of the outer peripheral edge (299) around the central axis (X).
5. The planet carrier (213) according to any one of claims 1 to 4, wherein: -the top of the convex curved section (298 b) of the inner peripheral edge (298) being located on a circumference (C1) centered on the central axis (C1) having a first diameter (D1), the top of the concave curved section (298 a) of the inner peripheral edge (298) being located on another circumference (C2) centered on the central axis (X) having a second diameter (D2), the difference between the second diameter and the first diameter (D1, D2) being less than or equal to the minimum radial thickness (E1) of the material of the disc (236, 238) surrounding the bearing aperture (292, 294) of the disc at the level of the outer peripheral edge (298), And/or: -the top of the concave curved section (299 a) of the peripheral edge (299) is located on a circumference (C3) with a third diameter (D3) centered on the central axis (X), the top of the convex curved section (299 b) of the peripheral edge (299) is located on another circumference (C2) with a second diameter (D4) centered on the central axis (X), the difference between the second diameter and the first diameter (D3, D4) being greater than or equal to the minimum radial thickness (E2) of material of the disc (236, 238) surrounding the bearing aperture (392, 394) of the disc at the level of the peripheral edge (299).
6. The planet carrier (313) according to any one of the preceding claims, wherein the second plane (P2) is also a plane of symmetry of the hole (400).
7. The planet carrier (313) according to any one of the preceding claims, wherein the or each disc (336, 338) comprising a pair of bearing apertures (392, 394) comprises at least one additional through hole (401, 402) located circumferentially between each pair of bearing apertures (392, 394), the at least one additional through hole being located radially above or below the first hole (400) and intersecting the first plane (P1).
8. The planet carrier (313) according to claim 7, wherein the first aperture (400) and the or each additional aperture (401, 402) have the same shape and size.
9. The planet carrier (313) according to any one of the preceding claims, wherein the or each disc (336, 338) comprising a pair of bearing apertures (392, 394) comprises at least one through opening (380 a) located circumferentially between each pair of bearing apertures (392, 394), the first plane (P1) also being a plane of symmetry of the opening (380 a).
10. The planet carrier (313) according to claim 9, wherein the or each disc (336, 338) has a material thickness (Z1) measured between an inner peripheral edge of the disc (336, 338) and the first aperture (400) along a radial direction with respect to the central axis (X), the material thickness (Z1) being smaller than a second material thickness (Z2) measured between the first aperture (400) and the opening (380 a) along the same direction.
11. A mechanical reduction gear (10, 110) for an aircraft turbine engine, comprising a planet carrier (213,313) according to any one of the preceding claims, the reduction gear further comprising: -a sun gear (11) centred on said central axis (X) and mounted between discs (236,238,336,338) of said planet carrier (213,313), -A planetary gear (12) centred on the bearing axis (Y) and mounted between the discs (236,238,336,338) of the planet carrier (213,313), the planetary gear (12) being guided in rotation by bearings (8) housed respectively in the first and second bearing apertures (292,294,392,394) of the discs (236,238,336,338), and -A ring gear (14) centred on the central axis (X) and extending around the sun gear (11) and the planet gears (12), the planet gears (12) meshing with the sun gear (11) and the ring gear (14).
12. Turbine engine (1), in particular for an aircraft, comprising a reduction gear (10, 110) according to claim 11.

Description

Planet carrier for a mechanical reduction gear of an aircraft turbine engine, reduction gear and aircraft turbine engine comprising a reduction gear Technical Field The present invention relates to a planet carrier and a mechanical reduction gear for an aircraft turbine engine, and a turbine engine comprising such a planet carrier or reduction gear. Background The prior art includes, inter aliA, literature FR-A1-2 987 416、FR-A1-2 853 382、FR-A1-3 041 054、FR-A1-3 073 915、FR-A1-3 084 428、JP-A-2006/009994、EP-B1-4 056 469、US-A-3,227,006、FR-A1-3 132 133 and US-A-5,466,198. The function of the mechanical reduction gear is to change the gear ratio and torque between the input and output shafts of the mechanism. A new generation of dual flow turbine engines, particularly those with high bypass ratios, include a mechanical reduction gear to drive the shaft of the fan. The general purpose of a reduction gear is to convert the rotational speed of the shaft of the power turbine (referred to as high speed) into a slower rotational speed for driving the shaft of the fan. Such reduction gears include a sun pinion, known as a sun gear, a ring gear, and pinions, known as planet gears, which mesh between the sun gear and the ring gear. The planet gears are held by a frame called a planet carrier. The sun gear, ring gear and planet carrier are planetary gears in that the axes of rotation of the three coincide with the longitudinal axis of the turbine engine. The planet gears each have a different axis of rotation and are equally spaced apart on the same operating diameter about the axis of the planet gears. These axes are parallel to the longitudinal axis of the turbine engine. There are several reduction gear architectures. In the prior art of dual flow turbine engines, the reduction gear is a planetary or epicyclic reduction gear. In other similar applications, there are architectures known as differential or "composite". On the planetary reduction gear, the planet carrier is stationary and the ring gear is the output shaft of the device, which rotates in the opposite direction to the sun gear. In an epicyclic reduction gear, the ring gear is stationary and the planet carrier is the output shaft of the device, which rotates in the same direction as the sun gear. On the compound reduction gear, no element is attached rotationally. The ring gear rotates in a direction opposite the sun gear and the carrier. The reduction gear may be comprised of one or more meshing stages. This engagement is ensured in different ways, for example by contact, friction or by a magnetic field. There are several types of contact engagement, for example, contact engagement by straight teeth or chevron teeth. The planet carrier may be an integral planet carrier or may be in the form of a cage and a cage carrier. The cage includes an inner cavity in which the sun gear, the planet gears and the guide bearings for the planet gears are received. The sun gear includes an internal spline for coupling to a first shaft of the turbine engine, and the cage bracket includes a cylindrical section including an external spline for coupling to another shaft. The connection of the cage to the cage bracket is typically a rigid connection. Alternatively, a technique is conceivable in which the cage is connected to the cage bracket by a "flexible" connection, as described in document FR-A1-2 853 382. In this case, the cage bracket comprises an annular row of axial fingers carrying the first connecting element. These first connection elements cooperate with second connection elements mounted in the housing of the holder to form a flexible connection between the holder bracket and the holder, thereby allowing at least one degree of freedom. During operation, the planet carrier is subjected to forces tending to deform the planet carrier. This is the case for an integrated planet carrier or cage and cage carrier. These deformations lead to tilting of the planet gears, leading to degradation of the meshing, and the risk of an asymmetrical oil film when sliding or dynamic-pressure planet gear guide bearings are used, or of roller tilting when planet gear rolling guide bearings are used. These forces and strains must be balanced in order to limit or even counteract these effects. The planet carrier also includes an aperture to receive an end of the planet gear guide bearing. The orifices may be machined and machining tolerances may result in dimensional and positional errors in the orifices. To reduce the positional tolerances of the orifices, they may be ground, which is limited from an industrial point of view. The material of the planet carrier may also be chosen to reduce the stiffness of the planet carrier, for example using titanium or aluminium instead of steel. However, this also creates additional constraints (processability, mechanical strength, tribological behaviour, etc.). Misalignment of the planet bearings (whether they are plain bearings or rolling bearings) a