Gearbox ring for aircraft turbomachine, gearbox fitted with such a gear ring, and aircraft turbomachine equipped with such a gear ring

Abstract

This geared ring gear for an aircraft turbomachine gearbox comprises two parts (9, 10), each with teeth (8) and means for bolting the two parts together. It has markers (15) configured to locate the relative angular positions of the two ring gear parts (9, 10). These markers are positioned on the two ring gear parts to identify an alignment position for the teeth and the means for bolting the two respective ring gear parts. (See Figure 2 for abbreviations.)

Description

Title of the invention: Gearbox ring for aircraft turbomachine, gearbox fitted with such a gear ring, and aircraft turbomachine equipped with such a gearbox technical field

[0001] The invention relates, in general, to mechanical reducers for aircraft turbomachinery and relates more particularly to a toothed ring for such a reducer. Previous techniques

[0002] The role of a mechanical reducer is to modify the speed and torque ratio between the input shaft and the output shaft of a mechanical system.

[0003] With regard to aircraft turbomachinery, and in particular double-flow turbomachinery, especially those with a very high bypass ratio, the mechanical reducer has the role of driving the shaft of a fan by transforming the so-called high rotational speed of the shaft of a power turbine into a slower rotational speed for the shaft driving the fan.

[0004] Such a reducer comprises a central pinion, called a solar pinion, a ring gear and pinions called satellites which are meshed between the solar pinion and the ring gear.

[0005] The satellites are held by a chassis called a satellite carrier. The solar array, the corona, and the satellite carrier are planetary because their axis of revolution coincides with the longitudinal axis X of the turbomachine.

[0006] The satellites have different axes of revolution distributed over the same operating diameter around the axis of the planar elements

[0007] These axes are parallel to the longitudinal axis X.

[0008] There are several reducer architectures.

[0009] In the state of the art of double-flow turbomachinery, the reducers are of the planetary or epicyclic type.

[0010] In other similar applications, there are so-called differential architectures.

[0011] On a planetary reducer, the planet carrier is fixed and the ring constitutes the output shaft of the device which rotates in the opposite direction to the solar.

[0012] On an epicycloidal reducer, the ring is fixed and the planet carrier constitutes the output shaft of the device which rotates in the same direction as the sun.

[0013] On a differential reducer, no element is fixed for rotation. The ring rotates in the opposite direction to the sun and the satellite carrier.

[0014] Furthermore, reducers can be composed of one or more gearing stages.

[0015] This meshing is ensured in different ways, for example, by contact, by friction, or by magnetic field.

[0016] There are also several types of contact meshing, in particular with straight, helical or chevron teeth.

[0017] Generally, the crown of a gear train is made in two parts in order to make assembly possible.

[0018] This is particularly the case for herringbone gear trains.

[0019] Most often, the two half-crowns are bolted together, which requires drilling in each half-crown for the passage of assembly screws.

[0020] When assembling the half-crowns to form the gear ring, the screw holes must be perfectly aligned.

[0021] Similarly, the teeth must be aligned so that the meshing is correct.

[0022] For example, for a crown with 143 teeth and 80 screw holes, there are a single relative angular position of the two half-crowns which ensures at the same time that the screw holes and the teeth are aligned.

[0023] Thus, during assembly, the half-crowns must be oriented relative to each other as simply as possible to facilitate the assembly operation. There is only one angular position in which the half-crowns must be assembled. Description of the invention

[0024] In view of the foregoing, the object of the invention is to facilitate the assembly operation of a gear reducer toothed ring for aircraft turbomachine, which facilitates the identification of the relative angular position between two half-rings, during assembly.

[0025] The invention therefore relates to a toothed ring of a reducer for an aircraft turbomachine, comprising two parts each comprising a toothing and means for assembling the two parts by bolting them together.

[0026] This crown has markers configured to locate the relative angular positions of the two crown parts, the markers being positioned on the two crown parts so as to locate an alignment position of the teeth and the means of assembly of the two respective parts of the crown.

[0027] Thanks to the markings, the relative angular position between the two half-crowns, which must be respected during assembly, can be indicated on the parts by a marking so that, during assembly, the half-crowns can only be oriented in one possible position, when the markings are aligned.

[0028] For example, the markers include punches formed in the two crown parts, on the periphery of said crown part.

[0029] Advantageously, each crown part includes a pair of markers.

[0030] This pair of reference marks, which must be aligned with a corresponding pair of reference marks, makes it easier to align and to easily find the only possible alignment position of the two crown parts.

[0031] The invention also relates to a reducer for an aircraft turbomachine, comprising a geared reducer ring as defined above.

[0032] The invention finally relates to an aircraft turbomachine, comprising a reducer as defined above. Brief description of the drawings

[0033] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0034] Fig. 1 schematically illustrates a portion of an aircraft turbomachine, equipped with a reducer according to the invention;

[0035] Figure 2 is a perspective view of a portion of a toothed crown of the reducer of the [Fig.l];

[0036] Figure 3 is a cross-sectional profile view of the crown of Figure 2; and

[0037] Figure 4 is a side view of the assembly area of ​​the two parts of the toothed crown of figures 2 and 3. Detailed description

[0038] A turbomachine of aircraft 1, equipped with a reducer according to the invention, designated by the general numerical reference 2, is schematically represented in [Fig.1].

[0039] The invention relates essentially to the turbomachine reducer which is interposed between the blower 3 and the turbine shaft 4, only the elements relating to the reducer have been included in this [Fig.1].

[0040] Conventionally, the reducer 2 comprises a ring gear 5, a central pinion 6, called solar, connected to the turbine shaft 4 and a set of pinions 7, called satellites which are meshed between the ring gear 5 and the central pinion 6.

[0041] Referring also to [Fig.2], the crown 5 internally carries chevron teeth 8 which are intended to mesh with the satellites.

[0042] The crown 5 is however made in two paired parts 9 and 10 which are assembled using assembly means comprising annular flanges 12 and 13 having holes 14 for the passage of screws for the assembly of the two parts of the crown by bolting.

[0043] During assembly, in order to ensure that the holes 14 made in the annular flanges 12 and 13 are perfectly aligned and that the teeth 8 are also aligned, the crown has markings to indicate the relative position of the two crown parts.

[0044] These markers consist of punches or include punches regularly distributed around the peripheral surface of the annular flanges 12 and 13, these punches, such as 15, being positioned such that the punches of one of the flanges are aligned, parallel to the axis of rotation of the reducer, with the punches of the other flange. In this alignment position, the holes 14 of the two flanges are aligned and the teeth 8 are aligned, as can be seen in Figures 2 and 3.

[0045] Locally, the markers may include a pair of punch 15.

[0046] Such an arrangement facilitates the assembly operation, as the orientation of the two crown halves is indicated by the markings. Furthermore, thanks to the presence of the pair of markings that must be aligned with a corresponding pair of markings, there is only one possible angular position in which the markings are all aligned, which simplifies assembly since the assembler only needs to orient the two crown halves in one possible angular position.

Claims

Demands

1. Gear reducer ring gear for aircraft turbomachine, comprising two parts (9, 10) each comprising a tooth (8) and means for bolting the two parts together, characterized in that it has markers (15) configured to locate the relative angular positions of the two ring gear parts (9, 10), the markers being positioned on the two ring gear parts so as to locate an alignment position of the teeth and the means for assembling the two respective ring gear parts.

2. Crown according to claim 1, wherein the markers comprise punches (15) formed in the two crown parts, on the periphery of said crown parts.

3. Crown according to any one of claims 1 and 2, wherein each crown part comprises a pair of markers (15) intended to be aligned with a pair of corresponding markers.

4. Aircraft turbomachine reducer comprising a ring gear (5) according to any one of claims 1 to 3.

5. Aircraft turbomachine comprising a reduction gear according to claim 4.

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