FR3126459A1 - Aircraft turbojet comprising a turbojet shaft and a shaft stiffener. - Google Patents

Abstract

Aircraft turbojet comprising an assembly (100), the assembly (100) comprising an aircraft turbojet shaft (109) extending along a central axis (∆) of the turbojet, the shaft (109) being hollow so as to define a recess (110) along the central axis (∆), a stiffener (120) arranged in the recess (110), and a connecting piece extending from the stiffener (120) to the shaft (110 ) so as to rigidly link the stiffener (120) and the shaft (109), the connecting part being configured to allow a fluid located in the recess (110) on one side of the connecting part with respect to the central axis to flow to the other side of the connecting piece. Figure for abstract: Fig. 4

Description

Aircraft turbojet comprising a turbojet shaft and a shaft stiffener.

FIELD OF THE INVENTION

The invention relates to the rotating parts of aircraft turbojet engines and in particular the low-pressure turbine shaft.

STATE OF THE ART

Aircraft turbojets comprising a fan and a low-pressure compressor driven in rotation by a low-pressure turbine via a low-pressure turbine shaft are known.

There schematically represents a low-pressure turbine shaft 9 extending along an engine axis Δ.

The turbine shaft 9 is hollow so as to define an interior space which extends in the direction of the motor axis Δ. With the aim of circulating lubricant, this interior space is occupied by a central vent tube 90 (also known in English by the term “ Center Vent Tube ” abbreviated as CVT) which defines a lubricant circuit at the inside the turbine shaft and sealed off from it.

Joints J1, J2, J3 and J4 are arranged around the central vent tube 90 in different axial positions in order, on the one hand, to maintain the different parts of the central vent tube 90 with respect to the low-pressure turbine shaft 9 and on the other hand prevent a fluid flowing in the central vent tube 90 from coming out of it. The connection between the central vent tube 90 and the low-pressure turbine shaft 9 is made impermeable by the various seals J1, J2, J3 and J4.

In this configuration, the dimensioning of the turbine shaft is constrained by the assembly of the central vent tube and the mechanical flexibility of the shaft is adjusted by modifying the thicknesses, the internal shapes and the external shapes of the shaft.

In order to adapt to a greater diversity of the neighborhood surrounding the shaft, there is a need to manufacture low-pressure turbine shafts with a greater range of geometries, shapes and mechanical flexibility than in the prior art. .

There is therefore a need for a shaft structure having more degrees of freedom to adjust its dimensions and mechanical properties.

An object of the invention is to provide a low-pressure shaft whose structure has more degrees of freedom to adjust the dimensions and the mechanical properties.

The object is achieved in the context of the present invention thanks to an aircraft turbojet engine comprising an assembly, the assembly comprising:
- an aircraft turbojet shaft extending along a central axis of the turbojet, the shaft being hollow so as to define a recess along the central axis,

- a stiffener arranged in the recess, and

- - a connection piece extending from the stiffener to the shaft so as to rigidly connect the stiffener and the shaft, the connection piece being configured to allow a fluid located in the recess on one side of the connecting piece with respect to the central axis to flow to the other side of the connecting piece.

The use of the recess in the turbomachine shaft to house a stiffener therein makes it possible to adjust the flexibility and the mechanical properties of the shaft by the choice of shape of the stiffener.

Such a turbojet is advantageously and optionally supplemented by the following different characteristics taken alone or in combination:

- the stiffener comprises a central part extending along the central axis, the central part being solid;

- the stiffener comprises a plurality of branches, each branch extending radially from the central part to the shaft, each section of the stiffener in a plane transverse to the central axis having at least three axes of symmetry;

- each branch extends along the central axis over an entire length of the stiffener;

- the shaft and the stiffener are made of different materials.

The invention also relates to an aircraft comprising a turbojet as just presented.

DESCRIPTION OF FIGURES

Other characteristics and advantages of the invention will emerge from the description which follows, which is purely illustrative and not limiting, and must be read in conjunction with the appended drawings in which:

there , already introduced, is a schematic representation of a low-pressure turbine shaft according to the prior art;

there schematically represents an aircraft turbojet engine; And

FIGS. 3 and 4 schematically represent an assembly composed of a low-pressure turbine shaft and a stiffener.

Claims (6)

Aircraft turbojet engine (1) comprising an assembly (100), the assembly (100) comprising:
- an aircraft turbojet engine shaft (109) extending along a central axis (∆) of the turbojet engine (1), the shaft (109) being hollow so as to define a recess (110) along the central axis ( ∆),
- a stiffener (120) arranged in the recess (110), and
- a connecting piece (122) extending from the stiffener (120) to the shaft (110) so as to rigidly connect the stiffener (120) and the shaft (109), the connecting piece (122) being configured to allow fluid located in the recess (110) on one side of the link piece (122) relative to the central axis to flow to the other side of the link piece (122). Aircraft turbojet according to Claim 1, in which the stiffener (120) comprises a central part (123) extending along the central axis (∆), the central part (123) being solid. Aircraft turbojet engine (1) according to Claim 2, in which the stiffener (120) comprises a plurality of branches (124, 126, 128), each branch (124, 126, 128) extending radially from the central part (123 ) up to the shaft (109), each section of the stiffener (120) in a plane transverse to the central axis (∆) having at least three axes of symmetry (S1, S2, S3). Aircraft turbojet engine (1) according to Claim 3, in which each branch (124, 126, 128) extends along the central axis (∆) over an entire length of the stiffener (120). Aircraft turbojet (1) according to one of the preceding claims, in which the shaft (109) and the stiffener (120) are made of different materials. Aircraft comprising a turbojet engine according to one of the preceding claims.