FR3116305A1 - CONNECTING SHAFT OF A HIGH PRESSURE BODY OF A TURBOMACHINE - Google Patents

Abstract

The invention relates to a connecting shaft (200) of a turbomachine high-pressure body, said connecting shaft (200) being configured to couple in rotation a rotary module, said connecting shaft (200) comprising a body (220) having at one of its ends an annular flange (210) configured to be coupled to the rotary module (100), said connecting shaft (200) being characterized in that it comprises a first circumferential groove (230) formed at the body wall (220) in a region adjacent said annular flange (210) and extending at least partially over a circumferential portion of the body wall (220). Abstract Figure: Figure 1.

Description

CONNECTING SHAFT OF A HIGH PRESSURE BODY OF A TURBOMACHINE

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the field of turbomachines, and is aimed in particular at the high pressure part of a turbomachine.

The invention relates more particularly to a high-pressure body of a turbomachine, and in particular a connecting module, such as a connecting shaft of a high-pressure body of a turbomachine.

TECHNICAL BACKGROUND

In the present application, the terms “upstream” and “downstream” are defined with respect to the normal flow direction of the gas (from upstream to downstream) through a turbomachine.

The "turbomachine axis" or "engine axis" is also called the axis of rotation of a turbomachine rotor. The axial direction corresponds to the direction of the axis of the turbomachine and a radial direction is a direction perpendicular to the axis of the turbomachine and intersecting this axis. Similarly, an axial plane is a plane containing the axis of the turbomachine, and a radial plane is a plane perpendicular to this axis.

Unless specified otherwise, the adjectives "interior", "internal", "exterior", "external" are used in the present application with reference to a radial direction so that the interior part of an element is, in a radial direction, closer to the axis of the turbomachine than the outer part of the same element.

Conventionally, a turbomachine comprises, upstream to downstream, that is to say in the direction of flow of the gas flows, a fan, one or more compressors, a combustion chamber, one or more turbines, and a nozzle for ejecting the combustion gases leaving the turbine or turbines.

The rotating assembly of a compressor is mechanically connected to the rotating assembly of a turbine, the rotating assembly of the turbine driving the rotating assembly of the compressor by recovering the energy resulting from the combustion of the gases in the chamber combustion.

The rotating assembly of a compressor attached to a rotating turbine assembly forms an assembly called the casing. A turbomachine can conventionally comprise one or more bodies, generally two or three rotating at different speeds.

Thus, a two-spool turbomachine comprises a low-pressure rotating body and a high-pressure rotating body.

In order to make the assembly of a turbomachine easier and to reduce the assembly and disassembly time thereof, the architecture of a rotating body is often compartmentalized and divided into different modules assembled together by flanges rings and bolted connections.

For example, for a high-pressure rotary body of a twin-spool turbomachine, there is a first rotary assembly upstream for the high-pressure compressor part and a second rotary assembly downstream for the low-pressure turbine part, the two rotary assemblies being assembled by means of a connecting module, or connecting shaft, and specific flanges able to transmit the engine torque from the turbine part to the compressor part of the body.

The connection between the rotating assemblies upstream and downstream and the connecting shaft must be strong enough to fulfill this function given the high thermomechanical stresses.

Given the torques to be transmitted and the temperature conditions, this connection zone is a critical zone, the seat of significant mechanical stresses.

Thus, the service life of this type of flanges is quite low and critical to the part. It is the critical area of the part that generates a more frequent change of this part. .

An object of the invention is to propose a solution making it possible to reduce the mechanical stresses undergone by the flanges of the connecting shaft of a high-pressure body during operation of the turbomachine, in order to increase the life of these flanges and therefore of the connecting shaft.

To this end, the subject of the invention is a connecting shaft of a high-pressure body of a turbomachine, said connecting shaft being configured to couple in rotation a rotary module, and comprising a body having at one from its ends an annular flange configured to be coupled to the rotary module, said connecting shaft being characterized in that it comprises a first circumferential groove formed at the level of the wall of the body in a region adjacent to said annular flange and extending at least partially over a circumferential portion of the body wall.

The production of a circumferential groove on the body of the connecting shaft at the level of a region close to the annular coupling flange makes it possible to create a zone of flexibility at the level of the body, in a portion close to the axial of the bolted connections , thus making it possible to promote local elastic deformation of the body close to the flange and to reduce the stresses at the level of the coupling connections of the annular flange of the connecting shaft with the rotary module.

Thus, thanks to the invention, the service life of the annular coupling flange of a connecting shaft of a turbomachine high-pressure body is increased.

Advantageously, said first circumferential groove is located at a distance d of less than 50mm from a radial coupling face of said annular flange, preferably said first circumferential groove is positioned at a distance d of between 15mm and 20mm from the radial coupling face of the annular flange. Thus, the zone of flexibility created by the reduction in thickness at the level of the groove is close to the annular flange.

Advantageously, the first circumferential groove is formed on a radially outer surface of the wall of the body or on a radially inner surface of the wall of the body. Thus, it is possible to adapt the invention according to the surrounding constraints and the possibilities of machining.

Advantageously, the first circumferential groove has a concave shape or a U-shape with a flat bottom.

Advantageously, the first circumferential groove has a maximum depth of between 20% and 30% of the thickness of the wall of the body. Thus, this local reduction in thickness from 20% to 30% makes it possible to guarantee a certain flexibility of the body of the connecting shaft in operation while ensuring sufficient resistance for the transmission of the engine torque.

Advantageously, said first circumferential groove is formed on a radially outer surface of the wall of the body and in that said connecting shaft comprises a second circumferential groove formed on a radially inner surface of the wall of the body, the first circumferential groove and the second circumferential groove being superposed radially one above the other. Thus, the stresses are evenly distributed in the thickness of the body wall.

Advantageously, said first circumferential groove and the second circumferential groove are configured to generate a 20% to 30% reduction in the thickness of the wall of the body.

Advantageously, said annular flange is an upstream annular flange configured to be coupled to an upstream rotary module.

Advantageously, the connecting shaft comprises an upstream annular flange configured to be coupled to an upstream rotary module and a downstream annular flange configured to be coupled to a downstream rotary module, said connecting shaft comprising a first circumferential groove provided at the level of the wall of the body in a region adjacent to said upstream annular flange and/or in a region adjacent to the downstream annular flange.

The invention also relates to a high-pressure turbomachine body comprising an upstream high-pressure compressor rotary module, a downstream high-pressure turbine rotary module, and a connecting shaft according to the invention coupled at its upstream annular flange to the upstream high pressure compressor rotary module and coupled at its downstream annular flange to the downstream high pressure turbine rotary module.

The invention also relates to a twin-spool turbomachine comprising a high-pressure spool according to the invention.

The invention and its various applications will be better understood on reading the following description and examining the accompanying figures.

BRIEF DESCRIPTION OF FIGURES

The figures are presented for information only and in no way limit the invention.

There illustrates a view in axial section along the turbomachine axis X of a portion of a high-pressure body of a turbomachine, illustrating more particularly the connection of the rotary assembly of a high-pressure compressor and a shaft connection according to the invention connected downstream to a rotating assembly of a high pressure turbine.

There is a perspective view illustrating the upstream portion of the connecting shaft shown in .

There is an axial sectional view along the turbomachine axis X of an upstream portion of the connecting shaft illustrated in .

There is an axial sectional view along the turbomachine axis X of an upstream portion of a second embodiment of a connecting shaft according to the invention.

There is an axial sectional view along the turbomachine axis X of an upstream portion of a third embodiment of a connecting shaft according to the invention.

There is an axial sectional view along the turbomachine axis X of an upstream portion of a fourth embodiment of a connecting shaft according to the invention.

Unless specified otherwise, the same element appearing in different figures has a single reference.

DETAILED DESCRIPTION

There illustrates a view in axial section along the turbomachine axis X of a portion of a high pressure body 10 of a turbomachine, illustrating more particularly the connection between a high pressure compressor module 100 and a connecting shaft 200 according to invention, the connecting shaft 200 also being integral downstream with a high-pressure turbine module (not shown).

It is recalled that a high pressure rotary body of a turbomachine is an assembly composed of an upstream rotary module forming the high pressure compressor module and a downstream rotary module forming the high pressure turbine module, the two modules being assembled by the through a connecting shaft 200 and specific flanges configured to transmit the engine torque from the high pressure turbine module to the high pressure compressor module.

The high pressure compressor module 100 comprises a plurality of mobile compressor discs, each mobile disc having a hub extending radially towards the inside of the turbomachine and a rim forming the radially outer part of the disc on which a plurality of vanes compressor is mounted.

The moving compressor discs are secured to each other via upstream and/or downstream annular flanges and by means of bolted connections.

On the one can see on the left of the figure a downstream annular flange 111 of a downstream compressor disk 110 of the high pressure compressor module 100.

On the compressor module 100, it is known to mount a sealing disc 300 downstream of the last mobile compressor disc 110. This sealing disc 300 has a symmetry of revolution with respect to the axis X of the turbomachine.

• un moyeu 310 s’étendant vers une direction radialement interne de la turbomachine et dont l’épaisseur croit en allant vers l’axe X de turbomachine ;
• une virole de couplage 320 présentant une pluralité d’alésages régulièrement reparties autour de l’axe X de turbomachine ;
• des lames annulaires 330 s’étendant sensiblement selon une direction radiale par rapport à l’axe X de la turbomachine , les lames annulaires 330 formant la partie tournante d’un joint d’étanchéité 400 de type labyrinthe.

The sealing disc 300 comprises:

• a hub 310 extending towards a radially internal direction of the turbomachine and whose thickness increases as it goes towards the axis X of the turbomachine;
• a coupling shroud 320 having a plurality of bores regularly distributed around the axis X of the turbomachine;
• annular blades 330 extending substantially in a radial direction with respect to the axis X of the turbomachine, the annular blades 330 forming the rotating part of a seal 400 of the labyrinth type.

The sealing disc 300 is also used as a coupling element between the high pressure compressor module 100 upstream and the connecting shaft 200 downstream.

The upstream face of the coupling ring 320 cooperates with the downstream annular flange 111 of the downstream compressor disk 110 and the downstream face of the coupling ring 320 cooperates with an upstream annular flange 210 of the connecting shaft 200.

The assembly is fixed by bolting via bolted connections 150.

The bolted connections 150 have a through member 151 having a head and a rod passing through a bore machined in the downstream annular flange 111, a bore in the coupling shell 320, as well as a bore machined in the upstream annular flange 210 of the connecting shaft. The through member 151 cooperates with a nut 152 to ensure the coupling of the parts.

The connecting shaft 200 comprises a body 220 of substantially cylindrical shape extending along the axis X of the turbomachine and having a wall of substantially constant thickness. On either side of the body 220, the connecting shaft 200 comprises an annular flange 210 for coupling the connecting shaft both to the high pressure compressor module 100 and to the high pressure turbine module (not shown). The body 220 and the annular flanges 210 are integral.

There illustrates in perspective the upstream end of the connecting shaft 200 and in particular a zone close to the upstream annular flange 210.

The upstream annular flange 210 comprises a plurality of holes 211 machined and configured to allow the passage of a through member 151 of a bolted connection 150. The holes 211 are regularly distributed around the axis X of the turbomachine.

The connecting shaft 200 according to the invention further comprises at least one groove 230 arranged circumferentially with respect to the axis X of the turbomachine. The circumferential groove 230 is formed at the level of the cylindrical wall of the body 220.

Advantageously, the circumferential groove 230 has a symmetry of revolution with respect to the axis X of the turbomachine.

Advantageously, the circumferential groove 230 extends over the entire periphery of the wall of the body 220.

Advantageously, the circumferential groove 230 extends at least over a circumferential portion of the wall of the body 220.

Advantageously, the circumferential groove 230 is formed by several portions extending at the periphery of the wall of the body 220 and distributed angularly in a uniform and equidistant manner.

The circumferential groove 230 forms a depression or cavity making it possible to locally reduce the thickness of the cylindrical wall of the body 220.

For this purpose, the illustrates an axial sectional view along the turbomachine axis X of the upstream portion of the connecting shaft 200 of the .

Advantageously, the circumferential groove 230 has a maximum depth of the order of 20% to 30% of the thickness of the cylindrical wall of the body 220 at the level of the circumferential cavity 230.

The circumferential groove 230 can have different shapes. Advantageously, it has a rounded shape so as to limit sharp edges.

For example, according to a first exemplary embodiment illustrated in and at the , the circumferential groove 230 is of concave shape, for example in the shape of a half-moon.

According to a second exemplary embodiment illustrated in , the connecting shaft 200a may have a circumferential groove 230a having the shape of a U with a flat bottom.

The circumferential groove 230, 230a, 230b, 230c can be made at the level of the radially outer surface 221 of the body 220 as shown in and in [fig. 3] or even at the level of the radially inner surface 222 of the body 220 as shown in a third embodiment of a connecting shaft 200b illustrated in .

According to a fourth exemplary embodiment illustrated in , the connecting shaft 200c may comprise two circumferential grooves 230c, for example each of smaller dimensions than the circumferential groove represented with reference to the , a first circumferential groove 230c formed at the level of the radially outer surface 221 of the body 220 and a second circumferential groove 230c formed at the level of the radially inner surface 222 of the body 220.

The two circumferential grooves 230c are for example superposed radially one above the other as illustrated in , or they may have an axial offset relative to the axis X of the turbomachine.

The circumferential groove 230, 230a, 230b, 230c is formed in a region of the body 220 close to the upstream annular flange 210. By way of example, the circumferential groove 230, 230a, 230b, 230c is formed at a distance d less than 50mm from the upstream coupling radial face 212 of the upstream annular flange 210.

By way of example, the circumferential groove 230, 230a, 230b, 230c can be arranged at a distance d of between 15mm and 20mm from the upstream radial coupling face 212 of the upstream annular flange 210.

Advantageously, the circumferential groove 230, 230a, 230b, 230c is positioned axially close to the upstream annular flange 210 and the bolted connections 150.

Advantageously, the circumferential groove 230, 230a, 230b, 230c is positioned axially at the level of the upstream end of the body 220 of the connecting shaft 200, 200a, 200b, 200c, that is to say at the level of the "virtual" junction between the body 220 of constant thickness and the start of the upstream annular flange 210, the downstream end of which is symbolized by an increase in the thickness of the wall of the connecting shaft 200, 200a, 200b, 200c.

The circumferential groove or grooves 230, 230a, 230b, 230c are produced for example by machining.

The production of a circumferential groove 230, 230a, 230b, 230c at the level of the body 220 of the connecting shaft 200, 200a, 200b, 200c makes it possible to create a zone of flexibility at the level of the body 220, in a portion near axial of the bolted connections, thus making it possible to promote local elastic deformation of the body 220 and to reduce the stresses at the level of the bolted connections of the upstream annular flange 210 of the connecting shaft 200 but also of the coupling ring 320 of the disc d waterproofness 300.

Thus, thanks to the invention, the service life of the coupling parts of a turbomachine high-pressure body, and in particular of a connecting shaft, is increased.

The invention has been particularly described at the level of the annular coupling flange upstream of the connecting shaft between the connecting shaft and the high pressure compressor module. However, the invention is also applicable at the level of an annular flange downstream of a connecting shaft coupled to the high pressure turbine module. Thus, all of the characteristics and embodiments described above with reference to the upstream side of the connecting shaft are also applicable to the downstream side of the connecting shaft.

The invention is also applicable to any coupling part comprising annular flanges and bolted connections of a high-pressure body of a turbomachine.

Claims (11)

Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body, said connecting shaft (200, 200a, 200b, 200c) being configured to couple in rotation to a rotary module, said connecting shaft ( 200, 200a, 200b, 200c) comprising a body (220) having at one of its ends an annular flange (210) configured to be coupled to the rotary module (100), said connecting shaft (200, 200a, 200b, 200c) being characterized in that it comprises a first circumferential groove (230, 230a, 230b, 230c) formed at the level of the wall of the body (220) in a region adjacent to said annular flange (210) and s' extending at least partially over a circumferential portion of the body wall (220). Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body according to the preceding claim, characterized in that said first circumferential groove (230, 230a, 230b, 230c) is located at a distance d of less than 50 mm from a radial coupling face (212) of said annular flange (210). Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that the first circumferential groove (230, 230a, 230b, 230c) is formed on a surface radially outer surface (221) of the body wall (220) or on a radially inner surface (222) of the body wall (220). Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that the first circumferential groove (230, 230a, 230b, 230c) has a concave shape or a U-shape with a flat bottom. Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that the first circumferential groove (230, 230a, 230b, 230c) has a maximum depth of between 20% and 30% of body wall thickness (220). Connecting shaft (200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that the said first circumferential groove (230c) is provided on a radially outer surface (221) of the wall of the body (220) and in that said connecting shaft (200c) comprises a second circumferential groove (230c) provided on a radially inner surface (222) of the wall of the body (220), the first circumferential groove and the second circumferential groove being superposed radially l one above the other. Connecting shaft (200c) of a turbomachine high-pressure body according to the preceding claim, characterized in that the said first circumferential groove (230c) and the second circumferential groove (230c) are configured to generate a reduction of 20% to 30% of the thickness of the body wall (220). Connecting shaft (200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that said annular flange (210) is an upstream annular flange configured to be coupled to an upstream rotary module (100). Connecting shaft (200, 200a, 200b, 200c) of a turbomachine high-pressure body according to one of the preceding claims, characterized in that it comprises an upstream annular flange (210) configured to be coupled to an upstream rotary module (100) and a downstream annular flange configured to be coupled to a downstream rotary module, said connecting shaft (200, 200a, 200b, 200c) comprising a first circumferential groove (230, 230a, 230b, 230c) provided at the level of the wall of the body (220) in a region adjacent to said upstream annular flange (210) and/or in a region adjacent to the downstream annular flange. High-pressure body of a turbomachine comprising:

• a high pressure compressor upstream rotary module (100);
• a rotary module downstream of the high pressure turbine:
• a connecting shaft (200, 200a, 200b, 200c) according to the preceding claim coupled at its upstream annular flange (210) to the upstream rotary module of the high pressure compressor (100) and coupled at its downstream annular flange to the module downstream of the high pressure turbine.

Turbomachine comprising a high-pressure body according to the preceding claim.