FR3054265A1 - TRAINING A ROTOR OF EQUIPMENT IN A TURBOMACHINE - Google Patents

Abstract

An aircraft turbomachine, comprising: - a fan wheel (S) having an axis of rotation A, - at least one rotor shaft configured to drive the fan wheel (S) about said axis A, - a cone (28) a rotation axis air inlet A, and - an equipment (30) comprising a stator (34) and a rotor (32) of axis of rotation A, and situated in the vicinity of the fan wheel and / or the inlet cone, characterized in that the stator of the equipment is integral with the blower wheel and in that the rotor of the equipment is secured to a bladed wheel (35) configured to be traversed and driven by a flow of air (F) taken in operation at said air intake cone.

Description

TECHNICAL AREA

The present invention relates to the driving of an equipment rotor in a turbomachine.

STATE OF THE ART

Conventionally, an aircraft requires electrical and hydraulic energy from a turbomachine in addition to the thrust. On traditional turbomachinery, this power is taken mechanically from the high pressure shaft (HP) to drive the input shaft of an accessory box (AGB, Accessory Gear Box) placed on a casing of the turbomachine. This input shaft is rotated by a transmission shaft driven by a pinion secured to the HP shaft. An electrical (generator) or hydraulic (pump) conversion unit is then placed on this accessory box.

There are engine architectures, in particular turboprop or Open Rotor, which have a particularity with regard to the supply of engine functions: some of these functions are placed in a rotating reference frame. Indeed, the propeller pitch control mechanism as well as the defrosting of these propellers are fully rotating.

Whether in electrical or hydraulic, systems are therefore needed to transmit energy from a rotating reference to a fixed reference. For electrical energy (used mainly for defrosting), a rotating collector system can be used, with all the negative impacts on the life of the system that this implies. A rotary transformer can also be used, as in document W0-A1-2009 / 128724. Many solutions have been devised for the hydraulic pitch timing system (see for example document CA-A1-2 813 366). All these solutions are complex to integrate and maintain because they are very buried in the engine. Environmental constraints can become strong and require good management of the tightness of the systems.

An alternative solution to avoid having to transfer energy is to install this generator radially inside the blower wheel or even also inside the air inlet cone located just upstream of the blower wheel. . The problem with such an installation is as follows: there is no fixed part to which to link the stator in this space. The solutions are therefore limited:

- either make a rotating stator, by connecting the stator (or the rotor) to the low pressure shaft (BP) and the other to the high pressure shaft (HP); it is however complicated to do in most of the targeted architectures, the two transmission lines not generally being accessible from the blower wheel;

- either we manage to bring a housing element inside the air intake cone; the only way on a conventional engine being to bring it from the rear engine through the BP shaft (itself crossing the HP body), but this has a large number of drawbacks (stiffness, mass, and we again undergoes the high temperatures of the combustion gas ejection cone located downstream of the engine).

- Either adding a structure fixing the air inlet cone to the fan casing to hold the stator, as in document FR-A1-2 919 896; however, this is not ideal as this structure causes losses in aerodynamic performance.

The state of the art also includes documents FR-A1-2 878 286 and W0-A1-2015 / 128563.

The present invention provides in particular a simple, effective and economical solution to the above problem, by proposing an alternative to current technologies.

STATEMENT OF THE INVENTION

The invention provides an aircraft turbomachine comprising:

- a fan wheel having an axis of rotation A,

- at least one rotor shaft configured to drive the fan wheel around said axis A,

- an air inlet cone of axis of rotation A, and

an item of equipment comprising a stator and a rotor of axis of rotation A, and located in the vicinity of the fan wheel and / or of the inlet cone, characterized in that the stator of the equipment is integral with the wheel of blower and in that the rotor of the equipment is integral with a bladed wheel configured to be traversed and driven by a flow of air taken in operation at said air inlet cone.

Thus, the difference in speeds between the rotor and the stator of the equipment depends on the difference in speeds between the rotor of the equipment and the fan wheel. Unlike a real turbine, the air flow taken is not intended to provide energy to the rotor of the equipment: it just serves to impose an aerodynamic torque on it without necessarily making it rotate (therefore by limiting losses), thus causing a speed difference between the rotor and the stator.

The present invention is based on a decoupling of the rotational speeds of the stator and the rotor of the equipment. In other words, in the rotary reference linked to the stator (speed of rotation of the fan wheel), the rotor could have a counter-rotating movement. One can also imagine that the stator and the rotor rotate in the same direction but not at the same speed, the rotor being for example just braked. In order to achieve this, various means can be envisaged and will be described below.

The turbomachine according to the invention comprises one or more of the following characteristics, taken in isolation from one another or in combination with each other:

- said equipment is electrical equipment, such as a generator, or a pump, in particular for lubrication,

- said equipment is a machine generating electrical, hydraulic or pneumatic energy from a difference in rotational speed,

- said air inlet cone is located upstream of the fan wheel,

- said cone comprises at least one substantially axial orifice for withdrawing air flow and supplying the bladed wheel,

- Said cone comprises a first part secured to the blower wheel and a second part secured to the bladed wheel, the first and second parts delimiting between them at least one substantially axial orifice for withdrawing air flow and supplying the bladed wheel,

- said at least one orifice opens into an annular duct extending around said axis A,

- said duct has a generally tubular shape around the axis A and is crossed substantially radially by arms,

- said arms are arranged upstream of the bladed wheel and the air inlet cone comprises two parts, respectively radially internal and external, connected by these arms,

- said arms are arranged downstream of the bladed wheel and the stator of the equipment is connected by these arms to a radially external part of the ejection cone,

the equipment rotor is guided in rotation about said axis A by means of a first upstream bearing located upstream of the bladed wheel and a second downstream bearing located downstream of the equipment, and

- The stator of the equipment is fixed to the blower wheel by an annular wall pierced with axial air passage holes, such as the aforementioned air flow after crossing the bladed wheel.

DESCRIPTION OF THE FIGURES

The invention will be better understood and other details, characteristics and advantages of the invention will appear on reading the following description given by way of non-limiting example and with reference to the accompanying drawings in which:

- Figure 1 is a very schematic half-view in axial section of a turbomachine,

FIG. 2 is a very schematic partial view in axial section of a turbomachine according to the invention,

FIG. 3 is a very diagrammatic view in axial section of an embodiment of a turbomachine according to the invention,

FIG. 4 is a very schematic view in axial section of another embodiment of a turbomachine according to the invention, and

- Figure 5 is a schematic view in axial section of an exemplary embodiment of a turbomachine according to the invention.

DETAILED DESCRIPTION

Referring to Figure 1, we see a turbomachine 1 of the turbofan type with double flow and double body which comprises, conventionally, from upstream to downstream (in the direction of gas flow along the longitudinal axis A of the turbomachine), a fan S, a low pressure compressor 1a, a high pressure compressor 1b, a combustion chamber 1c, a high pressure turbine 1 d, a low pressure turbine 1e and an exhaust nozzle 1h.

The rotors of the high pressure compressor 1b and the high pressure turbine 1d are connected by a high pressure shaft 2 and form with it a high pressure body (HP). The rotors of the low pressure compressor 1a and of the low pressure turbine 1e are connected by a low pressure shaft 3 and form with it a low pressure body (BP).

The BP and HP compressors are separated from each other by an intermediate casing 22. This type of casing comprises a hub 22a and a ferrule 22b surrounding the hub and connected to the latter by substantially radial arms 22c passing through the veins 24 , 26 of the primary and secondary flows, respectively. The primary flow or hot flow is that which flows inside the engine, from the BP compressor 1a to the BP turbine 1e and the nozzle 1h, and the secondary flow or cold flow flows around the engine. The air flow which enters the turbomachine and which passes through the fan S is divided by an annular separator 27 into a radially internal part which enters the LP compressor forming the primary flow, and into a radially external part which forms the flow secondary. A downstream extension 27a of the separator 27 is carried by the arms 22b of the intermediate casing.

In the configuration shown which relates to a conventional turbojet, without reduction gear, the disc on which the blades of the fan S are mounted is driven by a fan shaft 4, or LP journal, which is itself directly driven by the BP shaft 3. An air inlet cone 28 is mounted upstream of the fan wheel S and is integral in rotation with the latter.

FIG. 2 illustrates the general principle of the invention which consists in integrating a rotor equipment 30 in the vicinity of the fan wheel S and the inlet cone 28. This equipment 30 is for example an electric generator and comprises a rotor 32 of axis A and a stator 34 which surrounds the rotor. In the example shown, the stator is connected by conductors to a unit 33 such as a battery. The stator 34 of the equipment 30 is secured to the blower wheel S and the rotor 32 of the equipment is secured to a bladed wheel 35 configured to be traversed and driven by a flow of air F taken in operation at the level of the air inlet cone 28.

FIG. 3 represents a first embodiment of the invention in which the air intake cone 28 is entirely integral with the fan wheel S. The cone 28 comprises two annular parts, respectively radially internal 28a and external 28b. The radially external part 28b has a substantially frustoconical shape flared towards the downstream and the radially internal part 28a has a conical shape flared towards the downstream. The two parts of the cone 28 are separated axially from one another so as to define between them an axial annular passage or an annular row of axial orifices 36 for the removal of the aforementioned air flow F. The two parts of the cone 28 are interconnected by arms 38 or fixed vanes of substantially radial orientation relative to the axis A.

The passage or the orifices 36 of the cone 28 opens (s) into an annular conduit 40 of generally tubular shape and extending substantially around the axis A. In the example shown very schematically, the conduit 40 is delimited radially to the exterior by a substantially cylindrical wall 42 integral with the cone 28 and connected at its upstream longitudinal end substantially at the level of the external radial ends of the arms 38 or fixed blades. The duct 40 is delimited radially inside, on the one hand by a substantially cylindrical upstream wall 44 integral with the cone 28 and connected to the internal radial ends of the arms 38 or fixed blades, and on the other hand to a downstream wall 46 substantially cylindrical secured to the stator 34 of the equipment, this stator being secured to the fan wheel S.

Between the radially internal upstream 44 and downstream 46 walls of the duct 40 is arranged the bladed wheel 35 integral with the rotor 32 of the equipment 30. This wheel 35 comprises an annular row of substantially radial vanes which extend substantially over the entire height or radial dimension of the vein defined by the conduit 40.

In this embodiment, the bladed wheel 35 can be qualified as resistance because it will aim to slow down as much as possible the rotation of the rotor 32 of the equipment 30 relative to the stator 34. Ideally, the bladed wheel 35 is made so as to generate a torque in the opposite direction to the rotation of the blower S.

FIG. 4 represents an alternative embodiment of the invention in which the air intake cone 28 ′ comprises two independent parts, respectively radially internal 28a ’and external 28b’. The radially external part 28b ’has a substantially frustoconical shape flared towards the downstream and the radially internal part 28a’ has a conical shape flared towards the downstream. The radially external part 28b ’is integral with the fan wheel S and thus rotates with the latter. On the contrary, the radially internal part 28a ’is not secured to the wheel S and therefore not rotated with it. The two parts of the cone 28 ′ are separated axially from one another so as to define between them an axial annular passage or an annular row of axial orifices 36 ′ for the removal of the aforementioned air flow F.

The passage or the orifices 36 'of the cone 28' opens (s) into an annular conduit 40 'of generally tubular shape and extending substantially around the axis A. In the example shown very schematically, the conduit 40' is delimited radially on the outside by a substantially cylindrical wall 42 'integral with the part 28b' of the cone and connected at its longitudinal upstream end substantially at the level of the external radial ends of the arms 38 'or fixed vanes. The duct 40 'is delimited radially inside, on the one hand by an upstream wall 44' substantially cylindrical integral with the conical part 28a 'of the cone and the rotor 32. This wall 44' is connected by its longitudinal end upstream to the conical part 28a ′ of the cone and by its downstream longitudinal end to the internal radial ends of the blades of the bladed wheel 35 ′. The conduit 40 ′ is also delimited radially on the inside by a downstream wall 46 ’substantially cylindrical secured to the radially external part 28b’ of the cone and the stator 34 of the equipment. This wall 42 ′ is connected by its longitudinal upstream end to the internal radial ends of the arms 38 ′ or fixed blades whose external radial ends are connected to the external radial wall 42 ′ of the conduit 40 ′, and by its longitudinal downstream end to the stator 34 equipment.

The paddle wheel 35 ’can also be described as resistance in this variant embodiment.

Figure 5 is a detailed embodiment of the embodiment of Figure 3 in which the cone 28 is fully integral in rotation with the fan wheel S. The reference numerals and the description used with reference to Figure 3 are used in Figure 5 to designate the same elements.

FIG. 5 makes it possible on the one hand to show the means for fixing the equipment 30, and in particular of its stator 34, to the fan wheel S. The stator 34 of the equipment has a generally tubular shape and is connected at its periphery, substantially in its middle along the axis A, at a substantially frustoconical wall 50 flared downstream and connected at its external periphery to an external radial flange 52 for attachment to the fan wheel S. In the 'example shown, this flange 52 is sandwiched between an internal radial flange 54 located at the downstream end of the cone 28, and an internal radial flange 56 located at the upstream end of the blower disc. The frustoconical wall 50 comprises an annular row of axial orifices 58 for passage of the air flow F leaving the duct 40.

FIG. 5 also illustrates an example of the means for guiding and centering the rotor 32 of the equipment 30. In the example shown, these means comprise bearings 60, 62 with bearings and more particularly with balls. There are two of them, respectively upstream and downstream of the equipment.

The upstream bearing 60 is located on a circumference centered on the axis A of diameter smaller than that of the circumference of the downstream bearing 62. The upstream bearing 60 is located upstream of the bladed wheel 35, substantially radially inside the arms 38 or fixed vanes of the cone 28. The upstream bearing 60 comprises an external ring integral with the internal periphery of a substantially frustoconical wall 64 whose external periphery is connected to the radially internal part 28a of the cone, substantially at the radially internal ends arms 38. The inner ring of the upstream bearing 60 is secured to a longitudinal end upstream of a substantially cylindrical wall 66 of axis A, the downstream longitudinal end of which is connected to the disc of the bladed wheel 35, at its internal periphery. This disc is also connected to the rotor 32 of the equipment by a cylindrical wall 68 of axis A extending in the extension of the above-mentioned wall 66.

The downstream bearing 62 is located downstream of the equipment, radially inside the fan wheel S. It is located on a circumference axially aligned with the annular space 70 located between the rotor 32 and the stator 34 of the equipment 30. The downstream bearing 62 comprises an outer ring 72 secured to the inner periphery of a wall 73 substantially frustoconical whose outer periphery is connected to the stator 34 of the equipment, and an inner ring 74 secured to the outer periphery d 'A wall 75 substantially frustoconical whose internal periphery is connected to the rotor of the equipment. The rotor 32 is thus directly linked to the stator 34 by the bearing 62. This limits the deflection of the rotor 32 as much as possible, and therefore maximizes the efficiency of the generator.

In another alternative embodiment, not shown, the bladed wheel 35 also forms a resistance turbine, but this is powered by a series of scoops placed on the air inlet cone. In this configuration, ίο the scoops would be placed at an angle to the axis A to be at best aligned with the air flow according to the rotation of the blower S.

In the embodiments described in the foregoing, the mechanical torque applied by the paddle wheel 35, 35 ’may vary depending on the instantaneous aerodynamic conditions. It is conceivable to protect the system against reversal of direction by a mechanical system such as a ratchet system between the rotor 32 and the stator 34 of the equipment. To stabilize the speed and keep the paddle wheel 35, 35 'as immobile as possible, it can be associated with an inertial system with for example flyweights or a flywheel (which can be the disc retaining the blades of the wheel blown). The variant of Figure 4 presented above is a possible application, with the inlet cone 28 'which acts as inertia.

The problem of no longer supplying the functions of the cone 28, 28 ’with the rest of the engine is that one can lose the additional functions linked to this link. For example, with a conventional synchronous electric generator, it would require power electronics to drive it. One solution could be to use a Permanent Magnet Generator (PMG) instead. Such a machine would not need piloting: the electronic unit would therefore be limited to monitoring / protection functions, and could be adapted to the powers necessary for the functions of a cone 28, 28 ’(<10kW). This power would be compatible with the difficulty of cooling the oil in this area.

Alternatively, the power electronics can be provided in the air inlet cone: the environment is not problematic, and its supply could be by winding the generator or a small additional generator. In addition, defrosting, if it is done with so-called “resistive” technologies (heating mat, etc.), does not need a high quality electrical network: we are just trying to dissipate the energy, this which will limit the associated electronics.

Certain functions (variable timing, defrosting, etc.) are controlled by the aircraft or the engine control unit. We can therefore have a means of transmitting the command from the fixed part of the engine to the cone 28, 28 ’. The transmission of information from the fixed reference to the rotating reference is easier than that of power. We can consider several possible solutions: information rotary connectors (more reliable than for power), optical connection, connection by magnetic field (ex: wifi / wireless, etc.). For certain functions (defrosting), we could also have a system independent of the rest of the engine and managing its needs itself.

A specific problem of this system is the generation of power at zero aircraft speed. When the engine is not started, there is no problem: the functions do not have to be powered. When the engine is started but the aircraft is stopped, we still have to provide power. Several solutions are possible for this:

- or to take the air downstream of the blower, since it is in idle rotation on certain engine architectures; depending on the engine configuration, it is possible in the same way to take samples at the inlet of the primary or cold / primary flow;

- or to force an air flow, for example by putting blades in compressor configuration (fixed relative to the cone) upstream of the rotor.

The need to accommodate particles (sand, ice, etc.) can also be taken into account. It may therefore be preferable to place the air intake in a favorable configuration (e.g. behind the blower / in the secondary vein: sand filtration, etc.).

Finally, it is preferable to generate energy from the lowest speed of rotation of the motor during which we want to use the functions of the front cone: for this, we will probably put a reduction gear (planetary gear, etc.) upstream of the rotor and allowing to adapt its speed.

Claims (10)

1. Aircraft turbomachine (1), comprising: - a fan wheel (S) having an axis of rotation A, - at least one rotor shaft (3) configured to drive the fan wheel (S) around said axis A, - an air inlet cone (28) with a rotation axis A, and - an equipment (30) comprising a stator (34) and a rotor (32) of axis of rotation A, and located in the vicinity of the fan wheel and / or the inlet cone, characterized in that the stator of the equipment is secured to the blower wheel and in that the rotor of the equipment is secured to a bladed wheel (35) configured to be traversed and driven by an air flow (F) taken in operation at the level said air inlet cone. 2. Turbomachine (1) according to claim 1, characterized in that said equipment (30) is electrical equipment, such as a generator, or a pump in particular for lubrication. 3. Turbomachine (1) according to claim 1 or 2, characterized in that said cone (28) comprises at least one orifice (36) substantially axial for taking air flow (F) and supplying the bladed wheel (35). 4. Turbomachine (1) according to claim 1 or 2, characterized in that said cone (28) comprises a first part (28b) integral with the fan wheel (S) and a second part (28a) integral with the bladed wheel (36), said first and second parts delimiting between them at least one orifice (36) substantially axial for sampling air flow (F) and supplying the bladed wheel. 5. Turbomachine (1) according to claim 3 or 4, characterized in that said at least one orifice (36) opens into an annular duct (40) extending around said axis A. 6. Turbomachine (1) according to the preceding claim, characterized in that said duct (40) has a generally tubular shape around the axis A and is crossed substantially radially by arms (38). 7. Turbomachine (1) according to the preceding claim, characterized in that said arms (38) are arranged upstream of the bladed wheel (35) and the cone (28) of air inlet comprises two parts, respectively radially internal (28a) and external (28b), connected by these arms. 8. Turbomachine (1) according to claim 6, characterized in that said arms (38) are arranged downstream of the bladed wheel (35) and the stator (34) of 10 the equipment is connected by these arms to a radially external part (28b) of the ejection cone. 9. Turbomachine according to one of the preceding claims, characterized in that the rotor (32) of the equipment is guided in rotation about said axis A by means of a first upstream bearing (60) located upstream of 15 the paddle wheel and a second downstream bearing (62) located downstream of the equipment. 10. Turbomachine according to one of the preceding claims, characterized in that the stator (34) of the equipment (30) is fixed to the fan wheel (S) by an annular wall (50) pierced with axial orifices ( 58) for air passage. 1/3 22b co CN σ> 2/3 28 ' 28b ' 3/3 S