FR3110933A1 - TURBOMACHINE EQUIPPED WITH ELECTRIC MACHINES - Google Patents

Abstract

TITLE: TURBOMACHINE EQUIPPED WITH ELECTRIC MACHINES The invention relates to a turbomachine comprising a fan, a first casing of longitudinal axis X in which is driven in rotation a motor shaft along the longitudinal axis, a second casing surrounding and coaxial with the first casing , and at least a first drive shaft connected on the one hand to the motor shaft and on the other hand, to at least one piece of equipment via a power transmission bevel gear device. According to the invention, the equipment is an electric machine which is intended to take or inject power on the motor shaft and in that the power transmission bevel gear device is housed in a casing formed of a one piece with the second housing (23). Figure for the abstract: Figure 2

Description

TURBOMACHINE EQUIPPED WITH ELECTRIC MACHINES

Field of invention

The present invention relates to the field of turbomachines for aircraft, and in particular turbomachines equipped with electric machines.

State of the art

An aircraft turbomachine such as a dual-flow turbomachine generally comprises a ducted fan disposed at the inlet of the turbomachine and which is driven in rotation by a low-pressure shaft. A reduction gear can be interposed between the fan and the low pressure shaft so that the fan rotates at a lower speed than that of the low pressure shaft. Reducing the speed also makes it possible to increase the size of the blower, thus making it possible to achieve high bypass ratios.

In addition to the propulsion of the aircraft, the turbomachine ensures the production of electric current typically using a permanent magnet alternator (generally called PMA meaning "Permanent Magnet Alternator") of an accessory box known as English acronym AGB (for Accessory Gear Box) to supply various equipment or accessories necessary for the operation of the turbine engine or the aircraft such as, for example, the lighting of the aircraft cabin, the operability of a conditioning system and air pressurization of the cabin of the aircraft or the supply of a pump for lubricating rotating members of the turbomachine.

It is known to equip the accessory box of an electric machine which is an electromechanical device based on electromagnetism allowing the conversion of electric energy, for example into mechanical energy (generator mode) or reversibly, allowing the production electricity from mechanical energy (motor mode). The electric machine can also behave in generator mode as well as in motor mode.

Faced with the environmental challenge in the aeronautical field and the growing electrical power needs concomitantly with the number of equipment and new functions of the aircraft, it is necessary to find and supplement these energy sources; the question of the hybridization of the turbomachine therefore arises.

The arrangement of the electric machine within the AGB does not make it possible to provide a significant gain in electric power for the increase in the electric power of all the functions of the aircraft and the efficiency of the conversion of the mechanical power into electrical power is not at its maximum. In addition, the integration of the electric machine in various zones of the turbomachine proves to be complex and is constrained by the size, the temperature resistance of certain components of the electric machine, the accessibility, the performance of the turbomachine itself -even, etc

The object of the present invention is in particular to provide a solution allowing the integration of one or more items of equipment in the turbomachine while avoiding penalizing the mass of the turbomachine.

We achieve this objective, in accordance with the invention, thanks to a turbomachine comprising a fan, a first casing of longitudinal axis X in which is driven in rotation a motor shaft along the longitudinal axis, a second casing surrounding and coaxial with the first casing, and at least one first drive shaft connected on the one hand to the motor shaft and on the other hand to at least one piece of equipment via a power transmission bevel gear device, the equipment being an electrical machine which is intended to take or inject power on the motor shaft and in that the power transmission bevel gear device is housed in a casing formed integrally with the second casing.

Thus, this solution achieves the above objective. In particular, thanks to the box and the second casing which are one-piece, the integration of the equipment, in particular the electric machine, is facilitated and avoids oversizing of the turbomachine casings.

The turbomachine also includes one or more of the following features, taken alone or in combination:

• the first drive shaft extends in a structural element which extends substantially radially at least partially between the first casing and the second casing.
• the structural member includes a stator vane that extends between the first housing and the second housing.
• the turbomachine comprises a third casing which is coaxial and surrounds the second casing, the second casing and the third casing at least partially delimiting a flow path for a flow of secondary air generated by the fan, and in that the electric machine is arranged in the flow channel.
• the power transmission bevel gear device includes a first input gear mounted on a first end of the first drive shaft and an output wheel mounted on a power transmission shaft coupled to the electric machine.
• the motor shaft carries an input wheel coaxial with the longitudinal axis X and cooperating with a first output pinion mounted at a second end of the first drive shaft.
• the turbomachine comprises two electric machines, respectively a first electric machine and a second electric machine, which are mounted in parallel and each connected to the motor shaft.
• a second drive shaft is connected, on the one hand, to the motor shaft and, on the other hand, to the second electric machine via a power transmission bevel gear device formed integrally with the second crankcase.
• the first and second drive shafts each extend along a substantially radial axis.
• the fan is driven by the motor shaft via a speed reducer.
• the first casing and the second casing delimit at least in part a flow path for a primary flow generated by the fan.
• the sprockets and the wheels are conical.

The invention also relates to a turbomachine comprising a fan, a first casing of longitudinal axis X in which a motor shaft is rotated along the longitudinal axis, a third casing surrounding the fan and coaxial with the first casing, and at least a first drive shaft connected on the one hand to the motor shaft and on the other hand to at least one piece of equipment via a power transmission bevel gear device, the equipment being an electric machine which is intended to take or inject power on the motor shaft and in that the power transmission bevel gear device is housed in a casing formed integrally with the third casing. This configuration also saves space and facilitates the integration of at least one piece of equipment, such as an electric machine in the turbomachine and avoids oversizing of the turbomachine casings. According to this embodiment, the electric machine can be arranged radially outside the third casing.

The invention also relates to a turbomachine comprising a fan, a first casing of longitudinal axis X in which a motor shaft is rotated along the longitudinal axis, a third casing surrounding the fan and coaxial with the first casing, and at least a first drive shaft connected on the one hand to the motor shaft and on the other hand to at least one piece of equipment via a power transmission bevel gear device, the equipment being an electric machine which is intended to take or inject power on the motor shaft and in that the power transmission bevel gear device is housed in a housing formed integrally with the first casing. This configuration also saves space and facilitates the integration of at least one piece of equipment, such as an electric machine in the turbomachine and avoids oversizing of the turbomachine casings. According to this embodiment, the electric machine can be arranged radially outside the first casing.

Brief description of figures

The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the following appended figures:

FIG. 1 is a schematic view in axial section of a turbofan engine according to the invention;

FIG. 2 is a schematic view, in axial section, partial and in detail, of another embodiment of a power transmission between a motor shaft of the turbomachine and equipment of the turbomachine according to the invention;

FIG. 3 is a schematic view of the arrangement of a motor shaft, of a power transmission and of an electric machine according to the invention;

FIG. 4 is a perspective view of another embodiment of an arrangement of several items of equipment connected to the turbine engine according to the invention; And

FIG. 5 is a schematic view, in axial section, partial and in detail, of another embodiment of a power transmission between a motor shaft of the turbomachine and equipment of the turbomachine according to the invention.

Detailed description of the invention

FIG. 1 shows an axial sectional view of a turbomachine 1 with longitudinal axis X to which the invention applies. The turbine engine represented is a double-flow, double-body turbomachine intended to be mounted on an aircraft. Of course, the invention is not limited to this type of turbomachine.

In the present application, the terms "upstream", "downstream", "axial" and "axially" are defined with respect to the direction of circulation of the gases in the turbomachine and also along the longitudinal axis (and even from left to right on Figure 1). The terms "radial", "radially", "internal" and "external" are also defined with respect to a radial axis Z which is perpendicular to the axis X of the turbomachine.

This turbomachine 1 with double flow and double body comprises a fan 2 which is mounted upstream of a gas generator or gas turbine engine 3. The fan 2 comprises a plurality of fan blades 4 which extend radially from the periphery of a disk 5 traversed by a fan shaft 6.

The turbomachine comprises a motor shaft which extends along the longitudinal axis X in a first casing. A second casing is mounted around and coaxial with the first casing. A third casing is mounted around and coaxial with the second casing. The third casing is also coaxial with the first casing.

The gas generator 3 comprises, from upstream to downstream and according to a schematic representation, a low pressure (LP) compressor 9, a high pressure (HP) compressor 10, a combustion chamber 11, a high pressure turbine 12 and a low turbine pressure 13. The HP compressor 10 is connected to the HP turbine via an HP shaft 14 centered on the longitudinal axis to form a first so-called high pressure body. The LP compressor is connected to the LP turbine via a LP 15 shaft centered on the longitudinal axis to form a second so-called low pressure body. The BP 15 shaft extends inside the HP 14 shaft.

The HP shaft 14, which is a first motor shaft, is rotated along the longitudinal axis in the first casing (called internal casing 16).

The fan 2 is surrounded by the third casing (called the fan casing 7) which is coaxial with the internal casing 16. The fan casing 7 is carried by a nacelle 8 which extends around the gas generator 3 and along the axis longitudinal X. The fan shaft 6 is connected to a second motor shaft which drives it in rotation around the longitudinal axis X.

An air flow F which enters the turbomachine via the fan 2 is divided by a separation nozzle 17 of the turbomachine into a primary air flow F1 which passes through the gas generator 3 and in particular in a primary stream 18, and in a secondary air flow F2 which circulates around the gas generator 3 in a secondary stream 19. The primary stream 18 and the secondary stream 19 are coaxial. The secondary air flow F2 is ejected by a secondary nozzle 20 terminating the nacelle 8 while the primary air flow F1 is ejected outside the turbomachine via an ejection nozzle 21 located downstream of the gas generator . The primary and secondary air flows meet at the outlet of their respective nozzles.

The primary vein 18 is delimited at least in part, radially, by the first casing (internal casing 16) and the second casing. The secondary stream 19 is for its part delimited at least in part, radially, by the second casing and the third casing (fan casing 7 with the nacelle 8). An inlet casing 22 carries the separation spout 15 upstream and is extended downstream by an inter-vein casing 23 which carries the ejection nozzle 21. The inter-vein casing 23 is here the second casing.

Stator blades, outlet guides (known by the acronym OGV) (not shown) which structurally connect the inlet casing 22 to the fan casing 7, extend substantially radially into the secondary air flow and around the longitudinal axis X.

In the present example, the second motor shaft is the BP shaft 15. A power transmission mechanism can be interposed between the fan shaft 6 and the BP shaft 15. The power transmission mechanism makes it possible to reduce the speed of the fan 2 at a lower speed than that of the BP shaft 15. On the other hand, the power transmission mechanism allows the arrangement of a fan with a large diameter so as to increase the bypass rate. The dilution rate of the fan is advantageously greater than 10. Preferably, the dilution rate is between 15 and 20.

Referring to Figure 1, the power transmission mechanism includes a reducer 24 which here is a planetary speed reducer. Of course a speed reducer with planetary gear is possible. The reducer is housed in a lubrication chamber arranged upstream of the gas generator 3 and the internal casing 16 which is annular. The speed reducer gear train 24 typically includes a sun gear (or inner sun gear) (not shown), a plurality of planet gears (not shown), a planet gear carrier (not shown), and a ring gear (outer planet gear) ( not shown). The solar is centered on the longitudinal axis X and is coupled in rotation with the BP shaft along the longitudinal axis X. The satellites are carried by the planet carrier and are each guided in rotation around a satellite axis, here, parallel to the longitudinal axis X. Each satellite meshes with external gearing of the sun gear and internal gearing of the crown. In the case of a planetary gear, the planet carrier is locked in rotation and is integral with a stator casing of the turbomachine, and the crown, centered on the longitudinal axis X, surrounds the sun gear and is coupled in rotation with the fan shaft. Conversely, in the case of the epicyclic gear train, the planet carrier is coupled in rotation with the fan shaft and the ring gear, which is fixed in rotation, is integral with a stator casing of the turbomachine.

Referring to Figures 1 to 5, the turbine engine comprises a drive shaft 25 which is connected on the one hand to the high pressure shaft 14 and on the other hand to at least one piece of equipment or an accessory of the turbine engine. The equipment is intended to take or inject power (mechanical or electrical) on the motor shaft (the high pressure shaft 14). The equipment comprises at least one member which is driven in rotation by the high pressure shaft 14 via the drive shaft. The drive shaft 25 extends substantially radially (with an inclined angle between 5° and 25° relative to the radial axis for example) or radially. This also passes through a structural element which extends substantially radially at least in part between the internal casing 16 and the fan casing 7 and/or the nacelle 8.

In the present example, the structural element is a casing arm 26 which structurally connects the inner casing 16 to the fan casing 7. Alternatively, the structural element is a stator vane (OGV). In this event, the stator vane would be mounted in place of the arm 26 or axially close to it.

Referring to Figures 1 and 2, the equipment comprises an electric machine 30.

The electrical machine 30 comprises a rotor and a stator so as to benefit from additional electrical power in the turbomachine, to supply various components of the turbomachine and/or of the aircraft. The electric machine 30 operates advantageously, but not limitatively, as a generator, that is to say that it allows the conversion of mechanical energy into electrical energy. In particular, it takes mechanical power to transform it into electrical energy. The electric machine can of course operate in motor mode so as to convert electrical energy into mechanical energy. The mechanical energy generated is injected into the turbomachine. In this example, the electric machine is reversible, i.e. it operates in generator and motor mode.

As we can see precisely in Figures 1 to 3, an input wheel 35 is carried by the high pressure shaft 14. This input wheel 35 is centered on the longitudinal axis X and bears on its radially outer surface a series of teeth. The input wheel 35 is advantageously conical. The speed reducer 24 is arranged upstream of this input wheel 35.

The electric machine 30 is coupled to a power transmission shaft 36 which has an axis of rotation A. The power transmission shaft 36 comprises at one end an output wheel 37. The output wheel 37 is centered on the axis of rotation A and is toothed. The output wheel is also tapered.

The substantially radial drive shaft 25 comprises a first end which carries a first input pinion 38 and a second end which carries a first output pinion 39. These pinions 38, 39 are provided with teeth and are conical.

The output wheel 37 of the power transmission shaft 36 meshes with the first input pinion 38 of the drive shaft 25 forming a bevel gear. The angle transmission transmits a rotational movement between two shafts that are not parallel. The output wheel 37 and the first input pinion 38 of the drive shaft 25 form a first power transmission bevel gear device 40. The latter is kinematically disposed between the drive shaft 25 and the electric machine 30.

Following the example of FIG. 1, the first power transmission bevel gear device 40 is housed in a box or transmission casing 41 (cf. FIGS. 2, 4 and 5) which envelops and supports the gears (formed sprockets and wheels). The housing 41 is hollow in other words. The casing 41 is integral with the fan casing 7 (third casing). Advantageously, the casing 41 is formed in one piece (either in one piece) with the fan casing. Alternatively, the casing 41 is fixed to the fan casing by means of a welding of threaded elements (screwed flanges, etc.), connecting rods or any other fixing means. According to another alternative, the box 41 is made in one piece with the nacelle 8.

According to another embodiment shown in Figure 2, the housing 41 which surrounds and supports the gears (formed pinions and wheels) is integral with the inter-vein housing 23 (second housing shown schematically). Advantageously, the housing 41 is integrally formed (or integral) with the inter-vein casing 23. The housing may project radially outward from a radially outer surface 47 of the inter-vein casing. so as to be bathed by the secondary air flow. Alternatively, the box 41 is fixed to the inter-vein casing 23 by means of a weld, threaded elements (screwed flanges, etc.), connecting rods or any other fixing means. In this case, the drive shaft 25 extends substantially radially between the inner casing 16 and the inter-vein casing 23.

According to yet another embodiment which is illustrated in FIG. 5, the casing 41 is made in one piece with the internal casing 16. The casing 41 is in particular integral with a wall 48 of the internal casing. The housing may project from a radially outer surface of the inner casing wall 16 or from a radially inner surface of the inner casing wall. Alternatively, the box 41 is fixed to the internal casing by means of a weld, threaded elements (screwed flanges, etc.), connecting rods or any other fixing means. In this case, the drive shaft extends substantially radially inside the internal casing 16.

These configurations (one-piece housing with the internal casing or with the inter-vein casing) allow the electric machine to be placed at most of the "core zone" of the turbomachine and being substantially parallel to the axis of the turbomachine. The “core zone” is located in the internal casing 16 or in the inter-vein casing 23 (ie between the primary vein 18 and the secondary vein 19). In addition, the core zone is a fire zone (around the combustion chamber).

The housing is made of a metallic material or a metallic alloy. Advantageously, but not limitatively, the metal material or alloy comprises steel, aluminum, magnesium, titanium or even a metal alloy.

The housing can be produced by an additive manufacturing process, by foundry or even by machining.

Advantageously, the stator of the electric machine is fixed to a fixed element and the rotor is linked to the kinematic chain. In particular, the stator is fixed to the casing 41. The latter is for example mounted on the internal wall of the casing. Alternatively, the stator is mounted on the internal wall of a casing 46 of the electric machine 30, which casing is fixed and also fixed to the casing 41. The casing 46 of the electric machine 30 can be, according to the embodiments described above, fixed to the internal casing 16, the internal-vein casing 23 or the fan casing 7. As for the rotor of the electric machine 30, the latter is coupled in rotation with the power transmission shaft 36 (outside or inside the case).

The housing 41 comprises a first face 42 which is provided with a through hole 43. Referring to Figure 2, the first face 42 is defined in a radial plane. The power transmission shaft 36, coupled to the electric machine 30, extends from the first face 42, crossing this through hole. The axis of the power transmission shaft is parallel to the longitudinal axis. Likewise, the power transmission shaft 36 extends at least partly inside the housing 41.

According to an exemplary embodiment, as represented in FIG. 1, the electric machine 30 is arranged radially outside the fan casing 7. Advantageously, the latter is installed in the nacelle 8. The latter offers more latitude for the integration of the electric machine because it is less encumbered by equipment than in other parts of the turbomachine.

In another embodiment such as that of Figure 2, the electric machine 30 is arranged in the flow path 19 of the secondary air flow. The electric machine is housed around the radially outer surface 47 of the inter-vein casing 23. Advantageously, but not limitatively, the electric machine 30 is arranged substantially flush with the radially outer surface 47 of the second casing, here of the casing inter-vein 23. The installation of the electrical machine at this location saves space. In addition, the secondary air flow from the secondary vein, in which the electrical machine extends, allows it to be cooled.

By the term substantially flush, we mean that the casing of the electrical machine can be mounted directly on the surface of the casings or be remote from it so as to allow air circulation.

Furthermore, the input wheel 35 meshes with the first output pinion 39 of the drive shaft 25 forming a bevel gear. In particular, the input wheel 35 and the first output pinion 39 form a second power transmission bevel gear device 45 which is disposed between the high pressure shaft 14 and the drive shaft 25 as shown below. is illustrated in Figures 1 and 3. The cooperation between the input wheel 35 and the first output pinion 39 ensures, during a rotation of the high pressure shaft 14 along the longitudinal axis, the rotation also of the drive shaft 25 along its substantially radial axis. In this way, the rotation of the drive shaft causes the rotation of the power transmission shaft 36 along its axis of rotation A. In the case of Figures 1, 2 and 5, the axis of rotation of the The power transmission shaft is parallel to the longitudinal axis X.

Thus, in the case of motor operation of the electric machine, the power transmission shaft 36 supplies it with mechanical power during its rotation and which will be converted into electrical power. This additional electrical power will be available once the turbomachine has started, and in particular, during flight and in the landing phase. The electrical energy can advantageously be stored in an energy storage element on board the aircraft, such as a battery or at least one fuel cell, with the aim of supplying energy to the electrical machine 30. The electric machine and the storage element are electrically connected.

The turbomachine is also equipped with an electric motor which is intended to be supplied with electric current by the electric machine (in motor mode). For this purpose, the electric motor and the electric machine 30 are electrically connected by electrical wiring. This electric motor is arranged at the level of the fan casing and downstream of the electric machine. In the case of power injection on one of the motor shafts, the electrical power produced by the electric machine is sent to the motor shaft via the electric motor or alternatively via the battery or the cell. The electrical power drives the drive shaft in rotation which in turn drives the motor shaft, here the high pressure shaft 14. This makes it possible to improve the performance of the motor for example and to reduce fuel consumption to supply the combustion chamber 11.

According to an embodiment illustrated in FIG. 4, the turbomachine comprises two electric machines, namely a first electric machine 30 and a second electric machine 30'. These two machines 30, 30' are arranged parallel to each other. The numerical references are retained for identical or substantially identical elements and/or having the same function. In this exemplary embodiment, the first electric machine 30 is mounted in a manner similar to the embodiments illustrated in FIGS. 1 to 3 and 5. A second drive shaft 25', extending substantially radially, is connected by a hand, to the high pressure shaft 14, and secondly to the second electric machine 30 '. The first end of the second drive shaft 25' includes a second input gear and the second end of the second drive shaft 25' includes a second output gear 39'. The latter meshes with the input wheel 35. The second input pinion meshes with the second output wheel of a second power transmission shaft. These pinions also form a bevel gear and are housed in a one-piece casing 41' with the fan casing or with the inter-vein casing 23 or even with the internal casing 16. The two power transmission shafts extend parallel relative to each other. The power transmission shaft of the second machine 30' extends at least partially into the other housing 41'.

The two electric machines 30, 30' operate simultaneously and create redundancy so as to have more mechanical or electrical power. In particular, this makes it possible to have a minimum of power available if one of the electrical machines fails. According to an exemplary embodiment, the electric machines 30, 30' can operate independently of one another.

The axes of the first and second power transmission shafts are defined in the same radial plane, perpendicular to the longitudinal axis. The first and second drive shafts substantially form a V, with the apex of the V formed by the input wheel 35.

The machine(s) 30, 30' is/are configured to inject mechanical power into the high-pressure shaft by the electric motor which drives it in rotation.

Claims (10)

Turbomachine (1) comprising a fan (2), a first casing (16) of longitudinal axis X in which is driven in rotation a motor shaft (14, 15) along the longitudinal axis, a second casing (23) surrounding and coaxial with the first casing (16), and at least one first drive shaft (25) connected on the one hand to the motor shaft (14, 15) and on the other hand, to at least one piece of equipment via a device power transmission bevel gear (40), characterized in that the equipment is an electric machine (30, 30') which is intended to take or inject power on the motor shaft (14, 15) and in that the power transmission bevel gear device (40) is housed in a casing (41) formed integrally with the second casing (23). Turbomachine (1) according to the preceding claim, characterized in that the first drive shaft (25) extends in a structural element which extends substantially radially at least partly between the first casing (16) and the second casing (23). Turbomachine (1) according to the preceding claim, characterized in that the structural element comprises a stator vane which extends between the first casing (16) and the second casing (23). Turbomachine (1) according to any one of the preceding claims, characterized in that it comprises a third casing (7) which is coaxial and surrounds the second casing (23), the second casing (23) and the third casing (7 ) at least partially delimiting a flow path (19) of a secondary air flow generated by the fan (2), and in that the electric machine (30, 30') is arranged in the flow path flow (19). Turbomachine (1) according to any one of the preceding claims, characterized in that the power transmission bevel gear device (40) comprises a first input pinion (38) mounted on a first end of the first transmission shaft. drive (25) and an output wheel (37) mounted on a power transmission shaft (36) coupled to the electric machine (30, 30'). Turbomachine (1) according to any one of the preceding claims, characterized in that the motor shaft (14, 15) carries an input wheel (35) coaxial with the longitudinal axis X and cooperating with a first output pinion (39) mounted at a second end of the first drive shaft (25). Turbomachine (1) according to any one of the preceding claims, characterized in that it comprises two electric machines (30, 30'), respectively a first electric machine (30) and a second electric machine (30, 30'), which are mounted in parallel and each connected to the motor shaft (14, 15). Turbomachine (1) according to the preceding claim, characterized in that a second drive shaft (25') is connected on the one hand to the motor shaft (14, 15) and on the other hand to the second electric machine (30') via a power transmission bevel gear device (40') formed integrally with the second casing (23). Turbomachine (1) according to Claim 7 or 8, characterized in that the first and second drive shafts (25, 25') each extend along a substantially radial axis. Turbomachine (1) according to any one of the preceding claims, characterized in that the fan (2) is driven by the motor shaft (14, 15) via a speed reducer (24).