FR3110932A1 - TURBOMACHINE EQUIPPED WITH ELECTRIC MACHINES - Google Patents

Abstract

TITLE: TURBOMACHINE EQUIPPED WITH ELECTRIC MACHINES The invention relates to a turbomachine (1) comprising a fan (2), a first casing (16) with a longitudinal axis in which a motor shaft (14, 15) is driven in rotation along the longitudinal axis X, a second casing surrounding and coaxial with the first casing (16), and a drive shaft (25) connected on the one hand to the motor shaft (14, 15) and on the other hand to at least two pieces of equipment via a bevel transmission device (40). According to the invention, each item of equipment comprises an electric machine (30, 30') which is intended to take off and inject power on the motor shaft (14, 15) and in that the bevel transmission device of (40) is housed in a casing (41) from which extend at least two power transmission shafts (36) each coupled to an electric machine (30, 30'). Figure for the abstract: Figure 1

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 using typically 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 with a longitudinal axis in which is driven in rotation a motor shaft along the longitudinal axis X, a second casing surrounding and coaxial with the first casing, and a drive shaft connected, on the one hand, to the motor shaft and, on the other hand, to at least two pieces of equipment via a power transmission bevel gear device, each piece of equipment comprising a 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 from which extend at least two power transmission shafts each coupled to an electric machine.

Thus, this solution achieves the above objective. In particular, the configuration of a single casing housing the mechanical transmission device and of a single drive shaft facilitates the integration of several pieces of equipment such as electrical machines to increase the mechanical and electrical powers in the turbomachine and allows a gain in axial bulk.

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

• the casing of the power transmission bevel gear device is formed integrally with a casing, which is preferably the second casing.
• the drive shaft extends in a structural element which extends substantially radially at least partly between the first casing and the second casing.
• the structural element is a housing arm or a stator vane which extends at least partially between the first housing and the second housing.
• the first power transmission bevel gear comprises a first input gear mounted on a first end of the drive shaft and two output wheels each respectively mounted on a power transmission shaft which is coupled to a 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 drive shaft.
• the electrical machines are arranged so as to form a V between them.
• the drive shaft extends along a substantially radial axis.
• the turbomachine comprises a third casing which is coaxial and extends around the second casing, the second casing and the third casing defining at least in part a flow path for a secondary air flow generated by the fan, and that the electrical machines are housed around an outer surface of the second casing, in the flow path.
• the electric machine can be arranged radially outside the third casing.
• the electrical machines are housed in the nacelle.
• the fan is driven by the motor shaft via a speed reducer.
• the drive shaft extends substantially radially at least partially in the housing.
• the power transmission bevel gear device and the electrical machines are housed in the first casing or in a third casing which delimits with the second casing at least in part a flow path for a flow of secondary air generated by the blower.
• the casing of the power transmission bevel gear device is formed integrally with the third casing.
• the casing of the power transmission bevel gear device is formed integrally with the first casing or with the second casing.
• the first casing and the second casing delimit at least in part a flow path for a flow of primary air generated by the fan.
• the sprockets and the wheels are conical.
• a single drive shaft is connected to the motor shaft and to the two pieces of equipment.

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 of an embodiment of a power transmission between a motor shaft of the turbomachine and at least one item of equipment of the turbomachine with a substantially radial drive shaft according to the invention;

FIG. 3 is a schematic view of another embodiment of a power transmission between an engine shaft and at least one piece of turbomachine equipment according to the invention;

Figure 4 is a perspective view of the embodiment of Figure 2;

Figure 5 is a perspective view of the embodiment of Figure 3; And

FIG. 6 is a schematic view, in axial section, partial and in detail, of an 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 ratio. 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.

With reference to FIGS. 1, 2, 4 and 6, the turbomachine 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 turbomachine. 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 25. 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. In the present embodiment, there are at least two electric machines 30, 30 'coupled to the high pressure shaft 14 by the shaft of workout 25.

Each electrical machine 30, 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, 30' operates advantageously, but not limited to, 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. Each electric machine 30, 30' 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 6, 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 25.

Each electric machine 30, 30' is coupled to a power transmission shaft 36 which has an axis of rotation A. Each power transmission shaft 36 includes an output wheel 37 at one end. The output wheel 37 is centered on the axis of rotation A and is toothed. Each output wheel 37 is also tapered. Advantageously, each rotor of an electric machine 30, 30' is rotationally coupled with a power transmission shaft 36.

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.

Each 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 of each power transmission shaft and the first input pinion 38 of the drive shaft 25 form a first power transmission bevel gear device 40. The latter is disposed between the drive shaft 25 and the electric machine(s) 30, 30'.

The first power transmission angle transmission device 40 is housed in a casing or transmission casing 41 which envelops and supports the gears (formed of pinions and wheels). In other words, the case 41 is hollow. A single (single) box is provided here for the coupling of electrical machines.

A single (or single) drive shaft 25 is connected to the two electric machines 30, 30' via a single first power transmission bevel gear device 40. The two power transmission shafts 36 which are each coupled to an electric machine 30, 30' extend from the housing 41. Each power transmission shaft 36 extends at least partially inside the housing 41.

Referring to Figure 1, the housing 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 weld, 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.

The casing 41 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 box 41 can be made by an additive manufacturing process, by foundry or even by machining.

The housing 41 comprises a first and a second face 42a, 42b which are each provided with a through hole 43 (cf. figure 6). Each first and second face 42a, 42b is defined in a substantially radial plane. The axis of each orifice is perpendicular to the plane in which a first face 42a or a second face 42b is defined. The power transmission shaft 36, coupled to an electric machine 30, 30', extends from one of the first and second faces 42, crossing a through hole.

In the present embodiment, the axis of each power transmission shaft 36 is transverse to the longitudinal axis X. In particular, as we can see in Figure 4, the axes of the power transmission shafts 36 form a V. Similarly, the axes of rotation A extend in the same plane. The electric machines also extend on either side of the case. The configuration of these electric machines makes it possible to have a gain in terms of axial size.

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

In another embodiment such as that of Figures 2 and 6, the electrical machines 30 are arranged in the flow path 19 of the secondary air flow. The electrical machines are housed around a radially outer surface 47 of the inter-vein casing. Advantageously, but not limitatively, each electric machine 30, 30′ is arranged substantially flush with the radially outer surface 47 of the second casing. Installing the electric machine at this location saves space. In addition, the secondary flow of the secondary vein, in which the electrical machines extend, makes it possible to cool them.

By the term substantially flush, we mean that the enclosures of electrical machines 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 another power transmission angle transmission device 45 which is arranged between the high pressure shaft 14 and the drive shaft 25. 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 25 generates the rotation of the power transmission shafts 36 of each electric machine 30, 30' along its axis of rotation A.

Thus, in the case of motor operation of the electric machines, the power transmission shafts 36 provide 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 be stored advantageously 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 machines 30, 30 '. Each 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 each electric machine (in motor mode). To this end, the electric motor and each electric machine 30, 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 each electric machine is sent to the motor shaft (high pressure shaft) via the electric motor or alternatively via the battery or the cell. The electrical power drives the drive shaft 25 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 engine for example and to reduce fuel consumption for feed the combustion chamber 11.

According to another embodiment illustrated in FIGS. 3 and 5, the turbomachine comprises two electric machines 30, 30' which are also driven by the motor shaft (high-pressure shaft 14) via a first transmission bevel gear device mechanical. The numerical references are retained for identical or substantially identical elements and/or having the same function. This embodiment differs from the first embodiment in that there is no drive shaft which extends into a structural member, substantially radially, between the inner casing and the fan casing. The drive shaft 25 extends inside the housing 41 of the first power transmission bevel gear device 40 which is arranged in the internal casing 16 or in the inter-vein casing 23. According to a variant embodiment, the drive shaft extends radially into the inner casing or into the inter-vein casing (and out of the casing of the casing 41). Advantageously, but not limitatively, the electric machines are arranged close to or in the “core zone” 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 41 of the power transmission bevel gear device 41 is here formed in one piece with the internal casing 16 (first casing). The housing may project from a radially outer or inner surface of the inner housing 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. This configuration allows it to be placed at most of the "core zone" of the turbomachine and being substantially parallel to the axis of the turbomachine.

According to another embodiment shown in Figure 6, the housing 41 of the power transmission bevel gear device 41 is here formed in one piece with the inter-vein casing 23 (second casing). In this case, the casing may project radially outwards from the radially outer surface 47 of the inter-vein casing 23. Alternatively, the casing 41 is fixed to the inter-vein casing 23 by means of welding, threaded elements (screwed flanges, etc.), connecting rods or any other means of attachment. The first output gear 39 of the drive shaft is located outside the housing 41. The first output gear 39 meshes with the input wheel of the high pressure shaft.

Advantageously, the stator of each 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, 30', which casing is fixed and also fixed to the casing 41. The casing 46 of the electric machine 30 can be, depending on the modes embodiment described above, fixed to the inner casing 16, the inner-vein casing or the fan casing. As for the rotor of each electric machine 30, 30′, this is coupled in rotation with the power transmission shaft 36.

The two electrical machines operate simultaneously and create redundancy so that more mechanical or electrical power is available. 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 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) with a longitudinal axis in which a motor shaft (14, 15) is driven in rotation along the longitudinal axis X, a second casing (23) surrounding and coaxial with the first casing (16), and a drive shaft (25) connected on the one hand to the motor shaft (14, 15) and on the other hand to at least two items of equipment via a return device power transmission angle (40), characterized in that each piece of equipment comprises an electric machine (30, 30') which is intended to take or inject power on the motor shaft (14, 15) and in that the bevel gear device for transmitting power (40) is housed in a casing (41) from which extend at least two power transmission shafts (36) each coupled to an electric machine (30, 30'). Turbomachine (1) according to the preceding claim, characterized in that the casing (41) of the power transmission bevel gear device (40) is formed in one piece with a casing, which is preferably the second casing (23). Turbomachine (1) according to one of the preceding claims, characterized in that the drive shaft (25) extends in a structural element which extends substantially radially at least partly between the first casing (16) and the second housing (23). Turbomachine (1) according to the preceding claim, characterized in that the structural element is a casing arm (26) or a stator vane which extends at least in part between the first casing (16) and the second casing ( 23). 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 shaft drive (25) and two output wheels (37) each respectively mounted on a power transmission shaft (36) which is coupled to an 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 drive shaft (25). Turbomachine (1) according to any one of the preceding claims, characterized in that the electric machines (30, 30') are arranged so as to form a V between them. Turbomachine (1) according to any one of the preceding claims, characterized in that the drive shaft (25) extends along a substantially radial axis. Turbomachine (1) according to any one of the preceding claims, characterized in that it comprises a third casing (7,8) which is coaxial and extends around the second casing (23), the second casing and the third casing delimiting at least in part a flow path (19) of a secondary air flow generated by the fan (2) and in that the electric machines (30) are housed around an external surface (47) of the second housing (23), in the flow path (19) 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).