• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Turbomachine (10) comprising a fan shaft (12) driven by a turbine shaft (16) via a device (20) for reducing the speed of rotation, said turbine engine comprising means (28) for decoupling interposed between the reduction device (20) and the fan shaft (18), which are able to decouple the reduction device (20) from the fan shaft (18), characterized in that the reduction device (18) 20) is coupled to the fan shaft via a curvic trapezoidal gear coupling (17) having said decoupling means (28), said decoupling means (28) being configured to decouple the device (20) and the blower shaft (18) in response to exceeding a determined resistive torque (CD), said decoupling torque exerted between the blower shaft (18) and the blower unit (20). reduction.
    公开号:FR3061242A1
    申请号:FR1663359
    申请日:2016-12-23
    公开日:2018-06-29
    发明作者:Gilbert Roland Brault Michel；Fabien Patrick Becoulet Julien；Nicolas Negri Arnaud；Jean-Louis Yvon Didier
    申请人:Safran Aircraft Engines SAS；
    IPC主号:
    专利说明:

    @ Holder (s): SAFRAN AIRCRAFT ENGINES.
    O Extension request (s):
    Agent (s):
    GEVERS & ORES Public limited company.
    * 54) TURBOMACHINE COMPRISING A MEANS OF DECOUPLING OF A BLOWER.
    FR 3,061,242 - A1 (57) Turbomachine (10) comprising a fan shaft (12) driven by a turbine shaft (16) by means of a device (20) for reducing the speed of rotation, said turbomachine comprising decoupling means (28) interposed between the reduction device (20) and the fan shaft (18), which are capable of decoupling the reduction device (20) and the fan shaft (18), characterized in that the reduction device (20) is coupled to the blower shaft by means of a coupling (17) with trapezoidal teeth of curvic type which comprises said decoupling means (28), said decoupling means (28) being configured to decouple the reduction device (20) and the fan shaft (18) in response to the exceeding of a determined resistive torque (C D ) said decoupling torque exerted between the fan shaft (18) and the reduction device (20).

    Turbomachine comprising a means for decoupling a fan
    The field of the present invention is that of aeronautical turbomachines and, more particularly that of double-flow turbomachines comprising a reduction device for driving the fan.
    Conventionally, turbomachines comprise, starting from upstream, one or more compressor modules arranged in series, which compress air drawn into an air inlet. The air is then introduced into a combustion chamber where it is mixed with a fuel and burned. The combustion gases pass through one or more turbine modules which drive the compressor (s) via associated turbine shafts. The gases are finally ejected either in a nozzle to produce a propelling force or on a free turbine to produce power which is recovered on a transmission shaft.
    Current double-flow turbomachines with high dilution rate comprise several compressor stages, in particular a low pressure compressor (BP) and a high pressure compressor (HP), through which a primary flow passes. These low pressure (BP) and high pressure (HP) compressors are each driven by an associated respective low pressure (BP) or high pressure (HP) turbine shaft. Upstream of the low pressure compressor (BP) is arranged a wheel comprising large blades or moving blades, or blower, which feeds both the primary flow passing through the BP and HP compressors and a cold flow, or secondary flow, which is directed directly to a cold flow nozzle, called a secondary nozzle. The blower is driven by the LP turbine rotation shaft of the BP body and generally rotates at the same speed as it.
    It may be advantageous to rotate the blower at a rotational speed lower than that of the LP shaft, in particular when the latter is very large, in order to better adapt it aerodynamically. For this, there is a reduction device between the BP turbine shaft and a blower shaft, which carries the blower. Such a configuration is described in particular in patent applications FR-1,251,655 and FR-1,251,656 filed on February 23, 2012.
    In this configuration, it can happen that the fan loses a blade, for example in the event of ingestion of a foreign body such as a bird. This phenomenon, also known by the term Anglo-Saxon called "Fan Blade Out" (FBO) causes an eccentricity of the blower having the consequence of causing contact of the ends of its blades with the casing of the blower. This contact can suddenly brake the blower even though the reduction device and the turbine shaft are still driven by the LP turbine, which can create a high torque in the BP turbine shaft and in the reduction device. .
    The torsion of the shafts can lead to ruptures of the shafts at different points of the turbomachine, as taught by document EP-2,048,330-A2.
    Document EP-2,048,330-A2 discloses a turbomachine comprising a fan shaft and a compressor shaft each driven by a turbine shaft via two different torque paths coupled to the turbine shaft at the level an intersection arranged at a landing. The torque path drives the blower through a reduction device. The two torque paths are designed so that, in the event of a fortuitous break in one of the torque paths, the turbine remains loaded on the other torque path in order to avoid overspeeds of the turbine, while a unit of Turbine control can reduce the speed of the turbine. The turbomachine described in this document starts from the observation that a possible mechanical malfunction of the torque paths can occur, such as that which links the turbine shaft to the fan. However, this document does not explicitly specify the nature of this malfunction, which may or may not consist of a rupture, but which is in any case fortuitous and unpredictable. In the case of a break in the torque path of the turbine shaft to the blower, this accidental break occurs while the reduction device has already been subjected to significant torques and has probably already been damaged.
    Document EP-1,439,316-B1 describes and represents a turbomachine comprising a fan coupled to a shaft line by means of a reduction device. A decoupling device, which is interposed between a shaft of the blower and the reduction device allows the decoupling of the blower shaft in case of loss of a blade thereof. The triggering of the decoupling of the decoupling device is based on an axial displacement of the fan shaft due to the detection of an unbalance caused by the loss of a blade of the fan. The device comprises a first flange secured to a bearing support of the blower shaft and a second flange secured to the casing, arranged opposite the first flange, which surrounds this shaft, and which is coupled to the first flange by a first set of fuse screws. The unbalance causes the first set of fusible axial screws to rupture, which causes the axial separation and the advancement of the fan shaft. The device also comprises, downstream of these flanges, two plates of a coupling with straight teeth. A first plate is linked to the fan shaft and a second plate is linked to an input shaft of the reduction device. These plates are coupled by a second set of fusible screws. When the first set of fusible axial screws is broken, the blower shaft advances and drives the first plate so that the heads of the second set of fusible axial screws strike the second flange secured to the casing and break by shearing, which causes rupture of the coupling.
    This design has the disadvantage of subjecting the rupture of the coupling between the blower shaft and the reduction device only to the presence of an unbalance acting on the blower, and of not taking into account the resistant torsional torque exerted between the blower and the reduction device. In particular, this device cannot allow the decoupling of the blower in the event of seizure of the reduction device.
    In addition, this device has the drawback of triggering the rupture of the coupling as soon as an unbalance is present in the blower, and can therefore trigger the rupture of the coupling even while the blower, although operating with an unbalance , does not oppose torque capable of disturbing the operation of the reduction device and the turbomachine. In addition, this device is particularly bulky axially since it requires for its operation an axial decoupler on the bearings of the fan shaft arranged axially thereafter, and clearances corresponding to the movements of these parts.
    It is desirable to limit the resistive torque exerted between the blower shaft and the reduction device whatever its origin, whether this torque is due to the loss of a blade, or on the contrary, a blockage of the device. reduction.
    On the one hand, in fact, the existence of a high resistant torsional torque at the input of the reduction device in the event of loss of blade risks seriously damaging said reduction device, which could then lock up and make rotation impossible blower. Conversely, a fortuitous blocking of the reduction device could block the blower and make its rotation impossible.
    In either case, this would dramatically increase the aerodynamic drag of the engine, making the aircraft impossible to fly.
    To remedy this drawback, one solution consists in limiting the torsional torque which may be exerted between the fan shaft and the reduction device, in order to avoid blocking of the fan.
    Furthermore, the limitation of this torque makes it possible to avoid any oversizing of the members of the reduction device and of the low pressure turbine shaft, and consequently to lighten the design of the reduction device and of the LP turbine shaft. .
    To this end, the invention provides a turbomachine of the type described above, characterized in that the reduction device is coupled to the fan shaft by means of a coupling with trapezoidal teeth of the curvic type which comprises said means of decoupling, said decoupling means being configured to decouple the reduction device and the blower shaft in response to the exceeding of a determined resistive torque said decoupling torque exerted between the blower shaft and the reduction device.
    Advantageously, decoupling is therefore an event planned in response to the exceeding of a determined resisting torque exerted between the reduction device and the fan shaft, that is to say conditioned by the exceeding of this resisting torque. In addition, decoupling is carried out whatever the origin of this resistant torque.
    According to other characteristics of the turbomachine:
    - the teeth of the coupling with trapezoidal teeth of the curvic type extend axially and it comprises two toothed coupling plates meshing with one another and fixed to one another by means of axial screws fuses forming the decoupling means.
    the plates each comprise two coaxial sets of trapezoidal teeth, and the fusible axial screws pass through holes formed in the plates and arranged substantially along an intermediate radius between the two coaxial sets of teeth,
    the fusible axial screws each comprise a section of reduced diameter, forming a starting point and arranged between two main sections of diameter greater than said section of reduced diameter,
    - angles of inclination of inclined planes of the trapezoidal teeth, the number of fusible screws, the diameters of the breaking and main sections of the fusible screws, and a tightening torque of said fusible screws are configured to allow the rupture of said fusible screws therefore a torque exerted between the coupling plates exceeds the decoupling torque,
    the reduction device is a reduction gear of the epicyclic type, a planetary gear is driven in rotation by a turbine shaft of the turbomachine, at least one satellite gates of said reduction device rotates one of the plates with trapezoidal teeth of the coupling, and at least one ring of said reduction device, which is fixed to a casing of the turbomachine by means of an axially deformable support, allows an axial retraction of said reduction device according to which said ring, as soon as the plates of the couplings are separated following the rupture of the fusible screws, accompanies the recoil of said planet carrier on said sun gear,
    the planet carrier of said reduction device has holes which are arranged opposite the holes of said plate, said holes passing through said planet carrier and being configured to receive the ends of the threads of the fusible screws, the tightening nuts of the fusible screws, and to allow the passage of a tool for tightening said nuts through said holes,
    the turbomachine includes means for retaining the fusible screws,
    - the fusible screws are capable of being broken as soon as the curvic type coupling is subjected to a resistive torque greater than or equal to a decoupling torque corresponding to a resistive torque exerted by the blower on the speed reduction device in the event loss of at least one fan blade driven by said fan shaft,
    - the fusible screws are capable of being broken as soon as the curvic type coupling is subjected to a resistive torque greater than or equal to a decoupling torque corresponding to a resistive torque exerted by the speed reduction device on the shaft of blower and corresponding to a case of seizure of said reduction device,
    The invention will be better understood, and other objects, details, characteristics and advantages thereof will appear more clearly during the detailed explanatory description which follows, of an embodiment of the invention given by way of purely illustrative and nonlimiting example, with reference to the appended schematic drawings in which:
    - Figure 1 is an overall view of a turbomachine according to a prior art;
    - Figure 2 is a schematic sectional view of the front part of a turbomachine according to the invention;
    FIG. 3 is a perspective view of a coupling of the curvic type implemented in the invention,
    FIG. 4 is a detailed view of the curvic type coupling used in the invention prior to its decoupling,
    FIG. 5 is a detailed view of the curvic type coupling used in the invention prior to its decoupling during decoupling,
    FIG. 6 is a detailed view of a support for a reduction device used in the invention,
    FIG. 7 is an end view of a reduction device used in the invention,
    FIG. 8 is a detailed perspective view of a reduction device used in the invention,
    FIG. 9 is a sectional view of a variant of a reduction device used in the invention, and
    - Figure 10 is a diagram illustrating the resistive torque exerted by a fan shaft of the turbomachine on the speed reduction device as a function of time during the loss of a blade of the fan.
    In the following description, identical reference numerals designate identical parts or having similar functions.
    FIG. 1 shows a turbomachine such as a turbojet engine 10 produced according to a prior state of the art. In known manner, the turbojet engine 10 comprises, from upstream to downstream according to the flow F of gas flow, a blower 12, a low pressure compressor 14, a high pressure compressor, a combustion chamber, a high pressure turbine and a low pressure turbine (not shown). The blower 12 has blades 13. The high pressure compressor and the high pressure turbine are connected by a high pressure shaft and form with it a high pressure body. The low pressure compressor 14 and the low pressure turbine are connected by a low pressure shaft 16 and form with it a low pressure body. The fan 12 is, for its part, carried by a fan shaft 18 which, in the example shown, is linked in rotation to the BP shaft 16, by means of a device 20 for reducing the speed of rotation between the two shafts 16, 18.
    In fact, it is advantageous to rotate the blower 12 at a rotational speed lower than that of the LP shaft 16, in particular when the latter is very large, in order to better adapt it aerodynamically.
    The HP and BP 16 shafts extend along an axis A of rotation of the turbojet
    10.
    The turbojet engine 10 also conventionally comprises a fan casing (not shown) which makes it possible to channel the gases sucked in by the fan 12 towards a stream 22 of primary flow, which passes through the LP and HP bodies, and a stream of secondary flow ( not shown) which envelops a casing of the LP and HP bodies and joins the primary flow stream in a nozzle (not shown) of the turbojet engine.
    As illustrated in FIG. 1, the reduction device 20 is positioned between the fan shaft 18 and the LP shaft 16. This reduction device, for example of the epicyclic type, is represented in the schematic form of rectangles not showing than its size. It is, in a nonlimiting manner of the invention, driven by a planetary pinion 24 (represented by the trace of its teeth) carried by an input shaft 26 which is linked in rotation to the BP shaft 16, the shaft 16 being, by way of example only, received without play by fitting into the shaft 26. It also comprises a planet carrier 49 (represented by the axis of its satellites) secured to a casing 46 of the turbomachine, and a crown 48 which drives the shaft 18 of the fan 12.
    In this configuration, it can happen that a resistant torque comes to be exerted between the shaft 18 of the fan 12 and the reduction device 20. This type of situation can occur when the fan 12 loses a blade 13, for example. example in the event of ingestion of a foreign body such as a bird or following a rupture in fatigue resulting from an inadequate maintenance. This phenomenon, also known by the term Anglo-Saxon called "Fan Blade Out" (FBO) causes eccentricity of the fan 12 relative to the axis A, which results in causing contact of the ends of its blades 13 with the casing (not shown) of the blower 12. This contact can suddenly brake the blower 12 even though the reduction device 20 and the BP turbine shaft 16 are still driven by the BP turbine, which can create a high torque in the BP 16 turbine shaft and in the reduction device 20.
    Such a torque in the event of loss of a blade 13 risks seriously damaging the reduction device 20, which could then become blocked and make rotation of the fan impossible 12.
    This type of situation can also occur in the event of seizure or blockage of the reduction device, the outlet of which can be unexpectedly blocked or braked even while the fan is still under the effect of its inertia. This can result in a rupture of the fan shaft 18, which in turn causes the fan to eccentric, then to block the latter.
    In both cases, a blockage of the fan 12 would have the consequence of suddenly increasing the aerodynamic drag of the engine, making the airplane impossible to pilot.
    To remedy this drawback, it has already been proposed in the state of the art decoupling devices arranged between the fan shaft 18 and the reduction device 20. However, these are exclusively intended to be triggered in the event of loss of a blade, in particular due to the appearance of an imbalance caused by the loss of this blade, and not in the event of blockage or jamming of the reduction device. Therefore, they provide only limited protection to the drive train.
    To remedy this drawback, one solution consists in limiting the torsional torque which may be exerted between the fan shaft 18 and the reduction device 20, whatever the origin of its appearance.
    The limitation of the torque has another advantage, which is to avoid oversizing the members of the reduction device 20 or the fan shaft 18 in order to ensure their resistance to such a torque when overtaking. of a determined resistant couple. A decoupling device acting between the speed reduction device 20 and the fan shaft 18 makes it possible to avoid any oversizing of the internal members of the reduction device 20 and of the fan shaft 18, and consequently to reduce the mass and inertia of the reduction device 20 and of the fan shaft 18.
    To this end, as illustrated in FIG. 2, the invention proposes a turbomachine 10 of the type described above comprising decoupling means 28 between the reduction device 20 and the fan shaft 18 and in which the reduction device 20 is coupled to the fan shaft 18 by means of a coupling 17 with trapezoidal teeth of the curvic type which comprises these decoupling means 28. The decoupling means 28 are configured to decouple the reduction device 20 and the shaft 18 of the fan in response to exceeding a determined resistive torque C D said decoupling torque acting between the fan shaft 18 and the reduction device 20.
    More particularly, as illustrated in FIG. 2, the coupling 17 with trapezoidal teeth of the curvic type is interposed between an outlet flange 50 of the reduction device 20 and the fan shaft 18. As illustrated in FIG. 3, it comprises two toothed coupling plates 19A, 19B, namely the plate 19A secured to the fan shaft 18 and the plate 19B linked in rotation to the outlet flange 50 of the reduction device 20 The plates 19A, 19B each comprise two coaxial sets of trapezoidal teeth respectively. The plate 19A has a set of internal teeth 21A and a set of external teeth 21 C, and the plate 19B has a set of internal teeth 21B and a set of external teeth 21 D. The internal teeth 21A and 21B mesh one with the other and the outer teeth 21 C, 21D mesh with each other. The direction of the height of the corresponding trapezoids of the teeth 21 A, 21 B, 21 C, 21D extends parallel to the axial direction.
    The teeth 21 A, 21 B, 21 C, 21D have inclined planes arranged in contact with each other. In Figure 3, there is shown the planes 27A, 27B of the teeth 21 A, 21 B, inclined at an angle a. The plates 19A, 19B are joined to each other by means of axial fusible axial screws 30 which pass through holes 23A, 23B arranged substantially along an intermediate radius R of the plates 19A, 19B between the teeth 21 A, 21B on the one hand and 21 C, 21D on the other hand. Advantageously, the fusible axial screws 30 also pass through the outlet flange 50 and allow its connection in rotation to the plate 19B by means of nuts 31 which tighten the output flange 50 against the plate 19B. The angle a is preferably chosen in a range between 20 ° and 70 ° relative to the motor axis, even more preferably between 20 ° and 40 °.
    As illustrated in FIGS. 3 and 4, a functional clearance J is arranged between the ends of the teeth 21A and the bottoms of the teeth 21B to guarantee good contact between the inclined planes 27A, 27B.
    As a variant, each of the plates 19A, 19B could comprise, instead of two sets of coaxial teeth, only one set of teeth crossed by fusible screws similar to the screws 31.
    It will be noted that, as a variant, the plate 19B and the flange 50 can be combined and form a single piece.
    More particularly, as illustrated in FIG. 4, the fusible axial screws 30 each comprise a section 25 of reduced diameter d forming a tensile breaking initiator disposed between two sections 33 of main diameter D. As shown in FIG. 3, such a coupling is subjected to a torque between its two plates 19A, 19B, the trapezoidal teeth 21 A, 21 B, 21 C, 21D transform, by their inclined planes 27A, 27B, the forces resulting from the torque resulting axial force F between the plates 19A, 19B and which is exerted in the form of a tensile force on the screws 30, as shown in FIG. 5. This tensile force has the consequence of causing rupture screws 30 when they are subjected to a tensile stress at their sections 25 of reduced diameter.
    It will be understood that inclination angles a of inclined planes 27A, 27B of the trapezoidal teeth 21 A, 21 B, inclination angles a of inclined planes of the trapezoidal teeth 21 C, 21 D, the number of fusible screws diameter d breaking sections 25 and the diameter D of the sections 33 of main diameter D of the fusible screws, as well as a tightening torque of said fusible screws 30 by the nuts 31 are calculated beforehand during the design of the decoupling device so that their configuration allows the rupture of these fusible screws when a torque exerted between the plates of the coupling 19A, 19B exceeds the decoupling torque C D.
    As illustrated in FIG. 2, the reduction device 20 is linked to a casing 46 of the turbomachine by at least one of its members. For example, in a nonlimiting manner of the invention, as illustrated in FIG. 9, a ring 48 of the reduction device 20 is linked to the casing 46 by means of a support 52 axially deformable, while a door -satellites 49 of the reduction device 20 is coupled to the fan shaft 18 and a sun gear 24 is coupled to the turbine shaft 16.
    It will be understood that this arrangement is not limitative of the invention and that the elements of the reduction device 20 could be linked in a different manner to the casing 46, to the fan shaft 18, and to the turbine shaft 16 . This configuration makes it possible to guarantee that once the reduction device 20 has been decoupled from the turbine shaft 16 and from the fan shaft 18, it nevertheless remains maintained in the casing 46 of the turbomachine.
    In particular, the ring gear 48 of the reduction device 20 could be linked to the fan shaft 18, the planet carrier 49 of the reduction device 20 could be linked to the casing 46 of the turbomachine, while the sun gear 24 would be coupled to the turbine shaft 16, similar to the configuration of FIG. 1.
    In addition, in the case of a reduction device 20 of the planetary or planetary type, the input shaft 26 is mounted in this reduction device 20, that is to say here in the planetary 24, via of grooves 54. The sliding of the inclined planes 27A, 27B of the sets of teeth sets apart the plates 19A, 19B, and therefore requires an axial movement of the speed reduction device 20.
    Advantageously, the reduction device 20 can, by means of the groove set 54 interposed between the input shaft of the reduction device 20 and the sun gear 24, and of the support 52 of the crown 48 which deforms to accompany the crown 48 of the reduction device 20, move back axially, as illustrated by arrow E in FIGS. 2 and 6. This movement, initiated as soon as the coupling 17 is subjected to a torque, continues after the rupture of the screws 30 in order to allow greater axial recoil of the reduction device 20, and in doing so, the spacing of the flange 50 and the fan shaft 18.
    This configuration is particularly advantageous because, by allowing the reduction of the reduction device, it avoids any stress on the shaft 18 of the fan 12. Therefore, there is no need to provide a decoupling bearing for this shaft 18, which can remain rotating on ordinary bearings.
    Once decoupled, the fan 12 is subjected to a free speed of rotation or windmilling which allows the turbojet engine to produce only a reduced drag, thus making it possible to maintain a certain maneuverability in the airplane equipped with the turbomachine.
    In the particular case of a speed reduction device 20 of planetary or planetary type in which the planet carrier 49 drives one of the plates 19B with trapezoidal teeth of the coupling 17, it is possible to provide a compact arrangement of the screws 30 To this end, as illustrated in FIGS. 7 and 8, the planet carrier has holes 56 which are arranged opposite the holes 23B of the plate 19B. These holes 56 passing through the planet carrier 49 and they are configured to receive the ends of the threads of the fusible screws 30 and the nuts 31 for tightening the fusible screws, and above all to allow the passage of a tool for tightening the nuts 31 through holes 56. Thus, an operator in charge of mounting the turbomachine can very simply tighten the nuts 31 by inserting a pipe wrench into the holes 56 on the side of the reduction device 20 opposite the flange 50.
    According to a variant of the invention, the turbomachine comprises means for retaining the fusible screws 30. Preferably, as illustrated in FIG. 7, these means comprise a flange 58 secured to the plate 19A of the curvic coupling, which is intended to immobilize the heads 60 of the screws 30 after their rupture. On the opposite side the holes 56 of the planet carrier 49 receive shutters 62 intended to prevent the body of the screws 30 from coming out of these holes.
    It will be understood that this configuration is not limitative of the invention and that other retention means can be used.
    In the preferred embodiment of the invention, the rupture of the fusible screws 30 of the decoupling means 28 can be provided at a minimum and this, as soon as a single blade 13 is lost. This configuration is not limiting of the invention and the loss of more blades could be tolerated.
    Conversely, if provision is made for the rupture of the fusible screws 30 to occur only in the event of the rupture or loss of a blade 13, it is intended that this rupture does not occur in the event of simple deceleration of the fan 12.
    Thus, it is provided that the determined torque C D is strictly greater than any torque corresponding to a resistant torque exerted by the blower 12 on the speed reduction device 20, in the event of ingestion of a bird without loss of blade by said fan 12. Such an event can indeed produce a tangential force slowing down the fan 12, but does not risk damaging the reduction device 20 or the shaft 18. In this case, the occurrence of an event such as the ingestion of a bird does not cause the fusible screws to rupture 30.
    The rupture is however planned for an event corresponding to a determined percentage of the maximum torque to which the shaft 18 of the fan 12 is subjected. For example, it is possible to tare the rupture torque C D to respond to the loss of a blade, as we saw previously. In the configuration of the aforementioned turbomachine, this torque C D is then situated in a range of 120% to 200% of the maximum torque to which the shaft 18 of the fan 12 is subjected.
    It is also possible to choose another criterion for breaking the screws 30, such as, for example, seizure, blockage of the speed reduction device 20. In this case, the torque C D is situated in a range of 200% to 300% of the maximum torque C D to which the shaft 18 of the fan 12 is subjected.
    The values of the above-mentioned decoupling torque C D depend on the material of the fan. Its value will be different depending on whether the blower has metal blades, or blades made of composite material.
    By way of example only, and without limitation of the invention, we place ourselves for example in the case of a turbomachine having a maximum thrust between 100kN and 300kN, with a fan 12 with a diameter between 2 and 3m , and a speed reduction device having a reduction ratio between 2.5 and 5. In this case, the maximum torque at the output of the speed reduction device 20 is between 50,000 and 170,000 N.
    In this configuration, without limitation of the invention, the value of the decoupling torque determined in the three embodiments of the case decoupling means 28 therefore varies substantially between 60,000 N.m and 510000 N.m.
    It will of course be understood that these values are only indicative and depend on the architecture and the dimensioning of the turbomachine.
    Advantageously, means for detecting the decoupling of the reduction device 20 and the fan shaft 18 by the decoupling means 28 can be provided to control at least a reduction in speed of the turbine, or even a complete shutdown of the turbojet engine.
    Thus, it is possible to measure the speed of the outlet flange 50 of the speed reduction device 20. A detection of the runaway of this speed relative to that of the fan 12 can thus be interpreted as a decoupling and trigger the activation of engine regulation devices. It is therefore possible to limit the flow of fuel to drop the speed of the turbine, and if there is a turbine comprising an axial brake between a rotor part and a stator part, to activate this brake to slow down and / or stop the turbine.
    FIG. 10 illustrates in a comparative manner the resistive torque C transmitted, on the ordinate, as a function of time t on the abscissa, in the event of a fan blade 13 breaking.
    As can be seen on the curve in strong lines, in a conventional turbomachine, from an optimal operating torque C o , there may occur at a time T R a rupture of a blade 13. This rupture leads to a increase in the resistive torque up to a limit value C max corresponding to the blocking of the reduction device 20 and of the blower 12, or more exactly to a risk of blocking according to the specifications of the reduction device, making it unfit for use .
    In the turbomachine according to the invention, the maximum torque is tared to a torque C D or decoupling torque. Therefore, during operation, it can also occur at an instant T R a rupture of a blade 13, which leads to an increase in the resistive torque up to the value C D or decoupling torque value. The torque then decreases, according to the dotted curve, up to a value C min corresponding to a state of free rotation of the fan 12.
    It will of course be understood that these values are only indicative and depend as much on the type of blade used, as on the architecture and sizing of the engine.
    It will be understood that, when decoupling occurs due to a loss of blade, from the moment when the fan 12 is decoupled from the turbine shaft 16, the turbine 16 is no longer subjected to a resistive torque from said blower. There is therefore a risk of runaway of the turbine if the speed reduction device 20 is not uncoupled, this runaway driving the speed reduction device 20 at speeds for which it is not intended to operate.
    Thus, preferably, the turbomachine or turbojet engine 10 comprises means for detecting the decoupling of the reduction device 20 and the fan shaft 18 capable of controlling at least a reduction in speed of the turbine, or even a complete shutdown of the turbojet engine.
    Thus, it is known to measure the speed of the fan shaft 18 by a speed sensor. A detection of the runaway of the measured speed can thus be interpreted as a decoupling and trigger the activation of engine regulation members. It is therefore possible to limit the flow of fuel to drop the speed of the turbine, or, if there is a turbine comprising an axial brake between a rotor part and a stator part, activate this brake to slow down and / or stop the turbine.
    The invention therefore provides a safe solution to the risks of overspeed of a kinematic line of a turbomachine, in particular in the event of a rupture of the fan blade of the turbomachine or of blockage of said speed reduction device. The decoupling device makes it possible not only to protect the connection between the blower and the speed reduction device, but also the internal elements of the speed reduction device, but also the rotating elements placed upstream of the reducer according to the power path. drive, namely the BP compressor shaft, the BP turbine shaft and the BP turbine.
    权利要求:
    Claims (10)
    [1" id="c-fr-0001]
    1. Turbomachine (10) comprising a fan shaft (12) driven by a turbine shaft (16) by means of a device (20) for reducing the speed of rotation, said turbomachine comprising means (28) decoupling interposed between the reduction device (20) and the fan shaft (18), which are capable of decoupling the reduction device (20) and the fan shaft (18), characterized in that the device reduction (20) is coupled to the fan shaft via a coupling (17) with trapezoidal teeth of curvic type which comprises said decoupling means (28), said decoupling means (28) being configured to decouple the reduction device (20) and the fan shaft (18) in response to the exceeding of a determined resistive torque (C D ) said decoupling torque exerted between the fan shaft (18) and the device ( 20) reduction.
    [2" id="c-fr-0002]
    2. Turbomachine (10) according to the preceding claim, characterized in that the teeth of the coupling with trapezoidal teeth (17) of the curvic type extend axially and in that it comprises two coupling plates (19A, 19B ) toothed meshing with each other and fixed to each other by means of fusible axial screws (30) forming the decoupling means (28).
    [3" id="c-fr-0003]
    3. Turbomachine (10) according to the preceding claim, characterized in that the plates (19A, 19B) each comprise two coaxial sets of trapezoidal teeth (21 A, 21 B), and in that the axial fusible screws (30) pass through holes (23A, 23B) formed in the plates (19A, 19B) and arranged substantially along an intermediate radius (R) between the two sets (21 A, 21 B, 21 C, 21 D) coaxial teeth.
    [4" id="c-fr-0004]
    4. Turbomachine (10) according to one of claims 2 or 3, characterized in that the fusible axial screws (30) each comprise a section of reduced diameter (d), forming initiation of rupture in traction and disposed between two main sections (33) of diameter (D) greater than said section (25) of reduced diameter.
    [5" id="c-fr-0005]
    5. Turbomachine (10) according to claim 4, characterized in that the angles of inclination (a) of inclined planes (27A, 27B) of the trapezoidal teeth (21 A, 21 B, 21 C, 21 D), the number of fusible screws (30), the diameters (d, D) of the breaking (25) and main (33) sections of the fusible screws (30), and a tightening torque of said fusible screws (30) are configured to allow rupture said fusible screws (30) when a torque exerted between the plates (19A, 19B) of the coupling exceeds the decoupling torque (C D ).
    [6" id="c-fr-0006]
    6. Turbomachine (10) according to one of claims 2 to 5, characterized in that the reduction device (20) is a reduction gear of the epicyclic type, in that a sun gear (24) is rotated by a shaft turbine (16) of the turbomachine, in that at least one planet carrier (49) of said reduction device (20) rotates one of the plates (19B) with trapezoidal teeth of the coupling, and in that '' at least one ring (48) of said reduction device, which is fixed to a casing (46) of the turbomachine via an axially deformable support (52), allows axial reduction of said reduction device (20) according to which said crown (48), as soon as the plates (19A, 19B) of the coupling (17) are separated following the rupture of the fusible screws (30), accompanies the retreat of said planet carrier (49) on said planetary (24).
    [7" id="c-fr-0007]
    7. Turbomachine (10) according to the preceding claim, characterized in that the planet carrier (49) of said reduction device (20) has holes (56) which are arranged opposite the holes (23B) of said plate (19B) , said holes (56) passing through said planet carrier (49) and being configured to receive the ends of the threads of the fusible screws (30), the nuts (31) for tightening the fusible screws (30), and to allow the passage of 'a tool for tightening said nuts (31) through said holes (56).
    [8" id="c-fr-0008]
    8. Turbomachine (10) according to one of claims 2 to 7, characterized in that it comprises retention means (58, 60) of the fusible screws (30).
    [9" id="c-fr-0009]
    9. Turbomachine (10) according to one of claims 2 to 8, characterized in that the fusible screws (30) are capable of being broken as soon as the coupling of the curvic type is subjected to a resistive torque greater than or equal to a decoupling torque (C D ) corresponding to a resistant torque exerted by the blower (12) on the speed reduction device (20) in the event of the loss of at least one blade (13) of the driven blower (12) by said fan shaft (18) (12).
    [10" id="c-fr-0010]
    10. Turbomachine (10) according to one of claims 2 to 8, characterized in that the fusible screws (30) are capable of being broken as soon as the coupling of the curvic type (17) is subjected to a resistant torque greater than or equal to a decoupling torque (C D ) corresponding to a resistant torque exerted by the speed reduction device (20) on the fan shaft (18) and corresponding to a case of blockage of said reduction device (20 ).
    1/5
    3/5
    类似技术:
    公开号 | 公开日 | 专利标题
    EP3161270B1|2020-08-05|Turbomachine comprising means for decoupling a fan
    EP3559416B1|2020-09-02|Turbomachine comprising a means for decoupling a fan
    EP1270903B1|2006-05-17|Safety device for restarting windmilling turbojet
    EP2721260B1|2018-02-28|Coupling arrangement for a turbofan engine
    EP3000986B1|2017-07-05|A method of stopping a rotorcraft engine in overspeed and a rotorcraft associated therewith
    WO2012123684A1|2012-09-20|Method for optimizing the speed of a twin-spool turbojet engine fan, and architecture for implementing same
    FR3034140A1|2016-09-30|AIRCRAFT TURBOMACHINE WITH PLANETARY OR EPICYCLOIDAL REDUCER
    FR3075863B1|2019-11-22|TURBOMACHINE TURBINE HAVING A DEVICE FOR LIMITING OVERSPEED
    FR3075864B1|2019-11-15|TURBOMACHINE COMPRISING A TURBINE-DISCHARGING BLOWER THROUGH AN ELASTICALLY REMOVABLE CURVIC COUPLING
    WO2017168090A1|2017-10-05|Device for limiting overspeeding of a turbine shaft of a turbomachine, and associated control method
    EP3011157B1|2019-10-02|Turbomachine accessory gearbox equipped with a centrifugal pump
    EP3513050B1|2020-05-13|Shaft break device for an electrical generator
    EP3775500B1|2021-12-29|Turbine shaft of a turbomachine and method for overspeed protection of the shaft
    WO2012032270A1|2012-03-15|Hyperstatic truss comprising connecting rods
    FR3093146A1|2020-08-28|DRIVE SHAFT INCLUDING A FUSE SECTION AND PROCESS FOR PROTECTION AGAINST OVER-TORQUE OF SUCH DRIVE SHAFT
    FR3075862A1|2019-06-28|DEVICE FOR BRAKING A TURBOMACHINE BLOWER
    WO2021181031A1|2021-09-16|Turbomachine module equipped with an electric machine rotor
    FR3109401A1|2021-10-22|AIRCRAFT TURBOMACHINE EQUIPPED WITH FUSIBLE SCREWS
    FR3092140A1|2020-07-31|Improved turbomachine comprising an inertial system.
    FR2992678A1|2014-01-03|Turbopropeller for propulsion of aircraft, has bearing guide for guiding propeller shaft in casing, and standby guide mounted between casing and propeller shaft, so as to guide propeller shaft in event of malfunction of bearing guide
    FR3057909A1|2018-04-27|AIRCRAFT TURBOMACHINE COMPRISING A FUSIBLE ZONE AGENCED ON A SWIVEL ARBOR
    同族专利:
    公开号 | 公开日
    WO2018115763A1|2018-06-28|
    CN110088427B|2022-02-18|
    FR3061242B1|2019-05-17|
    EP3559416B1|2020-09-02|
    US20200018181A1|2020-01-16|
    CN110088427A|2019-08-02|
    EP3559416A1|2019-10-30|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR2541724A1|1981-03-28|1984-08-31|Rolls Royce|DRIVE MECHANISM OF A ROTOR ASSEMBLY|
    US4827712A|1986-12-23|1989-05-09|Rolls-Royce Plc|Turbofan gas turbine engine|
    US20130324343A1|2012-05-30|2013-12-05|Snecma|Reduction gear with epicyclic gear train having roller-bearing-mounted planet spindles|
    US20150377027A1|2014-05-19|2015-12-31|Rolls-Royce Plc|Fan disc|
    FR1251655A|1960-03-18|1961-01-20|Camping tent|
    FR2850140B1|2003-01-17|2005-02-25|Snecma Moteurs|RETAINING DEVICE FOR BONDING MEMBER, AND DECOUPLER SYSTEM EQUIPPED WITH SUCH A DEVICE|
    FR2907861B1|2006-10-26|2008-12-26|Snecma Sa|BEARING ARRANGEMENT OF A ROTATING SHAFT AND TURBOREACTOR EQUIPPED WITH SUCH AN ARRANGEMENT|
    US8104289B2|2007-10-09|2012-01-31|United Technologies Corp.|Systems and methods involving multiple torque paths for gas turbine engines|
    FR2976623B1|2011-06-20|2013-06-28|Snecma|DECOUPLING DEVICE FOR DOUBLE FLOW TURBOMOTEUR|
    CN103775212B|2012-10-25|2016-11-23|中航商用航空发动机有限责任公司|A kind of fan fails brake unit of aero-engine|US11215265B2|2019-10-03|2022-01-04|Rolls-Royce Corporation|Static curvic joint for epicyclical gear system housing assembly|
    CN113047959A|2019-12-27|2021-06-29|中国航发商用航空发动机有限责任公司|Aeroengine braking device and aeroengine|
    FR3106363A1|2020-01-22|2021-07-23|Safran Aircraft Engines|BLOWER MODULE FOR AN AIRCRAFT TURBOMACHINE TEST BENCH|
    FR3108140A1|2020-03-10|2021-09-17|Safran Aircraft Engines|TURBOMACHINE MODULE EQUIPPED WITH AN ELECTRIC MACHINE ROTOR|
    法律状态:
    2017-11-20| PLFP| Fee payment|Year of fee payment: 2 |
    2018-06-29| PLSC| Publication of the preliminary search report|Effective date: 20180629 |
    2018-11-27| PLFP| Fee payment|Year of fee payment: 3 |
    2019-11-20| PLFP| Fee payment|Year of fee payment: 4 |
    2020-11-20| PLFP| Fee payment|Year of fee payment: 5 |
    2021-11-18| PLFP| Fee payment|Year of fee payment: 6 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1663359A|FR3061242B1|2016-12-23|2016-12-23|TURBOMACHINE COMPRISING A MEANS FOR DECOUPLING A BLOWER|
    FR1663359|2016-12-23|FR1663359A| FR3061242B1|2016-12-23|2016-12-23|TURBOMACHINE COMPRISING A MEANS FOR DECOUPLING A BLOWER|
    US16/471,489| US20200018181A1|2016-12-23|2017-12-21|Turbomachine comprising a means for decoupling a fan|
    CN201780079299.6A| CN110088427B|2016-12-23|2017-12-21|Turbomachine comprising means for uncoupling a fan|
    PCT/FR2017/053765| WO2018115763A1|2016-12-23|2017-12-21|Turbomachine comprising a means for decoupling a fan|
    EP17832264.0A| EP3559416B1|2016-12-23|2017-12-21|Turbomachine comprising a means for decoupling a fan|
    [返回顶部]