• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
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    • 专利摘要:
    The invention relates to a turbofan engine (1) comprising: - a low pressure shaft (6) supported by at least two low pressure bearings (BP # 1 to BP # 4), - a high pressure shaft (8) supported by at least two high pressure bearings (HP # 1, HP # 2), - a fan shaft (7) supported by at least two blower bearings (S # 1, S # 2), - a reduction mechanism (10) , coupling the low pressure shaft (6) and the fan shaft (7), - enclosures (A to D) housing the low pressure bearings (BP # 1 to BP # 4), the high pressure bearings (HP # 1, HP # 2), the blower bearings (S # 1, S # 2) and the reduction mechanism (10), and - a lubrication unit (20) comprising a closed oil circuit configured to supply the loudspeakers (A to D) in oil to cool said bearings and the reduction mechanism and at most five recovery pumps (28a to 28d) configured to recover the oil in the enclosures (A to D).
    公开号:FR3049007A1
    申请号:FR1652170
    申请日:2016-03-15
    公开日:2017-09-22
    发明作者:Romain Guillaume Cuvillier；Nils Edouard Romain Bordoni；Michel Gilbert Roland Brault；Sebastien Christophe Chalaud；Guillaume Patrice Kubiak；Arnaud Nicolas Negri；Nathalie Nowakowski
    申请人:SNECMA SAS；
    IPC主号:
    专利说明:

    FIELD OF THE INVENTION The invention relates to the general field of turbomachines with a double flow, and more particularly turbomachines having a high degree of dilution.
    BACKGROUND
    A turbofan engine generally comprises, upstream to downstream in the direction of gas flow, a streamlined fan housed in a fan casing, a primary flow annulus and an annular secondary flow space. The air mass sucked by the fan is thus divided into a primary flow, which flows in the primary flow space, and a secondary flow, which is concentric with the primary flow and flows in the flow space. secondary. The primary flow space passes through a primary body comprising one or more stages of compressors, for example a low pressure compressor and a high pressure compressor, a combustion chamber, one or more turbine stages, for example a high pressure turbine, and a low pressure turbine, and a gas exhaust nozzle.
    Typically, the high pressure turbine rotates the high pressure compressor through a first shaft, said high pressure shaft, while the low pressure turbine rotates the low pressure compressor and the blower through a second tree, called low pressure tree. The low pressure shaft is generally housed in the high pressure shaft, said shafts being fixed to the structural parts of the turbojet engine via bearings.
    In order to improve the propulsive efficiency of the turbojet and to reduce its specific consumption as well as the noise emitted by the blower, it has been proposed turbojet engines having a rate of dilution ("bypass ratio" in English, which corresponds to the ratio between the flow rate secondary flow (cold) and primary flow rate (hot, which passes through the primary body)) high.
    To achieve such dilution rates, the blower is decoupled from the low pressure turbine, thereby independently to optimize their respective rotational speed. For example, the decoupling can be performed using a gear such as a reduction mechanism epicyclic ("star gear reduction mechanics" in English) or planetary gear ("planetary gear reduction mechanics" in English), placed between the upstream end (with respect to the direction of flow of the gases in the turbojet) of the low pressure shaft and the blower. The blower is then driven by the low pressure shaft through the reduction mechanism and an additional shaft, said blower shaft, which is fixed between the reduction mechanism and the blower disk.
    This decoupling makes it possible to reduce the rotation speed and the fan pressure ratio, and to increase the power extracted by the low pressure turbine. Thanks to the reduction mechanism, the low pressure shaft can indeed rotate at higher rotational speeds than in conventional turbojets. The high-pressure shaft is attached to the structural parts of the engine via an HP # 1 front bearing and an HP # 2 rear bearing. The HP # 1 front bearing is usually mounted on the high pressure shaft and on the sump housing upstream of the high pressure compressor. The HP # 2 rear bearing is mounted on the high pressure shaft and on the inter-turbine casing (that is to say on the casing extending between the casing). housing the high pressure turbine and the housing housing the low pressure turbine).
    A third high pressure bearing may be provided between the HP # 1 front bearing and the HP # 2 rear bearing. The third upper front bearing preferably extends upstream of a combustion chamber of the turbojet engine 1. The low pressure shaft is generally supported by three bearings BP # 1, BP # 2 and BP # 3. The first bearing BP # 1 is located the most upstream of the low pressure shaft and can be mounted on the one hand on the low pressure shaft and on the other hand between the reduction mechanism and the booster 3 (on the crankcase "entry"). The third BP # 3 bearing, which is located furthest downstream of the low pressure shaft, can be mounted on the low pressure shaft and on the turbojet exhaust casing. The position of the bearings BP # 1 and BP # 3 being conventional, it will not be further detailed in the following.
    The second bearing BP # 2, which is adjacent to the third bearing BP # 3, can be mounted on the low pressure shaft and on the inter-turbine casing, upstream of the low pressure turbine or on the exhaust casing as the BP # 3 bearing. In one embodiment, the second BP # 2 bearing extends downstream of the HP # 2 rear bearing. The fan shaft, which is mounted between the output of the reduction mechanism and the rotor of the fan, is further supported by an upstream bearing S # 1 disposed under the fan and a downstream bearing S # 2 disposed at the level of the inlet of the secondary flow space, upstream of the reduction mechanism.
    The turbojet engine further comprises a gear configured to take power on the high pressure shaft. This gear is usually placed upstream of the bearing before HP # 1.
    These different bearings, the reduction mechanism and the gear must be lubricated and cooled. For this purpose, the turbojet engine generally comprises a lubricating unit supplying a closed oil circuit, enclosures in which the bearings are housed, the reduction mechanism and the gearing, nozzles configured to inject oil into the enclosures. and recovery pumps configured to recycle oil that has been injected into the enclosures.
    Each enclosure comprises for this purpose bearings interposed between an inner ring and an outer ring coaxial with the axis X of the turbojet and substantially annular. The outer ring may be fixed relative to the structural elements of the turbojet while the inner ring is fixed on rotating parts of the turbojet engine and thus rotatable about its axis X. Alternatively, the two rings are rotating. The equipment housed in the enclosures is lubricated and cooled by oil which is thrown into the chamber by the nozzles to form a mist of droplets in suspension. Sealing means are provided in the areas where the rings meet to allow the passage of a flow of air in order to pressurize the chamber and retain the maximum oil inside the chamber. this. In addition, an oil recovery pump is provided to evacuate an equivalent volume of oil to that which is injected into the chamber via the nozzles.
    Such a configuration thus makes it possible to lubricate and cool these equipment efficiently. However, the enclosures and recovery pumps have a significant impact on the size and weight of the engine, thus increasing the specific consumption of the turbojet engine.
    SUMMARY OF THE INVENTION
    An object of the invention is therefore to provide a turbofan engine which has a reduced mass in comparison with conventional turbofan engines while ensuring optimum lubrication and cooling of its equipment such as its bearings and where appropriate its reduction mechanism and avoiding the risks of oil retention.
    For this, the invention proposes a turbofan engine comprising: a low pressure shaft supported by at least two low pressure bearings, a high pressure shaft supported by at least two high pressure bearings, a fan shaft supported by at least two blower bearings, - a reduction mechanism, coupling the low-pressure shaft and the blower shaft, - housings housing the low-pressure bearings, the high-pressure bearings, the blower bearings and the reduction mechanism, and a lubricating group comprising a closed oil circuit configured to supply the oil chambers for cooling said bearings and the reduction mechanism, said lubrication group comprising at most five recovery pumps configured to recover the oil in the enclosures .
    Certain preferred but non-limiting characteristics of the turbojet engine described above are the following, taken individually or in combination: the turbojet engine comprises at most four recovery pumps configured to recover the oil in the chambers; the turbojet engine comprises at most as many as recovery pumps as enclosures, each recovery pump being associated with at most one respective enclosure, - the fan bearings, the reduction mechanism and at least one of the low pressure bearings are housed in the same enclosure, and in which a single recovery pump is configured to recover the oil injected into said enclosure, - the other low pressure bearings, the high pressure bearings and the blower bearings are housed in at most four enclosures, and wherein the lubrication unit comprises exactly three or four recovery pumps configured to recover the oil injected into said four enclosures, - only one of the recovery pumps of the lubricating group is configured to recover the oil in the enclosure or enclosures housing the blower bearings, the reduction mechanism and one of the low pressure bearing. the high-pressure bearings comprise a high-pressure front bearing and a high-pressure rear bearing, the low-pressure bearings comprise a low-pressure front bearing and a low-pressure rear bearing, the lubricating group comprising a recovery pump configured to recover the oil in the enclosure housing the rear high pressure bearing and a recovery pump configured to recover the oil in the enclosure housing the rear low pressure bearing. Optionally, the lubrication group comprises a recovery pump configured to recover the oil in the enclosure housing the front high pressure bearing and a recovery pump configured to recover the oil in the chamber housing the reduction mechanism, - the high-pressure bearings include a high-pressure front bearing and a high-pressure rear bearing, the low-pressure bearings comprise a low-pressure front bearing and a low-pressure rear bearing, only one of the lubricating group recovery pumps being configured to recover the oil in the enclosure (s) housing the high pressure rear bearing and the rear low pressure bearing, Optionally, the lubrication unit comprises a recovery pump configured to recover the oil in the enclosure housing the front high pressure bearing and a recovery pump configured to recover the oil in the pregnant e housing the reduction mechanism. the low pressure shaft is supported by at least three low pressure bearings, a first and a second of said low pressure bearings being positioned between the fan bearings and the high pressure bearings; or a single recovery pump of the recovery unit is configured to recover the oil in the enclosure (s) housing the reduction mechanism and the second low pressure stage, ie a single recovery unit recovery pump is configured to recover the oil in the enclosure (s) housing one of the high pressure bearings and the second low pressure bearing, - the low pressure shaft is supported by four low pressure bearings, a first and a second one of the low pressure bearings being positioned between the fan bearings and the high pressure bearings while a third and a fourth of the low pressure bearings are positioned downstream of the high pressure bearings, the upstream and the downstream being defined in a direction of gas flow in the turbojet engine. Optionally, exactly three recovery pumps of the lubrication group are configured to recover the oil in the housings respectively housing the third low pressure bearing, the fourth low pressure bearing and the high pressure bearings, - the high pressure bearings comprise a high pressure bearing forward and a high pressure rear bearing, the low pressure bearings comprise a first, a second and a third low pressure bearing, and wherein the enclosure of the high pressure rear bearing, the enclosure of the third low pressure bearing and the enclosure of the fourth low pressure bearings are not ventilated, - the high pressure bearings comprise two high pressure front bearings, placed upstream of a combustion chamber, and a high pressure rear bearing, placed downstream of the combustion chamber, the high pressure bearing before being housed in the same enclosure and associated with the same recovery pump n, the low pressure bearings comprise exactly three or four low pressure bearings, including one or two low pressure bearings placed upstream of a combustion chamber, and one or two low pressure bearings placed downstream of the combustion chamber; the turbojet has a dilution ratio greater than or equal to 10, preferably greater than or equal to 18, for example between 12 and 18, and / or the reduction mechanism comprises an epicyclic or planetary reduction mechanism having a reduction ratio of between 2.6 and 5.
    BRIEF DESCRIPTION OF THE DRAWINGS Other features, objects and advantages of the present invention will appear better on reading the detailed description which follows, and with reference to the appended drawings given by way of non-limiting examples and in which:
    FIGS. 1a to 3c are diagrammatic and sectional views of embodiments of a turbojet according to the invention, and
    FIG. 4 is a diagrammatic view illustrating an exemplary embodiment of a lubricating group that can be implemented in a turbojet according to the invention, and in particular in the embodiments in which the lubrication group comprises exactly four recovery.
    DETAILED DESCRIPTION OF AN EMBODIMENT
    In what follows, a turbojet engine will now be described with reference to the appended figures.
    The turbojet engine 1 comprises, in a conventional manner, a fan 2 and a primary body. The primary body comprises, in the direction of gas flow, a low pressure compressor 3 (booster), a high pressure compressor 4, a combustion chamber 5, a high pressure turbine 6, a low pressure turbine 7, and a nozzle exhaust gas 8.
    The blower 2 comprises a blower disc provided with fan blades at its periphery which, when they are rotated, cause the flow of air into the primary and secondary flow spaces of the turbojet engine 1. The blower disk is rotated by a low pressure shaft 6a of the low pressure turbine 7.
    In one embodiment, the turbojet engine 1 has a high dilution ratio. By high dilution rate, here will be understood a dilution ratio greater than 10, for example between 12 and 18. For this, the fan 2 is decoupled from the low pressure turbine 7 to independently optimize their respective rotational speed, for example with the aid of an epicyclic or planetary type reduction gear placed between the upstream end (with respect to the direction of flow of the gases in the turbojet engine 1) of the low pressure shaft 6a and the fan 2.
    The fan 2 is then driven by the low pressure shaft 6a through the reduction mechanism 10 and a fan shaft 2a, which is fixed between the reduction mechanism 10 and the fan disk 2.
    To calculate the dilution ratio, the flow rate of the secondary flow and the flow rate of the primary flow are measured when the turbojet engine 1 is stationary in a standard atmosphere (as defined by the manual of the International Civil Aviation Organization (ICAO) Doc 7488/3, 3rd edition) and at sea level.
    In one embodiment, the reduction mechanism 10 comprises an epicyclic or planetary reduction mechanism.
    The reduction ratio of the reduction mechanism 10 is preferably between 2.6 and 5.
    The diameter of the blower 2 may be between eighty inches (203.2 centimeters) and one hundred and ten inches (279.4 centimeters), preferably between eighty inches (203.2 centimeters) and ninety inches (228.6 inches). centimeters). The fan shaft 2a, the high pressure shaft 7a and the low pressure shaft 6a are centered on the axis X of the turbojet engine 1 by a series of bearings.
    In this particular case, the fan shaft 2a is supported by the upstream bearing S # 1 and the downstream bearing S # 2, the high pressure shaft 7a is supported by the front bearing HP # 1, the rear bearing HP # 2 and if necessary a third high pressure bearing, while the low pressure shaft 6a is supported by the three bearings BP # 1, BP # 2 and BP # 3. These seven or even eight levels being conventional and having been previously described, they will not be further detailed here.
    In an embodiment illustrated in FIGS. 1a to 2c, the low pressure shaft 6a can also be supported by a fourth bearing BP # 4, placed between the first bearing BP # 1, which is the bearing the most upstream of the low pressure shaft 6a, and the front bearing HP # 1 of the high pressure shaft 7a. This fourth bearing BP # 4 can in particular be mounted on the low pressure shaft 6a and on the inter-compressor housing, either between the housing housing the booster 3 and the housing housing the high pressure compressor 4.
    The assembly of the low pressure shaft 6a on four bearings BP # 1 to BP # 4 makes it possible to efficiently move the modes of displacement of the low pressure shaft 6a, which is supercritical (that is to say with a bending mode in the operating range) in order to position the transient bending modes of the turbojet engine 1 with safety margins relative to the stabilized speeds. By stabilized regime, here will be understood a regime defined by a rotation speed spectrum of the low pressure shaft 6a in which the turbojet 1 can be placed and maintained for a relatively long time (between a few minutes and several hours). Examples of stabilized regimes include idle, idle in flight, cruising, or take-off. By transient regime, here will be understood a regime corresponding to the transition from a steady state to another in which the speed of rotation of the low pressure shaft 6a varies rapidly. Indeed, the stabilized speeds do not cover the entire spectrum between the idle and the redline (English term designating the maximum absolute speed encountered by the low pressure shaft 6a throughout the flight), so it may be necessary according to the stabilized regime to be reached, to go through a transient regime to reach this stabilized regime.
    Thus, thanks to the addition of the low pressure bearing BP # 4, the first bending mode of the low pressure shaft 6a is moved to about 8000 rpm, or between the idle speed on the ground (which corresponds to a speed rotation of the low pressure shaft 6a from 2000 to 4500 revolutions per minute (rpm)) and the cruising speed (which corresponds to a rotational speed of the low pressure shaft 6a from 8500 to 9500 rpm) , for a turbojet engine 1 having a redline between 10,000 rpm and 12,000 rpm.
    It also becomes possible to reduce the diameter of the low pressure shaft 6a and therefore the size of the primary body to reach, with the reduction mechanism 10 and the large diameter of the fan 2, a high dilution ratio for the turbojet engine. 1. Typically, the low pressure shaft 6a may have an outer diameter of less than fifty millimeters, for example less than forty-five millimeters.
    This positioning of the bearings also makes it possible to reduce the game consumptions (radial displacement) of the booster 3, which is now placed between two levels BP # 1 and BP # 4.
    The turbojet engine 1 also generally comprises a gear 12 configured to take power from the high pressure shaft. Here it is a conical wheel gear connected to a radial shaft. This gear is usually placed upstream of the bearing before HP # 1.
    The turbojet engine 1 comprises a lubricating unit 20 comprising, in a conventional manner per se, a reservoir 22 housing oil which is maintained, by known systems of exchangers, at a sufficiently low temperature to allow the cooling of the bearings and the reduction mechanism 10. The lubrication unit 20 comprises an oil circulation pump 21 and oil supply pipes respectively in the enclosures A to D, where the oil is injected onto the parts to be cooled by the oil. intermediate of one or more nozzles 24. Recovery pipes 26 at the output of the enclosures A to D collect the oil mist through recovery pumps 28a to 28d. The fog recovered on the various enclosures A to D opens into the tank which has a de-oiler.
    The nozzles 24 may be placed in the upper part of the speakers A to D (the bottom and the top being defined relative to the position occupied in normal flight of the turbojet engine 1), to the right of the associated bearings. The recovery pipes 26 are positioned at the bottom of the enclosures A to D so as to recover the oil by depression.
    In one embodiment, the lubricating unit 20 of the turbojet engine 1 comprises at most five recovery pumps 28a to 28d, preferably at most four recovery pumps 28a to 28d, configured to recycle the oil that has been injected into the enclosures A More specifically, the lubricating unit 20 comprises exactly three or four recovery pumps 28a to 28d. The recovery pumps 28a to 28d may for example be housed in the body of the turbojet engine 1 with the reservoir 22, between the outer casing housing the primary body and the platform defining the internal surface of the secondary vein.
    Similarly, the turbojet engine 1 comprises at most five enclosures A to D, configured to contain the oil introduced by the nozzles 24 to lubricate and cool all the bearings and the reduction mechanism 10. More specifically, the turbojet engine 1 comprises an enclosure A to D by recovery pump 28a to 28d. For this purpose, the two fan bearings S # 1 and S # 2 and the reduction mechanism 10, and optionally the low pressure bearing BP # 1, can be housed in the same enclosure A. A recovery pump 28a is then associated with this speaker A. The other bearings can be housed in dedicated speakers or on the contrary in several common speakers, to reduce the number of speakers required. It should be noted that for these other bearings, a maximum of one oil recovery pump per enclosure is necessary. Typically, the same recovery pump can be used for two speakers or three speakers.
    The number of recovery pumps 28a-28d and of speakers A to D is therefore greatly reduced in comparison with the prior art, which places each equipment (S # 1, S # 2, HP # 1, HP # 2, BP # 1 to BP # 4 or reduction mechanism 10) in a chamber with a dedicated recovery pump. The lubrication circuit is therefore greatly simplified by reducing the number of recovery pumps. The mass of the turbojet engine 1 is also very greatly reduced, as are the radial dimensions and the axial bulk resulting from the presence of the recovery pumps 28a to 28d and the enclosures A to D.
    Each enclosure A to D comprises for this purpose an inner ring and an outer ring coaxial with the axis X of the turbojet engine 1 and substantially annular. The outer ring is fixed relative to the structural elements of the turbojet engine 1 while the inner ring is fixed on rotating parts of the turbojet engine 1 and thus mobile in rotation about its axis X. When the enclosure houses a bearing, the support of said bearing is therefore fixed on the outer ring of the enclosure.
    In the exemplary embodiments illustrated in FIGS. 1a to 2c, the turbojet engine 1 comprises two fan bearings S # 1 and S # 2, a reduction mechanism 10, two HP # 1 and HP # 2 high-pressure bearings and four low-level bearings. pressure BP # 1, BP # 2, BP # 3 and BP # 4.
    The lubricating unit 20 can then comprise exactly three or four recovery pumps 28a to 28d. Each of the recovery pumps 28a to 28d is preferably associated with an enclosure A to D, the bearings (S # 1, S # 2, BP # 1 to BP # 4, HP # 1 and HP # 2) and the mechanism of 10 reduction being distributed as follows in these three or four speakers A to D.
    In the exemplary embodiment illustrated in FIG. 1a, the turbojet engine 1 comprises at most four recovery pumps 28a to 28d, each recovery pump being associated with an enclosure A to D, namely: an enclosure A housing the two bearings blower S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearing BP # 1, - an enclosure B housing the low pressure bearing BP # 4 and the high pressure bearing before HP # 1. - an enclosure C housing the HP high pressure rear bearing # 2. an enclosure D housing the low pressure bearings BP # 2 and BP # 3.
    In this exemplary embodiment, the lubricating unit 20 thus comprises: a recovery pump 28a configured to recover the oil in the enclosure A which houses the two fan bearings S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearing BP # 1, - a recovery pump 28b configured to recover the oil in the enclosure B which houses the low pressure bearing BP # 4 and the high pressure bearing before HP # 1, - a pump of recovery 28c configured to recover the oil in the enclosure C which houses the high pressure rear bearing HP # 2, and - a recovery pump 28d configured to recover the oil in the enclosure D which houses the low pressure bearings BP # 2 and BP # 3.
    As a variant, the turbojet engine 1 could comprise exactly three recovery pumps, the recovery pump 28c then being configured to recover the oil in the enclosure C which houses the HP high-pressure rear bearing # 2 and in the enclosure D which houses the low pressure bearings BP # 2 and BP # 3. In this case, the recovery pump 28d is removed. The exemplary embodiment illustrated in FIG. 1b is identical to that illustrated in FIG. 1a, except that the low pressure bearing BP # 2 is placed in the enclosure C. As for FIG. 1a, the same recovery pump 28c can then be used to recover the oil in the enclosures C and D, the turbojet 1 then comprising only three recovery pumps 28a to 28c. The exemplary embodiment illustrated in FIG. 1c is identical to that illustrated in FIG. 1a, except that the turbojet engine 1 only includes the enclosures A, B and C, the enclosure C housing the HP high pressure rear bearing # 2 and the bearings low pressure BP # 2 and BP # 3. In this embodiment, the turbojet engine 1 therefore comprises three recovery pumps 28a, 28b and 28c exactly, namely a recovery pump 28a to 28c per chamber A to C (respectively).
    In an exemplary embodiment not shown in the figures, the turbojet engine 1 comprises five enclosures. A first enclosure A houses the two blower bearings S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearing BP # 1. A second enclosure B houses the low pressure bearing BP # 4 and the high pressure bearing before HP # 1. A third, a fourth and a fifth enclosure house respectively the HP high pressure rear bearing # 2, the second low pressure bearing BP # 2 and the third low pressure bearing BP # 3. In this case, the turbojet engine 1 comprises at most five recovery pumps (namely at most one pump per enclosure). Thus, the turbojet engine 1 may comprise a recovery pump for the first enclosure, a recovery pump for the second enclosure, and between one and three recovery pumps for the third, fourth and fifth enclosures.
    It will be noted that, regardless of the exemplary embodiment, the low pressure bearing BP # 4 and the high pressure bearing before HP # 1 can be housed either in the same enclosure B (as illustrated and described above), or in separate speakers (not visible in the figures). In the case of separate enclosures, either a recovery pump is associated with each enclosure, or a single recovery pump is used to recover the oil injected into the two enclosures.
    In the exemplary embodiment illustrated in FIG. 2a, the turbojet engine 1 comprises at most four recovery pumps 28a to 28d, each recovery pump 28a to 28d being associated with at least one enclosure A to D, namely: an enclosure A housing the two blower bearings S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearings BP # 1 and BP # 4. - an enclosure B housing the high pressure bearing before HP # 1. - an enclosure C housing the HP high pressure rear bearing # 2. an enclosure D housing the low pressure bearings BP # 2 and BP # 3.
    This exemplary embodiment is therefore identical to that illustrated in FIG. 1b, except that the low pressure bearing BP # 4 is placed in the enclosure A rather than in the enclosure B.
    Here again, the turbojet engine 1 could comprise exactly three recovery pumps, the recovery pump 28c being then configured to recover the oil in the enclosure C which houses the high pressure rear bearing HP # 2 and in the enclosure D which houses the low pressure bearings BP # 2 and BP # 3. In this case, the recovery pump 28d is removed. The exemplary embodiment illustrated in FIG. 2b is identical to that illustrated in FIG. 2a, except that the low pressure bearing BP # 2 is placed in the enclosure C. As for FIG. 2a, the same recovery pump 28c can then be used to recover the oil in the enclosures C and D, the turbojet 2 then comprising only three recovery pumps 28a to 28c. The exemplary embodiment illustrated in FIG. 2c is identical to that illustrated in FIG. 2a, except that the turbojet engine 1 only comprises the enclosures A, B and C, the enclosure C housing the HP high pressure rear bearing # 2 and the bearings low pressure BP # 2 and BP # 3. In this embodiment, the turbojet engine 1 therefore comprises three recovery pumps 28a, 28b and 28c exactly, namely a recovery pump 28a to 28c per chamber A to C (respectively).
    In an exemplary embodiment not shown in the figures, the turbojet engine 1 comprises five enclosures. A first enclosure A houses the two blower bearings S # 1 and S # 2, the reduction mechanism 10, the low pressure bearing BP # 1 and the fourth low pressure bearing BP # 4. A second speaker B houses the high pressure bearing before HP # 1. A third, a fourth and a fifth enclosure house respectively the HP high pressure rear bearing # 2, the second low pressure bearing BP # 2 and the third low pressure bearing BP # 3. In this case, the turbojet engine 1 comprises at most five recovery pumps (namely at most one pump per enclosure). Thus, the turbojet engine 1 may comprise a recovery pump for the first enclosure, a recovery pump for the second enclosure, and between one and three recovery pumps for the third, fourth and fifth enclosures.
    In the exemplary embodiments illustrated in FIGS. 3a to 3c, the turbojet engine 1 comprises two fan bearings S # 1 and S # 2, a reduction mechanism 10, two HP # 1 and HP # 2 high-pressure bearings and three low-level bearings. pressure BP # 1, BP # 2 and BP # 3.
    In the exemplary embodiment illustrated in FIG. 3a, the turbojet engine 1 comprises at most four recovery pumps 28a to 28d, each recovery pump 28a to 28d being associated with at least one enclosure A to D, namely four enclosures A to D: - a chamber A housing the two blower bearings S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearing BP # 1, - an enclosure B housing the high pressure bearing before HP # 1. - an enclosure C housing the HP high pressure rear bearing # 2. an enclosure D housing the low pressure bearings BP # 2 and BP # 3.
    Here again, the turbojet engine 1 could comprise exactly three recovery pumps, the recovery pump 28c being then configured to recover the oil in the enclosure C which houses the high pressure rear bearing HP # 2 and in the enclosure D which houses the low pressure bearings BP # 2 and BP # 3. In this case, the recovery pump 28d is removed. The exemplary embodiment illustrated in FIG. 3b is identical to that illustrated in FIG. 1a, except that the low pressure bearing BP # 2 is placed in the enclosure C. As for FIG. 3a, the same recovery pump 28c can then be used to recover the oil in the enclosures C and D, the turbojet engine 1 then comprising only three recovery pumps 28a to 28c. The embodiment example illustrated in FIG. 3c is identical to that illustrated in FIG. 3a, except that the turbojet engine 1 includes only speakers A, B and C, enclosure C housing the HP high pressure rear bearing # 2 and low pressure bearings BP # 2 and BP # 3. In this embodiment, the turbojet engine 1 therefore comprises three recovery pumps 28a, 28b and 28c exactly, namely a recovery pump 28a to 28c per chamber A to C (respectively).
    In an exemplary embodiment not shown in the figures, the turbojet engine 1 comprises five enclosures. A first enclosure A houses the two blower bearings S # 1 and S # 2, the reduction mechanism 10 and the low pressure bearing BP # 1. A second speaker B houses the high pressure bearing before HP # 1. A third, a fourth and a fifth enclosure house respectively the HP high pressure rear bearing # 2, the second low pressure bearing BP # 2 and the third low pressure bearing BP # 3. In this case, the turbojet engine 1 comprises at most five recovery pumps (namely at most one pump per enclosure). Thus, the turbojet engine 1 may comprise a recovery pump for the first enclosure, a recovery pump for the second enclosure, and between one and three recovery pumps for the third, fourth and fifth enclosures.
    Note that, generally, when the second and third low pressure bearing BP # 2 and BP # 3 are housed in the same enclosure (as illustrated for example in Figure 1a, but also in the embodiments of Figures 2a and 3a), the second bearing BP # 2 is preferably attached to the exhaust casing. Moreover, when the second low pressure bearing BP # 2 and the high pressure rear bearing HP # 2 are housed in the same enclosure (as illustrated for example in Figures 1b, 2b and 3b), the second bearing BP # 2 is preferably fixed on the inter-turbine casing. On the other hand, when the second low pressure stage BP # 2, the third low pressure stage BP # 3 and the rear bearing HP # 2 of the high pressure shaft are housed in the same enclosure or in three separate enclosures, the second stage BP # 2 may be attached either to the exhaust casing (as shown in Figures 1c, 2c) or to the inter-turbine casing (as shown in Figure 3c).
    Optionally, the low pressure shaft is further connected to the casing of the low pressure turbine by a link 14. This connection is preferably fixed between two enclosures and so as not to cross the connection between a bearing (for example BP # 2 ) and the low pressure shaft. Thus, in the case of FIGS. 1a, 2a and 3a, where the second low pressure bearing BP # 2 is housed in the same enclosure as the third low pressure bearing BP # 3, the connection 14 extends between the high pressure rear bearing HP # 2 and the second low pressure bearing BP # 2; whereas in the case of FIGS. 1b, 2b and 3b, where the second low pressure bearing BP # 2 is housed in the same enclosure as the high pressure rear bearing HP # 2, the connection 14 extends between the second low pressure bearing BP # 2 and the third low pressure step BP # 3.
    Optionally, regardless of the embodiment, the enclosure housing the front bearing HP # 1 can also accommodate the gear 12 configured to take the power on the high pressure shaft. This configuration makes it possible to pool the recovery pump of the front bearing HP # 1 and the gear in question.
    In addition, irrespective of the embodiment, the turbojet engine 1 does not comprise a second low pressure bearing BP # 2 or a third low pressure bearing BP # 3. In this case, the HP high pressure rear bearing # 2 and the remaining bearing (third low pressure step BP # 3 or second low pressure bearing BP # 2) are either housed in separate enclosures or in the same enclosure. The number of recovery pumps associated with the high pressure rear bearing HP # 2 and the remaining bearing (BP # 3 or BP # 2) is then equal to one or two.
    When the high-pressure shaft 7a is supported only by a single front bearing HP # 1, the bearing HP # 1 preferably comprises a ball bearing. Alternatively, the high pressure shaft 7a may further comprise a third high pressure bearing (not visible in the figures), placed between the HP # 1 front bearing and the HP # 2 rear bearing. In this case, regardless of the embodiment example (including those illustrated in Figures 1a to 3c), the third high pressure bearing is housed in the enclosure B, with the high pressure bearing before HP # 1.
    Optionally, the second level BP # 2 can be deleted.
    Enclosures A to D may be ventilated or unventilated.
    By unvented enclosure ("non vented" in English), there will be understood here an enclosure which is not directly in fluid communication with the open air and which does not include a degassing tube. For this purpose, an oil recovery pump connected to a recovery port, can be placed at the low point of the engine to recover oil and air from the unventilated enclosure and thus create an air intake through the joints of the enclosure. The pump advantageously has a pumping rate greater than that of the oil inlet in the chamber for lubricating the bearing (s) and, where appropriate, the reduction mechanism 10. In this case, it is preferable to have a flow of air through both upstream and downstream seals, to retain the oil at the two seals. In addition, for there to be air flows passing through the two oil chamber joints, it is preferable that the pressure upstream of the two joints is substantially equal in order to avoid the formation of a preferential path of the airflow that would compromise the sealing performance of one of the joints.
    By ventilated enclosure ("vented" in English), there will be understood here an enclosure capable of being in communication with the open air while being maintained at a pressure close to atmospheric pressure. The bearings inside such enclosures are bathed by an oil mist which is extracted from the enclosure continuously by a degassing tube, the air and the oil then being separated in a de-oiler. In such a chamber, the recovery pump has a pumping rate substantially equal to that of the arrival of oil in the enclosure (via nozzles). Furthermore, it is possible to have air flows passing through the upstream and downstream sealing of the enclosure, said air flows having a pressure greater than or equal to that prevailing in the enclosure.
    In one embodiment, when the enclosure comprises at most two seals, the enclosure is preferably unventilated. Similarly, when the enclosure comprises more than two seals, the enclosure is preferably ventilated.
    Typically, whatever the embodiment, the enclosure A is preferably ventilated to the extent that it systematically comprises a first seal corresponding to the interface between the rotor of the fan 2 and the fan casing 2 (the enclosure A housing the fan bearings S # 1 and S # 2), a second interface between the fan shaft 7 and the low pressure shaft 6 (the enclosure A housing the reduction mechanism 10) and a third interface between the low pressure shaft 6 and the inter-compressor housing (enclosure A housing the low pressure bearing LP # 1). This enclosure A therefore necessarily includes a dedicated recovery pump.
    In the case where the HP # 2, BP # 2 and BP # 3 rear bearings are each housed in a respective enclosure, said enclosures may be unventilated. Moreover, for these enclosures and as described with reference to the figures above, the recovery pumps can (optionally) be pooled, that is to say that the lubrication group comprises at most three recovery pumps to recover l oil in these three chambers, preferably exactly two recovery pumps, or even a single recovery pump.
    On the other hand, in the exemplary embodiments illustrated in FIGS. 1c, 2c and 3c, the rear bearings HP # 2, BP # 2 and BP # 3 are all housed in the same enclosure C, which is therefore preferably ventilated. In this case, a recovery pump is associated with this enclosure C.
    When the high pressure front bearing HP # 1 is alone in its enclosure B (or only associated with the gear 12), the enclosure B may be unventilated. When its enclosure further comprises the gear 12, the enclosure may be ventilated or not ventilated. The recovery pump associated with this unventilated enclosure can then be shared with another non-ventilated enclosure.
    Similarly, when the HP # 2 high pressure rear bearing is alone in its enclosure, the enclosure may be unventilated. The recovery pump associated with this unventilated enclosure can then be shared with another non-ventilated enclosure.
    When the high pressure rear bearing HP # 2 is housed in the same enclosure as the second low pressure bearing BP # 2 (but in a different enclosure of the third low pressure bearing LP # 3), said enclosure can be ventilated or not ventilated.
    The fan bearing S # 1 may be of the roller bearing type and comprise an inner ring and a coaxial outer ring between which rollers are mounted. In addition, the fan bearing S # 2 may be of the ball bearing type and comprise an inner ring and a coaxial outer ring between which balls are mounted. By way of comparison, in the prior art, the front fan bearing and the rear fan bearing each comprise a tapered roller bearing, which can be dynamically assimilated to a single bearing. In contrast, the implementation of a roller bearing and a ball bearing for the front fan bearing S # 1 and the rear fan bearing S # 2 respectively allows to have two "real" bearings, thus allowing to have a more precise guidance in rotation.
    The low pressure bearing BP # 1 may be of the ball bearing type and comprise an inner ring and a coaxial outer ring between which balls are mounted.
    The low pressure bearings BP # 2, BP # 3 and, if appropriate, BP # 4 can be of the roller bearing type.
    Finally, the high pressure front HP # 1 and HP # 2 rear bearings can be roller bearing type.
    权利要求:
    Claims (10)
    [1" id="c-fr-0001]
    1. A turbofan engine (1) comprising: - a low pressure shaft (6) supported by at least two low pressure bearings (BP # 1 to BP # 4), - a high pressure shaft (8) supported by at least two high pressure bearings (HP # 1, HP # 2), - a fan shaft (7) supported by at least two fan bearings (S # 1, S # 2), - a reduction mechanism (10), coupling the low pressure shaft (6) and blower shaft (7), - enclosures (A to D) housing the low pressure bearings (BP # 1 to BP # 4), the high pressure bearings (HP # 1, HP # 2), the fan bearings (S # 1, S # 2) and the reduction mechanism (10), and - a lubricating unit (20) comprising a closed oil circuit configured to supply the loudspeakers (A to D) in oil to cool said bearings and the reduction mechanism, the turbojet (1) being characterized in that the lubrication unit (20) comprises at most five recovery pumps (28a to 28d) configured for recovery rinse the oil in the enclosures (A to D).
    [2" id="c-fr-0002]
    2. Turbojet engine (1) according to claim 1, comprising at most four recovery pumps (28a to 28d) configured to recover the oil in the enclosures (A to D).
    [3" id="c-fr-0003]
    3. Turbojet engine (1) according to one of claims 1 or 2, said turbojet comprising at least as many recovery pumps (28a to 28d) as enclosures (A to D), each recovery pump (28a to 28d) being associated with at most one enclosure (A to D) respectively.
    [4" id="c-fr-0004]
    4. Turbojet engine (1) according to one of claims 1 to 3, wherein the fan bearings (S # 1, S # 2), the reduction mechanism (10) and at least one of the low pressure bearings (BP # 1, BP # 4) are housed in the same enclosure (A), and in which a single recovery pump (28a) is configured to recover the oil injected into said enclosure (A).
    [5" id="c-fr-0005]
    5. Turbojet engine (1) according to one of claims 1 to 4, wherein the other low pressure bearings (BP # 1 to BP # 4), the high pressure bearings (HP # 1, HP # 2) and the bearings of blower (S # 1, S # 2) are housed in at most four enclosures (A to D), and wherein the lubrication group (20) comprises exactly three or four recovery pumps (28b to 28d) configured to recover oil injected into said four enclosures (B to D).
    [6" id="c-fr-0006]
    6. turbojet engine (1) according to one of claims 1 to 5, wherein the high pressure bearings (HP # 1, HP # 2) comprise a front high pressure bearing (HP # 1) and a rear high pressure bearing (HP # 2), the low pressure bearings (BP # 1 to BP # 4) comprise a first, a second and a third low pressure bearing (BP # 1, BP # 2 and BP # 3), and wherein the enclosure ( C) of the rear high pressure bearing, the enclosure (C, D) of the third low pressure bearing and the enclosure (D) of the fourth low pressure bearing are unventilated.
    [7" id="c-fr-0007]
    7. Turbojet engine (1) according to one of claims 1 to 6, wherein the high pressure bearings (HP # 1, HP # 2) comprise two front high pressure bearings (HP # 1), placed upstream of a chamber combustion, and a high pressure rear bearing (HP # 2), placed downstream of the combustion chamber, the front high pressure bearing (HP # 1) being housed in the same enclosure (B) and associated with the same pump recovery (28b).
    [8" id="c-fr-0008]
    8. Turbojet engine (1) according to one of claims 1 to 7, wherein the low pressure bearings (BP # 1 to BP # 4) comprise exactly three or four low pressure bearings, including one or two low pressure bearings (BP # 1, BP # 4) placed upstream of a combustion chamber, and one or two low pressure bearings (BP # 2, BP # 3) placed downstream of the combustion chamber.
    [9" id="c-fr-0009]
    9. Turbojet engine (1) according to one of claims 1 to 8, having a dilution ratio greater than or equal to 10, preferably greater than or equal to 18, for example between 12 and 18.
    [10" id="c-fr-0010]
    10. Turbojet engine (1) according to one of claims 1 to 9, wherein the reduction mechanism (10) comprises an epicyclic reduction mechanism or planetary having a reduction ratio of between 2.6 and 5.
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    同族专利:
    公开号 | 公开日
    CN109072715A|2018-12-21|
    EP3430243B1|2021-01-06|
    US20190101081A1|2019-04-04|
    CN109072715B|2021-04-09|
    FR3049007B1|2019-05-10|
    EP3430243A1|2019-01-23|
    US10837317B2|2020-11-17|
    WO2017158298A1|2017-09-21|
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    法律状态:
    2017-03-08| PLFP| Fee payment|Year of fee payment: 2 |
    2017-09-22| PLSC| Publication of the preliminary search report|Effective date: 20170922 |
    2018-02-20| PLFP| Fee payment|Year of fee payment: 3 |
    2020-02-20| PLFP| Fee payment|Year of fee payment: 5 |
    2020-04-10| CD| Change of name or company name|Owner name: SAFRAN AIRCRAFT ENGINES, FR Effective date: 20200304 |
    2021-02-19| PLFP| Fee payment|Year of fee payment: 6 |
    2022-02-21| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1652170A|FR3049007B1|2016-03-15|2016-03-15|TURBOREACTOR HAVING A SIMPLIFIED BEARING LUBRICATION GROUP|
    FR1652170|2016-03-15|FR1652170A| FR3049007B1|2016-03-15|2016-03-15|TURBOREACTOR HAVING A SIMPLIFIED BEARING LUBRICATION GROUP|
    CN201780023660.3A| CN109072715B|2016-03-15|2017-03-15|Turbojet engine comprising a simplified bearing lubrication assembly|
    US16/085,394| US10837317B2|2016-03-15|2017-03-15|Turbofan comprising a simplified bearing lubrication assembly|
    EP17714871.5A| EP3430243B1|2016-03-15|2017-03-15|Turbojet engine comprising a simplified bearing lubrication assembly|
    PCT/FR2017/050600| WO2017158298A1|2016-03-15|2017-03-15|Turbojet engine comprising a simplified bearing lubrication assembly|
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