Turbomachine accessory relay box

Abstract

This document describes an aircraft accessory relay housing (12) comprising a casing (14), at least one gear train mounted in the casing (14), the gear train having a plurality of gears (15) meshing with each other, at least one primary gear (40) comprising a primary shaft (42) extending along a primary axis (X), characterized in that it comprises a transmission system (51) arranged at a first end (44a) of the primary shaft (42) and intended to transmit power to equipment (34), said power transmission system (51) comprising an internally toothed ring gear (54) and a gear (52) meshing with the internal teeth of the ring gear (54), said transmission gear (52) having as its axis of rotation at least one of the primary axis (X) and an axis parallel (Y) to The primary axis (X). Abbreviated figure: Figure 4

Description

Title of the invention: Turbomachine accessory relay box technical field

[0001] This disclosure relates to an accessory relay box for an aircraft turbomachine, such as for example an aircraft turbojet or turboprop, or an industrial machine. Previous technique

[0002] Figure 1 represents a prior art turbomachine 1 comprising, from upstream to downstream in the direction of gas flow within the turbomachine 1, a fan 2, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber 5, a high-pressure turbine 6, and a low-pressure turbine 7. The air entering the turbomachine 1 is divided into a primary airflow (arrow A) which flows in a so-called primary air stream 8 inside the low- and high-pressure compressors 3 and 4 towards the combustion chamber 5 and then through the high- and low-pressure turbines 6 and 7, and into a secondary airflow (arrow B) which flows in a so-called secondary air stream 9 bypassing the compressors 3 and 4, the combustion chamber 5, and the turbines 6 and 7. The streams 8 and 9 are traversed by structural arms 10. extending radially.A structural arm 10 houses a power transmission shaft 11 extending substantially radially, the radially inner end of which is driven in rotation by the shaft of the high-pressure compressor 4. The radially outer end of the power transmission shaft 11 drives in rotation one end of a power transfer shaft 19 to an accessory relay box 12 of the turbomachine 1. This box 12 is conventionally arranged in a nacelle 13 forming a peripheral enclosure of the turbomachine 1.

[0003] As illustrated in [Fig.2], this accessory relay box 12, commonly called AGB for "Accessory Gear Box", comprises a fixed housing 14 and a gear train comprising a succession of gears 15 meshing with each other and whose diameters are adapted so that some gears 15 are integral with output shafts 17, each serving to drive at least one piece of equipment 16, at a given speed.

[0004] These 16 pieces of equipment may include various pumps for the production of hydraulic power, fuel supply, lubrication, electric generators for the production of electrical power, etc.

[0005] As shown in Figures 3A, 3B, 3C, the accessory housing comprises a first side wall 18 and a second side wall 20 facing each other. Each piece of equipment 16 is generally mounted against one of these walls. The lateral components 18 and 20 of the housing 14 are driven by a shaft 17 passing through the housing 14 at an opening 22 in the housing 14 and coupled to one of the gears 15 of the gear train. The accessory relay housing 12 is thus arranged in tiers, each tier comprising a shaft 17 and a gear 15.

[0006] The accessory relay housing 12 comprises a width along a direction I, a length along a direction J, and a height along a direction K.

[0007] These devices 16 may require different, specific rotational speeds. Typically, some electric generators can reach rotational speeds six times greater than accessories with the lowest rotational speeds. This difference in rotational speed between devices necessitates arranging devices requiring different rotational speeds on separate stages of the accessory relay box.

[0008] Figure 3A represents a first embodiment of the prior art in which a first stage 24 comprises a first gear 26 of diameter dl and a first piece of equipment 28. A second stage 30 comprises a gear 32 of diameter d2, such that d2 > dl, meshing with the first gear 26. Said second stage 30 further comprises a second piece of equipment 34. In operation, the first gear 26 drives the first piece of equipment 28 in rotation at a rotational speed col. The first gear 26 drives the second gear 32 in rotation, which is meshed with the first gear 26, and the second gear 32 drives the second piece of equipment 34 in rotation at a rotational speed co2, such that co2 < col. The presence of the second stage 30 at which the second large diameter gear 32 is mounted requires increasing the length and height of the casing 14 in order to accommodate the second gear 32.

[0009] Figure 3B represents a second embodiment of the prior art in which a first stage 24 comprises a first gear 26 of diameter dl, an additional transmission gear 36 of diameter dl' such that dl' < dl, and a first piece of equipment 28. A second stage 30 comprises a second gear 32 of diameter d2, such that d2 > dl > dl', meshing with the additional gear 36. This second stage 30 further comprises a second piece of equipment 34. In operation, the first gear 26 drives the first piece of equipment 28 in rotation at a rotational speed col. The additional transmission gear 36 drives the second gear 32 in rotation, and the second gear 32 in turn drives the second piece of equipment 34 in rotation at a rotational speed co2, such that co2 < col.The presence of the second stage 30, at which the second gear 32 and the additional gear 36 are mounted, requires increasing the length and width of the casing 14 respectively.

[0010] Figure 3C represents a third embodiment of the prior art in which The housing 14 has at its end an offset portion 38. A first stage 24 includes a first gear 26 of diameter dl, an additional transmission gear 36 of diameter dl' such that dl' < dl, said additional transmission gear 36 being arranged in the offset portion 38 of the housing 14, and a first piece of equipment 28. A second stage 30 arranged in the offset portion 38 of the housing 14 includes a second gear 32 of diameter d2, such that d2 > dl > dl', meshing with the additional transmission gear 36, said second stage 30 further includes a second piece of equipment 34. In operation, the first gear 26 drives the first piece of equipment 28 in rotation having a rotational speed col. The additional transmission gear 36 drives the second gear 32 in rotation, and the second gear 32 in turn drives the second equipment 34 in rotation having a rotational speed co2, such that co2 < col.The presence of the second stage 30, at which the second gear 32 and the offset part 38 of the housing 14 are mounted, requires increasing the length and width of the housing 14 respectively.

[0011] Certain turbomachinery designs require the accessory relay box 12 to be positioned around the high-pressure compressor 4, where space is limited. Adding equipment can therefore be complicated due to the sizing issues mentioned previously in relation to Figures 3A, 3B, and 3C. Consequently, the compactness of an accessory relay box is a key characteristic for its integration into a turbomachine.

[0012] In document FR 3 008 462, it was proposed that one of the gears form an external ring of a device with an epicyclic configuration. While this configuration allows for a power output at a speed different from that of the ring, it proves difficult to mount in the accessory relay housing.

[0013] A compact accessory relay box is proposed allowing the mounting of accessories with different rotation speeds. Summary

[0014] For this purpose, the present disclosure relates to an aircraft accessory relay box comprising:

[0015] - a housing having a first wall and a second wall opposite the first wall;

[0016] - at least one gear train mounted in the housing, the gear train comprising a plurality of parallel axis pinions meshing with each other;

[0017] - at least one primary pinion of said plurality of pinions comprising a shaft primary extending transversely between the first and second walls of the casing along a primary axis;

[0018] characterized in that it comprises a transmission system arranged at a first end of the primary shaft and intended to transmit power to equipment, said first end of the primary shaft being oriented towards the first wall of the casing, said power transmission system being located at least partially in a recess in the first wall of the casing, the recess extending towards the second wall, said power transmission system comprising:

[0019] — a crown with internal teeth; and

[0020] — a power transmission gear meshing with the internal teeth of the crown, said toothed wheel having as its axis of rotation at least one of the primary axis and of an axis parallel to the primary axis.

[0021] The terms axial and radial are defined with respect to the primary axis.

[0022] According to this document, the power transmission system is located at less partially in a recess in the housing. More specifically, the power transmission system is located outside the housing. A first piece of equipment can be rotationally coupled to the primary shaft at its first end via the power transmission system and can thus rotate at a different speed than the primary shaft. A second piece of equipment can be rotationally coupled to the primary shaft at a second end opposite the first end and can thus rotate at the same speed as the primary shaft. Therefore, the proposed configuration allows two pieces of equipment with different rotational speeds to be placed opposite each other on the first and second walls of the housing, and at a single stage of the accessory relay box.

[0023] Compared to the embodiment of [Fig.3A], the invention therefore makes it possible to reduce the length (along the direction J) and the height (along the direction K) of the housing.

[0024] Compared to the embodiment of [Fig.3B], the invention therefore makes it possible to reduce the width (along the direction I) of the housing.

[0025] Compared to the embodiment of [Fig.3C], the invention therefore makes it possible to reduce the length (along the direction J) and the width (along the direction I) of the housing.

[0026] Furthermore, the embodiments shown in Figures 3A, 3B, and 3C feature meshing between the external teeth of the first and second stage gears. Compared to the embodiments in Figures 3A, 3B, and 3C, the invention thus makes it possible to reduce the length of the housing because the power transmission gear meshes with the internal teeth of the ring gear.

[0027] Compactness is then gained along the length, width and / or height, the bulk is then reduced and the integration of the housing into a turbomachine is facilitated.

[0028] The accessory relay box may further include a first and a second primary bearing bearings located on either side of the primary pinion and mounted around the primary shaft, said first primary bearing bearing being located axially between the first wall of the housing and the primary pinion, said second primary bearing bearing being located axially between the second wall of the housing and the primary pinion.

[0029] The first and second bearing supports allow the primary pinion to be guided in rotation within the accessory housing.

[0030] The first end of the primary shaft may have splines, and the transmission gear may have a central opening, said central opening comprising splines adapted to cooperate by sliding along the primary axis with the splines of the primary shaft so as to ensure rotational locking of the two parts.

[0031] The accessory relay housing may further include a secondary bearing mounted around the ring.

[0032] The arrangement of the secondary bearing around the ring allows the radial forces of power transmission from the power transmission gear to the ring to be taken up due to the misalignment of the axis of the ring forming the output of the transmission system and the power input axis, i.e. the axis of the power transmission gear.

[0033] Roller bearings may be provided to efficiently absorb radial loads. Ball bearings are also a possibility.

[0034] The ring may include at an internal end, around which the secondary bearing is mounted, a radially external shoulder, an inner ring of the secondary bearing being arranged axially against said radially external shoulder. In this way, the inner ring of the secondary bearing is axially locked on one side.

[0035] The accessory relay housing may further include an external nut mounted around the crown and axially supported against an internal ring of the secondary bearing.

[0036] The power transmission system can be partially or fully integrated into the equipment.

[0037] The inner ring of the bearing used to absorb radial forces can thus be held axially between the shoulder of the ring on the first side and by the external nut on a second opposite side.

[0038] An axial stop may be provided for an outer ring of the secondary rolling bearing, said axial stop comprising an annular portion bearing axially against the outer ring of the secondary rolling bearing and a cylindrical portion located at a radially internal end of the annular portion, said cylindrical portion extending towards the bearings and being arranged between a cage and the outer ring of the secondary bearing. Thus, the axial stop can have a radial cross-section in the general shape of an L. In this way, the outer ring of the secondary bearing and the bearings are locked at the second side.

[0039] The cylindrical part can be arranged between the cage and the inner ring of the secondary bearing. In this way, the inner ring of the bearing and the bearings are locked at the second side.

[0040] The primary shaft may include at its first end a cylindrical bearing on which is mounted the transmission gear which is axially blocked at a first end by a shoulder of said cylindrical bearing and at a second opposite end by an internal nut screwed onto an internal surface of the cylindrical bearing.

[0041] This assembly allows the transmission gear to be held axially between the internal nut and the shoulder of the primary shaft.

[0042] The internal nut may further comprise an annular portion in axial contact with the first end of the primary shaft and a cylindrical portion located at a radially internal end of the annular portion of the internal nut, said cylindrical portion extending axially towards the interior of the housing and comprising a radially external surface, said radially external surface having a thread adapted to cooperate with the internal wall of the cylindrical bearing surface. Thus, the internal nut may have a radial cross-section generally shaped like an L.

[0043] The internal nut can be screwed onto an external wall of the cylindrical bearing surface and arranged as an axial stop against the transmission gear. In this way, the assembly allows the transmission gear to be held axially between the internal nut and the shoulder of the primary shaft.

[0044] The crown may include a first cylindrical part carrying the internal teeth and a second cylindrical part connected to a disc including a central passage in which is mounted at least one lubrication oil jet.

[0045] The central passage may include teeth on a radially internal surface in contact with teeth on a radially external surface of the lubricating oil jet.

[0046] The central passage in the disc allows lubricating oil to be supplied to the inside of the ring gear, the oil then circulating to the meshing point between the internal teeth of the ring gear and the teeth of the transmission gear. This oil can also circulate to the secondary bearing.

[0047] The internal nut may include at least one oil circulation orifice formed through the cylindrical portion of the internal nut and extending from a radially internal surface of the cylindrical portion of the internal nut to a radially external surface external part of the cylindrical part of the internal nut. In this way, the circulation orifice allows oil to circulate at the point of engagement between the internal teeth of the transmission gear and the splines of the first end of the primary shaft.

[0048] The accessory relay housing may further include at least one radial orifice formed through the ring for circulating oil to the secondary bearing and an annular oil recovery scoop arranged radially opposite said radial orifice. In a particular case, the housing may include one or a plurality of radial orifices.

[0049] A first leveling ring may be provided comprising an annular portion in axial contact with the cylindrical surface of the central passage, and a cylindrical portion extending axially from a radially external end of the annular portion. The cylindrical portion may be mounted around the central passage of the ring disc, and the first leveling ring may have a radial cross-section generally shaped like an L. In this way, centrifugal oil can be concentrated at the point of engagement between the teeth of the radially internal surface of the central passage and the teeth of the radially external surface of the nozzle.

[0050] According to another feature, the accessory relay housing may include a second and a third level ring housed in two radial grooves in the ring gear, these grooves opening radially inwards and being located on either side of the ring gear teeth. In this way, centrifugal oil can be concentrated at the point of meshing between the internal teeth of the ring gear and the teeth of the transmission gear.

[0051] The transmission system may include an epicyclic gear train comprising:

[0052] - a solar pinion with a primary axis;

[0053] - a plurality of satellite gears, one of which is formed by the toothed wheel of transmission, the said satellite gears being in contact with the crown wheel and with the solar pinion;

[0054] - a planet carrier on which said planetary gears are mounted for free rotation,

[0055] wherein at least a first element among the solar pinion, the satellite carrier and the ring is connected to the first end of the primary shaft, a second element among the satellite carrier and the ring is integral with the housing and a third element among the solar pinion, the satellite carrier and the ring is intended to be connected to equipment.

[0056] In this assembly, power transmission is achieved via an epicyclic gear train. This allows for good axisymmetric balancing of the radial load transmitted from the primary shaft to a shaft The output shaft is integral with the third element. Furthermore, power transmission via an epicyclic gear train offers an additional compactness advantage compared to the previous design. In operation, power is transmitted from the primary pinion to the primary shaft, then to the first element, the second element, the third element, and finally to the equipment.

[0057] The accessory relay housing may include a tertiary bearing with a roller guiding in rotation at least the third element.

[0058] The epicyclic gear train may include radially arranged planetary bearings between the planetary gears and projecting cylindrical portions of the planet carrier on which the planetary gears are freely mounted for rotation. In this way, the planetary bearings guide the rotation of the projecting cylindrical portions of the planet carrier and the planetary gears.

[0059] The tertiary bearing can guide the first element in rotation.

[0060] The tertiary bearing may include an outer ring integral with the housing and an inner ring integral with the third element. In other words, the tertiary bearing can be arranged radially outside the crown so that the outer ring is supported by the housing and the inner ring is rotationally fixed to the crown.

[0061] The first element may include an end inserted and rotationally coupled into the first end of the primary shaft.

[0062] The first element may have splines that engage with a toothed section of the inner wall of the first end of the primary shaft. In this way, the first element is mechanically connected to the primary shaft.

[0063] The first end of the primary tree can be joined to the end of the first element.

[0064] The first primary bearing can be arranged radially at least partly around said end of the first element.

[0065] The arrangement of the primary bearing around the end of the first element makes it possible to efficiently take up the radial forces and to ensure guidance of the first element by limiting its overhang on the first end of the primary shaft.

[0066] The tertiary bearing can be arranged in a radial plane passing through the planet gears, the ring gear, and the sun gear. Such an arrangement of the tertiary bearing allows for the efficient transfer of radial forces in the radial plane.

[0067] The tertiary bearing can be arranged radially inside the satellite gears and thus ensures guidance of the first element with the third element.

[0068] The first and second primary bearing, the secondary bearing and the tertiary bearing can be double row angular contact ball bearings or hydrodynamic bearings.

[0069] This disclosure also relates to a turbomachine comprising an accessory relay box of the type described above.

[0070] Said turbomachine may be a turbojet or an aircraft turboprop.

[0071] Said turbomachine may be a hybrid propulsion assembly comprising a electric machine and a heat engine. Said sealing assembly can be located at the interfaces between a power transmission and the heat engine, on the one hand, or the electric machine, on the other hand.

[0072] This document also relates to an aircraft comprising at least one turbomachine of the aforementioned type.

[0073] Said aircraft may be an airplane or a rotary-wing aircraft such as, for example, a helicopter. Brief description of the drawings

[0074] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analysis of the accompanying drawings, on which:

[0075] [Fig-1] is a schematic longitudinal cross-sectional view of a state-of-the-art turbomachine prior,

[0076] [Fig.2] is a schematic perspective view of a prior art accessory relay box,

[0077] [Fig.3A] is a schematic longitudinal cross-sectional view of a prior art accessory relay box according to a first embodiment,

[0078] [Fig.3B] is a schematic longitudinal cross-sectional view of a prior art accessory relay box according to a second embodiment,

[0079] [Fig. 3C] is a schematic longitudinal cross-sectional view of a relay box accessories of the prior art according to a third embodiment,

[0080] [Fig.4] is an axial cross-sectional view of the accessory relay housing according to a first embodiment of this document,

[0081] [Fig.5A] is an axial and perspective cross-sectional view of part of the accessory relay housing of [Fig.4],

[0082] [Fig.5B] is an axial cross-sectional view of the accessory relay housing of [Fig.5A],

[0083] [Fig.6A] is a perspective view of the accessory relay housing according to a second embodiment of this document comprising a power transmission system with an epicyclic configuration,

[0084] [Fig.6B] is a view of the accessory relay housing of [Fig.6A] along the axis of a solar pinion of the epicyclic gear train and from outside the housing from the accessory relay box,

[0085] [Fig.6C] is an axial sectional view of the accessory relay housing of [Fig.6A] according to a sectional plane VI C of [Fig.6B] comprising the axis of rotation of a primary pinion forming an input of the epicyclic gear train,

[0086] [Fig.7A] is a perspective view of the accessory relay housing according to a third embodiment of this document comprising a power transmission system with an epicyclic configuration,

[0087] [Fig.7B] is a view of the accessory relay housing of [Fig.7A] along the axis of a solar pinion of the epicyclic gear train and from outside the housing of the accessory relay housing,

[0088] [Fig.7C] is an axial sectional view of the accessory relay housing of [Fig.7A] according to a sectional plane VII C of [Fig.7B] comprising the axis of rotation of a primary pinion forming an input of the epicyclic gear train,

[0089] [Fig.8A] is a perspective view of the accessory relay housing according to a fourth embodiment of this document comprising a power transmission system with an epicyclic configuration,

[0090] [Fig.8B] is a view of the accessory relay housing of [Fig.8A] along the axis of a solar pinion of the epicyclic gear train and from outside the housing of the accessory relay housing,

[0091] [Fig.8C] is an axial sectional view of the accessory relay housing of [Fig.8A] according to a sectional plane VIII C of [Fig.8B] comprising the axis of rotation of a primary pinion forming an input of the epicyclic gear train,

[0092] [Fig.9A] is a perspective view of the accessory relay housing according to a fifth embodiment of this document comprising a power transmission system with an epicyclic configuration,

[0093] [Fig.9B] is a view of the accessory relay housing of [Fig.9A] along the axis of a solar pinion of the epicyclic gear train and from outside the accessory relay housing, and

[0094] [Fig.9C] is an axial sectional view of the accessory relay housing of [Fig.9A] according to a sectional plane IX C of [Fig.9B] comprising the axis of rotation of a primary pinion forming an input of the epicyclic gear train. Description of the implementation methods

[0095] Figures 4, 5A and 5B illustrate an accessory relay box according to a first embodiment of this document.

[0096] The accessory relay housing 12 extends along a longitudinal axis L and comprises a casing 14 having a first wall 18 and a second wall 20 arranged opposite the first wall 18. A gear train is mounted at the interior of the casing 14, between the first wall 18 and the second wall 20 and comprises a plurality of gears 15 in mesh with each other, each gear 15 being connected to a shaft 17. The axes of the shafts 17, that is to say the axes of the gears 15 are parallel to each other.

[0097] A plurality of equipment 16 is arranged axially against one of the first wall 18 or the second wall 20 of the housing 14. Each piece of equipment is rotationally connected to a shaft 17 of the gear train.

[0098] As illustrated in [Fig.4], a longitudinal end of the gear train comprises a primary pinion 40 through which a primary shaft 42 passes in its center extending between the first 18 and the second wall 20 of the housing 14. The primary pinion and the rotation shaft are able to rotate about an axis of rotation called the primary axis X, which comprises a first direction XI oriented towards the first wall 18 and a second direction X2 oriented towards the second wall 20.

[0099] As illustrated in Figures 5A and 5B, the primary tree 42 comprises a first Part 44 is oriented from the primary pinion 40 towards the first wall 18 of the housing 14 (direction XI) and has a first end 44a. The primary shaft 42 includes a second part 46 which is oriented from the primary pinion 40 towards the second wall 20 of the housing 14 (direction X2) and has a second end 46a.

[0100] As illustrated in [Fig.1], a power transfer shaft 19 forms a power input for the gear train.

[0101] In operation, the power transfer shaft 19 provides input power to the gear train, which enables the gears 15 and their connecting shafts 17 to be rotated together, and then the plurality of equipment 16 coupled in rotation to the plurality of connecting shafts 17.

[0102] Reference is now made to Figures 4, 5A and 5B, which illustrate on a larger scale the connection of the primary shaft 42 to the power transmission system according to this document and according to a first embodiment. According to this document, said power transmission system is located at least partially in a recess 21 of the first wall 18 of the housing 14, the recess 21 extending towards the second wall 20.

[0103] The first portion 44 of the primary shaft 42 comprises a frustoconical wall 44b with a cross-section increasing towards the first wall 18 and extending towards the first wall 18 by a cylindrical bearing surface 44c. The cylindrical bearing surface 44c comprises externally a first cylindrical surface 44f-1 extending into a radial shoulder 44d and then into a second cylindrical surface 44f-2 which has grooves. The radially internal surface of the cylindrical bearing surface 44c comprises a threaded portion 44g opening at the first end 44a of the primary shaft 44.

[0104] First 48 and second 50 primary bearings are mounted on either side of the primary pinion 40 and around the first cylindrical bearing surface 44c of the first part of the primary shaft 42 and the second part of the primary shaft 42, respectively. More specifically, the primary bearing 48 is mounted around the first cylindrical surface 44f-l and is engaged as a butt in the second direction X2 against an annular flange 49 of the second part 46 of the primary shaft 44. Said first 48 and second 50 primary bearings comprise radially internal rings 48a, 50a in radial contact with the first cylindrical bearing surface 44c of the first part 44 of the primary shaft 42 and the second part 46 of the primary shaft 42, respectively. The first 48 and second 50 primary bearings also comprise an outer ring 48b, 50b.

[0105] A power transmission system 51 is arranged at the first end 44a of the first part 44 of the primary shaft 42 so as to transmit the rotational torque of the primary pinion to the shaft.

[0106] The transmission system includes a transmission gear 52 which is arranged around the cylindrical bearing and more precisely on the second surface 44f-2 of the cylindrical bearing and along the second direction X2. The radially internal surface of the gear 52 includes splines cooperating by sliding about the primary axis with the splines of the second surface 44f-2. The transmission system also includes a ring 54 having an axis of rotation Y parallel to the primary axis X. The ring 54 includes a first cylindrical portion 56 surrounding the gear 52, said first cylindrical portion 56 comprising an internal annular toothing 56a meshing with an external toothing 52b of the gear 52. The first cylindrical portion of the ring 54 includes a radial annular rim 56b extending radially outwards from an end 56c of the first cylindrical portion 56 oriented along the second direction X2.

[0107] The ring 54 further comprises a second cylindrical part 58 located at a second end 56d of the first cylindrical part 56 and oriented along the first direction XL. The end of the second cylindrical part 58 opposite the first cylindrical part 56 is connected to a disk 60 having a central passage 62 in the form of an axially projecting tubular part 62 extending on either side of the disk 60. The axially projecting tubular part 62, along the Y axis of the ring 54, comprising teeth located on an internal cylindrical wall 62a.

[0108] An internal nut 64 is screwed onto the threaded portion 44g of the internal surface of the cylindrical bearing surface 44c. This internal nut 64 comprises a cylindrical portion 64a arranged radially inside said internal surface of the cylindrical bearing surface 44c. The internal nut 64 may also comprise a radial annular portion 64b extending radially outward from one end of the cylindrical portion. 64a oriented along the second direction X2, the annular part 64b being in axial contact with the first end 44a of the primary shaft 44 and ensures an axial locking of the gear 52 along the first direction XI, the locking of the gear 52 along the second direction being carried out on the shoulder 44d.

[0109] A secondary bearing 66 can be arranged around the first cylindrical part 56 of the ring 54. It can thus comprise a radially internal ring 66a in radial contact with the first cylindrical part 56 of the ring 54 and in axial contact against the annular rim 56b of the first cylindrical part 56 of the ring 54. A radially external ring 66b and bearings 66c, for example of the roller type, are mounted radially between the internal ring 66a and the external ring 66b and cooperate with a cage 66d of said secondary bearing 66.

[0110] The outer ring 66b comprises a base 66e, said base 66e comprising a first end 66f oriented along the second direction X2 and a second end 66g oriented along the first direction XL. The outer ring 66b may further comprise a first branch 66h extending radially inwards from the first end 66f of the base 66e and a second branch 66i extending radially outwards from the second end 66g of the base 66e, so that the outer ring 66b has a radial section in the general shape of Z.

[0111] An external nut 68 is mounted around the second cylindrical part of the ring 54 and so as to come into axial contact with the inner ring 66a of the secondary bearing 66.

[0112] Thus, the inner ring 66a of the secondary bearing 66 is held axially between the annular rim 56b of the first cylindrical part 56 of the ring 54 and the external nut 68.

[0113] An axial retaining member 70 is applied against the outer ring 66b of the secondary bearing 66 and in the second direction X2. This retaining member 70 comprises an annular part 70a in radial contact with the second branch 66i of the outer ring 66b and a cylindrical part 70b extending from an end 70c radially internal to the annular part 70a and in the second direction X2, the cylindrical part 70b being located partly radially between the cage 66d and the base 66e of the outer ring 66b of the secondary bearing 66.

[0114] The axial stop member 70 thus allows the outer ring 66b to be axially blocked in the first direction XL The cylindrical part 70b allows the bearings of the secondary bearing 66 to be axially blocked in the first direction.

[0115] The transmission system is intended to receive a shaft 72 of a piece of equipment 34. This shaft is engaged in the axially projecting tubular part 62 of the ring 58 and includes an external toothing 72a in contact with the internal toothing of the tubular part of the disc 60 of the ring 58.

[0116] In operation, the plurality of pinions 15 of the gear train drives in rotation the primary pinion 40, then the primary shaft 42, the transmission gear 52, then the ring gear 54, and finally the equipment 34. It is observed that the external diameter of the gear is less than the internal diameter of the ring gear, so that the transmission system allows a speed reduction between the speed col of the primary shaft 44 and the speed co2 of the shaft 72 of the equipment in a reduced space, unlike the prior art as described with reference to Figures 3A, 3B, and 3C.

[0117] A lubricating oil jet 76 can be formed in the shaft 72 of the equipment 34 and can include at least one, in particular two, jet orifice 76a, 76b whose axis is oriented obliquely with respect to the axis of rotation Y of the ring 54 and towards the interior of the housing 14.

[0118] During operation, lubricating oil is ejected through the orifices 76a, 76b of the nozzle 76 and flows towards the teeth of the gear 52 and the ring 54.

[0119] A radial orifice 78 delimiting the first 56 and the second 58 cylindrical part of the ring 54 extends from a radially internal cylindrical surface 56e of the ring 54 to a radially external surface 68a of the external nut 68.

[0120] An annular scoop 80 is arranged partly in axial contact with the axial stopping member 70 and may include an axial recess 80a oriented along the first direction XI and connected to a radial annular wall 80b extending radially inwards.

[0121] In operation, the lubricating oil flows through the radial orifice 78 and is redirected to the roller 66e of the secondary bearing 66 by the annular scoop 80.

[0122] Two level rings 82, 84 are located at the level of the first cylindrical part 56 of the crown 54 and are housed in two radial orifices 56f, 56g arranged on either side of the internal teeth 56a of the crown 54.

[0123] In operation, the centrifuged oil is concentrated in two annular spaces delimited by the internal teeth 56a of the crown 54 and the two level rings 82, 84. In this way, the lubrication of the meshing between the internal teeth 56a of the crown 54 and the external teeth 52b of the transmission gear 52 is improved.

[0124] Two radial orifices 86, 88 are located at the level of the cylindrical part 64a of the internal nut 64 and extend from a radially internal surface 64c to a radially external surface 64d of the cylindrical part 64a of the internal nut 64 opening opposite onto the cylindrical bearing surface 44c of the primary shaft 42.

[0125] During operation, oil circulates through the radial orifices 86, 88 of the internal nut 64. In this way, the lubrication of the meshing between the splines of the cylindrical bearing 44c and an internal tooth 52a of the transmission gear is provided. 52 is improved.

[0126] Figures 6A, 6B, 6C, 7A, 7B, 7C, 8A, 8B, 8C, 9A, 9B and 9C illustrate embodiments comprising a transmission system including a gear train with an epicyclic configuration.

[0127] In the configurations illustrated in Figures 6A, 6B, 6C, 7A, 7B, 7C, 8A, 8B, 8C, 9A, 9B and 9C, the epicyclic gear train comprises:

[0128] - a solar pinion 90 with primary axis X;

[0129] - a plurality of satellite gears 94, one of which forms the transmission gear 52, the said satellite pinions 94 being in contact with the ring 54 and with the solar pinion 90;

[0130] - a planet carrier 96 on which said pinions are mounted freely for rotation tellites 94.

[0131] According to these embodiments, at least one first element among the solar pinion 90, the satellite carrier 96 and the ring 54 is connected to the first end 44a of the primary shaft 42, a second element among the satellite carrier 96 and the ring 54 is integral with the housing 14 and a third element among the solar pinion 90, the satellite carrier 96 and the ring 54 is intended to be connected to a piece of equipment 34.

[0132] Figures 6A, 6B and 6C illustrate an accessory relay box according to a second embodiment of this document.

[0133] The second embodiment has a similar architecture to the first embodiment and differs from it in that:

[0134] - the transmission system 51 is an epically configured gear train cloidal,

[0135] - the first part 44 of the primary tree 42 carries only the first bearing primary bearing 48 and therefore does not carry the power transmission gear since the latter is integrated into the epicyclic gear train.

[0136] The first wall 18 of the housing 14 also has a recess 21 which is oriented towards the second wall 20 of the housing 14. The recess 21 is delimited by a first radial annular wall 21a, one radially external end of which is connected to a first cylindrical wall 21b, one end of which, oriented along the first direction XI, is connected to a longitudinal portion of the wall 14. The radially internal end of the first radial annular wall 21a surrounds the outer ring 48b of the first primary bearing 48. In this way, the circumference of the radially internal end of the first radial annular wall 21a ensures centering of the outer ring 48b of the first primary bearing 48, and the inner ring ensures rotational guidance of the primary shaft 44.

[0137] The second wall 20 of the housing 14 includes an opening 20a in which is mounted the outer ring 50b of the second primary bearing 50.

[0138] The crown 54 is arranged at the first end 44a of the primary shaft 44 and is housed in the recess 11 of the first wall 18 of the housing 14.

[0139] This ring 54 comprises a disk 54a arranged axially along the primary axis X between the first radial annular wall 21a and the planetary gears 94. The disk 54a is connected at its radially external end to an external cylindrical wall 54b carrying internal teeth meshing with the planetary gears 94. The radially internal end of the disk 54a comprises a central portion 54c extending along the primary axis X and which may include a central orifice 55 as illustrated in [Fig. 6C]. A cylindrical wall 54d extends in the second direction X2 from the disk 54a and is arranged radially between the central portion 54c and the external cylindrical wall 54b.

[0140] The cylindrical wall 54d of the ring 54 is integral with the cylindrical bearing surface 44c of the primary shaft 42. In this way, the ring 54 forms the power input of the power transmission system.

[0141] A solar pinion 90 is arranged around the central portion 54c of the ring 54 and comprises a first cylindrical bearing 90a including an external toothing, followed by a radially internal shoulder 90b and a second cylindrical bearing 90c intended to form the output of the transmission system 51. This second cylindrical bearing 90c of the solar pinion is intended to be connected to a piece of equipment 34.

[0142] A tertiary bearing 92 is mounted radially between the central portion 54c of the ring 54 and the first cylindrical bearing surface 90a of the sun pinion 90. This tertiary bearing 92 has an inner ring 92a in radial contact with the central portion 54c of the ring 54 and an outer ring 92b in radial contact with the first cylindrical bearing surface 90a of the sun pinion 90. The inner ring 92a and the outer ring 92b of the tertiary bearing 92 are axially butted against the shoulder 90b of the sun pinion 90.

[0143] At least two satellite pinions 94, in the example shown three satellite pinions 94, are arranged radially between the outer cylindrical wall 54b of the ring 54 and the sun pinion 90 and have an external toothing 94a in contact with the internal toothing of the outer cylindrical wall 54b of the ring 54 and the external toothing of the first cylindrical bearing 90a of the sun pinion 90.

[0144] A satellite carrier 96 comprises a ring 96a arranged outside the recess 21 of the first wall 18 of the housing 14 and connected to a perforated disc 96b which is formed as a single unit with the ring 96a. The ring 96a is connected to the perforated disc 96b by means of several branches 96d, here three branches, defining with the ring and the disc three perforated areas 96c. The branches can extend substantially radially. The perforated disc 96b includes a central opening 96b allowing passage of the second cylindrical bearing 90c of the sun pinion 90. An axial rod 96f extends from each branch along the second direction X2 and is engaged in a satellite pinion 94. The ring 96 of the satellite carrier includes lugs 97 each having an opening for the passage of a fixing screw to the first wall 18.

[0145] A satellite bearing 98 is mounted around each rod 96f and in a central opening 94b of a satellite pinion 94. Each bearing comprises an inner ring 98a and an outer ring 98b.

[0146] In operation, power transmission occurs from the primary pinion 40 to the primary shaft 42, then to the ring gear 54, to the satellite gears 94, and finally to the solar pinion 90. Thus, the ring gear 54 and the solar pinion 90 form respectively the input and output of the power transmission system 51 which is a multiplying epicyclic gear train.

[0147] A radial plane P perpendicular to the X axis passes through the satellite pinions 94, the satellite carrier 96 and the solar pinion 90.

[0148] Figures 7A, 7B and 7C illustrate an accessory relay box 12 according to a third embodiment of this document.

[0149] The third embodiment has a similar architecture to the second embodiment and differs in that:

[0150] - the crown 54 is arranged in the radial plane P,

[0151] - the ring 96a and the perforated disc 96b of the satellite carrier 96 are located axially between the solar pinion 90 and the cylindrical bearing 44c of the primary shaft 42, and

[0152] - the satellite carrier 96 has a different shape from that illustrated in the figures 6A, 6B and 6C. This planet carrier 96 thus comprises a central portion 96g in axial projection which is mounted radially inside and in radial contact with the inner ring 92a of the tertiary bearing 92. The planet carrier also has a cylindrical wall 96h oriented in the second direction X2 and engaged inside the cylindrical bearing surface 44c of the first part 44 of the primary shaft 4. Thus, the planet carrier forms the power input of the power transmission system.

[0153] It is observed that the outer crown includes ears 97 each having an opening for the passage of a fixing screw to the first wall 18.

[0154] In operation, power transmission occurs from the primary pinion 40 to the primary shaft 42, then to the planet carrier 96, to the planetary pinions 94, and finally to the solar pinion 90. Thus, the planet carrier 96 and the solar pinion 90 form respectively the input and output of the power transmission system 51 which is a multiplying epicyclic gear train.

[0155] Figures 8A, 8B and 8C illustrate an accessory relay box 12 according to a fourth embodiment of this document.

[0156] The fourth embodiment has a similar architecture to the third embodiment and differs in that:

[0157] - the solar gable 90 includes an additional axially projecting cylindrical part 90d oriented towards the inside of the housing 14, located radially inside the cylindrical bearing surface 44c of the first part 44 of the primary shaft 42 and an annular part 90e extending radially outwards and comprising at one end 90f a toothing in contact with an internal toothing of the cylindrical bearing surface 44c of the first part 44 of the primary shaft 42,

[0158] - the recess 21 is delimited by the first radial annular wall 21a connected to its radially external end to the first cylindrical wall 21b which is itself externally connected to a second radial annular wall 21c which is connected to a second cylindrical wall 21d,

[0159] - the ring 96a of the satellite carrier 96 is mounted and secured to the first cylindrical part 21b of the recess 21,

[0160] - the crown 54 includes a disc 60 located outside the recess 21 of the first wall 18 of the casing 14, a central tubular portion projecting 62 oriented outwards from the casing 14, that is to say in the first direction XI and intended to be coupled, by grooves for example to a piece of equipment 34, and

[0161] - the tertiary bearing 92 is located radially between the second part cy the indrique 21d of the recess 21 and the ring 54, the inner ring 92a of the tertiary bearing 92 being in radial contact with the ring 54 and the outer ring 92b of the tertiary bearing 92 being in radial contact with the shoulder 18c of the first wall 18 of the housing 14.

[0162] In operation, power is transmitted from the primary pinion 40 to the primary shaft 42, then to the sun pinion 90, to the satellite pinions 94, and finally to the ring gear 54. Thus, the sun pinion 96 and the ring gear 54 form respectively the input and output of the power transmission system 51 which is a reducing epicyclic gear train.

[0163] Figures 9A, 9B and 9C illustrate an accessory relay box 12 according to a fifth embodiment of this document.

[0164] The fifth embodiment has a similar architecture to the fourth embodiment and differs in that:

[0165] - the tertiary bearing 92 is radially located inside the solar pinion 90, the radially internal ring 92a of the tertiary bearing 92 being in radial contact with the solar pinion 90,

[0166] - the perforated disc 96b of the satellite carrier 96 is located outside the recess 21 of the first wall 18 of the housing 14, the planet carrier 96 comprises a first part with additional axial projection 96g oriented towards the interior of the housing 14 and in radial contact with the inner ring 92a of the tertiary bearing 92 and a second part with additional axial projection 96h oriented towards the exterior of the housing 14 intended to be linked to equipment 34, and

[0167] - the crown 54 is integral with the first cylindrical wall 21b of the recess 21.

[0168] In operation, power transmission occurs from the primary pinion 40 to the primary shaft 42, then to the solar pinion 90, to the planetary pinions 94, and finally to the planet carrier 96. Thus, the solar pinion 90 and the planet carrier 96 form respectively the input and output of the power transmission system 51 which is a reducing epicyclic gear train.

Claims

Claims

1. An accessory relay housing (12) for an aircraft comprising: - a casing (14) having a first wall (18) and a second wall (20) facing the first wall (18); - at least one gear train mounted in the casing (14), the gear train comprising a plurality of pinions (15) with parallel axes meshing with each other; - at least one primary pinion (40) of said plurality of pinions (15) comprising a primary shaft (42) extending transversely between the first (18) and the second wall (20) of the casing (14) along a primary axis (X);characterized in that it comprises a transmission system (51) arranged at a first end (44a) of the primary shaft (42) and intended to transmit power to equipment (34), said first end (44a) of the primary shaft (42) being oriented towards the first wall (18) of the casing (14), said power transmission system (51) being located at least partially in a recess (21) of the first wall (18) of the casing (14), the recess (21) extending towards the second wall (20), said power transmission system (51) comprising: — a crown (54) with internal teeth; and — a power transmission gear wheel (52) meshing with the internal teeth of the crown wheel (54), said transmission gear wheel (52) having as its axis of rotation at least one of the primary axis (X) and an axis parallel (Y) to the primary axis (X).;

2. An accessory relay housing (12) according to the preceding claim, further comprising a first (48) and a second primary rolling bearing (50) located on either side of the primary pinion (40) and mounted around the primary shaft (42), said first primary rolling bearing (48) being located axially between the first wall (18) of the housing (14) and the primary pinion (40), said second primary rolling bearing (50) being located axially between the second wall (20) of the housing (14) and the primary pinion (40).

3. An accessory relay housing (12) according to one of the preceding claims, wherein the power transmission system (51) further comprises a secondary rolling bearing (66) mounted around the ring gear (54).

4. Accessory relay housing (12) according to the preceding claim, wherein it further comprises an external nut (68) mounted around the crown (54) and axially bearing against an internal ring (66a) of the secondary rolling bearing (66).

5. Accessory relay housing (12) according to the preceding claim, wherein the primary shaft (42) comprises at its first end (44a) a cylindrical bearing surface (44c) on which is mounted the transmission toothed wheel (52) which is axially locked at a first end by a shoulder (44d) of said cylindrical bearing surface (44c) and at a second opposite end by an internal nut (64) screwed onto an internal surface of the cylindrical bearing surface (44c).

6. Accessory relay housing (12) according to one of the preceding claims, in which the crown (54) comprises a first cylindrical part (56) carrying the internal teeth and a second cylindrical part (58) connected to a disc (60) comprising a central passage (62) in which is mounted at least one nozzle (76) of lubricating oil.

7. Accessory relay housing (12) according to the preceding claim, further comprising at least one radial orifice (78) formed through the crown (54) for the circulation of oil to the secondary rolling bearing (66) and an annular scoop (80) for recovering oil arranged radially opposite said radial orifice (78).

8. Accessory relay housing (12) according to claim 1 or 2, wherein the transmission system (51) comprises a gear train with epicyclic configuration comprising: - a sun gear (90) with primary axis (X); - a plurality of planet gears (94), one of which is formed by the transmission gear wheel (52), said planet gears (94) being engaged with the crown wheel (54) and with the sun gear (90); - a planet carrier (96) on which said planet gears (90) are mounted to rotate freely, in which at least a first element among the sun gear (90), the planet carrier (96) and the crown (54) is connected to the first end (44a) of the primary shaft (42), a second element among the planet carrier (96) and the crown (54) is secured to the casing (14) and a third element among the sun gear (90), the planet carrier (96) and the crown (54) is intended to be connected to the equipment (34).

9. Accessory relay box (12) according to the preceding claim, comprising a tertiary rolling bearing (92) guiding at least the third element in rotation.

10. An accessory relay housing (12) according to claim 9, wherein the tertiary rolling bearing (92) rotationally guides the first member.

11. An accessory relay housing (12) according to claim 9, wherein the tertiary rolling bearing (92) comprises an outer ring (92b) integral with the housing (14) and an inner ring (92a) integral with the third element.

12. An accessory relay housing (12) according to one of claims 8 to 11, wherein the first member comprises an end inserted and rotatably coupled into the first end (44a) of the primary shaft (42).

13. An accessory relay housing (12) according to claim 12, wherein the first primary rolling bearing (48) is arranged radially at least partially around said end of the first member.

14. An accessory relay housing (12) according to claim 13 wherein the tertiary rolling bearing (92) is arranged in a radial plane (P) passing through the planet gears (94), the ring gear (54) and the sun gear (90).

15. Turbomachine, such as an aircraft turbojet or turboprop, comprising an accessory relay box (12) according to one of the preceding claims.

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