Planetary gear carrier for a reduction gear with planetary gear of a turbo engine and method for assembling such a planetary gear carrier

Description

Scope of the invention

[0001] The present invention relates to the field of epicyclic gear speed reducers for turbomachinery, in particular for aircraft, as well as to the elements which make up a reducer of this type such as nozzles, a planet carrier, a wheel, etc. State of the art

[0002] The state of the art includes in particular the documents WO-A1-2010 / 092263, FR-A1-2 987 416, FR-A1-3 036 763, which forms the basis for the two-part form of claim 1, WO-A2-2014 / 099087, US-A1-2012 / 028756 and FR-A1-3 041 054.

[0003] Modern turbomachinery, especially turbomachinery with one or more propellers blowing a secondary flow, includes a transmission system, called a reduction gear, to drive this or these propellers to the correct rotational speed from the power turbine shaft of the engine's primary body.

[0004] The operation of gearboxes, particularly on turbomachinery with high bypass ratio blower propellers, requires a particularly high oil flow rate, on the order of 6000 to 7000 liters per hour at takeoff, to ensure the lubrication and cooling of their gears and bearings.

[0005] Among the reducers used are planetary and epicyclic (gear) reducers which have the advantage of offering significant reduction ratios of rotational speed in small spaces.

[0006] Such a reducer includes a planetary pinion or central pinion, called a sun gear, an outer ring gear and satellite pinions, called satellites, which mesh with the sun gear and with the ring gear, the support of one of these three components having to be locked in rotation for the operation of the gear train.

[0007] When the satellite carrier is fixed in rotation, the sun and the corona are leading and driven, respectively, or vice versa. The reduction gear is then of the "planetary" type.

[0008] In the opposite case, the most frequent, of an epicyclic gear reducer, the outer ring is fixed in rotation and the solar and satellite carrier are driving and driven.

[0009] However, this type of gearbox has drawbacks. One problem is related to ensuring proper lubrication of the gears on the satellites and the solar array. The oil must flow from a stationary part of the motor to a high-speed rotating part. Once in the rotating part, the oil is no longer under pressure. At high speed, it is difficult for the oil to reach the solar array due to centrifugal force. Therefore, it is crucial to position the nozzle as close as possible to the solar array. Another problem is related to the complexity of the assembly.

[0010] The present invention proposes an improvement which provides a simple, effective and economical solution to at least some of these problems. Description of the invention

[0011] The aforementioned disadvantages and associated problems of the prior art are solved by a satellite carrier according to claim 1 and a method of assembling such a satellite carrier according to claim 9. Advantageous configurations are defined in the dependent claims. Brief description of the figures

[0012] Other features and advantages will become apparent from the following description of a non-limiting embodiment of the invention with reference to the accompanying drawings in which: there figure 1 is a schematic axial cross-sectional view of a turbomachine using the invention, the figure 2 is a schematic axial cross-sectional view of an epicyclic gear reducer, the figure 3is a schematic perspective view of an embodiment of an epicyclic gear reducer, with a planet carrier according to the invention, the figure 4 is a schematic perspective view of an assembly comprising a gear and nozzles of the reducer of the figure 3 , there figure 5 is a schematic perspective view of a satellite carrier according to the invention of the reducer of the figure 3 , there figure 6 is another schematic perspective view of the reducer of the figure 3 , and shows an assembly step, the figure 7 is a partial schematic view in axial section and at a larger scale of a detail of the reducer of the figure 3 , and in particular a nozzle of the reducer, and the figure 8 is a partial schematic cross-sectional and larger-scale view of a detail of the reducer of the figure 3 , and in particular a nozzle of the reducer. Detailed description of an embodiment of the invention

[0013] There figure 1Figure 1 shows a turbomachine comprising, in a conventional manner, a fan propeller S, a low-pressure compressor 1a, a high-pressure compressor 1b, an annular combustion chamber 1c, a high-pressure turbine 1d, a low-pressure turbine 1e, and an exhaust nozzle 1h. The high-pressure compressor 1b and the high-pressure turbine 1d are connected by a high-pressure shaft 2 and together form a high-pressure (HP) unit. The low-pressure compressor 1a and the low-pressure turbine 1e are connected by a low-pressure shaft 3 and together form a low-pressure (LP) unit.

[0014] The blower propeller S is driven by a blower shaft 4 which is coupled to the BP shaft 3 by means of an epicyclic gear reducer 10 shown here schematically.

[0015] The reducer 10 is positioned in the front part of the turbomachine. A fixed structure schematically comprising an upstream part 5a and a downstream part 5b is arranged to form an enclosure E1 surrounding the reducer 10. This enclosure E1 is closed upstream by seals at the level of a bearing allowing the passage of the blower shaft 4, and downstream by seals at the level of the passage of the BP shaft 3.

[0016] With reference to the figure 2The reduction gear 10 includes a ring gear 14 which is fixed, via a ring carrier (not shown), to the fixed structure 5a, 5b. Flexible means are arranged to allow the ring carrier to follow any movements of the blower shaft 4, for example, in certain degraded operating conditions. In a planetary gear system, the ring carrier consists of a more or less flexible part that drives the ring gear and a shaft supported by bearings or bushings, on which the blower is mounted. These fastening means are known to those skilled in the art and are not detailed here. A brief description can be found, for example, in FR-A1-2987416.

[0017] The reducer 10 engages on one side with the BP3 shaft via splines 7 which drive a planetary or solar gear pinion 11, and on the other side with the blower shaft 4 which is attached to a planet carrier 13. Conventionally, the solar 11, whose axis of rotation X coincides with that of the turbomachine, drives a series of planetary gears or planets 12, which are regularly distributed around the circumference of the reducer 10. The number of planets 12 is generally defined between three and six. The satellites 12 also rotate around the X axis of the turbomachine except in the case of a planetary gear where they rotate only around their axes of revolution, by engaging with internal teeth of the ring gear 14, which is fixed to a stator of the turbomachine by means of flanges 20 in the case of an epicyclic gear or fixed to a rotor of the turbomachine in the case of a planetary gear.Each of the satellites 12 rotates freely around a satellite axis 16 connected to the satellite carrier 13, using a bearing which may be smooth, as shown in the . figure 2 , or a rolling element bearing (ball or roller bearings).

[0018] The rotation of the satellites 12 around their satellite axis 16, due to the cooperation of their pinions with the teeth of the ring 14, causes the rotation of the satellite carrier 13 around the X axis, and consequently that of the blower shaft 4 which is linked to it, at a rotational speed which is lower than that of the BP shaft 3.

[0019] There figure 2 shows the flow of oil to the reducer 10 and its path within it. Arrows on the figure 2The path followed by the oil, in this example, from a buffer reservoir linked to the fixed structure of the turbomachine, to the gears and bearings to be lubricated. The lubrication system typically comprises three parts: a first part linked to the fixed structure and delivering the oil to the rotating parts of the gearbox 10, a rotating impeller with the planet carrier 13 receiving this oil in the case of an epicyclic gear and a distributor assembled to the planet carrier, which are fixed on a planetary configuration, and oil distribution circuits supplied with oil by the impeller to convey it to the areas to be lubricated.

[0020] THE figures 3 to 8 illustrate the example of the realization of a satellite carrier for a 110 reducer according to the invention.

[0021] Reference 130 designates the satellite carrier of the reducer 110, which is here of the monobloc type comprising a part forming a cage 134 and a part forming a shaft 142. The cage has two coaxial annular walls 136, 138 connected at their periphery by a cylindrical wall 140.

[0022] The annular wall 136 is integral with the substantially cylindrical, partially visible shaft 142, which includes means for engaging with a turbomachine blower disk. The coupling means are, for example, longitudinal grooves.

[0023] In the example shown, the cylindrical wall 140 is perforated and includes radially passing lights 143 allowing the mounting of the satellites.

[0024] The wall 138 includes a central opening 144 (allowing the mounting of the solar element) centered on the X axis and a series of orifices 146 regularly distributed around the X axis, the opening 144 and the orifices 146 being through-holes in the axial direction ( figure 5 ).

[0025] The openings 146 are used for mounting the rotation axes 148 of the satellites 150. The axes 148 are parallel to the X-axis and are mounted in the cage 134 by axial translation through the openings 146. They are fixed at their longitudinal ends to the walls 136, 138, respectively. Each axis 148 is integral with a plain bearing 149 around which the satellite 150 is mounted ( figure 6). The shaft 148 is hollow and includes an internal cylindrical cavity 152. The shaft 148 and the bearing 149 are traversed by at least one radial conduit (not visible) which opens at its radially internal end into the cavity 152, and at its radially external end into a longitudinal groove in the periphery of the bearing for the purpose of supplying it with oil.

[0026] As can be seen in the figure 6 , the satellites 150 mounted for rotation on the axes 148 have their external peripheries which pass in part through the slots 143 in view of their meshing with the external ring of the reducer intended to surround the cage 134.

[0027] The satellites 150 mesh with the solar 151 which includes internal straight grooves 151a for coupling to another shaft such as a turbine shaft.

[0028] A gear 120 is attached to and fixed on the wall 138, on its outer face, that is, the side not facing the satellites 150. The gear 120 lubricates the reduction gear 110 and includes lubrication means configured to supply lubricant to nozzles 172 and to the shafts 148 and bearings 149. The oil supply to the nozzles lubricates the meshing teeth of the satellites 150 and the solar element 151, as will be described in more detail below with reference to the figure 8 .

[0029] The wheel 120 has a generally annular shape and comprises arms 120a projecting radially outwards, five in number in the example shown. The wheel 120 is intended to be mounted coaxially on the wall 138 and has a face 120b for bearing and fixing to this wall.

[0030] The wheel 120 has a central opening 120c delimited externally by an annular portion defining two coaxial annular grooves 158a, 158b arranged axially side by side. These grooves 158a, 158b extend around the X-axis and open radially inwards. Their radially external bottom wall includes orifices in fluidic communication with radial channels 160, on the one hand, and radial conduits 162, on the other.

[0031] Although not shown, oil is intended to be sprayed into the grooves 158a, 158b by means of lubricant supply. These means generally comprise a series of injectors arranged around the X-axis and passing through the openings 120c, 144. The injectors are carried by a stator and spray lubricant radially outwards directly into the grooves 158a, 158b, from where it then flows into the channels 160 and conduits 162.

[0032] In the example shown, the number of channels 160 is equal to the number of conduits 162, which is equal to the number of axes 148 and satellites 150. This number is five here. The channels 160 are regularly distributed around the X-axis, and the conduits 162 are regularly distributed around the X-axis, each conduit 162 being positioned between two adjacent channels 160. The conduits and channels are formed in the overthicknesses 165, 166 of the wheel ( figure 3The raised sections 165 and 166, in which the channels 160 and conduits 162 are formed, extend radially outwards from the portion in which the grooves 158a and 158b are formed. The raised sections 166, in which the conduits 162 are formed, extend over the arms 120a of the wheel. The raised sections 165, in which the channels 150 are formed, can be considered to extend over fingers 120d projecting radially outwards from the wheel. The fingers 120d have a radial extent shorter than that of the arms 120a and are each positioned between two adjacent arms.

[0033] Each of the conduits 162 communicates at its radially external end with a cavity 152 of a shaft 148 for the purpose of supplying lubricant to this shaft 148 and the associated bearing 149. The lubricant supplied by the conduits 162 is intended to be injected into the cavities 152, then to flow through the aforementioned conduits to the periphery of the bearings 149.

[0034] Each of the channels 160 communicates at its radially external end with a longitudinal end of a nozzle 172 visible in particular at figures 4 And 6 The nozzles 172 have an elongated shape and extend parallel to the X-axis. Their axes of elongation are denoted B. There are five of them, regularly distributed around the X-axis, each positioned between two adjacent axes 148. Each channel 160 communicates with a cylindrical housing 160a for engaging a longitudinal end 172a of the nozzle ( figure 7 ). This longitudinal end 172a includes an external annular groove in which a sealing O-ring is mounted, which cooperates with the wall of the housing 160a. Each nozzle includes an opposite longitudinal end 172b which is closed.

[0035] This longitudinal end 172a of the nozzle forms a lubricant inlet and further includes a tab 175 for attachment to the impeller. The tab 175 is formed as a single piece with the substantially tubular body of the nozzle, and it extends in a plane substantially perpendicular to the longitudinal axis B of this body.

[0036] As we can see at the figure 4 The lug 175 is intended to be applied against the face 120b of the wheel 120 or a recess 121 in this face. The lug 175 includes a passage for a fixing screw, which is screwed into a tapped hole 175a in the free end of the corresponding finger 120d.

[0037] Each nozzle 172 comprises a longitudinal internal cavity 174 connected to the aforementioned lubricant inlet and, in addition, substantially radial orifices 176 distributed along its length, which open into the cavity 174. The lubricant brought through the channels 160 to the nozzles 172 is intended to be sprayed through the orifices 176 onto the teeth of the satellites 150 and the solar 151 in operation (cf. figure 8 ).

[0038] As can be seen more clearly in figures 4 And 8 , the orifices 176 are formed in at least one boss 176a of the nozzle body, this boss 176a projecting radially outwards.

[0039] In the example shown, each nozzle 172 comprises two bosses 176a spaced axially apart from each other with respect to the longitudinal axis B of the nozzle. Each boss 176a comprises six orifices 176 arranged in two rows of three regularly spaced orifices.

[0040] Each boss 176a has an angular extent β around the elongation axis B of the nozzle, which is less than or equal to 360°, and preferably 180° ( figure 8 ). Here, in cross-section, it has a general trapezoidal shape, the smaller base 176b of which is defined by the radially external end of the boss onto which the orifices open ( figure 8 This small base 176b has a generally convex, curved shape. The sides of the trapezoid form an angle α between 0 and 180°, and preferably between 0 and 90°. Alternatively, these sides could be substantially parallel. Finally, as can be seen in the figure 8 , the tubular wall has a wall thickness E and each boss forms an overthickness on this wall, which is equal to E' with E' greater than or equal to E in the example shown.

[0041] The orifices 176 are oriented so that the oil is directed towards the teeth to be lubricated. In the example shown, the orifices in each row of each boss spray oil onto one tooth, these orifices extending in a plane not parallel to that in which the orifices of the other row extend. In the example shown, each nozzle 172 is configured to spray oil onto the solar element 151 and one of the satellites 150.

[0042] Each nozzle 172 is fixed to the impeller 120 prior to the mounting and fixing of the impeller to the planet carrier 130. The longitudinal end of each nozzle, forming a lubricant inlet, is engaged in the corresponding housing of the impeller and its tab 175 is fixed to the impeller as mentioned above. As also mentioned above, the tab 175 can be housed in a recess 121 of the bearing face 120b of the impeller ( figure 4This recess 121 has a depth at least equal to the thickness of the tab 175 so that, when the bearing face 120b of the impeller is pressed against the outer receiving face of the second wall 138 of the planet carrier, the tab does not interfere with this contact. It is further understood that the tabs 175 of the nozzles 172 will be trapped between the planet carrier and the impeller after these components are assembled. This is because the nozzle tabs are sandwiched between the impeller and the planet carrier.

[0043] In the mounted position of the nozzles 172 on the satellite carrier 130 shown in the figure 4 The 176a bosses of the nozzles are oriented rather radially inwards. More precisely, as can be seen in the figure 8 , one of the sides of the boss of each nozzle can be substantially parallel to a peripheral edge of a notch 173 of the wall 138 of the satellite carrier.

[0044] The notches 173 are formed on the inner peripheral edge of the opening 144 of the planet carrier and each has a generally triangular or trapezoidal shape to allow the mounting and movement of the bossed body of each nozzle in the planet carrier ( Figures 5 And 6 ).

[0045] The base of the triangle or the larger base of the trapezoid of each of these notches 173 is located at the level of the peripheral edge ( figure 8 ). The vertices of the triangle or trapezoid are also rounded.

[0046] There figure 6 shows a step in mounting the impeller 120 equipped with the nozzles 172 onto the planet carrier 130. The impeller is centered on the planet carrier and moved towards it along the X-axis, so that the nozzles pass through the notches 173. The receiving face of the wall 138 includes counterbores 177 of generally circular shape, which are intended to receive the heads of the screws 177a for fixing the nozzles ( figure 7), so as to allow the face 120b to bear against this receiving face. The screws 177a are screwed into tapped holes in the wheel. In this mounted position, the nozzles 172 have their free ends 172b at a short axial distance from the wall 136 of the planet carrier.

[0047] On either side of each counterbore 177, the receiving face of the wall 138 includes two tapped holes 179 for screwing screws 184 for fixing the wheel. These screws 184 pass through holes in the wheel, which are arranged on either side of each finger 120d ( Figures 5 And 6 ).

[0048] These 184 screws, which secure the wheel to the planet carrier, improve force transmission and prevent misalignment. With this configuration, the wheel becomes a structural component and absorbs some of the forces from the planet carrier.

[0049] Examples of the benefits provided by the invention include: The clamping function of the wheel and that of the jets are separated, which allows for less hyperstaticity. Less hyperstaticity is also obtained thanks to the jet mounted in a blind housing in the first embodiment, which allows limiting one centering and one O-ring, an oil supply geometry as close as possible to the jet, an isostatic mounting of the jets, easy mounting of the jets in the wheel and then mounting of the assembly on the planet carrier, fewer machining operations on the wheel and jets compared to the previous technique, captive jet fixing screws in the first embodiment, no caps at the free ends of the jets in the first embodiment, less stress in the planet carrier, less misalignment of the teeth, jets slightly shorter from their fixing tabs, which reduces the amplitude of their oscillations in dynamics.

Claims

1. Planetary carrier for a planetary carrier speed reducer (110) of a turbine engine, said planetary carrier comprising a cage (134) defining an inner space for mounting a central sun gear (151) of axis of rotation X and an annular row of planetary carriers (150) arranged about the axis X and meshed with said sun gear, said sun gear comprising means for coupling (151a) to a first shaft, said cage comprising two annular walls (136, 138), a first (136) of said annular walls being connected to a substantially cylindrical body comprising means for coupling to a second shaft, and a second (138) of said annular walls on which are mounted a lubrication wheel (120) and lubricant nozzles (172), the wheel comprising lubrication means configured to bring lubricant to the nozzles and to the bearings (149) of the planetary carriers (150) of said reducer, said wheel being intended to be mounted coaxially on said second annular wall (138), said lubricant nozzles being distributed about said axis X and each having an elongate shape, said nozzles comprising first longitudinal ends (172a) fluidly connecting to said means for lubricating said wheel, said first ends of said nozzles comprising means (175) for attaching to said wheel, said nozzles being configured to be attached to said wheel before mounting the wheel on said second annular wall, characterized in that: - the first (136) and second (138) annular walls of the cage (134) are substantially parallel and centred on said axis X, said cage (134) further comprising a cylindrical wall connecting said annular wall (136, 138) at their external periphery; - said lubrication wheel comprises a bearing and attachment surface (120b) on said second annular wall (138).

2. Planetary carrier according to the preceding claim, wherein said attachment means of each nozzle (172) comprise a tab (175) for attaching to said wheel (120), said tab extending in a plane substantially perpendicular to an axis of elongation of the nozzle and being applied and attached on said bearing surface (120b) of said wheel or a recess (121) provided on this bearing surface.

3. Planetary carrier according to claim 1 or 2, wherein each nozzle (172) comprises, opposite said first end, a second free end (172b).

4. Planetary carrier according to the preceding claim, wherein each nozzle (172) comprises an inner longitudinal cavity (174) opening at said first end (172a) and closed at said second end (172b).

5. Planetary carrier according to claim 2, wherein said second annular wall (138) comprises a surface for receiving said bearing surface (120b), said receiving surface comprising a recess (121) or counterbore for housing said tab (175) of each nozzle (172), or a means for attaching this tab.

6. Planetary carrier according to claim 5, wherein said second wall (138) comprises an annular row of orifices or notches (173) for the passage of said nozzles (172) during the mounting of the wheel (120) equipped with nozzles on said second wall.

7. Planetary carrier according to the preceding claim, wherein said orifices or said notches (173) have a triangular or trapezoidal shape.

8. Planetary carrier according to one of the preceding claims, wherein said nozzles (172) are attached to the wheel (120) by screws (177a) screwed in the tapped orifices of the wheel.

9. Method for assembling a planetary carrier according to one of the preceding claims, comprising the steps of: - attaching said nozzles (172) to said wheel (120), - mounting the wheel equipped with nozzles on said second wall (138).

10. Method according to the preceding claim, wherein said wheel (120) is mounted on said second wall (138) by making said nozzles (172) pass through notches (173) of a triangular or trapezoidal shape.

11. Method according to claim 9 or 10, wherein said wheel (120) is attached to said second wall (138) by screws (184) of which two are arranged on either side of each nozzle (172) and are screwed in tapped holes (179) of said second wall.