BE1026074B1 - LUBRICATION GROUP WITH CREEPINE FOR TURBOMACHINE - Google Patents

Abstract

The invention relates to a method of manufacturing a pump body, in particular a turbojet lubricating group. The pump body includes a main recess for receiving gerotor-type mobile pumping members, an inlet duct and a hydraulically connected delivery duct via the main recess, and an oil filtering strainer. The method comprising the steps of: (a) fabricating the body (100), and (b) fabricating the strainer (102) that are made simultaneously. The manufacturing is an additive manufacturing based powder layers, to directly produce the strainer in one of the conduits so that they came from material.

Description

Description

STRAINER LUBRICATION UNIT FOR TURBOMACHINE

Technical area

The invention relates to the integration of a strainer in a lubrication group. The invention also relates to a process for manufacturing a turbomachine lubrication unit. The invention also relates to an axial turbomachine, in particular an aircraft turbojet or an aircraft turboprop.

Prior art

Like any complex mechanical assembly with moving parts, a turbojet engine has a lubrication circuit whose reliability contributes to that of the engine. In parallel with distribution and drainage activities, the circuit allows monitoring of particles in circulation. Locally, these particles and debris are separated from the oil in order to filter it. To this end, the circuit may include strainers whose meshes intercept foreign grains before the oil is again used in the turbojet.

Document EP 3 123 592 A1 discloses a turbojet engine comprising a strainer for turbomachine oil, the strainer comprising: a curved mesh filtering a fluid passing through it; a lattice holding structure forming a thickening. The structure and the trellis came from material and are made by additive manufacturing by layers. The turbojet engine further includes a lubrication group with a body to which the strainer is attached. However, the compactness of such a strainer remains perfectible as the space necessary for the support structure is taken over that occupied by the trellis.

Summary of the invention

Technical problem

The object of the invention is to solve at least one of the problems posed by the prior art. More specifically, the invention aims to increase the filtration capacity of a strainer housed in a pump body. The invention also aims to provide a simple, resistant, light solution,

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BE2018 / 5132 2 economical, reliable, easy to produce, convenient to maintain, easy to inspect, and improves performance.

Technical solution

In general, the invention relates to a pump body and its production, where the pump body comprises at least one duct and a strainer shaped in the duct, the duct and the strainer being made of one piece.

The subject of the invention is a method of manufacturing a pump body, in particular a turbojet engine lubrication group, the pump body comprising a main clearance intended to receive mobile pumping members, an intake duct and a discharge conduit hydraulically connected via the main clearance, and a strainer capable of blocking debris entering the body; the method comprising the steps: (a) making the body, (b) making the strainer, remarkable in that during steps (a) and (b) making the body and the strainer, the body and the strainer are manufactured simultaneously by additive manufacturing by manufacturing the strainer in one of the conduits so that they have come in one piece. According to advantageous modes of the invention, the process can include one or more of the following characteristics, taken in isolation or according to all possible technical combinations:

- The strainer includes a filter screen in contact with the internal surface of the associated duct.

- The strainer has a hemispherical shape, the circumference of which is in circular contact with the duct.

- The strainer has a series of through holes distributed over its filtering surface.

- The orifices represent at most the majority of the filtering surface of the strainer.

- Each orifice is at a distance from the internal surface of the duct.

- The conduit associated with the strainer has an inlet, the strainer being in contact and / or extending from said inlet.

- The strainer defines an internal space remote from the internal surface of the associated duct.

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- The body includes a bead at the circular junction between the duct and the strainer.

- The body has a mounting plane, in particular with fixing flanges, the strainer extending from said mounting plane.

- The assembly plan includes mounting apertures with central axes parallel to the conduit associated with the strainer.

- Additive manufacturing includes making a stack of layers of material, said layers forming layers of the body and layers of the strainer, each layer of the strainer being in contact with one of the layers of the body, possibly each orifice touched several layers.

- The additive manufacturing process comprises a manufacturing direction, and the strainer forms a concave basket with a concave face opposite or inclined relative to the manufacturing direction.

- The intake duct is a first intake duct, and the delivery duct is a first delivery duct; the body further having a second and a third separate and distinct intake duct, and a second and a third separate and distinct discharge duct.

- The strainer has a main elongation which is transverse to the manufacturing direction.

- Each and / or the openings are opposite the entrance.

- The body is in one piece and made of material.

- The orifices have widths between 0.5mm and 1.5mm, possibly less than or equal to 0.80mm.

- The orifices represent and / or occupy between: 10% and 80%, or between 25% and 75%, or between 40% and 36% of the surface of the strainer.

- The screen has a constant thickness.

- The duct completely houses the associated strainer.

The invention also relates to a turbomachine lubrication group, the lubrication group comprising a body with: a first duct, in particular an intake duct; a second conduit, in particular a discharge conduit, a main clearance with several organs of

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BE2018 / 5132 mobile pumping, a strainer arranged in the first conduit, remarkable in that it has a one-piece stack of layers coming from material which form the first conduit and the strainer, the body being in particular as in the invention.

According to advantageous modes of the invention, the lubrication group can comprise one or more of the following characteristics, taken in isolation or according to all the possible technical combinations:

- The lubrication group includes a drive shaft coupled to each movable pumping member of the main release, and possibly passing through the main release,

- The drive shaft passes through the body at a main elongation of the body.

- The mobile pumping members include mobile sets of toothed rings, at least two toothed rings having a common axis of rotation.

The invention also relates to a turbomachine, in particular an aircraft turbojet engine capable of operating with negative vertical acceleration, the turbomachine comprising a lubrication circuit with an oil reservoir and a lubrication group, remarkable in that the group lubrication is in accordance with the invention, preferably the turbomachine is a turbojet where the lubrication circuit is adapted to an oil heated to at least: 200 ° C, or 230 ° C.

According to an advantageous embodiment of the invention, the lubrication circuit comprises a hydraulic line hydraulically connecting the oil tank to the second conduit.

In general, the advantageous modes of each object of the invention are also applicable to the other objects of the invention. Each object of the invention can be combined with the other objects, and the objects of the invention can also be combined with the embodiments of the description, which in addition can be combined with one another, according to all possible technical combinations, unless the opposite is not explicitly mentioned.

Benefits

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The invention makes it possible to bring the filter meshes as close as possible to the internal surface of the fitted conduits. In addition, the entire surface of its partition remains available to make holes therein. Thus, the useful surfaces of the strainer increase, without being at the expense of rigidity since the duct surfaces in turn form the necessary support.

Thus, for a duct of a given size, the filtration capacity can be increased. The strainer can be shortened, which makes it easier to integrate into small and / or bent conduits. The integration of other equipment such as sensors placed directly after the strainer is simplified.

Brief description of the drawings

FIG. 1 represents an axial turbomachine according to the invention.

Figure 2 sketches a lubrication group according to the invention.

FIG. 3 represents an enlargement of a strainer placed in its associated conduit according to the invention.

FIG. 4 is a diagram of a method of manufacturing a body of a lubrication group according to the invention.

Description of the embodiments

In the following description, the terms "internal" and "external" refer to a positioning relative to the axis of rotation of an axial turbomachine.

Figure 1 shows a simplified axial turbomachine. In this case, it is a double-flow turbojet engine. The turbojet engine 2 comprises a first level of compression, called a low-pressure compressor 4, a second level of compression, called a high-pressure compressor 6, a combustion chamber 8 and one or more levels of turbines 10 receiving the energy of the products of combustion.

In operation, the mechanical power of the turbine 10 transmitted via the central shaft to the rotor 12 sets in motion the two compressors 4 and

6. The latter comprise several rows of rotor blades associated with rows of stator blades. The rotation of the rotor around its axis of rotation 14 thus makes it possible to generate an air flow and to gradually compress the latter up to the inlet of the combustion chamber 8.

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An inlet fan commonly designated as a fan or blower 16 is coupled to the rotor 12 and generates an air flow which is divided into a primary flow 18 passing through the various above-mentioned levels of the turbomachine, and a secondary flow 20 passing through an annular duct (partially shown) along the machine to then join the primary flow at the turbine outlet. The secondary flow can be accelerated so as to generate a thrust reaction allowing the flight of the associated aircraft.

Reduction means 21 can increase the speed of rotation transmitted to the compressors. The reduction means 21 may include an epicyclic reduction gear. The heat produced by the operation of the reduction gear 12 may be greater than 100 kW.

The turbomachine 2 comprises a pressurized oil circuit 24. This oil lubricates and cools the bearings 25 as the reduction gear 21. These bearings 25 make it possible to articulate the low-pressure shaft, the high-pressure shaft, and the blower shaft 16. The oil can be used in hydraulic actuators thanks to its pressure.

The circuit 24 may include one or more pumps 26 for delivering or entraining or sucking the oil into lubrication chambers. The oil circulates in a heat exchanger 28, in a tank 30. Different lines, possibly independent, can make it possible to lubricate the members independently. To this end, the circuit 24 can form several loops. It is obvious that the circuit can follow any route arising from the needs of the turbomachine 2.

The pumps 26 or at least several pumps 26 can be combined in a lubrication group 32 (GDL), also a distribution unit. A hydraulic line 33, for example on the discharge side, can hydraulically connect the lubrication group 32 to the reservoir 30.

The lubrication group 32 can have a strainer 34 making it possible to collect particles circulating in the oil. These particles can come from the bearings 25 or from the transmission 21, the wear of which releases certain fragments in the form of metallic grains. Advantageously, one or more strainers 34 will be placed upstream of the moving parts of the pumps 26, the sealing of which is necessary in order to guarantee a flow rate and a pressure

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BE2018 / 5132 7 oil. The strainers 34 participate in the purification of the oil by forming a sieve capturing the solid pollutants.

FIG. 2 is a section through a lubrication group 32 fitted with strainers 34, for example such as that of FIG. 1.

The lubrication group 32 comprises a body 36, in particular a main body or pump body. The body 36 can be in one piece, and form a block of material. It has a main clearance 38 which can extend over its entire height. The body 34 may have one or more intake conduits 40 sucking the oil, and one or more discharge conduits 42 through which the oil escapes. Each intake duct 40 can communicate hydraulically with a discharge duct 42 via one of the chambers 44 forming the main clearance 38. The clearance 38 may have an axis of symmetry 46 around which its surfaces are generated.

The lubrication group 32 can comprise a drive shaft 48 with an axis of rotation 50, for example offset from the axis of symmetry 46. The drive shaft 48 it can be coupled to the shaft of the turbine engine. It can pass through all the chambers 44, and can extend over the majority of the body 36 and / or over the entire clearance 38.

The lubrication group 32 can receive at least one pumping member, preferably several pumping members. These members can form sets, each housed in a chamber 44. They can in particular comprise toothed rings, with an internal ring 52 associated with an external ring 54 in order to form a set of rings (a single set being represented for the sake of clarity ). Their external and internal teeth, respectively, allow a rotation drive along the axes 46 and 50; in addition to defining compression chambers necessary for pumping a liquid. For example, the pumps placed in the lubrication group 32 can be of the GEROTOR type, however vane pumps are also possible.

The lubrication group 32 can have several faces, including a mounting face, for example materialized by one or more mounting planes 56. Fixing openings 58 can be formed from one of the mounting plans

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BE2018 / 5132 partner. The fixing openings 58 may show central axes 60, for example perpendicular to the associated mounting plane 56.

This lesson is detailed in relation to a lubrication group

32, however the present body could be that of a hydraulic pump, or even a fuel pump.

Figure 3 is a section of a portion of the body 36 with a first conduit 62 housing a strainer 34. The body 36 may correspond to that described in connection with Figure 2, and the strainer 34 may correspond to that described in relation to Figure 1 and / or with Figure 2. The first conduit 62 is associated with the strainer 34, and may correspond to the intake conduit or the discharge conduit.

The body 36 came integrally with the strainer 34. They form a block of material, in particular homogeneous. It may have a stack of layers 64 in a stacking direction 66. The layers 64 are in particular parallel and / or of constant and equal thickness. Their thickness can be equal to 200 μm. Each layer 64 comprises a body portion 36, and a strainer portion 34 at the level of the duct 62. This can result in the fact that the layers forming the strainer extend into the material of the body 36.

The strainer 34 may have a shape of revolution (only its profile being shown). It forms a screen 68, such as a calibrated sieve for collecting debris 70. It forms a barrier crossing the conduit 62. The strainer 34 may have a partition 74, or shell.

A series of orifices 72 passes through the strainer 34, and therefore the partition 74. The orifices are distributed over the filtering surface of the strainer 34. Their size is smaller than that of the debris 70 in order to block and store them. For this purpose, the strainer 34 forms a hollow receptacle, or internal space 78. The interior volume of the internal space 78 makes it possible to receive a certain amount of debris 70 before the strainer is completely clogged.

The conduit 62 has an internal surface 80, for example of annular shape.

The strainer 34, in particular its partition 74 extends from said internal surface 80. Thus, the partition 74 forming most of the structure of the strainer 34 is in contact with the internal surface 80. This arrangement optimizes the use of material inside the duct 62, and makes it possible to place a maximum of orifices 72 of a

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BE2018 / 5132 size given in conduit 62. This reduces pressure losses, while retaining the capacity to capture debris 70.

The conduit 62 can start from the assembly plane 56. The strainer 34 can also start against this assembly plane 56. A stop 84 can delimit them, and mark their interface.

The inner surface 86, for example the concave surface 86; or upstream surface; of the strainer 86 can connect the mounting plane 56 via the stop 84. In contrast, the outer surface 88, or convex surface 88 possibly called the downstream surface, can be opposite and in contact with the surface internal 80 of conduit 62. It can be considered that the internal surface 86 forms the filtering surface since it receives the debris 70.

The strainer 34 can thus form a basket. Depending on its thickness, and therefore on the thickness of its partition 74 and / or its orifices 72, it has two opposite surfaces, in this case the concave surface 86 and the convex surface 88.

The inlet 90 of the conduit 62 may be common with the inlet of the strainer 34. It may be surrounded by the stop 84. It may coincide with the assembly plane 56.

The body 36 can be produced by additive manufacturing per layer, a process which can give rise to the layers 64 one after the other. These layers 64 can be stacked progressively in an order according to the stacking direction 66. When the body 36 is produced by layers 64, in particular by additive manufacturing, the stacking direction 66 can correspond to the manufacturing direction 66. The stacking direction 66 can be inclined by 5 ° to 15 ° relative to the axis of rotation of the drive shaft.

At the strainer 34, each orifice 72 can cut and pass through the same layer 64 according to its width. Therefore, the layers 64 can be discontinuous. The continuity of material can be ensured thanks to the neighboring layers. The same orifice 72 can cut several layers 64. Conversely, the same layer can be interrupted by several orifices 72. In the strainer, the same layer 64 can therefore comprise several sections of layer interspersed with orifices 72.

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The orifices 72 may be at a distance from the interior surface 80 of the conduit 62. For example, the conduit 62 includes a circular recess 82, or toric, between the strainer 34 and the interior surface 80. The circular recess 82 may surround the screen 68, and in particular the partition 74. The circular recess 82 can separate each orifice 72 from the interior surface 80 of the duct 62, and can be completely empty.

The body 62 can have a bead 92. This bead 92 can form the circular junction between the strainer 34, in particular the partition 74, and the conduit 62. The orifices can be spaced from the bead 92.

Figure 4 is a diagram of the method of manufacturing a pump body. Both the body and the pump can correspond to those described in the previous figures.

The method comprises a step (a) making the body 100 and a step (b) making the strainer 102. These steps (100; 102) are advantageously carried out simultaneously, for example by additive manufacturing. Thus, the body and the strainer came from matter. They form a homogeneous block in at least two directions.

Additive manufacturing by layers, also called 3D printing or generative manufacturing, is a process well known to those skilled in the art. Generally, a mobile support receives a layer of powder locally solidified by an energy beam. Subsequently a new layer of powder is applied to the previous one, and is solidified thereon on the previously solidified parts. The result can be recognized on the strainer and the body by performing a micrographic analysis from which it will appear that the strainer and the body share the same layers. By extensions, certain layers form both the strainer and the body.

The process can be based on powder as a filler material, for example titanium or steel powder. The thicknesses of the layers can be less than 1.00 mm, preferably less than 0.50 mm, more preferably less than 0.050 mm thick.

Claims (20)

claims 1. A method of manufacturing a pump body (36) (26), in particular a lubrication group (32) of a turbojet engine, the pump body (36) (26) comprising a main clearance (38) intended to receive movable pumping members, an intake duct (40) and a discharge duct (42) hydraulically connected via the main clearance (38), and a strainer (34) capable of blocking debris (70) entering the body (36); the process comprising the steps: (a) manufacture (100) of the body (36), (b) manufacture (102) of the strainer (34), characterized in that during steps (a) and (b) of manufacture of the body (36) and the strainer (34), the body (36) and the strainer (34) are manufactured simultaneously by additive manufacturing by manufacturing the strainer (34) in one of the conduits (40; 42; 62) so that they came from matter. 2. Method according to claim 1, characterized in that the strainer (34) comprises a filter screen (68) in contact with the internal surface (80) of the associated duct (40; 42; 62). 3. Method according to one of claims 1 to 2, characterized in that the strainer (34) has a hemispherical shape whose circumference is in circular contact with the conduit (40; 42; 62). 4. Method according to one of claims 1 to 3, characterized in that the strainer (34) has a series of through holes (72) distributed over its filtering surface. 5. Method according to claim 4, characterized in that the orifices (72) represent at most half of the filtering surface of the strainer (34). 6. Method according to one of claims 4 to 5, characterized in that each orifice (72) is at a distance from the internal surface of the conduit (40; 42; 62). 2018/5132 BE2018 / 5132 7. Method according to one of claims 1 to 6, characterized in that the duct associated (40; 42; 62) with the strainer (34) has an inlet (90), the strainer (34) being in contact and / or extending from said entrance (90). 8. Method according to one of claims 1 to 7, characterized in that the strainer (34) defines an internal space (78) at a distance from the internal surface (80) of the associated conduit (40; 42; 62). 9. Method according to one of claims 1 to 8, characterized in that the body (36) comprises a bead (92) at the circular junction between the conduit (40; 42; 62) and the strainer (34). 10. Method according to one of claims 1 to 9, characterized in that the body (36) has a mounting plane (56), in particular with fixing flanges, the strainer (34) extending from said plane mounting (56). 11. Method according to claim 10, characterized in that the mounting plane (56) comprises mounting openings (58) with central axes (60) parallel to the associated conduit (40; 42; 62) to the strainer (34 ). 12. Method according to one of claims 1 to 11, characterized in that the additive manufacturing comprises producing a stack of layers (64) of material, said layers (64) forming layers (64) of the body (36 ) and layers (64) of the strainer (34), each layer (64) of the strainer (34) being in contact with one of the layers (64) of the body (36), possibly each orifice (72) touches several layers (64). 13. Method according to one of claims 1 to 12, characterized in that the additive manufacturing method comprises a manufacturing direction (66), and the strainer (34) forms a concave basket with a concave surface (86) opposite or inclined with respect to the manufacturing direction (66). 14. Method according to one of claims 1 to 13, characterized in that the intake duct (40) is a first intake duct, and the discharge duct (42) is a first discharge duct; the body (36) further having a second and a third intake duct 2018/5132 BE2018 / 5132 separate and distinct; and a second and a third separate and distinct delivery conduit. 15. Lubrication group (32) of a turbomachine (2), the lubrication group (32) comprising a body (36) with: - a first conduit (62), in particular an intake conduit (40); - a second conduit (62), in particular a discharge conduit (42), - a main clearance (38) with several mobile pumping members, - a strainer (34) disposed in the first conduit (40; 42; 62), characterized in that it has a one-piece stack of layers (64) made of material which form the first conduit (40; 42; 62) and the strainer (34), the body (36) being in particular as in one of claims 1 to 14. 16. Lubrication group (32) according to claim 15, characterized in that it comprises a drive shaft (48) coupled to each movable pumping member of the main release (38), and possibly passing through the main release (38 ) 17. Lubrication group (32) according to one of claims 15 to 16, characterized in that the drive shaft passes through the body (36) according to a main elongation of the body (36). 18. Lubrication unit (32) according to one of claims 15 to 17, characterized in that the mobile pumping members comprise mobile sets of toothed rings (52; 54), at least two toothed rings (52; 54) having a common axis of rotation (46; 50). 19. Turbomachine (2), in particular an aircraft turbojet engine capable of operating with negative vertical acceleration, the turbomachine (2) comprising a lubrication circuit (24) with an oil reservoir (30) and a lubrication group ( 32), characterized in that the lubrication group (32) conforms to one of claims 15 to 18, preferably the turbomachine is a turbojet where the circuit 2018/5132 BE2018 / 5132 lubrication (24) is suitable for oil heated to at least: 200 ° C, or 230 ° C. 20. Turbomachine (2) according to claim 19, characterized in that the lubrication circuit (24) comprises a hydraulic line (33) connecting 5 hydraulically the oil tank (30) at the second conduit (42).