阅读说明：本技术 带有分段鼓部的混合转子 (Mixing rotor with segmented drum portion ) 是由 A.德克莱 于 2020-02-03 设计创作，主要内容包括：一种用于轴流式涡轮机的转子(12),该转子(12)包括由几个部件形成的鼓部,这些部件包括由复合材料制成的复合环(40)和插在复合环(40)之间的金属环(50)。金属环(50)承载转子叶片(24)。金属环(50)具有轴向重叠于复合环(40)的轴向分支(52)和与复合环(40)接触的至少一个径向分支(54)。(A rotor (12) for an axial flow turbomachine, the rotor (12) comprising a drum formed of several components including composite rings (40) made of composite material and metal rings (50) interposed between the composite rings (40). The metal ring (50) carries the rotor blades (24). The metallic ring (50) has an axial branch (52) axially overlapping the composite ring (40) and at least one radial branch (54) in contact with the composite ring (40).)

1. A rotor (12) for a compressor (4, 6) of a turbomachine (2), such as an aircraft turbojet, comprising:

a composite ring (40) having a substantially axisymmetric shape and made of a composite material;

metal rings (50), each metal ring supporting a respective annular row of rotor blades (24), each metal ring (50) being axially interposed between two of the composite rings (40) and having a cross section (51) with axial branches (52) which axially overlap in part with said two of the composite rings (40);

wherein the metallic rings (50) are connected in pairs by only one of the composite rings (40).

2. The rotor (12) of claim 1, wherein the cross-section (51) is T-shaped, includes a radial branch (54), each of the two composite rings (40) having a radially extending end (44), and is contiguously disposed on the radial branch (54) of the metallic ring (50).

3. The rotor (12) of claim 2, wherein a screw (62) or a substantially axially disposed rivet passes through the radial branch (54) of the metallic ring (50) and through the respective end (44) of each of the two composite rings (40).

4. The rotor (12) of claim 2 or 3, wherein the radial branch (54) has an inner radial end comprising axial thickened portions (56) projecting upstream and downstream of the radial branch (54), the thickened portions (56) defining two radially outer surfaces (58) for centering the respective ends (44) of the two compound rings (40) on the metallic ring (50).

5. The rotor (12) of claim 1, wherein the cross-section (51) is in the shape of the greek letter pi, comprises two radial branches (54), each of the two compound rings (40) having a radially extending end (44) and being arranged in abutment on one of the respective radial branches (54) of the metallic ring (50).

6. The rotor (12) of claim 1, wherein the composite ring (40) has a U-shaped cross-section that opens radially inward or outward.

7. The rotor (12) of claim 1, wherein the composite ring (40) has an outer surface with a groove (46) provided with metal wipers (60) projecting radially from the groove (46).

8. A compressor (4, 6) comprising:

-a rotor (12) according to any one of claims 1 to 7;

at least one row of stator blades (26) axially arranged between two consecutive annular rows of rotor blades (24),

the stator vanes (26) are supported by an inner collar (32) that axially overlaps the composite ring (40), and seals (34, 60, 70, 80, 90) are disposed between the inner collar (32) and the composite ring (40).

9. A compressor (4, 6) as claimed in claim 8, wherein said seal (80) is a brush seal (80) provided with sealing bristles, each bristle being fixed at one end to the inner collar (32) and sliding at its other end on the composite ring (40).

10. Compressor (4, 6) according to claim 9, wherein said seal (90) is a J-shaped ring seal (90) defining a main branch (91) and an auxiliary branch (92), the main branch (91) of the J being fixed to said composite ring (40) and said auxiliary branch (92) sliding on an annular pad (94) of said inner collar (32).

Technical Field

The present invention relates to the design of turbomachines, in particular of aircraft turbojet engines or aircraft turboprop engines with fans driven by reduction gears. The invention relates in particular to a rotor for a compressor, which rotor consists of several parts, including a drum (drum) made of mixed material.

Background

Document EP 2818635 a1 describes a compressor rotor for a turbomachine. The drum is arranged there, supporting several rows of annular rotor blades, at least one of which is integral with the rotor. This hybrid design saves time in the production and assembly process because not all of the blades are integral with the drum. However, this design may be improved from the rotor weight point of view. Weight is a detrimental aspect to the compressor rotor not only because it requires more energy to rotate, reducing the efficiency of the engine, but also because it contributes to the overall weight of the aircraft and therefore to the fuel requirements of the aircraft flight.

Document EP 2287445 a1 describes a compressor rotor consisting of composite material and metal ring segments. The latter is provided with dovetail slots for receiving the rotor blades.

This design may have non-uniformity in axial weight distribution because the dovetail requires a large metal crown. In addition, there is room for improvement in the overall size and weight of the rotor.

Machining the dovetail is also expensive and time consuming.

Disclosure of Invention

Technical problem

It is an object of the present invention to provide a lighter rotor which is more economical to manufacture and assemble.

Solution method

The invention relates to a rotor for a compressor of a turbomachine, such as an aircraft turbojet, comprising composite rings, each substantially axially symmetric in shape and made of a composite material; metal rings, each metal ring supporting a respective annular row of rotor blades, each metal ring being axially interposed between two composite rings and having a cross section with axial branches axially partially overlapping two of the composite rings; wherein the metal rings are connected in pairs and are connected by only one of the composite rings.

Thus, the drum is formed by the continuous arrangement of the composite ring and the metallic ring along the axis, the metallic ring only partially axially overlapping the composite ring.

According to a preferred embodiment, the cross-section is T-shaped and comprises radial branches, each of the two composite rings having a radially extending end and being arranged adjacent to a radial branch of the metal ring.

According to a preferred embodiment, the screws or rivets pass through the radial branches of the metal ring and through the respective end of each of the two composite rings.

According to a preferred embodiment, the radial branch has an inner radial end comprising axial thickened portions projecting upstream and downstream of the radial branch, the thickened portions defining two radially outer surfaces for centering the respective ends of the two composite rings on the metallic ring.

According to a preferred embodiment, the cross-section is in the shape of the greek letter pi, comprising two radial branches, each of the two compound rings having a radially extending end and being arranged to abut on one of the respective radial branches of the metal ring.

According to a preferred embodiment, the axial branches have an inner surface for centering the two composite rings. The inner surface may be subdivided into two surfaces arranged on each side of the radial branch, each of which cooperates with one of the composite rings.

According to a preferred embodiment, the metal ring and the rotor blade are formed integrally. Alternatively, the vanes may be welded to the metal ring.

According to a preferred embodiment, the composite ring is generally U-shaped, opening radially inward or outward.

According to a preferred embodiment, the composite ring has an outer surface with a groove provided with metal wipers protruding radially from the groove.

According to a preferred embodiment, a plurality of J-seals are fixed to the composite ring and are adapted to slide on the respective annular gaskets.

According to a preferred embodiment, an axial screw retains each J-seal on one of the composite rings and one of the metal rings.

According to a preferred embodiment, each metal ring has a radial branch and each composite ring has an end, the axial screws retaining the J-seal at the end of a respective one of the radial branch of the respective metal ring and the composite ring.

According to a preferred embodiment, a layer made of wear-resistant material is arranged on one of the composite rings.

According to a preferred embodiment, each composite ring comprises a groove with two axial ends, and wherein the layer made of wear resistant material is arranged at the axial ends of the groove in one of the composite rings.

The invention also relates to a rotor for a compressor of a turbomachine, such as an aircraft turbojet, comprising composite rings, each substantially axisymmetric and made of a composite material; metal rings, each metal ring supporting a respective annular row of rotor blades, each metal ring being axially interposed between two of the composite rings and having a cross section with an axial branch axially partially overlapping said two of the composite rings; wherein the cross-section is in the shape of the greek letter pi and comprises two radial branches, each of the two compound rings having a radially extending end and being arranged to abut one of the respective radial branches of the metal ring.

According to a preferred embodiment, the axial branches have an inner surface for centering the two composite rings.

The invention also relates to a rotor for a compressor of a turbomachine, such as an aircraft turbojet, comprising composite rings, each substantially axisymmetric and made of a composite material; a metallic ring, each metallic ring supporting a respective annular row of rotor blades, each metallic ring being axially interposed between two composite rings and having a cross section with an axial branch which axially partially overlaps said two composite rings, wherein the composite rings are substantially U-shaped, opening radially inwards or outwards.

The invention also relates to a compressor comprising a rotor as described above; at least one row of stator blades is axially arranged between two consecutive annular rows of rotor blades, the stator blades being supported by an inner collar axially overlapping the composite ring, a seal being arranged between the inner collar and the composite ring.

According to a preferred embodiment, the seal is a brush seal provided with sealing bristles, each bristle being fixed at one end to the inner collar and sliding at the other end on the composite ring.

According to a preferred embodiment, the seal is a J-shaped ring seal defining a main branch fixed to the composite ring and an auxiliary branch sliding on an annular gasket of the inner collar. Alternatively, the J-seal may be fixed to the inner ferrule and may slide over the composite ring.

According to a preferred embodiment, the seal is made of a metal wiper on the inner collar, which interacts with a layer of wear resistant material arranged on the composite ring. The composite ring may have a groove, and a layer of wear resistant material is disposed at each axial end of the groove.

The invention also relates to a method of assembling a rotor according to one of the above embodiments, the method comprising alternately stacking composite rings and metallic rings.

The invention also relates to a method of assembling a compressor according to one of the above embodiments, comprising assembling the composite rings axially overlapping the inner stator shroud, then mounting the metallic rings in contact with the composite rings, then mounting the second composite ring against the metallic rings, and finally fixing the metallic rings to the two composite rings by means of screws or rivets.

Advantages of the invention

The hybrid design of the rotor according to the invention allows a significant weight reduction compared to a rotor with a complete metal drum. The manufacturing time is reduced compared to a one-piece rotor, since several elements can be manufactured in parallel before being assembled together. Furthermore, the axial weight distribution is more uniform.

Brief Description of Drawings

FIG. 1 shows an axial flow turbine;

figure 2 shows a schematic cross-section of a part of a compressor known in the prior art;

FIG. 3 shows a cross-sectional view of a rotor according to a first embodiment of the invention;

FIG. 4 shows a cross-sectional view of a rotor according to a second embodiment of the invention;

FIG. 5 shows a cross-sectional view of a rotor according to a third embodiment of the invention;

FIG. 6 shows a cross-sectional view of a rotor according to a fourth embodiment of the invention;

FIG. 7 shows a cross-sectional view of a rotor according to a fifth embodiment of the invention;

FIG. 8 shows a cross-sectional view of a rotor according to a sixth embodiment of the invention;

fig. 9 shows a cross-sectional view of a rotor according to a seventh embodiment of the invention.

Detailed Description

In the following description, the terms "inner" (or "inner") and "outer" (or "outer") refer to the positioning relative to the axis of rotation of an axial flow turbine. The axial direction corresponds to a direction along the axis of rotation of the turbine. Radially perpendicular to the axis of rotation. Upstream and downstream refer to the main flow direction in the turbine. The term "integral" is understood to mean integral rotation, in particular rigidly connected.

The figures schematically show elements, in particular not all components or sealing elements. The dimensions, particularly the radial thicknesses, of the elements are exaggerated to facilitate understanding of the figures.

Fig. 1 shows an axial turbomachine 2 or turbojet. The turbojet 2 comprises a low-pressure compressor 4 and a high-pressure compressor, a combustion chamber 8 and one or more turbines 10. In operation, mechanical power transmitted from the turbine 10 to the rotor 12 moves the two compressors 4 and 6. The latter includes a plurality of rows of rotor blades associated with a plurality of rows of stator blades. The rotation of the rotor about its axis of rotation 14 is thus able to generate and progressively compress an air flow towards the inlet of the combustion chamber 8.

A fan 16 is connected to the rotor 12 and generates an airflow which is divided into a primary flow 18 and a secondary flow 20 which pass along the engine through an annular duct (partially shown) and then join the primary flow at the outlet of the turbine.

The reduction means, for example the planetary reduction gear 22, can reduce the speed of rotation of the fan and/or of the low-pressure compressor with respect to the associated turbine. The secondary flow may be accelerated to produce the thrust reaction force required for aircraft flight.

Fig. 2 is a sectional view of a compressor of a known axial flow turbine. The compressor may be a low pressure compressor 4. A portion of the fan 16 and a separate nozzle 22 for the primary and secondary flows 18, 20 can be seen. Rotor 12 may include several rows of rotor blades 24.

The low pressure compressor 4 comprises at least one rectifier comprising a row of annular stator blades 26. Each rectifier is associated with a fan 16 or a row of rotor blades 24 to rectify the airflow (compensate for airflow velocity).

The low pressure compressor 4 comprises at least one casing 28. The housing 28 may have a generally circular or tubular shape. It may be an external compressor housing and may be made of a composite material. The housing 28 may include a retaining flange 30, such as an annular retaining flange 30. The annular flange 30 may be made of a composite material and may include fixing holes (not shown) to allow fixing by bolts.

Due to the composite material, the housing 28 may be 3 to 5 millimeters thick for diameters greater than 1 meter.

The stator vanes 26 extend substantially radially from the housing 28 to an inner collar (ferule) 32.

In this example of a known rotor, rotor 12 is integral with three rows of annular rotor blades 24, rotor blades 24 extending radially from rotor 12 to adjacent housing 28.

Fig. 3 shows a part of a rotor 12 according to the invention. The rotor 12 comprises several rings 40 made of composite material. The composite material may be of the carbon fibre type with an elastomeric matrix or an organic matrix. Each composite ring 40 is annular and has a generally tubular central portion 42 and radially extending ends 44. In the example of fig. 3, the end portions 44 extend radially inwardly, forming an inwardly open U-shaped profile with the central portion 42.

The rotor 12 also includes a metallic ring 50 interposed between the composite rings 40. The metal ring 50 is annular. The metal ring 50 has a cross-section 51 with at least one axially extending branch 52 and at least one radially extending branch 54. The cross-section may be T-shaped or pi-shaped (see the example in fig. 9). Axial branches 52 at least partially overhang or overlap composite ring 40. Overlapping means that a portion of the composite ring 40 and a portion of each metallic ring 50 share the same axial position. The radial branches 54 are in contact with the end 44 of the composite ring. Thus, the surface 55 of the radial branch 54 abuts the composite ring 40 by contacting the surface 45 of the composite ring 40. The contact between surface 55 and surface 45 is axial.

The radial limb 54 ends radially on the inside with a thickened portion 56. The thickened portion 56 has a surface 58, the surface 58 allowing the composite rings 40 to be centered by their contact with the radially inner surface 48 of the end 44 (centering).

The composite ring 40 may be shaped to provide a groove 46 on its outer surface 47. This may be in the form of an annular groove. In this groove 46 is provided a metal wiper 60, which may act as a seal. The wiper 60 protrudes from a metallic ring that is secured to the composite ring 40. These wipers 60 cooperate with a layer of abradable material 34 mounted inside the inner race 32 (which supports the stator vanes 26).

Axial branches 52 support rotor blades 24. Rotor blades 24 may be welded to axial branches 52. Alternatively, rotor blades 24 are integral with metallic ring 50. Such a design may be obtained at least in part by casting and then machining.

An array of annular fastening elements, such as axial screws 62, may be provided for assembling the metal ring 50 to the two composite rings 40.

Fig. 4 depicts an alternative embodiment of the rotor 12 of fig. 3. In this example, the centering of the composite ring 40 on the metallic ring 50 (or the centering of the metallic ring 50 on the composite ring 40) is created by a surface 49 on the exterior of the composite ring 40, which surface 49 is in contact with the inner surface 59 of the axial branch 52 of the metallic ring 50.

Fig. 5 depicts an alternative embodiment of the rotor 12 of fig. 3. In this example, the central portion 42 of the composite ring 40 is free of grooves and therefore has a regular surface, such as a conical, cylindrical, or ellipsoidal arc.

Fig. 6 depicts an alternative embodiment of the rotor 12 of fig. 3. In contrast to fig. 3, the metal wiper 70 is here carried by the inner collar 32, and the ring 72 of wear resistant material is provided with an annular groove 74 cooperating with the metal wiper 70. The groove 46 has two axial ends 461, 462 and the ring 72 is preferably arranged at these axial ends 461, 462.

Fig. 7 depicts another example of a design of the rotor 12. In this example, the cross-sectional profile of composite ring 40 is U-shaped opening towards the outside. The metal wiper 70 cooperates with a ring 72, which ring 72 may be disposed on the protrusions 46 of the composite ring 40.

Fig. 8 shows a rotor 12 similar to the previous figures, but with a different seal. In this example, the seal is a brush seal 80. A plurality of bristles extend radially for each seal 80. The bristles are attached at one end to the composite ring 40 and slide on the layer of abrasion resistant material 34 at the other end. Alternatively, the bristles may be attached at one end thereof to the inner collar 32 and may slide over a wear layer disposed on the composite ring 40.

Fig. 9 shows another embodiment. This example shows another variation of a seal between a ferrule and a composite ring. This example also shows different cross sections of the metal rings. Thus, fig. 9 shows a metal ring having a cross-section in the shape of the greek letter pi. In cross section, the metal ring has an axial branch 52 and two radial branches 54. Each radial branch of the metallic ring contacts a radial end 44 of the composite ring 40.

A J-section seal 90 is provided between the composite ring 40 (and particularly the radial end 44 thereof) and the stator casing 32. The seal 90 comprises a main branch 91 fixed to the composite ring 40 and an auxiliary branch 92 sliding on an annular pad 94 connected to the collar. Screws 96 may be provided to secure the main branch 91 to the composite ring 40.

The different figures show several possible embodiments of the composite ring, the metal ring and the seal. Those skilled in the art will note that the three elements (composite ring, metal ring, seal) are interchangeable from one embodiment to another, in particular, each type of seal can be used with each type of composite ring and metal ring.