Intermediary bearing outer ring mounting structure

Abstract

The application belongs to the field of aero-engines, and particularly relates to an intermediate bearing outer ring mounting structure. The structure comprises: the intermediate bearing outer ring is in a T-shaped cross section, the intermediate bearing outer ring comprises an outer ring main body and an outer ring mounting edge arranged in the middle of the outer ring main body, and mounting holes are arranged on the outer ring mounting edge; the spacer ring comprises a first spacer ring mounting edge, a second spacer ring mounting edge and a connecting beam connecting the first spacer ring mounting edge and the second spacer ring mounting edge, and mounting holes are arranged on the first spacer ring mounting edge and the second spacer ring mounting edge; and mounting holes are arranged on the low-pressure turbine shaft; wherein the first spacer ring mounting edge is overlapped on the intermediate bearing outer ring, and is sequentially connected through bolts passing through the mounting holes of the outer ring mounting edge, the mounting holes of the first spacer ring mounting edge, the mounting holes of the second spacer ring mounting edge and the mounting holes of the low-pressure turbine shaft, and is fixedly connected through a nut.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of aero-engines, and particularly relates to an intermediate bearing outer ring mounting structure. BACKGROUND

[0002] In the rotor support point layout of a dual-rotor small-bypass-ratio turbofan engine, an intermediate bearing (also called an inter-axle bearing) is often used to simplify the support structure. The intermediate bearing is usually arranged between the high-pressure turbine and the low-pressure turbine, and the temperature environment is harsh. The bearing cavity where the intermediate bearing is located is surrounded and heated by the secondary airflow of the turbine disc cavity, and the heat of the turbine disc is also conducted to the inner and outer rings of the intermediate bearing through the connecting structure.

[0003] With the increase of engine temperature load and the design demand for compact structure, the temperature and thermal deformation of the inner and outer rings of the intermediate bearing are particularly affected by the disc cavity airflow and the heat conduction and deformation of the turbine rotor (disc and shaft), and the uneven deformation of the bearing inner and outer ring tracks will worsen the contact load between the bearing rollers and the tracks, reduce the bearing life, and even endanger the safe operation of the engine. Therefore, measures need to be taken to reduce the influence of the turbine rotor on the heat conduction and deformation of the inner and outer rings of the intermediate bearing, and then control the deformation of the bearing track.

[0004] A typical intermediate bearing mounting method is shown in FIG. 1, in which the flange edge of the intermediate bearing outer ring is tightly fitted and mounted on the low-pressure turbine shaft, and the inner ring is mounted on the high-pressure turbine shaft. The disadvantages include: Figure 1

[0005] 1. During engine operation, the temperature of the turbine disc body is significantly higher than that of the bearing cavity, and the heat is conducted from the turbine disc to the bearing outer ring through the disc-shaft connection and the shaft-bearings outer ring flange connection. The temperature on the side of the bearing outer ring close to the flange edge is significantly higher than that on the side away from the flange edge, i.e., there is a significant axial temperature gradient, and the thermal deformation of the bearing outer ring is a "bell mouth" conical deformation.

[0006] 2. During engine operation, the temperature load of the disc-shaft connection part of the turbine shaft is high, and is affected by the partial centrifugal load of the turbine disc and itself, which causes the deformation of the turbine shaft and the bearing outer ring flange edge connection to be higher than that of the side of the bearing outer ring away from the flange edge, further aggravating the degree of conical deformation of the bearing outer ring.

[0007] This deformation condition will cause the bearing rollers to be unevenly loaded, worsen the contact load between the bearing rollers and the tracks, reduce the bearing life, and even endanger the safe operation of the engine.

[0008] Therefore, it is desirable to have a technical solution to overcome or at least alleviate at least one of the above-mentioned deficiencies of the prior art. SUMMARY

[0009] ​The purpose of the present application is to provide an intermediate bearing outer ring mounting structure to solve at least one problem existing in the prior art.

[0010] The technical solution of the present application is:

[0011] An intermediate bearing outer ring mounting structure comprises:

[0012] An intermediate bearing outer ring, which is T-shaped in cross section, comprises an outer ring body and an outer ring mounting edge arranged in the middle of the outer ring body, and mounting holes are arranged on the outer ring mounting edge;

[0013] An isolation ring, which comprises a first isolation ring mounting edge, a second isolation ring mounting edge, and a connecting beam connecting the first isolation ring mounting edge and the second isolation ring mounting edge, and mounting holes are arranged on the first isolation ring mounting edge and the second isolation ring mounting edge;

[0014] A low-pressure turbine shaft, which is provided with mounting holes;

[0015] Wherein, the first isolation ring mounting edge is overlapped on the intermediate bearing outer ring, and is fixedly connected by bolts passing through the mounting holes of the outer ring mounting edge, the mounting holes of the first isolation ring mounting edge, the mounting holes of the second isolation ring mounting edge, and the mounting holes of the low-pressure turbine shaft in sequence, and is connected with a nut.

[0016] In at least one embodiment of the present application, the outer edge of the outer ring mounting edge is provided with a U-shaped notch.

[0017] In at least one embodiment of the present application, the mounting holes and the U-shaped notches on the outer ring mounting edge are uniformly distributed circumferentially.

[0018] In at least one embodiment of the present application, one U-shaped notch is arranged every two mounting holes on the outer ring mounting edge.

[0019] In at least one embodiment of the present application, the outer edges of the first isolation ring mounting edge and the second isolation ring mounting edge are provided with U-shaped notches.

[0020] In at least one embodiment of the present application, the mounting holes and the U-shaped notches on the first isolation ring mounting edge and the second isolation ring mounting edge are uniformly distributed circumferentially.

[0021] In at least one embodiment of the present application, one U-shaped notch is arranged every two mounting holes on the first isolation ring mounting edge and the second isolation ring mounting edge.

[0022] In at least one embodiment of the present application, the connecting beams on the isolation ring are uniformly distributed in the circumferential direction, and a type hole is formed between two adjacent connecting beams, and the axial direction of the type hole is the local radial direction.

[0023] In at least one embodiment of the present application, the radial inner surface and the radial outer surface of the connecting beam are both cylindrical surfaces.

[0024] The present application has at least the following beneficial technical effects:

[0025] The intermediate bearing outer ring mounting structure of the present application can reduce the heat conduction of the turbine rotor to the intermediate bearing outer ring, alleviate the influence of the deformation of the turbine shaft-bearing connection on the intermediate bearing outer ring, and make the centrifugal force deformation and thermal deformation of the runway more uniform in the axial direction. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic diagram of a typical intermediate bearing mounting structure;

[0027] Figure 2 is a schematic diagram of the intermediate bearing outer ring mounting structure of one embodiment of the present application;

[0028] Figure 3 is a schematic diagram of the assembly of the isolation ring and the intermediate bearing outer ring of one embodiment of the present application;

[0029] Figure 4 is an exploded view of the isolation ring and the intermediate bearing outer ring of one embodiment of the present application;

[0030] Figure 5 is a side view of the outer ring mounting edge of one embodiment of the present application;

[0031] Figure 6 is a side view of the isolation ring of one embodiment of the present application;

[0032] Figure 7 is a view of A of Figure 6 ;

[0033] Figure 8 is a B-B view of Figure 6 ;

[0034] Wherein:

[0035] 1-bolt; 2-intermediate bearing outer ring; 3-isolation ring; 4-low pressure turbine shaft; 5-nut. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application. In the drawings, the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The described embodiments are part of the embodiments of the present application, rather than all the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation on the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application.

[0038] The embodiments of the present application will be described in detail below with reference to the drawings. Figures 1 to 8 The present application will be described in further detail.

[0039] The present application provides an intermediate bearing outer ring mounting structure, as shown in the drawings, comprising a bolt 1, an intermediate bearing outer ring 2, an isolation ring 3, a low-pressure turbine shaft 4 and a nut 5. The bolt 1 passes through the intermediate bearing outer ring 2, the isolation ring 3, the low-pressure turbine shaft 4 and other structural members in turn, and is fastened into one body by the nut 5. Figure 2

[0040] Specifically, the intermediate bearing outer ring 2 has a T-shaped cross section, and the intermediate bearing outer ring 2 comprises an outer ring main body and an outer ring mounting edge arranged at the middle part of the outer ring main body, and mounting holes are formed on the outer ring mounting edge. By arranging the outer ring mounting edge at the middle part of the outer ring main body, the difference in axial distribution of the radial deformation of the intermediate bearing outer ring 2 can be avoided. The isolation ring 3 comprises a first isolation ring mounting edge, a second isolation ring mounting edge and a connecting beam connecting the first isolation ring mounting edge and the second isolation ring mounting edge, and mounting holes are formed on the first isolation ring mounting edge and the second isolation ring mounting edge. The low-pressure turbine shaft 4 has mounting holes formed thereon; wherein the first isolation ring mounting edge is overlapped on the intermediate bearing outer ring 2, and the bolt 1 passes through the mounting holes of the outer ring mounting edge, the mounting holes of the first isolation ring mounting edge, the mounting holes of the second isolation ring mounting edge and the mounting holes of the low-pressure turbine shaft 4 in turn, and is fixedly connected by cooperating with the nut 5.

[0041] ​The intermediate bearing outer ring mounting structure of the application, the outer edge of the outer ring mounting edge of the intermediate bearing outer ring 2 is provided with a U-shaped notch to provide a lubricating oil flow channel. Preferably, the mounting holes and U-shaped notches on the outer ring mounting edge of the intermediate bearing outer ring 2 are uniformly distributed circumferentially. In the embodiment, one U-shaped notch is arranged every two mounting holes on the outer ring mounting edge, as shown in Figure 5 .

[0042] The intermediate bearing outer ring mounting structure of the application, the outer edge of the first isolation ring mounting edge and the second isolation ring mounting edge of the isolation ring 3 is provided with a U-shaped notch to provide a lubricating oil flow channel. Preferably, the mounting holes and U-shaped notches on the two mounting edges of the isolation ring 3 are uniformly distributed circumferentially. In the embodiment, one U-shaped notch is arranged every two mounting holes on the two mounting edges of the isolation ring 3, as shown in Figure 6 .

[0043] In the preferred embodiment of the application, the connecting beams on the isolation ring 3 are uniformly distributed circumferentially, and a type hole is formed between adjacent two connecting beams, so that the isolation ring 3 is hollow, and the axial direction of the type hole is the local radial direction. The type hole can be rectangular, circular or elliptical, and when the type hole is rectangular, the four corners are rounded. The cross section of the connecting beam is in the shape of a curved trapezoid, the radial inner surface and the radial outer surface are both cylindrical surfaces, and the side surface is a type hole processing surface.

[0044] The intermediate bearing outer ring mounting structure of the application, the connecting beam is the key to realize the heat transfer and deformation blocking function of the isolation ring 3. Compared with the intermediate bearing outer ring mounting structure of the Figure 1 , the connecting beam reduces the heat conduction area of the turbine axial intermediate bearing outer ring 2 and the connecting stiffness between the intermediate bearing outer ring 2 and the turbine shaft, thereby relieving and isolating the deformation influence of the turbine shaft heat and deformation on the intermediate bearing outer ring 2. By adjusting the number, length, cross-sectional size and other structural parameters of the connecting beam of the isolation ring 3, the heat conduction area and the connecting stiffness can be adjusted to optimize the radial deformation distribution of the intermediate bearing outer ring 2 to meet the bearing working condition requirements. In addition, the tightened bolt 1 also contributes part of the connecting stiffness.

[0045] The application provides an intermediate bearing outer ring mounting structure for reducing the influence of turbine rotor heat conduction and centrifugal deformation, and has the following beneficial effects:

[0046] (1) A hollow isolation ring is arranged between the outer ring mounting edge of the intermediate bearing outer ring and the low-pressure turbine shaft, which reduces the heat conduction of the turbine rotor to the intermediate bearing outer ring and reduces the axial temperature gradient of the intermediate bearing outer ring;

[0047] (2) The hollow heat insulation ring also has the characteristics of a flexible structure, which relieves the influence of the turbine shaft-bearing connection deformation on the bearing outer ring;

[0048] (3) The mounting edge on the outer ring of the intermediate bearing is arranged in the middle of the bearing raceway instead of one end, so that the centrifugal deformation and thermal deformation of the raceway is distributed more evenly in the axial direction, i.e. the degree of "bell-mouth" tapering is reduced.

[0049] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical scope disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An intermediate bearing outer ring mounting structure characterized by, The utility model relates to a kind of intermediate bearing outer ring (2), cross section is T type, the intermediate bearing outer ring (2) includes outer ring main body and the outer ring installation edge being arranged in the middle part of the outer ring main body, installation hole is set on the outer ring installation edge; Isolation ring (3), the isolation ring (3) includes first isolation ring installation edge, second isolation ring installation edge and the connecting beam connecting the first isolation ring installation edge with the second isolation ring installation edge, installation hole is set on the first isolation ring installation edge and the second isolation ring installation edge; Low-pressure turbine shaft (4), installation hole is set on the low-pressure turbine shaft (4); Wherein, the first isolation ring installation edge is overlapped on the intermediate bearing outer ring (2), and is sequentially passed through the installation hole of the outer ring installation edge, the installation hole of the first isolation ring installation edge, the installation hole of the second isolation ring installation edge and the installation hole of the low-pressure turbine shaft (4) by bolt (1), and is fixedly connected by cooperating nut (5); The connecting beam on the isolation ring (3) is evenly distributed along the circumference, and the type hole is formed between adjacent two connecting beams, and the axial direction of the type hole is local radial direction. The outer edge of the outer ring installation edge is provided with U-shaped notch.

2. The intermediate bearing outer ring mounting structure according to claim 1, characterized by The installation hole and U-shaped notch on the outer ring installation edge are evenly distributed along the circumference.

3. The intermediate bearing outer ring mounting structure of claim 2, wherein Every two installation holes are arranged with one U-shaped notch on the outer ring installation edge.

4. The intermediate bearing outer ring mounting structure according to claim 3, characterized by The outer edge of the first isolation ring installation edge and the second isolation ring installation edge is provided with U-shaped notch.

5. The intermediate bearing outer ring mounting structure according to claim 4, characterized by The installation hole and U-shaped notch on the first isolation ring installation edge and the second isolation ring installation edge are evenly distributed along the circumference.

6. The intermediate bearing outer ring mounting structure of claim 5, wherein Every two installation holes are arranged with one U-shaped notch on the first isolation ring installation edge and the second isolation ring installation edge.

7. The intermediate bearing outer ring mounting structure of claim 6, wherein The type hole is rectangular, circular or elliptical.

8. The intermediate bearing outer ring mounting structure of claim 1, wherein The radial inner surface and the radial outer surface of the connecting beam are both cylindrical surface.

9. The intermediate bearing outer ring mounting structure of claim 1, wherein ​

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