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Flange for connection between an axial compressor and high-pressure rotor disc unit in a gas turbine

Imported: 24 Feb '17 | Published: 06 Jan '04

Massimo Pinzauti, Carlo Bacciottini

USPTO - Utility Patents

Abstract

A flange (

20) for connection between an axial compressor and high-pressure rotor disc unit (

14) in a gas turbine (

10), wherein the flange (

20) has a body (

22) with a frusto-conical shape which is joined to a shaft (

12) of the axial compressor by means of a hub (

24) which has a cylindrical shape and which, at the larger base of the frustum of the cone of the body (

22) is connected to the rotor disc unit (

14) by means of an extension (

26) of the hub in the form of a circular ring, a circumferential recess (

28) provided in a surface (

29) of the extension (

26) which faces the rotor disc unit (

14) being connected by interference with a projection, which is complementary to the recess and is provided on the rotor disc unit (

14); the body (

22) has an outer generatrix which is inclined relative to the direction at right-angles to the axis (X) by an angle

1 of between 25° and 35° and an inner generatrix which is inclined by an angle

2 of between 12° and 18°.

Description

The characteristics and advantages of an improved flange for connection according to the present invention, between an axial compressor and a high-pressure rotor disc unit in a gas turbine will become clearer and more apparent from the following description provided by way of non-limiting example, with reference to the set of attached schematic drawings in which:

FIG. 1 is a cross-section of a gas turbine in which there can be seen a flange according to the known art, for connection between an axial compressor and a high-pressure rotor disc unit of the gas turbine;

FIG. 2 is an enlarged cross-section of a detail of FIG. 1, which shows the connection flange according to the known art; and

FIG. 3 is a cross-section which shows a connection flange produced according to the description of the present invention.

Claims

1. A flange for connection between an axial compressor and a high-pressure rotor disc unit in a gas turbine, said flange including a body having a frusto-conical shape, said body being joined to a shaft rotatable about a machine axis of said axial compressor by a hub having a cylindrical shape, said body being joined at a larger base of the frusto-conically-shaped body to said rotor disc unit by an extension of the hub in the form of a circular ring, said extension having a circumferential recess provided in a surface of said extension facing said rotor disc unit for connecting by interference with a projection complementary to the recess and provided on the rotor disc unit, said frusto-conically-shaped body having an outer generatrix inclined relative to a direction at right angles to the machine axis by an angle

2 between 25° and 35°, said frusto-conical body having an inner generatrix inclined relative to the direction at right angles to the machine axis by an angle

2 between 12° and 18°.

2. A flange according to claim 1 wherein said extension extends radially towards an exterior of said body in a direction at right angles to the machine axis and terminates in a diameter D

5, said surface of said circumferential recess extending at right angles to the axis (X) at a diameter D

4, the ratio between diameters D

4 and D

5 being between 0.7 and 0.85.

3. A flange according to claim 2 wherein said extension is connected to two inner and outer generatrices of the frusto-conical body, respectively, according to arcs of circumferences with radii R

2 and R

1, respectively, the connection with the outer generatrix being formed to a diameter D

1 relative to the machine axis (X), the ratio between radii R

2 and R

1 being between 0.8 and 1 and the ratio between diameters D

4 and D

1 being between 0.95 and 1.05.

4. A flange according to claim 3 wherein said hub is connected to the outer generatrix of the frusto-conical body along an arc of circumference with a radius R

3, the connection with the outer generatrix being formed in an area close to a diameter D

1 relative to the machine axis (X), the ratio between R

2 and R

3 being between 3.5 and 4.5, and the ratio between D

4 and D

3 being between 1.55 and 1.7.

5. A flange according to claim 2 wherein, at an end of the extension, said body has a thickness S

1, measured at right angles to the direction assumed by the outer generatrix of the frusto-conically-shaped body, and, at the opposite end of said extension, said flange having a thickness S

2 measured in the direction of the machine axis (X), the ratio between S

1 and D

4 being between 0.13 and 0.18, and the ratio between S

2 and D

4 being between 1.3 and 1.7.

6. A flange according to claim 1 wherein the inner generatrix of the frusto-conical body is coupled to the hub in a direction (Y), which, relative to the machine axis (X), forms an angle

3 of between 26° and 34°.

7. A flange according to claim 2 wherein said hub has a cylindrical shape and an inner diameter D

2, the ratio between D

4 and D

2 being between 5.2 and 6.5.

8. A flange according to claim 1 characterized in that said extension has a series of circumferential through holes extending in directions parallel to the machine axis (X), between said surface and a surface of the extension facing said axial compressor, said through holes receiving elements for securing between said flange and said rotor disc unit.

9. A flange according to claim 8 wherein said elements comprise tie rods.