RU2230195C2 - Multistage turbine rotor - Google Patents

Abstract

FIELD: power and transport engineering. SUBSTANCE: invention can be used in turbines of aircraft engines and gas-turbine plants of ground application. Proposed rotor of multistage turbine is provided with disks arranged in cantilever manner relative to supports and braced together with shaft by central bolt. Disks are furnished with flanges extended in axial direction. Flanges of neighbor disks being in contact over end face surfaces are aligned and fixed by precision pins. Shaft is provided with radial-conical envelope with attachment flange,

Description

The invention relates to power and transport engineering and can be used in turbines of aircraft engines and gas turbine installations for ground use.

A known rotor design of a multi-stage turbine, in which the disks are interconnected using several directional studs located approximately in the middle of the blade web. Through the studs, the torque is transmitted from one disk to another and to the rotor shaft, as well as the screed of the disks in the axial direction / 1 /.

The disadvantage of this design is that the holes made in the disks are stress concentrators and can become a source of cracks and fracture of disks operating under cyclic loads. During turbine operation, the temperature of the disks in such structures is usually higher than the temperature of the studs; therefore, the studs are stretched, i.e. screed disc pack unreliable.

The closest in design to the claimed is the rotor of a multi-stage turbine, in which the disks are connected to each other in the axial direction and with the shaft flange using the Hirth slots, are tightened by a central coupling bolt passing through the holes in the disk hub. Radial alignment and transmission of torque is also performed through the slots of Hirth / 2 /.

The main disadvantage of the known design is the weakening of the tightening of the rotor package due to the elongation of the coupling bolt operating under cyclic loads under various thermal expansion of the bolt and discs, which leads to the unbalance of the rotor and reduce the reliability of the design.

In addition, the known design is not rigid enough because of the remoteness of the front support of the rotor from its center of gravity.

The technical problem solved by the invention is to increase the reliability and rigidity of the structure by eliminating the weakening of the tightening of the rotor package and unbalance during cyclic loads, as well as the approach of the front rotor support to its center of gravity.

-образную форму, причем сужение конусного участка оболочки направлено в сторону присоединительного фланца, который скреплен с фланцем ближайшего диска, а между стяжным болтом и полотном диска первой ступени размещен упругий элемент в форме тарельчатой пружины.The essence of the invention lies in the fact that in the rotor of a multi-stage turbine with disks located cantilever relative to the supports and pulled together with a shaft by a central coupling bolt, according to the invention, the disks are provided with axially extended flanges, while the flanges of adjacent disks contact along the end surfaces, are centered between each other and fixed by tight-fitting pins, the shaft is equipped with a radial-conical shell with a connecting flange having a cross-section

-shaped shape, and the narrowing of the conical portion of the shell is directed towards the connecting flange, which is fastened to the flange of the nearest disc, and between the coupling bolt and the blade web of the first stage there is an elastic element in the form of a Belleville spring.

In addition, the discs can be centered using an intermediate part, such as a diaphragm.

Since the disks at the junction with each other have a temperature higher than the coupling bolt, it is likely that the coupling bolt will be pulled out and the joints will open along the disks. However, the difference in temperature expansion of the disk package and the coupling bolt will compensate for the Belleville spring, which will increase the reliability of the claimed design. The spring stiffness is selected constructively and depends on the mass of the package being pulled together, the tightening torque, the direction of the workload applied to the rotor, and other factors.

The supply of disks with axially extended flanges, as well as the contacting of the flanges of adjacent disks on end surfaces that are centered between each other and secured by prismatic pins, as well as the placement of an elastic element, eliminates the violation of the tightening of the disk package and unbalance of the rotor under cyclic loads. The difference in temperature expansions between the coupling bolt and the pack of contractible disks will be compensated by an elastic element in the form of a Belleville spring located under the supporting part of the coupling bolt and operating in the zone of elastic deformation.

-образную форму, позволяет сместить передний опорный подшипник в сторону центра тяжести ротора, тем самым уменьшить его консольность и, следовательно, повысить жесткость.The narrowing of the conical section of the radial conical shell is directed towards the connecting flange. The execution of the shell with radial and conical sections and a connecting flange, which in cross section have

-shaped shape, allows you to shift the front thrust bearing towards the center of gravity of the rotor, thereby reducing its cantileverness and, therefore, increase rigidity.

The invention is illustrated as follows.

Figure 1 shows the rotor of a multi-stage turbine of the claimed design.

Figure 2 shows an embodiment of a rotor with disks centered on the diaphragms.

The rotor of a multi-stage turbine consists of disks of the first stage 1, second stage 2 and third stage 3. Each of the disks is equipped with flanges 4, 5, which are axially extended. The flanges 4, 5 of the adjacent disks 1 and 2, 2 and 3 are in contact on the end surfaces 6. In the flanges 4 there are directed holes in which the pivot pins 7 are installed, thereby providing centering and fixing between the disks 1, 2 and 2, 3.

-образную форму, и выдвинут относительно ближайшего диска 3 в осевом направлении. Оболочка имеет конический участок 13, сужение которого идет в сторону присоединительного фланца 11.The disk 3 with a flange 8 with bolts 9 and nuts 10 is fastened to the connecting flange 11 of the shaft 12. The connecting flange 11 refers to a radially conical shell 13, which has

-shaped, and extended relative to the nearest disk 3 in the axial direction. The shell has a conical section 13, the narrowing of which goes towards the connecting flange 11.

The central coupling bolt 14 tightens a part package consisting of discs 1, 2, and 3 through a cup spring 15. One end of the coupling bolt 14 is provided with a thread 16 that is screwed into the mating thread on the sheath 13 of the shaft 12. To ensure maintainability, the thread can be made in additional details 17. To exclude the skew of the coupling bolt 14 when screwing under its head, a spherical washer 18 is installed.

The rotor shaft 12 is located on the front 19 and rear (not shown) bearing bearings.

Between the supporting part of the coupling bolt 14 and the webs of the disks 1, 2, 3 conjugated with it, intermediate elements are arranged in the form of a diaphragm 20.

The rotor of the claimed design works as follows.

When the turbine is operating, torque from disk 1 through the flange 4 and pins 7 is transmitted to the flange 5 of the disk 2, and from disks 1, 2 through the flange 4 of the disk 2 and pins 7, the torque is transmitted to the flange 5 of the disk 3. A from disks 1, 2 , 3 of the first, second, third stages, respectively, through the flange 4 of the disk of the third stage, bolts 9, the torque is transmitted to the flange 13 of the shaft 12.

During operation, due to the higher temperature, the axial expansion of the disc pack will be larger than the expansion of the coupling bolt. However, the extraction of the coupling bolt does not occur, because the difference of the extensions is compensated by the elastic disk spring 15.

Sources of information

1. Skubachevsky G.S. Aircraft gas turbine engines. Design and calculation of parts. - M.: Mechanical Engineering, 1981, p. 120.

2. Ibid., P. 124, Fig. 5.05.

Claims (2)

1. The rotor of a multi-stage turbine with disks located cantilever relative to the supports and pulled together with a shaft by a central coupling bolt, characterized in that the disks are provided with axially spaced flanges, while the flanges of adjacent disks contact along the end surfaces, are centered between each other and secured with prism pins, the shaft is equipped with a radial conical shell with a connecting flange, having in cross section

- shaped, and the narrowing of the conical portion of the shell is directed towards the connecting flange, which is fastened to the flange of the nearest disk, and between the coupling bolt and the canvas of the disk of the first stage there is an elastic element in the form of a disk spring. 2. The rotor of a multi-stage turbine, characterized in that the disks are centered using an intermediate part, for example, a diaphragm.

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