JPS5847199A - Axial-flow compressor - Google Patents

Abstract

PURPOSE:To prevent reduction of the surface pressure on a disk in revolution by forming in a disk during rotor revolution, ventilation holes for ventilating high-temperature gas and allowing a large thermal expansion to be generated on the disk. CONSTITUTION:A portion of the pressurized high-temperature gas goes to the hollow part 4b, passing through the gap 29 between a diaphragm 21 and an end piece 4 and a through-hole 11, and then a portion of said gas go to the hollow part 3b, passing through the ventilation holes 7 and 8 inside a disk 1, and the rest go to the hollow part 3b, passing through a slit 12, ventilation hole 9, and a slit 33, and then all the gas are joined and introduced outside, passing through ventilation holes 14, 16, 18 and 20, as shown with an arrow of solid line. As the disk 1 is thereby heated by the high-temperature gas, thermal expansion is generated, and reduction of the surface pressure on the disk in revolution can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides 41dl! The present invention relates to an axial flow compressor having a so-called stacked rotor structure in which a rotor is constructed by embedding L rotor blades in the outer periphery of a disk, stacking 41a disks and fastening them with tie bolts.

The rotor of an axial flow compressor having a stacked rotor structure lr: As shown in Fig. 1, a number of grooves are provided on the outer periphery of a disk l, and the roots of rotor blades 2 are buried in each groove. It is constructed by stacking a plurality of disks, clamping them from both sides with end beads 23.4 each having shafts 3a and 4a, and fastening the whole thing with a plurality of tie bolts 5.

In such a rotor, the Ig torque of the driver is transmitted from the end piece to the disk in contact with that end piece, and then on to the next disk, and so on due to the frictional force between the adjoining surfaces. conveyed by. In order to transmit the driving torque by the threshold frictional force between the surfaces of the disks that come into contact with each other, a certain amount of surface pressure must be generated between each disk surface and the surface that comes into contact with it. I need to keep it. However, since a centrifugal force acts on the disk in tgl@, the disk expands outward in the radial direction, and at the same time, conversely contracts in the axial direction due to the Igl ratio of Poisson's ratio. That is, the thickness of a rotating disk is relatively reduced compared to a stationary disk.

As a result, the tension present in the rotating tie bolt 5 will be relatively reduced compared to when it is stationary, so that
To maintain a certain amount of surface pressure at the threshold of the adjoining disk surfaces, a very small tension is applied to the stationary tie bolt to match the tension required in the rotating tie bolt. This may cause problems with the strength of the tie bolts,
There is one point in terms of reliability.

In view of one point of the prior art described above, the present invention aims to improve the reliability of the stacked rotor by reducing the initial tightening force of the tie bolts that tighten the disks of the stacked rotor.

In order to reduce the initial tension of tie bolts in a stacked rotor, the present invention provides ventilation holes in the disk to vent hot gas during rotation of the rotor, and by causing the disk to have a larger thermal expansion than the tie voids, during rotation. It is considered as t4 that the low disk surface pressure was prevented. Further, the present invention is characterized in that the tie bolt is provided with a vent hole that allows low-temperature gas to pass through the tie bolt during rotation of the rotor, thereby suppressing heat and expansion of the tie bolt and preventing a decrease in disk surface pressure. Further, according to the second aspect of the present invention, by providing both the high-temperature gas vent in the disc and the low-temperature gas vent in the tie bolt, the decrease in the disc surface pressure is better suppressed.

The present invention will be explained below with reference to embodiments shown in FIGS. 2 to 5. As shown in Figure 42, the stacked valley disks 1 are provided with a plurality of ventilation holes 8 in addition to the central ventilation hole 7 in the inner disk part, and a plurality of ventilation holes are also provided in the outer peripheral lip part. 9 is provided, and r! of the adjacent disk surface is provided on the outer circumference/g part. Prevent high temperature gas from leaking from a11a0
In this embodiment, in which the ring 1G is fitted into a groove provided on one side of the disk 1 over the entire circumference, the high temperature gas compressed by this compressor is used to heat the disk. A gap 29 is formed between the end piece 4 and the diamond 7mm 21 on the compressed gas discharge side of the casing 19 to which the casing 13 is attached.
A ventilation hole 11 is bored in the radial direction from b, and the contact surface Vζ of the end piece 4 with the disk is designed to prevent high temperature gas flowing into the inner space 4bK, as shown in FIG. A slit 12 leading to the ventilation hole 9 of the disc 5 is provided.

- The end piece 3 on the suction side of the sword is a suction cone 1 held by a rim 17ic inside the casing 19.
The end piece 3 is supported at the shaft 3aO portion within the disk, and the contact surface of the end piece 3 with the disk is filled with hot gas from the vent hole 7.8 that has passed through the vent hole 9 of each disk. +l
(ii) A slit 33 is formed to join the hot gas and guide it into the inner cavity 3b of the end piece 3. Moreover, the shaft 3a,
The suction cone 15, the rim 17, and the casing 19 have ventilation holes 14 that guide the high-temperature gas that has reached the inner cavity 3b to the outside.
．． 16, 18, and 20 are provided in communication.

Further, between the outer circumferential portion of the shaft 3a and the inner circumferential surface of the servo 7/co/15, two birinsing screws 27, 28 are provided to prevent high-temperature gas from leaking into the suction gas. Also between the diamond 7, the rubber 21 and the end piece 4, there is a two-hole packing 26 to prevent leakage of high temperature gas.

If such ventilation holes and slits are provided, a portion of the compressed high-temperature gas will be transferred to the gap 29 between the diaphragm 21 and the end piece 4, and the through hole 1lt- as shown by the solid line arrow.
After that, part of the air passes through the ventilation holes 7 and 8t on the inside of the disk l and reaches the internal space 13b, and the rest passes through the ventilation hole 9 and the slit 33. 9 to reach the inner cavity 3b, and merge into the ventilation holes 14, 16, 18, 2.
It is led to the outside through 0. Therefore, since the disk 1 is heated by the high temperature gas, it undergoes thermal expansion. At this time, in order to prevent the tie bolts 5 from being heated and thermally expanded due to heat transfer, the holes 6 through which the tie bolts 5 are inserted are slits 12 and 12 in contact with 14, as shown in FIG.
(33, 331) As shown in FIG.
It is preferable to take measures such as doing td[ at 4. In this way, by creating a difference in thermal tension between the disc 1 and the tie bolt 5, a decrease in the disc surface pressure due to one rotation of the rainbow 10 is prevented, and the initial tightening of the tie bolt 5 is performed with a sharp point that reduces the force. It is Noh.

i9. As shown in Fig. 4, by providing a ventilation hole 23 over the entire length of the tie bolt 5 and passing low-temperature gas through the ventilation hole 23, a decrease in surface pressure of the isk due to rotor rotation can be effectively prevented. In this embodiment, as shown in FIG. 5, a part of the cooler 2-32 provided in the discharge passage 35 of the compressor 31 is bled, and as shown in the dashed line in FIG. 2, eζ, The diamond 7 is introduced through the ventilation hole 30 provided in the diaphragm 21 and the end piece 4 into the space 34 partitioned by the two-hole packing 25 and 26 between the diaphragm 21 and the end piece 4, and after passing through the tie bolt 5, the end piece 3 and the t The suction gas is mixed with the suction gas from the tank.

In this case, the low-temperature gas, like the high-temperature gas, flows through the tie bolt 5 due to the pressure difference between the discharge side and the suction side of the compressor.

As described above, an effective increase in disk surface pressure can be achieved by flowing low-temperature gas to the disk side and low-temperature gas to the tie bolts 5, but it is also possible to achieve a significant increase by simply allowing low-temperature gas to flow through the tie bolts 5. An increase in surface pressure can be achieved. 2, due to the gas compression operation in the compressor.
When the temperature of the tie bolts 5 increases as the temperature of the disk increases, the tie bolts 5 expand, causing a decrease in disk surface pressure. This prevents the disk surface pressure from decreasing to some extent.
′ □ As explained above, according to the invention, in an axial flow compressor with a stacked rotor structure, the disk surface pressure during rotor rotation is prevented from decreasing, so the initial tightening force of the tie bolts is reduced. However, since it is possible to reliably transmit the driving torque during rotation, and since the force required to be significantly increased with a star, high-grade materials were required from the viewpoint of reliability, but according to the present invention, (You can use a lower grade material than before.)
jAl can also be reduced by 1m.

[Brief explanation of the drawings] Figure II & 1 is a vertical cross-sectional view of a conventional stacked rotor.
The figure is a longitudinal sectional view showing an embodiment of an axial flow compressor with a stacked rotor structure according to the present invention, Figure 1X3 is a perspective view showing an end piece of the ninth embodiment, and Figure 4 shows an example of a tie bolt of the embodiment. A side view of FIG. 5 is a gas supply system diagram of this embodiment. 1... Disc, 2... Moving blade, 3, 4... End goose, 5... Tie bolt, 7, 8, 9, 14.1!
, 18°20.30...Vent hole, 12.33...Slit, "19...Casing.

Claims (1)

[Claims] 1.a A disk with several rotor blades embedded in its outer periphery is fi,
Rotor structure 4 made by laminating several layers and fastening them with tie bolts? r
: An axial flow compressor comprising: an axial flow compressor, characterized in that the disk circle is provided with a vent hole through which gas flows while the rotor is rotating. Z41 In a trickle compressor with a rotor structure in which several disks with several Ill blades embedded in the outer periphery are connected by tie bolts, the tie bolts are provided with ventilation holes for flowing low-temperature gas while the rotor is rotating. Set σ shaku also known as t-t
Axial flow compressor with fi characteristics. In an axial flow compressor having a rotor structure in which a plurality of discs each having a plurality of 11Ell blades embedded in the outer periphery are laminated and fastened with tie bolts, a vent hole is provided in the disc through which pan-hot gas flows while the rotor is rotating. An axial flow compressor characterized in that the tie bolt is provided with a vent hole through which low-temperature gas flows during rotation of the rotor.