JPS6211314Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbine rotor mounting structure, and more particularly to a mounting structure to the shaft of a power turbine in a two-shaft gas turbine.

Generally, a power turbine is equipped with a reduction gear, such as a binion, on the same axis.When assembling these gears, the structure for attaching the power turbine rotor to the output shaft requires a bolted connection between the output shaft and the rotor. When installed in a turbine rotor, bolts may loosen due to the thermal effects of the turbine exposed to high temperatures, and cracks may occur in the rotor mounting holes due to centrifugal force due to high rotation. Therefore, in order to prevent this, the rotor disk of the turbine is not provided with a connecting part, and the shaft part formed integrally with the rotor is extended to the binion installation side, and the extended shaft part is further shaped into a bolt shape. The turbine rotor mounting structure is such that a hollow shaft and gears are sequentially fitted into the narrowed and extended shaft part, and a nut is screwed into the screw cut into the bolt-shaped shaft end. For example, on April 30, 1977, Chrysler Corporation issued an ERDA (Energy Research and
Development Administration (COO-2749-18).

FIG. 1 shows an example of such a turbine rotor mounting structure. In FIG. 1, 1 is a rotor disk of a power turbine;
further extending the shaft portion 1A formed integrally with the
Bolt-shaped extension shaft 1B having the same axis as the shaft portion 1A
is provided, and a screw 1C for screwing is carved into the end thereof. 2 is a hollow shaft whose end is fitted into the shaft 1A of the rotor disk 1, and the other end 2A of the hollow shaft 2 has a tapered hole 2 for positioning.
After the hollow shaft 2 is assembled with the rotor disk 1, the tapered nut 3 is fitted into the tapered hole 2B and screwed onto the end screw 1C of the extension shaft 1B, and the nut 3 is tightened. The rotor disk 1 and hollow shaft 2 are assembled.
Note that here, 4 is a bearing for the rotating shaft.

In the turbine rotor mounting structure configured in this way, the thicker shaft increases its rigidity, which is advantageous against critical speeds.
Since the shaft 2 is hollow, the weight does not increase, and the moment of inertia during high-speed rotation can be small. Further, since the tightening portion by the nut 3 is located at a distance from the rotor 1, which is a high temperature portion, loosening due to thermal expansion will not occur.

However, in this type of conventional turbine rotor mounting structure, the long shaft extending from the turbine rotor is connected to the hollow shaft at the end, so this extended shaft is the source of vibration during high-speed rotation. Not only that, but it is also bulky as a component, and requires troublesome handling during disassembly and assembly.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, eliminate the extension shaft, and directly connect the shaft protruding from the rotor to the hollow shaft with a tapered bolt, thereby reducing the moment of inertia of the shaft. Moreover, it is an object of the present invention to provide a turbine rotor mounting structure that does not cause loosening of coupling bolts and prevents vibrations from occurring.

In order to achieve such an object, the present invention provides a turbine rotor mounting structure for fixing a disk portion of a power turbine rotor to an output shaft, in which a shaft portion is provided protruding from the disk portion and aligned with the axial center at the end of the shaft portion. The output shaft is a hollow shaft, and the end of the output shaft on the disc side has a step part formed by making the diameter smaller than the inner diameter of the hollow shaft and the outside of the output shaft. A hollow shaft member comprising a hollow shaft portion having a hole drilled in a radial shape toward the direction, a hollow shaft portion having a tapered surface provided around the stepped portion, and a fitting shaft portion capable of fitting into the shaft portion of the disk portion. is provided and screwed into the screw hole,
It has a bolt that fixes the hollow shaft member to the disc part with the fitting shaft part fitted to the shaft part of the disc part, and the bolt has a seat surface corresponding to the tapered surface and a bolt that extends from the head of the bolt to It is characterized by providing a hole that extends in the axial direction, faces outward from the axial direction, and communicates with the radial hole of the hollow shaft portion.

The present invention will be explained below based on the drawings.

FIG. 2 shows an embodiment of the present invention, 11 is a turbine rotor disk, 12 is a rotor disk 11
The shaft part 12 has a spigot part 1 for fitting into the hollow shaft assembly member 13.
2A and a spline portion 12B are provided, and along the axis 14 of the shaft portion 12, a screw hole 12C matching the fixing bolt 15 is bored. A hollow shaft assembly member (hereinafter referred to as a hollow shaft member) 13 is a fitting part 1
3A, and the peripheral wall surface of this fitting part 13A is the shaft part 1
No. 2 inlet part 12A and spline part 12B
It is formed so as to be fitted with each other, and has a connection part 13B with the hollow shaft 16, and
A tapered surface 1 corresponding to the tapered portion 15A of the fixing bolt 15 is provided on the stepped portion of the mounting side end of the hollow shaft 16 of the mounting hole 13C provided along the axis 14.
Form 3D. The fixing bolt 15 has a hole in its head for inserting a mounting jig, for example, a cross hole 15B.
Set it up.

In this example, the hollow shaft member 13 and the hollow shaft 16 are formed separately because the hollow shaft 16 is long and the hollow shaft member 13 has a rotor disk 1.
This is because it is necessary to form a tapered surface 13D for centering when joining with 1, and considering the processing process, after fitting the hollow shaft member 13 and the hollow shaft 16, electron beam welding is performed. etc., it can be easily integrated. Furthermore, it goes without saying that the hollow shaft member 13 and the hollow shaft 16 may be integrally formed from the beginning.

When assembling the turbine rotor mounting structure configured in this way, the bearing 17 and the bearing holding member 18 are attached to the hollow shaft member 13 integrated with the hollow shaft 16.
After sequentially fitting the parts, the fitting part 12A and the spline part 12B provided on the shaft part 12 of the rotor disk 11 are respectively fitted into the fitting part 13A of the hollow shaft member 13, and the other end (not shown) of the hollow shaft 16 is fitted. A mounting jig (not shown) and a fixing bolt 15 attached to the tip of the jig are inserted from the side, and the bolt 15 is screwed into the screw hole 12C. Further, at this time, the centering of the rotor disk 11 is confirmed by the tapered portion 15A of the bolt 15 coming into contact with the tapered surface 13D of the hollow shaft member 13.

3A and 3B show another embodiment of the present invention, and hereinafter the same reference numerals will be used for similar parts to those in FIG. 2. In this example, rotor disk 1
1 and the hollow shaft 16 to protect the joint from heat so that the fastened state can be maintained even better.

Here, 21A is an air hole formed in the axial direction from the jig hole 15B of the bolt 15;
A suitable number of air holes 21B are further provided in the radial direction from 1A toward the outer periphery of the bolt 15. Furthermore, an air outflow hole 22 is provided from the attachment hole 13C of the hollow shaft member 13 toward the outer peripheral surface 13E of the hollow shaft member 13. This air outflow hole 22 is shown in FIG.
As shown in FIG. 2, the mounting hole 13C extends from the inner circumferential surface of the mounting hole 13C in a tangential direction so as to have an outer outlet in the direction opposite to the direction of rotation of the shaft 13.

In addition, in this example, the air hole 21B and the outflow hole 2
2 are arranged at equal positions on the circumference, but the number and arrangement positions are not limited to this example, and may be any suitable for air circulation. In addition, in this example, the space of the mounting hole 13C is expanded compared to the example shown in FIG.
The reason why a sufficient gap is provided between the outer periphery of the hollow shaft 16 and the housing 20 is to ensure good circulation of cooling air.

With the turbine rotor mounting structure configured in this way, in addition to the effects of the embodiment shown in FIG.
Air flows from the hollow part of the hollow shaft 16 to the fixing bolt 15.
The air is guided to the space of the mounting hole 13C through the air holes 21A and 21B provided in the hollow shaft 13.
Due to the negative pressure near the outlet of the air outlet hole 22 generated by the rotation of the
It is possible to cool the connecting parts such as the shaft part 12 and prevent them from seizing.

As explained above, according to the present invention, the shaft protrudes from the disk part, a screw hole is bored in the end of the shaft in alignment with the shaft center, the output shaft is made into a hollow shaft, and the output The end of the shaft on the disk side side has a step part formed by making the diameter smaller than the inner diameter of the hollow shaft and a hole drilled in a radial shape toward the outside of the output shaft. A hollow shaft member is provided, which includes a hollow shaft portion having a circumferential tapered surface and a fitting shaft portion that can be fitted to the shaft portion of the disk portion, and is screwed into a screw hole to connect the fitting shaft portion to the disk portion. The bolt has a bolt that fixes the hollow shaft member to the disk part when fitted to the shaft part of the disc part, and the bolt has a seat surface corresponding to the tapered surface and a bolt extending from the head of the bolt in the direction of its axis. In addition, since there is a hole facing outward from the axial direction and communicating with the radial hole in the hollow shaft part, there is no need to provide a long shaft extending from the rotor disk as in the conventional case, and it is especially easy to tighten bolts. This makes it easy to center the output shaft and rotor disk, and prevents vibrations during high-speed rotation.Moreover, the hollow shaft allows the moment of inertia to be kept small. Since holes for air circulation are provided in the fastening bolts and the hollow shaft member, parts that tend to get hot, such as around the bolts and the joint between the hollow shaft member and the rotor disk shaft, can be heated by the air flow flowing through these holes. Cooling can contribute to preventing seizure near the bearing and preventing bolt loosening.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional turbine rotor mounting structure having a hollow shaft, and FIG. 2 is a sectional view showing an example of the turbine rotor mounting structure of the present invention.
FIG. 3A is a sectional view showing the structure of another embodiment of the present invention, and FIG. 3B is a stepwise sectional view taken along the line X--X. 1...Rotor disk, 1A...Shaft part, 1B...
...Extension shaft, 1C...Screw, 2...Hollow shaft, 2A...
...End, 2B...Tapered hole, 3...Nut, 4...
... bearing, 11 ... rotor disk, 12 ... shaft section, 12A ... pilot section, 12B ... spline section, 12C ... screw hole, 13 ... hollow shaft member,
13A... Fitting part, 13B... Connection part, 13C...
...Mounting hole, 13D...Tapered surface, 13E...Outer peripheral surface, 14...Axis, 15...Fixing bolt, 1
5A... Taper part, 15B... Hole, 16... Hollow shaft, 17... Bearing, 18... Bearing pressing member, 20
...Housing, 21A, 21B...Air hole, 2
2...Air outflow hole.

Claims (1)

[Claims for Utility Model Registration] In a turbine rotor mounting structure for fixing a disk portion of a power turbine rotor to an output shaft, a shaft portion is provided protruding from the disk portion and a screw is aligned with the axial center at the end of the shaft portion. a hole is bored, the output shaft is a hollow shaft, and an end of the output shaft on the side of the disk part has a stepped part formed by having a diameter smaller than the inner diameter of the hollow shaft, and the output shaft. a hollow shaft portion having a hole drilled in a radial manner toward the outside, and a tapered surface provided around the stepped portion; and a fitting shaft portion that can be fitted to the shaft portion of the disk portion. and a bolt that is screwed into the screw hole to fix the hollow shaft member to the disc part in a state where the fitting shaft part is fitted to the shaft part of the disc part. death,
The bolt has a seat surface corresponding to the tapered surface,
A turbine rotor comprising a hole extending from the head of the bolt in the axial direction thereof, facing outward from the axial direction, and communicating with the radial hole of the hollow shaft part. Mounting structure.