JPS5970802A - Turbine rotor - Google Patents

Abstract

PURPOSE:To prevent cracks generated at a key seat by stress corrosion and thereby have sure torque transmission by embodying coupling of a turbine rotor through a torque ring, which is arranged adjacent to a wheel and transmits the torque to the shaft. CONSTITUTION:Torque from a wheel 3 is transmitted to the shaft 1 by the frictional force owing to hot fitting. If the wheel is heated more quickly than the shaft and it has brought about looseness, the transmission is made to a torque ring bore key 13 through a torque ring key 10, which is arranged as in a single piece with a torque ring 8, and then over to the shaft. The centrifugal force with this torque ring is small because of its small outside diameter and weight and the suface pressure owing to hot fitting is also small, so that the stress in the tangential direction at the inner surface will become small to lead to low stress concentration, which is likely to arise at the torque ring bore key 11. Thereby the key seat is free from fear of generation of cracks owing to stress corrosion. Thus the number of parts used can be suppressed as well as problems around the key seat such as stress concentration solved.

Description

[Detailed description of the invention] 1 Kanmei's technique {・To I field] The present invention relates to turbines.

[Kanmei's Technique 1 {, I's Back 1 La 11 A3 is generally used for low-pressure rotors of large steam turbines for power generation, etc.
In order to flow the steam, a large average diameter and thick blades are used.

In order to solve the manufacturing technology and economic problems of such a gigantic turbine rotor, the wheel into which the blades of each stage are implanted is made separately from the shaft, and then the wheel is heated and the coater shaft is heated. A so-called shrink-fit wheel is used to fit the shield.

FIG. 1 shows a steam turbine rotor having such a shrink-fitted wheel. This shirt 1-1 (with a moss and a blade 2 on the outer periphery) is fitted in the axial direction of Shi 1, No. There is.

Further, a locking key 5 is provided to control the movement of the wheel 3 in the axial direction.

And the turbine 1 'C' configured in this way is
1 energy of steam is converted into 1 ~ lux by the vane 2 and then transmitted to the wheel 3, and the transmission of 1 ~ lux from this wheel 3 to the shaft {-1 is due to the blood pressure of the small eel 3 as it shrinks. This is caused by frictional force and wheel bore key 4.

In other words, in a stage near the fish air inlet side where the pressure is relatively high and the temperature is relatively high, depending on the operating conditions, the heat pump heats up faster than the small wheel 3 or the shaft 1, and the shaft heats up faster than the shaft 1. 1 and the wheel 3 may become loose due to a temperature difference between the wheels 3 and 1. If the wheel 3 becomes loose, a 1.1 torque will be transmitted to the wheel hose key 4 from the wheel hose 4. The shrink fit surface on the inner surface of the boiler 3 keeps the blood pressure constant with respect to the shaft 1 and also maintains uniform stress in the tangential direction of the inner surface.

Problems with Background Art] However, in the turbine rotor configured in this way, a wheel bore key 6 is disposed on the inner surface of the wheel 3 in order to prevent the boiler key 4 from fitting into the wheel bore key groove 6. As shown in FIG. 2, there is a risk that stress corrosion cracking 7 (SCC) may occur around the wheel bore keyway 6.
When the wheel 3 is exposed to an atmosphere of 150°C, the wheel 3 becomes a high stress field, and the stress I is applied to the wheel bore key W46.
There is a possibility that Ig eclipse 7 may occur.

[Object of the Invention] The present invention has been made to address such conventional circumstances, and
Stress corrosion pJ that occurs in the wheel bore keyway
It is an object of the present invention to provide a turbine 11 which is capable of eliminating the fear of damage and which is capable of reliably transmitting one torque between the boiler and the shaft.

[Summary of the Invention 1 That is, the present invention provides a pin rotor in which a wheel having blades is fitted in a single stage or in multiple stages along the axial direction of a shaft. The eel is a turbine unit characterized in that it is connected to a coupling means to a torque ring which is disposed adjacent to the boiler and transmits torque to the shaft.

[Embodiment 1 of the Invention] The details of the present invention will be explained below with reference to an example shown in the drawings.

FIG. 3 shows a turbine according to an embodiment of the present invention, and in the figure, reference numeral 1 indicates the shaft of the turbine rotor. Then, a plurality of boilers 3 having blades 2 implanted on the outer peripheral surface of the shaft 1 are fitted along the axial direction. The wheels 3 located on the upstream side of the C turbine L1 are respectively arranged adjacent to the wheels 3 and are connected to the coupling means to the 1-luke ring 8 which transmits 1-luke to the shafts 1 and 1. .

The wheel 3 disposed on the downstream side of the steam inlet of the "iJ3 turbine J" is formed with a wheel key 1146 similar to the conventional one, and a wheel bore key 4 is inserted into 1 and 6 of this boiler key. There is C.

Figures 4a3 and 5 are enlarged views of the wheels 3iJ3 and 1 to 8 in Figure 3.
C{'J No. 3 indicates a small yield. On the side of wheel 3, there is a wheel key with a circumference of 180'J>21 laps! j/j9 is under-formed -C. wheel 3
A cylindrical 1-wheel ring ε3 is arranged adjacent to the C-wheel ring ε3, into which the C-wheel ring 1 and 1 are fitted, and on the side of this 1-wheel ring 8, the above-mentioned wheel which is integrally molded with these 1-4 ring 8 is disposed. A ring key 10 is inserted into the wheel key groove 9 of No. 3.

The inner peripheral surface of the torque ring 8 has an angle of 18°.
Torque ring bore key grooves 11 are formed.

A keyway 12 is formed in the position of the shaft 17 corresponding to the torque ring bore key 11, and a space formed by this keyway 12 and the torque ring bore keyway 11 is formed. Herkling box j': l-113 is not inserted. d3Figure 1. C cylinder number 5 indicates logging key.

The turbine configured as described above]' 1-luke from the wheel 3 is applied during operation of the turbine [1-item]. The frictional force is transmitted to the shaft 1.

Ichinowo, a small il ＼ ir 3 or sill 1 1-
If the wheel 3 becomes loose due to heating faster than 1, the torque of the small heel 3 is transmitted to the 1-lu ring key 10 formed on the torque ring ε3 to 13 to the 1-lu ring key 13, and this 1-lu ring bore key 1
3 to the shaft 1.

However, since the torque ring 8 has a smaller outer diameter and weight than the wheel 3, the centrifugal force acting on it during operation is very small, and the torque ring 8 is easily burnt out. It is possible to reduce the surface pressure of the fit to J13'7R.

Therefore, the stress in the direction of the inner surface of the C, 1-look ring 8 is not 1
i becomes small, 1-Lukringboakee vortex 11
The stress concentration that occurs in this case is reduced, and there is no risk of stress corrosion cracking occurring in the ring bore keyway 11.

In the turbine rotor configured as above,
Since the 1-Rukling keys 10 are integrally processed with the 1-Rukling 8, there is no need to provide a keyway for the 1-Rukling key 10 in the Torque ring 8, which reduces the number of parts and solves problems such as stress concentration in the keyway. It is possible to solve the problem.

Note that the axial positioning of the wheel 3 with respect to the stationary blade is as follows:
This can be easily achieved by controlling the gap between the ring 8 and the wheel 3, for example, by adjusting the gap between the ring 8 and the wheel 3.

[Effects of the Invention] As described above, according to the turbine rotor of the present invention,
It is possible to completely eliminate the stress corrosion cracking that conventionally occurs in the keyway formed on the inner peripheral surface of wheels, and
Torque transmission between the wheel and the shaft 1- can be reliably performed.

[Brief explanation of drawings]

Figure 1 is a longitudinal sectional view showing a conventional turbine rotor, Figure 2 is a longitudinal sectional view showing stress corrosion cracking occurring in the key part, and Figure 3 is a longitudinal sectional view showing a conventional turbine rotor.
The figure is a vertical cross-sectional view showing a turbine 1-1 of an embodiment of the present invention, FIG. FIG. 4 is a perspective view of FIG. 4; 1......Shaf]~2...
...Blade 3...Wheel 8...Torque ring 9...
・・・・・・Boile keyway 10・・・・・・・・・
・・・Torque ring key 13・・・・・・・・・・・・
Torque ring bore key 8

Claims (1)

[Claims] (1) A turbine L1 consisting of nine single-stage or multi-stage wheels fitted in the axial direction of the shaft with blades to the right; the boiler is disposed adjacent to the wheel; The special feature is the part that is connected to the 1-luke ring by a connecting means, which transmits 1-luke to the sear A.71.
Turbine [''Ichiya.