All About Engines

IÖ2 All About Engines Fig. 93 on Plate io, and a complete wheel in Fig. 94, Plate 11. Just as the high velocity of the steam when it enters the turbine rendered three nozzles sufficient for admitting it to the velocity wheel, so in the case of the earlier wheels steam is not admitted all round the diaphragm. Fig. 95 on Plate 11 shows the diaphragms used for ad- mi t t i n g steam to the earlier single-bladed wheels, and Fig. 96, Plate 11, shows the diaphragm used in the later stages. Now let us glance at the govern- ing arrange- Fig. 98.—Outside view showing governor ment. Fig. 97 shows a section through the governor end of the turbine, and Fig. 98 an outside view. A worm on the turbine shaft drives a toothed or worm wheel on the governor spindle, which is horizontal, and any change in speed affects the governor valve and varies the opening to steam. There is also an emergency, or overspeed safety device, which operates if the ordinary governor should fail to act, and shuts off steam if the speed becomes dangerously high. This is shown in Fig. 99. It will be seen that a