Method of and means for maintaining vacua or partial vacua

摘要

176,558. Shishkoff, P. Dec. 23, 1920. Machinery, vacuum. casings for reducing resistance in.-In means for maintaining a vacuum in the casing of geared machinery packing is provided for each of the geared shafts and so arranged that the difference in pressure of opposite sides of the packing diminishes with the increase in speed of the different shafts. In the driving gear for a dynamo shown in Fig. 2, the armature 22 is located in an airtight casing 23, the shaft 2, carrying a fly-wheel 21. being mounted in bearings 10, 11 provided with light packing washers 10. The shaft 2 is driven by gearings 3, 4, from a relatively slow-running shaft 1 mounted in bearings 8, 9, containing heavy packing 14. The casings 5, 7, and optionally also the casing 23, are exhausted by a belt driven air Dump 25. by way of a pipe 29 and cocks 32, 33. In the application to a turbine, the motor takes the place of the fly-wheel 21 and the gearing is located at the low pressure end, whereby the speed of the shaft 1 is reduced as required.