GB190803972A - Improvements in Steam Turbines. - Google Patents

Abstract

3972. Holly, S. T. Feb. 21, 1907, [date applied for under Section 91 of Patents &c. Act, 1907]. Elastic-fluid turbines. - A duplex turbine comprising impact buckets and axial-flow and radial-flow blading is constructed as shown in Fig. 2. The nozzles are controlled by a ring valve, Fig. 3. The rotor on the shaft 2 is built up of two dished plates 40, two side plates 16 carrying the running blades 14 of the radial-flow sections, and peripheral rings 42, 43 carrying the running blades 12 of the axial-flow sections. The impact buckets 10 are formed in a ring 41, and are provided with rearwardly - directed lateral outlets 11 formed in extensions of the plates 40. Bracing-pieces 49 may be fixed between the plates 40. The casing is built up of a central ring 20, side rings 21, and disks 25 secured between radial arms 23, 27. A bearing for the shaft 2 is provided in a part 24. A steam-supply trunk 5 is secured to the ring 20, and ports 6 connect it with the valve-chest 7. The valve-chest is bounded by rings 31 depending from the ring 20, and a ring 8 containing the nozzles 9. The nozzles may have liners 53. The stator blades 13 of the axial-flow sections are' carried by rings 33, 34, 36 secured to the rings 31, and the stator blades 15 of the radial-flow sections are carried by rings 37 secured to the rings 36. The rotor and stator parts may be taken down from either side. The nozzles 9 are controlled by sliding shoes 55, which have lugs 60 making loose fits in recesses in blocks 57. These blocks are connected by two circular bands 56. One or more of the blocks is provided with a rack adapted to be moved from the outside by gearing 63, 65. Rollers 59 may be fitted to prevent binding. The valve shoes 55 on the underside of the turbine may be held to their seats by springs 62. To allow for the decreasing velocity of the stream, the angle of inclination of the running blades to the direction of rotation decreases progressively in the axial-flow and radial-flow sections. The rotor blades 12, 14 are flat, and the stator blades are at right-angles to them and somewhat curved, as shown in Figs. 5 and 6. The blades 14, 15 may be formed on rings 50 which are screwed to the plates 16, 37. The blades 14 may be attached to the rings 50 by brazing the ends in place in suitable slots. The outer ends of the longer blades may have shrouding rings 70.