. The Street railway journal . lades. The tips of theblades are substantially bound together and protected by meansof a channel-shaped shroud ring (B, Fig. 4), in which are holespunched to receive the projections on the tips of the blades. CYLINDER 1 H1 1 a v/////// 3 — ■■ \ 1 C n m - :»*»■■■:■:• J f • — ii a y \ lc) 1 SPINDLE _l FIG. 4.—STEAM TURBINE BLADING Accurately spaced by a special machine, these holes match theslots in the foundation ring. The foundation rings themselves are of dovetail shape incross section, and, after receiving the roots of the blades, areinserted in dovetailed groo
. The Street railway journal . lades. The tips of theblades are substantially bound together and protected by meansof a channel-shaped shroud ring (B, Fig. 4), in which are holespunched to receive the projections on the tips of the blades. CYLINDER 1 H1 1 a v/////// 3 — ■■ \ 1 C n m - :»*»■■■:■:• J f • — ii a y \ lc) 1 SPINDLE _l FIG. 4.—STEAM TURBINE BLADING Accurately spaced by a special machine, these holes match theslots in the foundation ring. The foundation rings themselves are of dovetail shape incross section, and, after receiving the roots of the blades, areinserted in dovetailed grooves in the cylinder and rotor, wherethey are firmly held in place by key pieces. (C, Fig. 4.) Eachkey piece, when driven in place, is upset into an undercut groove(D, Fig. 4), thereby locking the whole structure together. After being inserted in the turbine, as above described, eachblade is so firmly held between the bottom of the slot in thefoundation ring and the side of the groove, owing to the dove-. ROTOR AND HALF-CYLINDER, SHOWING BLADING AND BALANCE-PISTONS between the smallest blades, and often as much as inchbetween the largest blades, thereby allowing ample room fordifference in expansion of rotor and cylinder. Necessity for small radial clearance soon demonstrated theadvisability of protecting the tips of the blades to prevent themfrom being knocked out through accidental contact with cylinderor rotor. Many interesting patents, in fact, endeavoring toaccomplish this, have been taken out by manufacturers of thistype of turbine. The one that experience has proved both prac-tical and effective is seen in the blading construction in Fig. 3and more in detail in Figs. 4 and 5. In this construction theblades are cut from drawn stock and each blade is formed byspecial machine tools so that at its root it is of angular dovetailshape, while at its tip there is a projection. To hold the roots tailed shape of its root, that it is impossible for a bla
Size: 2874px × 869px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
