Fig. 506.
Fig. 507.—See page [241].
Turbine pumps of excellent design (Fig. [507]) of high efficiency are built by the Byron Jackson Machine Works of San Francisco, California. The operating elements of these pumps are rotating impellers containing spirally-curved water passages, and fixed guide passage between successive impellers. The water enters the passages of each impeller at the center and by the rotation is forced out into a collecting chamber surrounding the periphery of the impeller. The ducts which lead the water from there back to the center of the next impeller are suitably curved to act as guide passages, similar in action to the guide buckets of a turbine. The water then enters the next impeller parallel with the shaft, its rotary motion having been transformed by the guide passages into rectilinear motion.
Fig. [509], a drawing of a vertical pump in section, shows the relative arrangement of impellers (marked A) and guide passages (B). This pump has the suction entrance at the top; the discharge leaves the collecting chamber of the last (lowest) impeller tangent to the circle. The shaft rests in a thrust bearing at the top, and is further held by bearings formed in the successive sections of the case. At the bottom it is provided with a special balancing arrangement, described here after.
