Fig. 240.
The high speed of the motor is reduced by two belt pulleys and two chain wheels. These pumps may be worked independently to produce pressure or vacuum as desired by a separate pipe for each pump.
MOTOR AND CENTRIFUGAL PUMP.
[Fig. 241] is intended to show the application of the electric motor to a centrifugal pump; these two machines are mounted on one bed plate, directly connected by a flange coupling between them. The motor shown, is almost identical with the machine illustrated, [Fig. 217], and described on [page 251]. The pump is so arranged that the discharge can be turned in any direction desired. Wherever electric power is available and the centrifugal pump is the form best adapted to the work, this combination presents advantages over a steam engine operated by a plain slide valve such as is generally used.
Fig. 241.
DIRECT DRIVEN MOTOR PUMP.
[Fig. 242] shows a double pump driven directly, without gears or belt, from the shaft of an electric motor. The pump crossheads are connected directly to cranks at each end of the motor shaft. The cranks are set at right angles and each pump is double acting, or has two plungers connected by outside rods and with outside packed stuffing-boxes, so that this portion of the pump is always accessible.