This improved cooling method, along with the higher
efficiency achieved with the PM technology, allows for an
increased power density in this type of motor design.
This increased power density offers the opportunity to fit
a low-speed motor in the same space as the right-angle
gearbox in cooling tower applications and to keep the
weight at a reasonable level. For comparison, a study was
performed to determine the approximate sizes and
weights of various motor types for possible use in this
application. The results of this study are shown in
Table 2. The rating is 50 hp at 208 r/min. Each motor
was designed for the same temperature rise.