The usage of direct drive fan motors is increasing. One concern about using the direct drive solution is the weight difference between this type of motor and the gearbox it replaces. The motors are located in the center of the fan hub where there is typically only a nominal amount of air movement. More air flow over the motor frame results in better heat dissipation and smaller, lighter motors. This paper investigates the effect of air flow on size and weight of direct drive motors of various diameters. A simple method to direct more air flow over the motor is presented.
11-01: Effect Of Air Flow On Size And Weight Of Direct Drive Permanent Magnet
Robbie McElveen and Bill Martin, Baldor Electric Co.