Direct Drive Pumps Explained

RD Pump Direct Drive Technology RD Pump Direct Drive Technology

A direct drive brushless DC design is categorized as an integral pump and motor assembly including driver electronics. Similar to a magnet drive design there is no direct connection between the motor shaft and the driven element. However the pump does not employ an external drive magnet mounted to a motor shaft to transmit the motor torque to the internal driven magnet assembly. Instead, the torque is transmitted directly by a brushless DC motor (BLDC).

The inner rotating magnet assembly is positioned as the rotor of a motor. The motor windings are wound around the rear housing. The inner rotating magnet assembly is driven by the rotating magnetic field of the BLDC motor. Commutation is performed electronically using sensors to detect the position of the inner rotating element. The sensor inputs are used by the driver circuit to energize the motor windings. The induced magnetic field drives the inner magnet assembly. This design eliminates the need for a separate motor armature, motor bearings, drive magnet mounted to the motor shaft, and shaft seals. As with magnet drive designs, the direct drive seal-less structure also eliminates leaks and problems involving seal replacement. The resulting package is compact, efficient and provides for a longer service life.