High efficiency dc motor developed for demanding hydraulics applications

A high efficiency dc motor for operation in hostile conditions has been developed by Astrosyn International Technology. The permanent magnet motor is intended to drive a hydraulic power pack for positioning the plough on a minefield clearance vehicle.

Its intended location in a confined, hot environment and its high power output of 6.2 kW meant that the motor's heat dissipation was a key consideration in its design. It is therefore fitted with a metal cooling fan and a slotted body area over its brush gear. A thermal sensor and thermal cut-out are also incorporated.

Its high efficiency design, with low losses and a low input current, is also important in minimising heat output.

A hollow shaft enables the motor to be close coupled with the hydraulic pump. The motor uses rare-earth permanent magnets and low-loss lamination steel, with novel designs for its construction and windings.