Compact underwater DC drives

Electrical actuated underwater vehicles like remote operated vehicles (ROVs) and autonomous unmanned vehicles (AUVs) require drives which are lightweight, efficient and compact. maxon's new underwater thrusters and actuators are oil filled and range in size from 16- to 42-millimetre diameter. The core element is a motor-gear combination based on a brushless DC-motor and a planetary gearhead. These underwater drives are designed with a high quality polymer housing to ensure protection against the harsh underwater elements. maxon’s MT-30 thruster is pressure tolerant up to 6,000 metres with oil compensation. The propeller is modified for low noise operation. Other features include: output power of 180W, Voltage of 48 and weighs slightly under 2 lbs. Using maxon motors slimline 48V brushless DC motors the thruster can achieve 10kg continual bollard thrust from a diameter of only 30mm. The small diameter helps to reduce water disturbance over the thruster body to maximise efficiency. Two power levels, 120W and 180W are available from the oil filled 22mm motor and 22mm planetary gearhead and the complete thruster has a mass of only 750g. The propeller has a diameter of 70mm contained in a fluted shroud of 82mm. Pressure compensated the units have a depth rating of 6km and the housing comes standard with a Subconn MCBH8M connector. Beside the connector there are x2 4mm diameter fittings, one for oil filling and one for compensator connection. It is possible for maxon motor to modify the thruster assembly to customer specific requirements and there are also modified maxon control units available for use in water.