Underwater Force Control of a Submersible Geared Electric Motor without Waterproof Seals

Abstract

This paper proposes a submersible geared electric motor without any waterproof seal made of elastic materials such as O-rings or V-rings. The gears and bearings are replaced with polymeric materials and ceramics, and the motor coil and magnetic sensor are treated to prevent them from being exposed to water. Since the gear is made of materials with low friction and no waterproof seal that disturb the movement, our gear motor is backdrivable even under the water. Therefore, it is expected to the underwater force control without using force/torque sensors.