Propulsion systems for the deep sea and outer space

The right drive technology is not an off-the-shelf product. Applications involving small drives, in particular, often require customized solutions. Flexible solutions can be developed by drawing upon extensive standard product ranges comprising motors, precision gearheads, linear actuators, encoders, controllers, and various accessories. However, for particularly demanding applications, standard offerings—even those involving modified standard components—are typically insufficient. Solutions designed for challenging operating conditions—such as those found in the deep sea or in outer space—specifically call for custom-engineered drive solutions developed through a collaborative co-engineering process.

Ultra Motion, a U.S. specialist in electromechanical servo systems, designs actuators specifically for use in harsh environments. Their solutions are particularly well-suited for conditions involving high shock and vibration loads, exposure to fluids, saltwater immersion, and electromagnetic interference (EMI/EMC). These specialists—renowned for their highly integrated electromechanical actuator systems featuring embedded control and position feedback—have developed several of their systems in collaboration with Faulhaber, an expert in small drive technology. A common thread running through all these solutions is the requirement for actuators that combine the utmost reliability with maximum power density.

Customized motors as the core component

Ultra Motion’s product portfolio includes, among others, the L-Series and T-Series. The L-Series offers high-precision linear positioning with maximum control stiffness and optional system redundancy; it is ideally suited for safety-critical, precision linear motion applications—such as flight control systems. The T-Series, conversely, provides reliable rotary motion under extreme mechanical or marine conditions. In both cases, brushless DC motors from Faulhaber’s BP4 family (see sidebar)—distinguished by their high power density—work in conjunction with precision planetary gearheads to deliver high torque within compact housing footprints. The result is a range of drive systems that impress with their exceptional dynamics and reliability, even under extreme conditions.

Engineering for extremes: deep-sea Pressure and vacuum

The T-series is also available in the T3U variant, which is specifically designed for deep-sea applications. A specially developed output shaft ensures increased torque capacity, while a vented, oil-filled configuration enables pressure-compensated operation down to depths of 6,000 meters. For the L-series, conversely, Faulhaber has implemented vacuum-optimized modifications to ensure reliable functionality in space environments.

Integrating these features into the actuators' specialized configurations requires a precise balance between high torque, dynamic performance, and long-term reliability. Environmental conditions in the deep sea or in space pose enormous challenges—harsh ambient factors such as saltwater, high pressures, extreme temperature fluctuations, or vacuum conditions (where the evaporation of lubricants must be prevented). These challenges can only be overcome through customized mechanical and material-specific adaptations. Thanks to the close development collaboration between Ultra Motion and Faulhaber, it was possible to clear these hurdles and deliver drive systems that perform without compromise, even in the most demanding scenarios. Both examples demonstrate how effectively products can be developed—in collaboration with drive technology experts—to meet specific requirements, and how customized solutions can significantly enhance the performance capabilities of Ultra Motion actuators.

Brushless DC servo motors: 4-Pole technology

The 4-pole brushless DC servo motors of the BP4 series stand out thanks to their exceptionally high torque—a feat achieved despite their compact form factor (available in 22 mm and 32 mm diameters) and low weight. At the heart of these motors lies a novel, innovative winding technology that not only enables a very high copper content in the stator but also features a high degree of electrical and geometric winding symmetry. This results in low losses and very high efficiency. The BP4 series is overload-capable and is suitable for applications requiring maximum power output—while minimizing overall weight and installation space—as well as for dynamic start-stop operation.