Underwater and Subsea Actuators

Subsea actuators play a crucial role in a wide range of underwater and subsea operations. These devices are designed to provide precise control over movement, positioning, and force in demanding marine environments. Subsea actuators are integral to applications such as remotely operated vehicles (ROVs), subsea production systems, and underwater robotics, where reliable and efficient motion is essential.

Subsea environments present unique challenges, including high pressures, low temperatures, and corrosion from saltwater exposure. To meet these demands, subsea actuators are built using advanced materials and technologies that ensure long-term performance and durability. This page provides an overview of the different types of subsea actuators and the technologies that enable their functionality in these challenging environments.

Types of Subsea Actuators

There are several types of actuators used in subsea applications, each serving specific functions based on the requirements of the operation. These include waterproof linear actuators, rotary actuators, and other specialized designs that utilize components such as stepper motors and brushless DC motors to deliver precise movements.

Linear Actuators

U-Series underwater and subsea actuators by Ultra Motion

Marine linear actuator technology is widely used in subsea applications where linear motion is required. These actuators convert rotational motion into straight-line movement, allowing them to control the position of valves, clamps, and other components in subsea systems.

For applications that require robust force and high precision, oil-filled designs are often implemented to ensure reliable performance under extreme pressure conditions. An underwater linear actuator is integral to underwater systems that demand exact positioning and motion control.

Advanced Linear Actuator Solutions for Subsea Applications
Electric linear actuators and waterproof linear actuators are essential for precise movement in underwater systems. These actuators often come with specialized features like pressure compensated designs and submersible capabilities to ensure durability. 

AU Series subsea linear actuators by Ultra Motion

In high-demand subsea environments, the integration of servo linear actuators and stepper motor controllers provides both precision and power. For systems requiring absolute positioning, linear actuator controllers and contactless absolute position feedback are critical for maintaining control and accuracy. The use of these advanced technologies makes linear actuators a reliable choice in subsea valve and clamp control.

Rotary Actuators

Rotary actuators are used when rotational motion is necessary. These actuators are common in subsea production systems, where they control the rotation of valves, hatches, and robotic arms. Subsea rotary actuators can be powered by various technologies, such as by a stepper motor or brushless DC motor, both of which offer smooth and precise rotation. 

The use of rotary actuators in underwater applications ensures accurate and repeatable motion control, making them essential for operations in marine environments.

T3U subsea rotary actuator by Ultra Motion

Subsea Valves and Actuation

Subsea valve actuators are employed in oil and gas production, underwater robotics, and other marine operations. These actuators must be capable of precise control, often utilizing servo actuators or linear servo actuators to achieve the desired motion. 

Pressure compensated designs and electric actuators ensure reliable performance in extreme underwater conditions. Subsea valves, paired with subsea electric actuators, contribute to the safe and efficient management of subsea production systems.

Motor Technologies in Subsea Actuators

Subsea actuators often rely on different motor technologies to achieve their performance goals. Two of the most common types of motors used in subsea applications are stepper motors and brushless DC motors.

Stepper Motors

Stepper motors are known for their ability to provide precise and controlled movement in discrete steps. This makes them ideal for applications where exact positioning is required, such as in ROVs or subsea manipulators. The advantage of stepper motors in subsea actuators lies in their reliability and ability to operate without the need for complex feedback systems.

Brushless DC Motors

Brushless DC motors are another widely used motor type in subsea applications. These motors offer higher efficiency and greater reliability compared to their brushed counterparts. 

By eliminating brushes, brushless DC motors reduce the risk of mechanical wear, which is crucial in subsea environments where maintenance can be difficult. These motors can be found in both rotary actuators and submersible linear actuators, where long-lasting performance and low maintenance are priorities.

Servo & BLDC Motors in Subsea Systems

Subsea applications frequently use BLDC motors and servo motors for their high efficiency and precision. Servo actuators, including both rotary servo and linear servo types, deliver precise control for demanding underwater tasks. 

BLDC controllers optimize performance by maintaining efficiency, while dc brushless motor systems provide durability in high-pressure environments. These technologies are indispensable for subsea robotics, where servo linear actuators and brushless motors enhance movement precision and reliability, even under harsh marine conditions.

Specialized Features for Subsea Applications

Subsea actuators often incorporate additional features to enhance their performance in underwater environments. One of the critical requirements for these devices is absolute position feedback, which allows operators to know the exact position of the actuator at all times. This capability is essential for subsea systems that require real-time monitoring and control of actuator movements.

Another important feature is the use of oil-filled housings. By filling the actuator housing with oil, these devices are better able to withstand the intense pressure found at subsea depths. The oil also provides a level of protection against corrosion and helps maintain consistent actuator performance over time.

Controllers & Feedback in Subsea Applications

Control systems such as a stepper motor controller or a linear actuator controller are integral for managing the movements of subsea actuators. These controllers provide the precision required in underwater systems. 

A BLDC motor controller can be used to optimize the performance of brushless motors in subsea applications. Additionally, contactless absolute position feedback systems enable real-time monitoring of actuator positions, a critical feature for maintaining control in deep-sea environments.

Marine Actuators in Subsea Robotics

Marine actuators are commonly found in subsea robotic systems, where they play a vital role in controlling movement and force. These actuators are designed to be compact yet powerful, allowing them to fit into tight spaces while still delivering the necessary torque or linear force. In ROVs and other underwater vehicles, marine actuators are responsible for manipulating robotic arms, adjusting buoyancy systems, and operating grippers.

By using subsea actuators with advanced motor technologies and specialized features, subsea robotic systems can perform complex tasks in hostile marine environments. These actuators contribute to the efficiency and effectiveness of subsea operations, allowing for remote intervention and control in areas that are difficult or impossible to access by human divers.