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Power Transmission: Submersible remote operated vehicle |
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Rudder and diving plane actuators for submersible remote operated vehicle
 Nova Marine Exploration, Inc., as a result of its extensive experience in commercial underwater exploration and recovery saw the need to improve the economic and, more importantly, the operating characteristics of existing submersible ROV (remotely operated vehicle) technologies.
Nova Ray, Inc. (a subsidiary of Nova Marine Exploration, Inc. ñ novaray.com), was founded to develop and market a submersible ROV that could:
? Operate in high current conditions (up to 10 mph) such asthose found in ports, harbors, rivers and inlets.
? Operate as a towed vehicle or operated using its own onboard thrusters.
? Be able to operate in depths to 500 ft.
? Operate in remote areas such as rivers and lakes.
? Be easily transported and affordable.
? Be easily adaptable to various conditions and assignments.
? Be rapidly deployed.
? Be equipped with TV monitor and be able to include sonar.
? Have remotely controlled robotic capabilities.
? Be controlled via digital operating system using a joystick, laptop computer or autopilot.
The Nova Ray submersible ROV was the answer. The ROV achieves its stability from its Arcuate wing and is controlled by flaps and a rudder actuated by Ultra Motion, LLC ìInner Spaceî linear actuators (ultramotion.com).
 The actuator was selected because it can withstand pressures of extreme depths and is compact, responsive, highly reliable, and cost effective. The body and the bellows of the linear actuators are oiled filled, which keeps internal and external pressures equalized and water out of the actuator.
The linear actuators are capable of operating at the very deepest part of the worldís oceans. Developed for use on unmanned submersible vehicles such as the Nova Ray ROV, the compact, lightweight, in-line actuators provide up to 100 lb of force and can be mounted outside of the submersible, eliminating the need for complicated linkage and concerns about seals. Units are available in 1, 2 and 4 in. stroke lengths, and move at up to 16 ips. The oil filled design allows for external and internal pressures to be continuously equalized. The linear actuators are suitable for use in controlling diving planes, rudders, camera and light positioning, and operating robotic arms for collecting samples and performing other underwater tasks such as welding.
Ball and Acme drive screws directly coupled to NEMA 17 sized, 2-phase stepper motor provide the user with the ability to specify a precision linear actuator specifically for their application. Motor/screw combinations include zero backlash, as well as combinations that cannot be back-driven. The linear actuator with a NEMA 17 stepper is 1.72 in. square x 2.30 in. long at the motor end with a 1.30 in. diameter housing tube. Totally sealed, these actuators are available in a variety of stroke lengths and drive screw combinations. Mounting is by stainless steel in-line rod bearing clevises. The only materials exposed to the water are stainless steel, rubber and plastic.
 The overall length is 9.0 in. longer than the stroke length. Home position sensing can be accomplished with externally adjustable reed switches. The actuators are also supplied with a sealed underwater electrical cable and connector. The operating temperature range is -29° to 49°C. Optionally, absolute (not incremental) analog position feedback can be provided.
The actuators are available with matching controllers and drivers for full, half step and micro-stepping operation. The nonmagnetic, stainless steel actuator shaft is also sealed so that no seawater can enter or exit the housing and it can be washed down.
The ìInner Spaceî linear actuators are used on the rudder and diving planes of the NovaRay ROV. The ROV is equipped with dual quartz lights and a high resolution TV camera with adjustable tilt. Forward and side scan sonar are available options. The ROV can also be fitted with robotic arms.
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