Danaher Motion developed a custom actuator that would be used for the azimuth and elevation axes in a new family of remote weapon stations. Commercial Off The Shelf products were combined with custom engineering solutions to reduce cost and product development time. Danaher Motion developed a low profile, lightweight, environmentally sealed, rugged and efficient actuator assembly. Since the weapon system is mounted on top of an armored vehicle, the actuator is exposed to the same environments as the exterior of the vehicle. The low profile was driven by the requirement to keep the weapon station as low as possible, both for vehicle clearance and to lower the center of gravity.

A lightweight system also helps to maintain the weight limit on the vehicle roof. To meet these requirements the actuator housing required extensive customization. The complete system was delivered to the first customer on time for live fire trials and complete evaluation. The weapon system testing was successful and a production order has since been awarded for over 200 systems.

Customer Challenge
Delco Systems designers began investigating an electromechanical (EM) conversion of the LAV-25 hydraulic turret drive in the early 1990's. The original turret system used a hydraulically-driven actuator and conventional ring or "bull" gear, along with the usual hydraulic accumulator, motor pump system and associated plumbing. Advances in magnetic material technology, digital electronics, and drive systems now made an EM solution feasible.

As a state-of-the-art upgrade, the electromechanical servo offers:

a significantly smaller system volume
elimination of hydraulic plumbing and accumulators
greater system safety
lower maintenance
higher Mean Time Between Failure (MTBF)
lower Mean time to Repair (MTR)
drastically lower levels of audible noise.

Kollmorgen Solution
Working closely with Delco engineers, the Kollmorgen system was designed to use the original bull gear, in combination with a new low cost brushless DC motor/gearhead, for both turret axes. This new drive system was particularly cost effective since it was derived from an existing motor and electronics design. The Commercial Off The Shelf (COTS) concept of using ruggedized and militarized "commercial type" hardware offered advantages to Delco and the end customer. Kollmorgen developed and integrated the drive electronics and COTS motor, enabling a matched system approach.

The End Result
The EM conversion of the Delco turret system is already a proven performer. Affordable, efficient, reliable, and quiet, the motor/drive system offers an integrated approach resulting in easier testing, maintenance, and logistics.

Direct drive Brushless Motors for Remote Weapon Station Pedestal Applications.

Kollmorgen has leveraged Commercially Available Off the Shelf (COTS) frameless brushless motor technology to provide precise azimuth and elevation motion control for Weapons Director applications.

Frameless brushless DC motors are often utilized for these applications, providing direct drive acceleration and minimizing need for gearing mechanisms.

Current applications include shipboard Fire Control Systems, and shipboard Protection Systems. Land based applications comprise remotely controlled weapon directors, automated protection suites.

Customer Challenge
The Phalanx CIWS is final line of shipboard defense against incoming threats such as enemy aircraft or missiles. The system uses a 20mm gun assembly which, operating in a closed loop spotting mode, can search for, detect, acquire, track, fire and sequentially destroy multiple incoming targets.

Permanet magnet motors are used in many of the motion servo loops such as gun azimuth and elevation, search and scan radar and tracking radar. Each application requires high performance, high reliability motor solutions.

Kollmorgen Solution
The use of rare-earth permanent magnet motors was a solution to the initial problem of motor demagnetization resulting from overdriving alnico (aluminum-nickel-cobalt) magnet motors.

Kollmorgen provided rare-earth samarium-cobalt magnet designs initially and, later, neodymium-iron-boron designs capable of being driven beyond their standard ratings without resulting in demagnetization.

The End Result
The Phalanx CIWS has been a highly successful defensive weapon system for the Navy since the early '80's. The use of rare-earth magnet motors has improved system reliability as well as system performance.

Kollmorgen provides housed, permanent magnet DC motor/tach/brake assemblies for the gun azimuth and elevation as well as frameless DC torque motors for the search/scan and track radar applications.

Some images courtesy of U.S. Department of Defense.