OKUMA Servo Drive

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AC Axis Servo Drive – OKUMA VAC-D-8A

The VAC-D-8A (internal code VACD8A) is an AC axis servo drive manufactured by OKUMA, a Japanese builder of CNC machine tools and proprietary CNC control systems. The unit belongs to the VAC-D series of AC servo drives integrated in the control cabinets of OKUMA machines equipped with the OSP (Open System Platform) CNC controller. The “8A” designation indicates the drive’s rated output current, typically 8 A continuous. The device receives position and speed references from the CNC and drives the corresponding axis servo motor by closing the regulation loops.

The servo drive is the core of an axis drive circuit: it converts the CNC’s digital commands into power signals for the servo motor, simultaneously managing the position, speed, and current control loops. A failure of the VAC-D-8A results in the complete loss of the controlled axis, an immediate machine halt, and a drive alarm; prompt replacement or repair is essential to restore production.

OKUMA is a Japanese company founded in 1898, one of the world’s leading manufacturers of CNC lathes, machining centres, and closed-loop CNC control systems. Unlike many competitors, OKUMA designs and manufactures both the machines and the CNC control (OSP) in-house, ensuring unique vertical integration in the industry. Products in the VAC-D series are legacy / discontinued and available exclusively as used, surplus, or through specialist repair.

Main Technical Specifications