Product Description:

The VAC3-D11 spindle drive is manufactured by Okuma as part of the VAC Spindle Drives series. It serves as the inverter stage for machine-tool spindles, converting the controller’s pulse commands into the variable-voltage output needed to spin cutting heads during automated machining. By integrating power semiconductors, protective hardware, and feedback processing into one chassis, the unit simplifies installation inside CNC cabinets and provides the closed-loop torque regulation required in precision production lines. This arrangement also lets the spindle respond smoothly to changing speed and load demands during machining cycles.

It receives Optical Pulses from the numerical controller through fiber links, giving noise-immune command resolution. The power section is built around IGBT + Hybrid IC devices; within this stage, 6 IGBT modules switch the DC bus that is smoothed by one capacitor and one choke coil. A single diode clamps reverse currents. Two spindle power ranges, 11/7.5 kW and 15/11 kW, let the same chassis drive medium or heavy loads. Twin fuses rated at 5.0 A and 0.5 A protect auxiliary supplies. A single magnet switch provides safe disconnection during faults, while one heat-sink fan moves air across the modules to control temperature. That combination supports stable power conversion while limiting stress on the switching stage during rapid spindle acceleration and deceleration.

Closed-loop operation is achieved with feedback from Resolver + Pulse Generator devices, whose differential signals enter at the CN2 port for precise rotor position and speed tracking. Diagnostic data reach the operator through 13 numbered status LEDs that flag individual alarm groups, 3 operation LEDs that indicate run, standby, or fault states, and 2 seven-segment displays that show hexadecimal error codes. Separate visual indicators make it easier to distinguish operating status from alarm conditions during normal use. The fixed D11 interface consolidates service wiring on the XB-CHG, XB-EPG, and XB-RES connectors, reducing setup time. With only one capacitor, one choke coil, and a single heat-sink fan, the design keeps component count low without compromising filtering or thermal stability.