Product Description:

The VAC2-D22-B spindle drive is manufactured by Okuma and belongs to the VAC Spindle Drives series. It regulates high-speed machine-tool spindles, converting three-phase input power into controlled output that matches motor torque and speed with cutting demands. By combining power switching, protection hardware, and internal cooling, the unit forms the link between the CNC controller and the spindle motor in automated machining centers. It also manages diagnostic signals through dedicated control boards, enabling rapid fault detection during production.

Inside the chassis, power conversion is handled by 100 A/800 V diode stacks that rectify the incoming bus and by 6 transistor modules that create the variable-frequency output waveform. Current sharing across the power stage is assisted by 3 diode modules arranged in parallel paths. Thermal loads are removed by 2 cooling fans, and their airflow is routed over heat sinks attached to the semiconductor packages. Surge protection for logic circuits is provided by a 1 A base fuse that isolates the control supply if an internal short occurs. Motor conductors enter the unit through an M8 motor terminal clamp, giving a secure high-current connection without cable lugs.

System-level protection continues on the supply side, where five 5 A main fuses protect the three-phase line that feeds the converter. Separate status outputs are protected by a 3.2 A warning fuse, while low-level auxiliaries are backed by 0.5 A auxiliary fuses to reduce nuisance trips in peripheral circuits. Two control boards handle gating signals and diagnostic feedback, and both receive power through the shared M4 fan cable terminal alongside the M8 supply connection. This arrangement keeps faults isolated to the affected branch and supports orderly shutdown of related circuits.