Product Description:

Bosch Rexroth Indramat produces the KDA 3.3-050-3-AP0-U1 spindle drive. The unit belongs to the KDA Spindle Drives series and supplies controlled three-phase power to high-speed machine-tool spindles. In an automation cell, it works as the intermediary between the central CNC controller and the motor. It translates velocity commands into regulated current so that the spindle accelerates, brakes, and holds speed with the required accuracy. This control structure is suited to spindle axes that must respond quickly to changing load and commanded speed.

Internally, the drive is fed from a direct-current bus at 300 VDC, and its power stage can deliver a continuous output of 50 A to the connected spindle motor. Thermal control is handled by a heat sink-mounted blower that draws ambient air across the power semiconductors, and this fan is energized from a 115 V/50–60 Hz auxiliary line. The unit uses forced cooling, which helps maintain component temperature without increasing the drive footprint. When precise rotor position is required, the integrated second-encoder input can accept spindle feedback or additional motor feedback so that phase alignment and orientation are retained during tapping or rigid threading cycles. No additional interface option is included, which keeps wiring simple and leaves front-panel space for essential fieldbus or diagnostic connectors.

The drive operates within an ambient range of 5 to 45 °C, which suits typical factory cabinet conditions. Reliable performance is specified up to 1000 m above sea level, allowing installation in most industrial regions without derating. Speed reference signals arrive as an analog voltage or current signal. This allows the unit to connect to legacy CNC control cards that supply proportional outputs instead of digital speed commands. The unit belongs to Series 3, indicating the third product generation within the KDA spindle drive line.