Product Description:

The KDA 2.1-150-3-AQD-U1 is a spindle drive manufactured by Bosch Rexroth Indramat as part of the KDA Spindle Drives series. It is installed in CNC machining centers to energize and regulate motorized spindles so cutting tools can reach commanded speeds quickly and hold them with closed-loop accuracy. By accepting reference signals from the machine controller and converting a stabilized DC bus into three-phase output, the unit forms the electrical link between a central power supply and the mechanical spindle that removes material during milling, boring, or grinding.

The drive is powered from a DC bus rated at 300 VDC and can deliver a continuous motor phase current of 150 A, enabling high torque at low spindle speeds and rapid acceleration toward top speed. Thermal energy generated by this output is removed through a mounted heat sink blower; the blower itself runs from a separate 115 V 50–60 Hz source. Airflow is pulled across the fins of the heat sink, and the housing forms the cooling channel so heat is carried away from the power semiconductors in a controlled path. This arrangement uses forced cooling and eliminates the need for external cabinet fans.

The KDA 2.1 hardware is specified for ambient temperatures between 5 to 45 °C, which covers typical factory floor conditions without additional conditioning. Installation is permitted up to 1000 m above sea level before derating is required, which helps maintain reliable operation where air density is lower. Spindle velocity is commanded through an analog speed reference, while position fine-tuning can be fed to the additional interface that accepts a digital position command value. These signal options allow the drive to integrate with both classic analog CNC loops and newer motion controllers that transmit discrete positioning data.