Product Description:

The KDA 2.1-100-3-APS-U1 spindle drive is manufactured by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. As a closed-loop power module, it regulates the torque and speed of high-speed machine tool spindles so that machining, drilling, or grinding processes can maintain commanded surface speeds and cutting forces. The unit integrates with Indramat drive controllers and CNC systems, providing the controlled three-phase output required to run synchronous or induction spindle motors in automated production cells.

This version of the drive is specified for a continuous output of 100 A, allowing it to energize medium-power spindles without current derating. Internal power circuits are supplied from a common DC bus at 300 VDC, so bus regulators or regenerative supplies in the cabinet must match that level. Thermal management is handled by a heat sink that operates under forced cooling; airflow is produced by a blower fed from a separate 115 V 50–60 Hz source, keeping semiconductor junctions within safe limits during extended duty cycles. For position-synchronized applications, the drive offers a second encoder input that accepts resolver or incremental signals to monitor spindle orientation or close an additional motor feedback loop.

The remaining operating limits focus on installation conditions and communication. The drive remains within rated accuracy between 5 to 45 °C, and no output derating is required up to 1000 m elevation, which suits most factory floors. Parameter download and diagnostic commands are sent through an integrated RS-232-C interface, allowing simple connection to a PC or controller. Speed references are delivered as an analog speed command, enabling uncomplicated interfacing with legacy motion controls or voltage-output CNC channels without additional fieldbus hardware.