Product Description:

The KDA 2.1-100-3-AP0-U1-115 spindle drive is built by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. Intended to control three-phase induction or synchronous spindle motors, the unit supplies regulated DC power and closed-loop velocity commands so that high-speed machining centers can maintain constant cutting speed under variable load. The drive operates as the power stage between a CNC controller and the spindle, integrating cooling hardware and feedback channels to keep the motor within thermal and positional limits during continuous machining cycles. That arrangement helps the spindle recover quickly from changing chip load during drilling, milling, and tapping operations.

Internal power for the inverter stage is derived from a DC bus of 300 VDC, and the converter can deliver a continuous armature current of 100 A to the spindle windings. This output level supports stable torque during acceleration and during long cuts at a constant commanded speed. A separate blower, supplied by 115 V/50–60 Hz mains, is fixed directly to the heatsink. Because the cooler is a heatsink-mounted blower, airflow is driven across the fin surfaces and the thermal design uses forced cooling. The model is built as Series 2 hardware and ships without additional communication option cards.

The permissible ambient range is 5 to 45 °C, allowing installation in standard workshop environments, and performance is supported up to 1000 m above sea level before cooling margins must be recalculated. Velocity references enter the control electronics as an analog speed command, enabling straightforward coupling with legacy CNC control loops. A dedicated second encoder input is available so the spindle can accept either an auxiliary motor encoder or direct spindle feedback for higher positioning precision. This added feedback path helps the control loop correct belt elasticity, backlash, or spindle-side disturbances during speed changes.