Product Description:

The KDA 3.1-100-3-AYS-U1 is a spindle drive produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. As a closed-loop power module, it converts DC-link energy from a matching supply unit into regulated output for high-speed machine tool spindles used in drilling, milling, and grinding centers. The drive accepts an external speed reference and returns encoder feedback to the CNC so spindle speed and torque remain controlled during machining. This makes it suitable for processes where speed stability affects surface finish and tool life. Closed-loop control also helps the spindle respond to load changes that occur during cutting.

The internal power stage is linked to a DC bus that operates at 300 VDC, and the unit can deliver a continuous phase current of 100 A to the motor windings. Thermal control is provided by a mounted heat sink blower powered from 115 V/50–60 Hz single-phase AC supply. The drive uses forced cooling, so airflow moves directly across the power semiconductors during operation. Because the blower is integrated, the cooling path is concentrated at the heat-producing components inside the unit. Continuous airflow helps limit heat buildup during low-speed spindle operation. Speed reference data enters through an analog input, allowing the CNC or PLC to vary spindle speed continuously rather than in fixed steps.

A diagnostic and parameter setup link is provided by an RS-232C serial interface for connection to a standard PC. The permissible operating environment ranges from 5 to 45 °C, and the drive can be used up to 1000 m above sea level without derating. For applications that require dual feedback devices, a second encoder input is available alongside a synchronous pulse input so both motor-mounted and workpiece encoders can be read. The serial connection supports diagnostics and access to operating settings during service. The synchronous pulse input also supports coordination between spindle motion and process timing.