Product Description:

The KDA 2.1-050-3-AYD-U1 belongs to the KDA Spindle Drives series produced by Bosch Rexroth Indramat. This spindle drive module converts the direct-current energy from the machine’s power supply into regulated three-phase output for high-speed tool spindles. In an automated machining cell, it governs torque, monitors encoder feedback, and powers its own cooling hardware, enabling the spindle to maintain programmed speeds during continuous milling, drilling, or grinding cycles while interfacing directly with Indramat CNC controllers.

The power stage is energized from a DC link at 300 VDC, a level selected to match standard Indramat supply units and provide adequate voltage headroom for fast spindle acceleration. Continuous output is limited to 50 A; this ceiling protects the IGBT bridge from overcurrent stress and limits the maximum spindle power the module can support. Thermal energy is extracted by a mounted heat sink blower that sits on the drive’s rear plate, so cabinet airflow planning is simplified. That blower runs from an auxiliary feed of 115 V at 50/60 Hz, allowing active cooling even when the main DC bus is de-energized. Air is moved under forced cooling, meaning fan speed is fixed and independent of ambient convection, which keeps semiconductor junction temperatures within limits during heavy cutting passes.

The unit operates in an ambient range of 5 to 45 °C, covering typical shop climates without needing external heaters or chillers. Installation is approved up to 1000 m above sea level; beyond this height, reduced air density can diminish cooling performance. The control board accepts an analog speed command, so the CNC can adjust spindle speed with a ±10 V signal, and it also processes a digital position command value for orientation moves or tapping cycles. A second encoder input is provided for synchronous applications such as spindle-to-axis gearing, eliminating extra interface cards and simplifying system wiring.