Product Description:

The KDA 2.1-050-3-LPD-U1 is a spindle drive developed by Bosch Rexroth Indramat for the KDA Spindle Drives series. In an automated machining line, this unit supplies regulated three-phase power and closed-loop control to high-speed spindle motors so cutting velocity remains stable during load changes. Integrated communication channels allow it to exchange speed and position data with higher-level CNC controllers, so toolpaths can be executed at the commanded feed rates without overshoot. The drive is intended for applications where spindle speed must track programmed values during acceleration, deceleration, and changing chip load.

The power section is energized from a DC bus rated at 300 VDC, and it can deliver a continuous output of 50 A to the spindle winding. Internally, the control electronics obtain auxiliary fan power from an AC source of 115 V/50–60 Hz, separating thermal management from the main drive supply. Motion commands arrive through the SERCOS interface, while an additional channel accepts a digital position command value for contouring moves that require exact angular synchronization. A second encoder input lets the unit process spindle feedback or an extra motor feedback device and apply that information directly to the current regulators during synchronized motion. This combination supports both speed-controlled spindle operation and coordinated motion tasks that rely on accurate angular response.

Thermal performance relies on a mounted heat sink blower that draws air across the aluminum fins, and the entire assembly uses forced cooling rather than passive convection. Reliable operation is permitted within an ambient range of 5 to 45 °C, and the unit can be installed at elevations up to 1000 m without loss of rated current capability. Because cooling depends on active airflow, the heat sink path must remain open so air can move freely across the fins. This airflow removes switching losses from the power stage during extended cutting duty in typical industrial machine enclosures.