Product Description:

The KDA 3.1-050-3-LPI-W1 spindle drive is manufactured by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. It functions as the power and control stage for high-speed machine-tool spindles, transforming shared DC-bus energy into regulated three-phase current. Through integrated encoder channels, it closes the speed loop and reports position to the CNC. This allows the spindle to follow commanded speed changes during cutting, drilling, and grinding operations.

Its power electronics deliver a continuous output of 50 A, giving the spindle the current margin needed for rapid acceleration and sustained material removal. The drive is tied to a common bus at 300 VDC, so incoming line variations do not propagate directly to the motor terminals. Heat from the switching devices is removed by a mounted heat-sink blower fixed to the rear panel. Operating in forced cooling mode, this assembly keeps the heat-sink temperature from depending on cabinet airflow alone. The blower motor is supplied from a dedicated 220 V, 50/60 Hz auxiliary circuit, allowing ventilation to continue even when the DC link is shut down. A second encoder input is also available for supplementary spindle or motor feedback when the application requires additional monitoring.

Velocity setpoints are transmitted over the SERCOS interface, enabling deterministic fiber-optic communication with the motion controller. For downstream devices, an incremental encoder output supplies real-time quadrature pulses. Reliable service is limited to ambient air between 5 to 45 °C, which helps prevent condensation and overtemperature faults. Installation elevation must remain below 1000 m above sea level so that air density remains sufficient for cooling. The drive is part of Series 3 and supports precise spindle regulation in milling centers, lathes, and boring machines.