Product Description:

Bosch Rexroth Indramat manufactures the KDA 3.1-100-3-LQI-W1 spindle drive within the KDA Spindle Drives series. As a regulated power module, it converts a shared DC bus into three-phase output current that energizes high-speed spindle motors used in machining centers and other automated tooling stations. By combining digital velocity commands from the control system with real-time current feedback, the unit maintains precise spindle speed and torque during cutting, drilling, and grinding tasks. It is intended for machine tools that require repeatable speed regulation as spindle load changes during production.

The drive uses a DC link of 300 VDC supplied by the central power supply, and from that bus it can deliver a continuous 100 A output to the motor phases. Speed reference data is received over the SERCOS interface, allowing synchronized updates with other motion axes on the network. Thermal energy produced by the power semiconductors is removed through a mounted heat sink blower that runs from an auxiliary line of 220 V/50–60 Hz, keeping the cooling circuit independent of the DC link. This arrangement lets the spindle axis operate as part of a coordinated machine system while the shared bus supplies the power stage.

A forced cooling mode maintains airflow across the heat sink even when the spindle is idle, so cabinet temperatures stay within the specified ambient range of 5 to 45 °C. The design supports installation up to 1000 m above sea level, which covers most workshop elevations without additional ventilation. For diagnostics and feedforward control, the front panel provides an incremental encoder output that mirrors the motor’s position feedback, enabling external devices such as speed monitors or controllers to read spindle velocity directly. This output can also support supervisory equipment that requires an external speed signal during machine operation.