Product Description:

The KDA 2.1-100-3-LQ0-U1 spindle drive is produced by Bosch Rexroth Indramat within the KDA Spindle Drives series. As a regulated power module, it converts a fixed DC supply into controlled three-phase output for high-speed machine tool spindles, allowing precise torque and speed regulation in automated machining centers. The unit serves as the master drive in closed-loop spindle axes that rely on digital command channels. This type of drive is suited to applications where spindle speed must respond quickly during cutting, tapping, and tool-change cycles. Closed-loop regulation helps maintain stable rotation as spindle load changes through the machining process.

The drive operates from a DC link of 300 VDC, and its power stage can deliver a continuous output of 100 A, giving headroom for rapid acceleration of low-inductance spindle motors. Heat generated at this load is removed through forced cooling, and the airflow is supplied by a cooling circuit powered at 115 V / 50–60 Hz rather than by the DC bus. Separating the blower supply from the main power section helps keep the cooling system independent of the output stage. Safe operation is permitted in ambient temperatures from 5 to 45 °C, which covers typical machine-room conditions without derating. These limits indicate how the drive should be wired and placed to avoid thermal shutdown or current foldback during demanding duty cycles.

The cooling assembly uses a heatsink-mounted blower, so the package can be installed against a control-cabinet wall without external ducting. Altitude capability reaches 1000 m; above that height, reduced air density lowers fan effectiveness and may require additional cooling measures. The unit is released as Series 2 and accepts speed setpoints only through the SERCOS interface. This gives the drive a single fiber-optic control path for spindle operation. The fixed communication method suits systems that already use optical rings for synchronized motion data.