Product Description:

The KDA 3.1-100-3-LQI-U1 is a spindle drive manufactured by Bosch Rexroth Indramat within the KDA Spindle Drives series. As a closed-loop power module, it supplies controlled three-phase power to high-speed machine tool spindles and translates digital velocity commands from the automation controller into regulated motor current. When used with compatible Indramat axis controllers, the unit supports rapid acceleration and stable speed holding during metal-cutting operations and other industrial processes that require accurate spindle control. It is intended for spindle applications where speed changes must follow command updates quickly and where load variations during cutting cannot cause noticeable speed sag.

Internally, the drive is fed from a DC bus rated at 300 VDC, and its power stage can deliver a continuous 100 A of motor current to the connected spindle under load. Thermal energy from the switching devices is removed by an actively cooled heat sink, and the blower is powered from an auxiliary 115 V, 50/60 Hz supply so that airflow remains independent of the DC bus. The drive uses forced cooling, which allows rated output when the cabinet temperature stays within the permitted range. Velocity references arrive through the SERCOS interface, enabling synchronous communication with digital CNC controls and reducing the drift associated with analog signaling. This arrangement helps the power section maintain stable thermal conditions during repeated acceleration, deceleration, and sustained high-speed operation.

The permissible ambient range is 5 to 45 °C, which supports normal operation in typical shop-floor environments, and the drive can be used at elevations up to 1000 m. Feedback signals for supervisory PLCs are available through an incremental encoder output, which passes spindle position information to external monitoring or synchronization functions. The encoder output also lets external control hardware observe spindle motion without interrupting the main control path. The unit is Series 3, and that series assignment distinguishes it within the KDA product line.