Product Description:

The KDA 3.1-050-3-API-W1 is a spindle drive produced by Bosch Rexroth Indramat and delivered as part of the KDA Spindle Drives series. As a Series 3 unit, it converts a regulated DC bus into three-phase power for high-speed machine tool spindles, letting a CNC controller apply precise velocity and torque commands to the work head. In an automation cell, the drive links the motion processor to the spindle motor and closes the electrical loop that governs cutting speed, tapping cycles, and surface finish.

The power section of the drive is energized from a 300 VDC intermediate circuit and can supply up to 50 A of continuous output current to the motor windings. Internal heat is removed by a mounted heat sink blower that forces air across the power semiconductors, and this blower is fed by a separate 220 V at 50–60 Hz AC line. Because the cooling path is fan-assisted, the assembly uses forced cooling, allowing the electronics to maintain safe junction temperatures during sustained high-speed cuts. The command channel accepts an analog velocity reference, so spindle speed can be modulated in real time by the CNC's DAC, and the unit includes a dedicated second encoder input for direct spindle feedback or auxiliary motor feedback.

Control integration is expanded with an incremental encoder output that mirrors spindle position to downstream motion axes, enabling synchronous tapping and tool-orientation routines when paired with the drive's analog speed channel set as analog. The drive can operate in ambient temperatures from 5 to 45 °C, while altitude is limited to 1000 m above sea level to preserve dielectric strength and thermal margin. The blower supports stable cooling across that ambient range, and the dual-encoder arrangement helps maintain position coherence between the spindle and machine axes without external signal splitters.