Product Description:

The KDA 3.1-150-3-API-U1 spindle drive is produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. It is installed between the machine controller and the spindle motor so that commanded speed profiles are reproduced without delay during drilling, milling, or grinding operations. By converting the numerical control system’s velocity references into regulated armature current, the unit supplies the mechanical power that keeps machining cycles synchronized with part programs. That control behavior is important in machining centers where spindle speed must remain steady as tool engagement and material removal rates change. It also supports coordinated motion between the spindle and the feed axes during programmed operations.

The power section runs from a DC link rated at 300 VDC, and its output capacity reaches 150 A. This current level allows the drive to handle large-inertia spindle loads during acceleration, deceleration, and continuous cutting duty. An integral heat sink blower is energized from a separate 115 V 50–60 Hz source, and the drive uses forced cooling to keep the semiconductor section within safe operating limits. The separate blower supply lets the cooling hardware operate independently of the main DC link section. Continuous duty is permissible while the ambient temperature remains in the 5 to 45 °C range.

For installation heights up to 1000 m above sea level, no derating factor is required. The controller accepts an analog speed command value and returns real-time spindle velocity through an incremental encoder output, allowing the CNC to monitor spindle speed during operation. A dedicated second encoder input is available when separate spindle feedback or auxiliary motor feedback is needed for positioning tasks. This arrangement supports applications that use one feedback path for spindle speed regulation and another for auxiliary positioning or orientation functions.