Product Description:

The KDA 2.1-050-3-LYI-U1 spindle drive is produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. It converts DC bus power into regulated three-phase output for high-speed machine tool spindles and closed-loop axis drives. The compact 50 A module slides into the Indramat cabinet rack, shares a common DC link with supply units, and communicates operating status to upper-level CNC or PLC controllers. It is suited to machine tool applications that combine spindle control with coordinated axis movement.

Its DC link operates at 300 VDC, and the inverter section can deliver a continuous phase current of 50 A, providing sufficient armature power for midsize milling or grinding heads. The heat sink is cooled by a heat sink-mounted blower that draws single-phase mains rated at 115 V / 50–60 Hz; this forced airflow helps keep semiconductor temperatures within limits during sustained load. Speed commands reach the drive through a SERCOS interface, so motion controllers can transmit setpoints and receive status data across a fiber-optic ring with deterministic timing. That communication path supports closed-loop control where the higher-level system expects predictable command timing and prompt status feedback. A second encoder input is provided for master-slave spindle arrangements or high-resolution position loops.

The drive is intended for cabinet installation. The drive functions across an ambient range of 5 to 45 °C. Elevations up to 1000 m above sea level are permissible without current derating. For feedback distribution, the additional incremental encoder output lets downstream devices monitor true spindle speed without separate sensors. A synchronous input channel allows phase referencing during tool change cycles, and the unit is design version 2. These channels allow actual spindle speed and phase information to be passed to related control functions during synchronized machine sequences.