Product Description:

The KDA 3.1-050-3-LPI-U1 spindle drive is manufactured by Bosch Rexroth Indramat as part of the KDA Spindle Drives series. It operates as the axis power stage in CNC machines, taking DC bus energy from a supply module and delivering controlled three-phase power to high-speed spindles. By linking electrical output to digital speed commands, the unit enables stable torque, rapid acceleration, and reliable braking in drilling, milling, and grinding processes. This arrangement helps the machine maintain consistent spindle response during cutting, speed changes, and deceleration between machining steps. It is intended for spindle applications that require repeatable speed control under changing mechanical load.

A DC bus of 300 VDC feeds the internal inverter section, and the drive can supply up to 50 A of continuous line current to the spindle windings. The heatsink blower that removes switching losses is powered from a separate 115 V/50-60 Hz source, so the cooling circuit can operate independently of the main DC bus supply. Air is moved across the heat sink by a mounted heat sink blower, which supports heat removal from the power section during sustained operation. Motion commands arrive through the SERCOS interface, allowing deterministic exchange of speed commands and status data with the numerical control. This communication path supports coordinated spindle behavior during speed regulation and braking events.

The drive uses forced cooling to keep semiconductor temperatures within limits even under prolonged heavy cutting. Position data can be forwarded through the built-in incremental encoder output, while a second encoder input is reserved for redundant spindle or auxiliary motor feedback. This helps the control system monitor spindle behavior without relying on a single feedback path. Installation altitude is limited to 1000 m above sea level, and ambient operation should stay between 5 to 45 °C to preserve component life. The unit uses the version 3 hardware platform.