Product Description:

The KDA 2.1-050-3-APD-W1 spindle drive is manufactured by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. It converts the fixed intermediate-circuit voltage from a supply module into a variable three-phase output that controls torque and speed for machine-tool spindles in automated cells. By housing power electronics, a heat sink, and field wiring terminals inside one chassis, the unit forms the primary interface between a motion controller and the mechanical spindle. The drive is Series 2 within the product family, indicating the revision level used with matching power supplies and feedback options.

The drive operates from a DC link of 300 VDC and can deliver up to 50 A of continuous phase current to the spindle motor. Thermal management relies on forced cooling, and a blower fixed to the rear heat sink pulls ambient air through the fins and exhausts the heat. That blower runs from a dedicated 220 V/50–60 Hz single-phase line so cooling capacity remains independent of spindle load. The electronics are specified for ambient temperatures of 5 to 45 °C, allowing full output in typical shop conditions. Installation is approved up to 1000 m above sea level without derating caused by reduced air density.

Control channels include an analog speed command that modulates inverter output in real time, while a separate port accepts a digital position command for applications that synchronize spindle rotation with feed axes. A second encoder input is available so the unit can process direct spindle feedback or an auxiliary motor sensor for greater accuracy at low speed. The cooling assembly is a factory-installed mounted heatsink blower, allowing cabinet integration without external ducting and keeping component temperatures within limits during sustained high-torque duty cycles.