Product Description:

The KDA 3.2-050-3-API-U1 spindle drive is produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. This unit is a closed-loop inverter that regulates torque and speed on high-speed machine-tool spindles by linking the DC power supply, position sensors, and the host CNC controller. By converting an analog speed command into precise stator currents, it keeps surface finish and feed rates consistent during cutting, drilling, and grinding operations. This arrangement also helps the drive respond quickly to changing spindle loads during machining.

Electrically, the drive is supplied from a DC link rated at 300 VDC, and it can deliver a continuous output of 50 A to the spindle motor. Thermal dissipation is handled by a heat sink-mounted blower, and airflow is provided by the unit’s forced cooling design to keep semiconductor junctions within limits during extended duty cycles. The blower itself runs from an auxiliary tap of 115 V/50-60 Hz, eliminating the need for a separate fan power source. Commanding uses an analog velocity reference, allowing direct connection to conventional CNC analog outputs. The continuous current rating supports sustained spindle operation when the machine remains under load for extended periods.

Installation parameters include an ambient operating range of 5 to 45 °C and permissible mounting elevations up to 1000 m above sea level, so cabinet ventilation and heat sink airflow remain effective in moderately warm workshops. A separate second encoder input can be wired for spindle feedback or auxiliary motor sensing, while a buffered incremental encoder output is available for downstream position loops. This added feedback flexibility supports machines that need spindle monitoring together with a related sensing channel. The unit is series 3 and version 2 within the KDA control architecture.