Product Description:

Bosch Rexroth Indramat manufactures the KDA 3.1-100-3-DQI-U1, a spindle drive positioned in the KDA Spindle Drives series. The unit supplies regulated power to induction or synchronous spindle motors so machining centers can keep tooling speed within tight tolerances during cutting, drilling, or grinding. By converting a shared DC bus into controlled three-phase output, the drive forms the axis-specific component of Indramat modular drive cabinets used throughout automated production lines. This arrangement lets multiple drive modules operate from a common power structure within the same cabinet.

The drive operates from a bus voltage of 300 VDC, and its power electronics can deliver 100 A continuously to high-power spindles. Speed references arrive through a 16-bit digital parallel interface, allowing numerical control systems to transmit exact velocity words instead of analog signals. Thermal management is handled by a mounted heat sink blower fed by an auxiliary supply of 115 V/50-60 Hz, and this dedicated fan removes switching losses from the IGBT stack to help prevent thermal shutdown at full load. Revision 3 adds dual-microprocessor supervision that monitors current loops, bus voltage, and fault memory. The control method suits machine tools that require repeatable spindle response during rapid load changes.

Airflow from the blower is directed through fin channels in a forced cooling arrangement, which keeps internal temperatures stable when the ambient air lies between 5 to 45 °C. The design tolerates installation up to 1000 m above sea level, where reduced air density still permits adequate heat extraction. A built-in feedback tap labeled incremental encoder output passes spindle position data to external indicators or following axes, eliminating separate signal splitters. Stable airflow across the heat sink surfaces helps the power stage remain within its thermal operating range during sustained spindle demand.