Product Description:

The KDA 2.1-150-3-AQI-U1 is a spindle drive manufactured by Bosch Rexroth Indramat for the KDA Spindle Drives series. As a closed-loop power module, it regulates the torque and speed of high-frequency machine-tool spindles, translating motion commands from a CNC controller into controlled three-phase output currents that keep the cutting process stable and accurate. This operating role makes it suitable for machining centers, grinding equipment, and similar spindle applications where rapid speed correction and smooth torque delivery are needed to support surface finish and dimensional consistency. Closed-loop feedback helps the controller correct speed deviations caused by changing tool engagement and spindle load.

The drive draws its DC bus from a supply of 300 VDC and can deliver a continuous phase output of 150 A, providing the current needed for rapid acceleration and sustained cutting loads. A separate blower circuit rated at 115 V/50-60 Hz powers the heat sink fan, and the internal algorithm references an analog speed command to modulate output frequency. Feedback is available through an incremental encoder output, enabling the host controller to read actual spindle speed without extra interface hardware. Thermal dissipation relies on forced cooling, so the unit can support continuous-duty operation in enclosed cabinets where heat from nearby motion hardware may accumulate.

The unit operates in ambient temperatures from 5 to 45 °C and at installation heights up to 1000 m above sea level without derating. A mounted heat sink blower removes heat directly from the power stage, so airflow is handled at the drive rather than by general cabinet ventilation alone. The product is part of design series 2, and its analog command structure together with encoder-based speed signaling suits spindle systems that use conventional CNC interfaces instead of networked fieldbus control. It also fits older machine platforms that use analog reference signals and discrete speed monitoring.