Product Description:

The KDA 3.1-050-3-D0D-U1 is produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. It is installed in CNC machines and machining centers to energize and regulate high-speed motor spindles, converting a constant DC link into coordinated three-phase output for commanded spindle motion across varying speed ranges. Its role is to supply controlled spindle power during cutting, positioning, and speed-regulated machining operations. Besides the speed channel, the additional interface accepts a digital position command value for contouring tasks and other coordinated spindle functions. The design omits a second encoder input, which keeps the feedback arrangement limited to the primary spindle sensor.

This unit draws a continuous output of 50 A from a DC bus held at 300 VDC, which provides the electrical capacity needed during acceleration and load rejection events. A separate blower takes its power from an auxiliary line rated at 115 V, 50/60 Hz, so heatsink cooling can remain active even when the main link is de-energized. Speed references arrive as a 16-bit parallel word, so the control loop receives 65,536 discrete velocity points without analog drift. Installation is permitted up to 1000 m above sea level before derating is required, which supports full current delivery in most plant locations.

The drive’s thermal envelope spans 5 to 45 °C, matching typical shop-floor conditions without requiring enclosure air conditioning. The unit uses forced cooling through a mounted heatsink blower, which pulls ambient air across the cooling surfaces during dense duty cycles. This arrangement keeps airflow directed at the cooling path during sustained spindle demand. The product is a spindle drive, so its protection schemes prioritize rapid current foldback rather than regenerative braking functions commonly associated with axis drives. Although there is no auxiliary encoder socket, the digital position channel still supports synchronized tapping or C-axis orientation when those functions are commanded by the machine controller.