Product Description:

The KDA 2.1-050-3-DPI-U1 is a spindle drive produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. It is intended for high-speed machining centers and turning equipment, where the spindle must follow commanded speed profiles without losing coordination with the rest of the motion system. In machine tools, that coordination helps maintain stable cutting conditions during acceleration, deceleration, and spindle orientation. The unit converts digital speed references from the CNC into controlled three-phase output for the spindle motor, coordinating torque and velocity with the connected servo system. By integrating a second encoder channel, it can read spindle position feedback while simultaneously passing motor position data back to the automation controller.

For power conversion, the drive uses a nominal DC link of 300 VDC from the shared power supply module and delivers up to 50 A of continuous output current to the spindle motor. Using the common DC bus also allows the drive to operate alongside other axis modules in the same power structure. Internal losses are removed by a mounted heat sink blower energized from an auxiliary 115 V/50-60 Hz source. The airflow path uses forced cooling, which helps stabilize the power section during sustained spindle loading and repeated acceleration. The speed reference arrives as a digital word, and the 2-series electronics process this command with one-cycle latency so rapid speed changes can be followed with very little delay.

Operation is permitted between 5 to 45 °C and at elevations up to 1000 m above sea level, which suits typical indoor industrial installations. The drive accepts a 16-bit parallel speed command, giving 65,536 discrete set points for accurate rpm control during tapping, drilling, or contour cutting. Diagnostic data can be streamed through the incremental encoder output, and a second encoder input is available for either spindle feedback or additional motor feedback. The encoder interfaces give the CNC access to motion data needed for spindle orientation, rigid tapping, and other synchronized spindle functions. This dual-feedback arrangement supports closed-loop speed supervision when the control system needs both position and velocity information.