Product Description:

The KDA 3.1-050-3-A0D-U1 is a spindle drive module produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. The unit is in series 3 within this product line. It converts DC-bus energy into three-phase output for high-speed spindles used in metal-cutting and grinding equipment. The drive accepts speed and position references from the machine controller and delivers regulated current to the motor windings. This arrangement supports both continuous spindle rotation and accurate spindle orientation within the same machine axis.

Electrically, the unit operates from a DC link of 300 VDC, which supplies the internal pulse-width modulation stages. The current regulator supplies up to 50 A continuously, giving the connected spindle a broad torque range for roughing passes and fine finishing work. A heat sink-mounted blower is fitted directly to the housing, and the cooling method is forced cooling to move heat away even when cabinet airflow is limited. The blower motor uses a separate single-phase supply of 115 V/50-60 Hz, so the cooling circuit remains independent of the main DC bus connection. The separate blower supply also allows the thermal system to continue supporting the power section during sustained machine operation.

The module is intended for indoor areas held at temperatures from 5 to 45 °C, and operation beyond that range reduces allowable current to protect the electronics. Installation altitude must remain at or below 1000 m above sea level because thinner air reduces cooling effectiveness. Control inputs include an analog speed command for spindle velocity regulation and a digital position command input for accurate spindle orientation during tool changes. Because the hardware does not include an auxiliary encoder socket, only the primary spindle feedback line needs to be wired, which keeps the control connection straightforward and avoids unnecessary interface complexity.