Product Description:

Bosch Rexroth Indramat manufactures the KDA 3.1-050-3-LYI-W1 within the KDA Spindle Drives series. This spindle control unit converts the constant DC link of a multi-axis supply into three-phase output so that machine-tool spindles can accelerate, brake, and hold speed under CNC command. It supports position, velocity, and torque loops using feedback, which allows the controller to regulate spindle behavior during cutting, indexing, and speed changes. Its compact format allows placement close to the spindle motor to minimize cable losses and reduce the length of high-current motor leads.

The power section is designed for a continuous load of 50 A drawn from a 300 VDC intermediate circuit. The unit is Series 3, which places it in the later KDA revision group. Heat produced under this current is removed by a heat sink-mounted blower that operates from a separate 220 V 50–60 Hz source; this airflow supports the drive’s forced cooling mode and helps prevent derating at elevated cabinet temperatures. For reliable operation, the unit must be installed no higher than 1000 m above sea level, and the ambient air must remain free of conductive dust.

Speed references enter the control card through a SERCOS interface, allowing synchronous motion commands to arrive over the same fiber ring used for the machine’s servo axes. This arrangement allows spindle commands to remain synchronized with coordinated axis motion in CNC systems. Diagnostic and position verification signals can be streamed via the dedicated incremental encoder output. A separate channel accepts a second encoder input and a synchronous input for dual-loop accuracy on compound spindle assemblies. The electronics are specified to function between 5 to 45 °C, and within this range the timing circuits stay within tolerance while lubrication in the blower bearings remains effective.