Product Description:

The KDA 2.1-150-3-L0S-U1 spindle drive is manufactured by Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series, design version 2. As a dedicated power stage for high-speed machine-tool spindles, it converts the shared DC bus into a variable output that keeps rotational speed closely aligned with program demand. Within an automated cell, the unit interfaces directly with numerical controls, allowing precise acceleration, deceleration, and holding torque without mechanical contactors. This arrangement supports stable spindle behavior during speed changes and helps maintain consistent cutting performance across different machining steps.

The drive operates from 300 VDC and provides a continuous output capability of 150 A, supplying the current needed for rapid spindle load changes. Thermal energy is removed by a heat sink fan powered from 115 V at 50/60 Hz, and the power section uses forced cooling to keep the internal IGBTs within safe operating limits. Velocity reference data arrives through the fiber-optic SERCOS interface, allowing deterministic speed commands at the drive level. The unit can operate in ambient temperatures from 5 to 45 °C. This control approach helps the spindle maintain repeatable speed during cutting, drilling, and rapid changes in workpiece engagement.

The drive includes a mounted heat sink blower, so it can be installed directly against the cabinet backplane without external ducting. It can be used at altitudes up to 1000 m above sea level before output reduction is required. An auxiliary serial interface (RS-232-C) provides access to operating data and diagnostic information when needed. The design does not include a second encoder input, so feedback is limited to the primary spindle encoder supplied by the machine builder. Using a single encoder path also reduces wiring complexity while preserving accurate speed feedback.