Product Description:

The KDA 3.1-100-3-LYI-U1 is a spindle drive produced by Bosch Rexroth Indramat within the KDA Spindle Drives series. This module converts a regulated DC bus into three-phase output for high-speed machine-tool spindles, allowing precise torque and speed regulation during milling, drilling, or grinding operations. By integrating with numerical control systems, the unit acts as the final power stage that translates motion commands into controlled spindle rotation for industrial automation cells.

The drive is energized from a DC bus of 300 VDC, and its power section can deliver a continuous output of 100 A, matching the current demands of large-frame spindle motors. Velocity setpoints arrive through the SERCOS interface, so the device exchanges real-time process data over a fiber-optic ring without additional analog wiring. Internal thermal management relies on a mounted heat sink blower, and this fan is supplied by a separate 115 V/50–60 Hz single-phase line that isolates the cooling circuit from the power electronics. Air moves across the exchanger in a forced cooling mode, allowing the unit to dissipate switching losses continuously and maintain semiconductor temperature within operating limits at full rated current.

The drive operates in ambient temperatures from 5 to 45 °C and at installation heights up to 1000 m above sea level, so it can be mounted in standard factory enclosures without derating when those conditions are maintained. The unit includes an integrated incremental encoder output for downstream position controllers and a dedicated second encoder input that accepts commutation or synchronous feedback from the spindle motor. These I/O ports support accurate phasing, spindle orientation, and diagnostic functions while keeping wiring centralized on the front panel.