Product Description:

The KDA 3.1-100-3-LQD-U1 is a spindle drive from Bosch Rexroth Indramat and belongs to the KDA Spindle Drives series. It converts the fixed DC link from an Indramat supply module into variable three-phase output for speed and torque control of high-performance machining spindles. In automated milling, drilling, and grinding systems, the unit maintains programmed spindle profiles so the CNC can keep cutting conditions consistent during operation. This makes it suitable for machine tools that require repeatable speed changes, controlled acceleration, and stable torque at the spindle.

The drive’s power stage is energized by a DC link voltage of 300 VDC, which gives the internal inverter enough headroom to generate fast spindle ramps without waveform clipping. Continuous output capability reaches 100 A, allowing large-frame motors to operate at their rated thermal limit. Thermal energy is removed by a mounted heat-sink blower that pulls air across the rear aluminum fins. The blower is powered from an auxiliary supply of 115 V/50/60 Hz, so the cooling circuit can operate independently of the main power stage. Airflow is provided through forced cooling, which helps keep semiconductor temperatures stable during long production shifts. This cooling arrangement supports sustained operation during repeated acceleration, constant-speed running, and deceleration.

Operation is specified from 5 to 45 °C, which suits conditioned shop-floor environments. Installation altitude is limited to 1000 m above sea level to reduce the effect of thinner air on cooling performance and DC-link behavior during braking. The drive accepts a digital position command input for precise reference handling, and spindle velocity is coordinated through the SERCOS interface for synchronized motion in multi-axis systems. This command path supports accurate transfer of control data from the CNC to the drive so spindle response remains consistent during coordinated machining moves.