Product Description:

Bosch Rexroth Indramat manufactures the KDA 2.1-050-3-AYS-U1 as part of the KDA Spindle Drives series. This spindle drive is the dedicated power stage for high-speed machine-tool spindles, translating controller setpoints into regulated three-phase motor voltage and current so that milling, turning, and grinding processes maintain commanded surface speeds, acceleration profiles, and dynamic braking within CNC production cells. The unit carries series code 2 within this product line.

Internally, the unit is connected to a common bus that supplies 300 VDC, and all vector-control and IGBT switching functions operate from this constant intermediate circuit voltage. The current path is rated for 50 A, allowing the spindle to generate the cutting torque needed during heavy stock removal without tripping current limits. Thermal energy is extracted by a heat sink-mounted blower, and airflow is increased through forced cooling so semiconductor junction temperature remains stable under continuous duty. The blower itself is powered from a separate auxiliary source of 115 V / 50-60 Hz, so the drive requires a single-phase service connection for the cooling circuit.

The drive operates in ambient temperatures from 5 to 45 °C, and installation altitude should not exceed 1000 m because thinner air reduces cooling performance. Command data enter through an analog speed channel identified as the analog speed command, giving external motion controllers direct voltage-proportional control over spindle rpm. Diagnostic and parameter access pass through the serial interface (RS-232-C), while a second encoder input provides phase-synchronous position feedback for orienting or rigid tapping tasks. The synchronous input terminal also supports precise spindle-to-axis coordination when required by the automation program.