Product Description:

Bosch Rexroth Indramat manufactures the KDA 3.1-050-3-APS-U1 spindle drive as part of the KDA Spindle Drives series. The unit regulates torque and speed for high-speed machine-tool spindles, converting commands from a CNC controller into controlled current for the attached motor during acceleration, cutting, and braking. By integrating gate firing, current control, and cooling hardware into one housing, the drive simplifies spindle-axis design and supports precise machining cycles in automated production cells. Its integrated layout also reduces the amount of separate spindle-control hardware needed inside the cabinet.

Internally, the power stage is supplied by a 300 V DC bus that delivers up to 50 A of regulated output to the spindle motor. This controller is part of series 3, so its board layout matches later supply modules used across the platform. The commanded velocity arrives as an analog speed reference, and the drive converts this signal into a PWM current profile suited to metal-cutting demands. A serial interface (RS-232C) is provided for parameter setting and diagnostic retrieval without removing the unit from the cabinet. Thermal energy generated by the IGBT modules is removed by a mounted heat sink blower, allowing full current delivery without derating. A second encoder socket lets the controller process spindle feedback or an additional motor sensor for synchronizing tool orientation with auxiliary axes.

The blower runs on 115 V at 50/60 Hz, keeping airflow active even when the DC bus is de-energized. Because the entire cooling path relies on forced cooling, the cabinet must have inlet and exhaust clearance so the heat sink can exchange heat effectively. The electronic assembly is specified to operate in ambient air from 5 to 45 °C, a range aligned with typical shop-floor climate control. Installation is limited to 1000 m above sea level to keep dielectric strength, fan performance, and component temperatures within acceptable limits.