Product Description:

The KDA 2.1-150-3-DYS-U1 spindle drive belongs to the KDA Spindle Drives series from Bosch Rexroth Indramat. It is installed in machine-tool cabinets to convert the shared DC bus energy into controlled three-phase power for high-speed spindles used in milling, turning, and grinding centers. By modulating current and voltage in real time, the unit keeps spindle speed tightly aligned with CNC setpoints and helps maintain stable cutting conditions during changing loads. This type of drive is used where a machine spindle must respond quickly to programmed speed changes, load disturbances, and orientation commands from the CNC. Its closed-loop operation supports repeatable spindle motion during demanding production cycles.

Electrically, the inverter section draws energy from a common DC link rated at 300 VDC. It can supply a continuous phase current of 150 A, enabling rapid acceleration and braking of low-inductance spindle motors. The integral heatsink fan is powered from an auxiliary line of 115 V/50-60 Hz, so the main power channel stays isolated from blower transients. Speed references arrive as a 16-bit parallel digital input, allowing the controller to process discrete velocity commands without analog drift. Parameters and fault logs are available through the built-in serial RS-232-C interface. The parallel command path suits CNC systems that issue direct digital speed words, which helps reduce susceptibility to electrical noise inside the cabinet. The control electronics use generation 2 hardware, which supports updated gating logic and faster response to spindle override signals.

The unit operates between 5 to 45 °C and at sites up to 1000 m above sea level without derating. A rear-mounted heatsink blower pushes air directly across the IGBT stack, and this forced cooling arrangement helps keep junction temperatures stable during prolonged high-speed machining. For applications requiring exact angular positioning, a second encoder input with synchronous capture is provided so the CNC can read spindle position in real time. That input supports rigid tapping, tool-change alignment, and orientation stop functions during coordinated machine cycles. This added feedback path helps the spindle respond accurately during noncutting movements as well as during synchronized machining tasks.