Product Description:

The KDA 3.1-100-3-L0I-U1 belongs to the KDA Spindle Drives series from Bosch Rexroth Indramat. As a spindle drive, it receives speed commands from CNC or PLC platforms and converts them into controlled three-phase output for high-speed machining spindles. This allows the spindle motor to respond to commanded speed changes during cutting, grinding, and orientation tasks. It is intended for applications where spindle speed must be adjusted quickly without losing control under demanding operating conditions. The unit integrates with other Indramat motion modules for closed-loop operation in metal-cutting and grinding centers.

This model is designed around a DC bus rated at 300 VDC, and the internal power section draws up to 100 A when accelerating heavy rotor masses. Heat generated at those current levels is removed by a mounted heat sink blower, while forced cooling maintains airflow to keep semiconductor junction temperatures within limits. The blower is supplied from an auxiliary line of 115 V/50–60 Hz, which keeps the cooling circuit separate from the main DC link so ventilation can continue during coast-down. A speed reference reaches the drive over a fiber-optic SERCOS interface, allowing stable velocity control and helping reduce noise sensitivity in the control link. Because the design does not include an additional input, a second encoder channel cannot be connected directly to this housing.

The drive operates between 5 to 45 °C and can be used up to 1000 m above sea level without derating. For position handoff to supervisory controllers, it provides an incremental encoder output derived from the primary spindle encoder, which supports spindle orientation and tool-change routines. That output can also be used where the higher-level control needs a spindle-related reference signal during synchronized machine movement. The lack of a second encoder socket reduces wiring density in multiaxis cabinets and leaves feedback expansion to upstream system components.