Product Description:

The KDA 2.1-050-3-D0I-W1 spindle drive is manufactured by Bosch Rexroth Indramat within the KDA Spindle Drives series. Designed as a power stage for synchronous and induction spindles, it operates with Rexroth motion controllers to regulate speed and torque during machining, drilling, and grinding. Series index 2 marks the second design generation, and the integrated power electronics convert a constant DC bus into variable three-phase output so spindle acceleration, deceleration, and holding torque can be controlled directly from the numerical control system. This arrangement helps the machine maintain stable spindle behavior when the cutting load changes during continuous production.

The drive draws its intermediate circuit energy from a 300 VDC bus and can deliver up to 50 A of continuous motor current, making it suitable for medium-power spindles that require rapid torque changes. Thermal management relies on forced cooling, and a heat sink fan powered by an auxiliary line of 220 V/50–60 Hz pushes air across the fins to keep semiconductor temperatures within a safe operating range. Rotation is commanded through a 16-bit digital parallel reference, allowing the controller to set spindle speed with 65,536 discrete increments and very little conversion delay. This command method supports direct speed setpoint transfer from the control system without the scaling drift associated with analog reference signals.

The drive operates reliably at ambient temperatures from 5 to 45 °C and at altitudes up to 1000 m. Feedback signals are routed to the control cabinet through an incremental encoder output, and no secondary encoder input is included, which keeps the feedback path simple for standard spindle layouts. The air path created by the mounted heat sink blower helps maintain stable component temperature during continuous operation. That cooling support allows the drive to sustain its output capability while preserving responsive digital speed control through long machining cycles.