Product Description:

The 1MR241D-A066 is a dedicated rotor supplied by Bosch Rexroth Indramat for use inside 1MB High-Speed Asynchronous Motors. As a frameless spindle component, it is fitted directly into the machine tool housing and couples with an external stator to deliver high peripheral velocity during cutting, grinding, or drilling cycles. Because only the active rotor assembly is provided, integrators can minimize overall spindle diameter and place cooling channels or sensors around the laminated core without disturbing magnetic symmetry.

The rotor belongs to frame designation 241, giving the outside diameter needed to match the corresponding 1MB stator bore. A through-bore measuring 66 mm allows the drawbar or workpiece clamping shaft to pass without contacting the laminated stack. Mechanical limits are set at 9000 rpm; below this ceiling, the centrifugal stress on the squirrel cage and the aluminum end rings stays within the fatigue margin of the alloy. The bare rotor carries protection code IP00, indicating that it must be installed inside a motor enclosure before exposure to coolant mist or chips. Every unit is machined and balanced at the factory so the magnetic center is aligned with the geometric axis, reducing vibration once the spindle is assembled.

Dynamic properties are governed by a moment of inertia of 0.135 kg·m²; this value affects how much torque the inverter must supply during rapid speed changes on tapping or tool change cycles. A solid mass of 31.3 kg helps damp minor torsional oscillations while still allowing responsive acceleration. Motor length code D indicates the axial stack height chosen for medium power ratings within the 241 frame. The rotor is machined with a step interference fit, so the press fit engages first at a pilot land and then at the full cylindrical surface, ensuring concentric seating in the shrink-fit hub without galling the bore.