Product Description:

The 1MR310D-A094 is a rotor element manufactured by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As the rotating core of a frameless spindle assembly, this component couples directly with a matching stator to convert drive currents into mechanical torque, enabling high-speed machining and grinding processes in automated production cells. Its frameless format allows it to be integrated into compact spindle structures where direct coupling and high rotational accuracy are required.

The rotor’s outer diameter of 228.7 mm establishes the air-gap geometry that influences magnetic flux density, while an internal bore of 94 mm provides clearance for the spindle shaft and toolholder drawbar. Overall magnetic path length is set by the 330 mm rotor body, coded as length variant D, and the steel stack weighs 79 kg. This mass contributes to a rotational inertia of 0.492 kg·m², which affects the torque required for acceleration and the damping of speed fluctuations during heavy cuts. The frame designation fixes the external mounting envelope, and the step interference-fit design secures the rotor to the shaft without keys while maintaining concentricity under thermal growth and centrifugal load.

A balance ring thread of M10 is provided so correction weights can be installed after final assembly. The minimum finished spindle length of 338 mm helps align the rotor with stator laminations and bearing seats in typical cartridge layouts. The component is sized for the 310 frame in this motor family. Three pole pairs, noted as 3, set the synchronous field frequency and help the drive achieve the high surface speeds expected from an asynchronous milling spindle. With an IP00 protection rating, the rotor is supplied without its own housing and relies on the machine enclosure for shielding while allowing direct coolant flow around the laminations for heat extraction.