Product Description:

The 1MR310D-A112 is a rotor component engineered by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. It serves as the rotating core of a frameless spindle motor, transmitting electromagnetic torque to the machine-tool shaft without the bulk of a conventional housing. By integrating directly inside the spindle head, the rotor contributes to higher speed capability and reduced axial length in automated milling, drilling, and grinding equipment. In high-duty production cells, reliable rotor construction helps maintain dimensional accuracy and surface finish over long service intervals.

Its frame size of 310 specifies the stator cavity diameter that this rotor can occupy, while an inner rotor bore of 112 mm provides the clearance required for a laminated shaft or coolant passage. The motor length code D indicates the axial stack height chosen to balance torque production and thermal limits. With 3 pole pairs, the rotor reaches a high synchronous speed when driven by high-frequency inverters, making it suitable for metal-cutting spindles. The rotor is manufactured with a step interference fit; this stepped geometry creates an intentional press fit between the rotor laminations and the shaft so torsional loads are transferred without slippage during rapid acceleration and deceleration.

Dynamic properties are governed by a moment of inertia of 0.492 kg·m², giving the matched drive a predictable acceleration profile during speed changes. A rotor mass of 71.9 kg adds thermal capacity that helps moderate short-term temperature rise during heavy cutting passes. Produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series, the rotor is intended for high-speed spindle service. Concentric balance is maintained so the spindle can run smoothly at operating speed.