Product Description:

The 1MR310D-A108 rotor is manufactured by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As the rotating core of a frameless spindle motor, it mates to the stator supplied by the machine builder and carries the cutting tool or workpiece chuck. The component is intended to deliver precise, high-speed torque in compact machining centers, and its dimensional tolerances help minimize imbalance and maintain shaft concentricity during continuous service.

The rotor belongs to frame size 310, which gives it a standardized outer envelope for matching 1MB stator segments. An outer diameter of 228.7 mm sets the air-gap clearance and guides bearing selection, while the overall rotor length of 330 mm sets the magnetic active section and influences inertia. Axial balance correction is performed through an optional ring that seats on the threaded hole sized M10, allowing residual vibration to be trimmed during balancing. The central bore is machined to fit class H6, ensuring a tight but serviceable interference fit with the spindle shaft to maintain rigid concentricity at operating speed.

Pressure oil for tool unclamping or bearing lubrication can be routed through the tapped passage marked M6, avoiding external hoses on the spindle nose. The inside diameter of 108 mm provides space for drawbars or sensor wiring while retaining sufficient wall thickness for strength. Length code D identifies the magnetic stack height used for this rotor variant, balancing torque output against rotor mass. A seating cone machined at 30° mates to the spindle nose and aligns with the 147 mm shoulder diameter, and this stepped interference fit locks the rotor axially without keys. The rotor-to-stator positioning offset of 60 mm keeps the active magnetic length centered within the stator pack and leaves clearance for end-ring ventilation.