Product Description:

The 1MR240D-A072 rotor is produced by Bosch Rexroth Indramat as a component of the 1MB High-Speed Asynchronous Motors series. This cylindrical part mounts directly onto the stator of a frameless spindle motor and establishes the rotating magnetic field that converts electrical input into mechanical output. Within industrial automation, the rotor allows high-speed machining spindles to deliver repeatable torque while keeping the overall motor envelope compact. That combination supports precise surface finishes at elevated cutting speeds in machine tools and grinding centers.

A frame size of 240 matches the stator cavity used for this rotor, while an inside rotor diameter of 72 mm leaves clearance for the drawbar or coolant tube commonly used in spindle assemblies. The laminated core and short-circuit ring are built for a maximum peripheral speed corresponding to 11000 rpm, so the structure can withstand centripetal stress during rapid acceleration. The electromagnetic circuit can transmit up to 205.4 Nm of torque when used with the matched inverter. An inertia of 0.097 kg·m² provides a balance between fast speed changes and vibration damping, which helps support contour accuracy on multi-axis machines.

The motor length follows code D, which aligns this rotor with stators of the same axial stack so the air gap remains symmetrical during operation. An outer diameter of 164.5 mm sets the press-fit boundary against the laminated core bore, and the rotor uses a step interference fit to create uniform frictional contact without additional locking compounds. The part is a Rotor for 1MB Frameless Spindle Motor and ships unbalanced so system-level balancing can be completed after the tool holder, encoder ring, and other rotating elements are installed. This arrangement allows the final rotating assembly to be balanced as a complete unit rather than as a standalone rotor.