Product Description:

The 1MR140H-A045 rotor is produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. This component is a separate laminated rotor core intended for integration into a frameless spindle motor, allowing machine builders to embed the drive directly into a milling or grinding spindle housing. Within an automation cell, the rotor converts the stator’s rotating magnetic field into mechanical speed needed for high-speed cutting and finishing operations.

Its dimensional profile governs how it mates with the shaft and bearings. The center bore runs through the rotor at 182 mm, giving clearance for coolant piping or drawbar actuation. Frame size 140 aligns the rotor with stators of matching diameter. External fit is controlled by a rotor outer diameter of 93.4 mm with a −0.05 tolerance, so the interference press into the spindle sleeve stays within a tight range. The rotor body is 245 mm long, while the steel laminations and copper squirrel cage bring the total mass to 7.3 kg. The spindle seat section measures 185 mm and the front spindle end adds 58 mm, allowing placement of tool retention hardware without extending shaft length.

The internal geometry supports mechanical balance and magnetic performance. An inside rotor diameter of 45 mm leaves material for the step interference fit that locks the rotor to the shaft. Magnetic polarity is fixed by 2 pole pairs, which sets synchronous speed limits and influences stator slotting. Dynamic response benefits from a moment of inertia of 0.0103 kgm², enabling rapid acceleration and deceleration. The shaft nose is finished to 57 mm for precise mounting of collet or chuck assemblies, and an M4 × 0.5 pressure-oil thread provides a path for hydraulic removal. Length code H identifies the variant and matches the corresponding stator stack.