Product Description:

The 1MR160D-A040 is a rotor subassembly produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. It functions as the rotating element in a frameless spindle motor, transferring electromagnetic torque to the machine tool spindle while relying on the stator for excitation. The step interference fit of this rotor ensures a secure mechanical bond with the shaft to handle high radial forces during continuous machining duty.

The rotor's dimensional profile governs its compatibility with the surrounding stator and spindle housing. A finished outside diameter of 106.3 mm with a -0.05 mm tolerance sets the running clearance inside the laminated core, while an inside diameter of 40.0 mm accommodates the drawbar or hollow shaft common in high-speed spindles. The mass of 7.3 kg directly affects gyroscopic loading and bearing life under rapid acceleration. Its polar inertia of 0.012 kg·m² influences the servo response time; lower inertia enables faster speed changes but demands higher motor current. A minimum spindle length requirement of 152 mm confirms the axial space needed to seat the rotor, labyrinth seals, and preload components without causing axial compression.

The frame size is 160, aligning the rotor with stators that share identical lamination outside diameters and cooling jackets. Two pole pairs, indicated by the value 2, determine the synchronous speed window when the drive frequency rises into the tens of kilohertz typical for grinding or drilling. The motor length code of D indicates a mid-range active length within the 1MB family, balancing torque output against spindle overhang. To secure balance weights or correction screws, the rotor hub includes an M6 thread for the balancing ring, supporting precise trim during high-speed balancing procedures.