Product Description:

The 1MR140B-A045 rotor comes from Bosch Rexroth Indramat and belongs to the 1MB High-Speed Asynchronous Motors series. It is the rotating core used in direct-drive spindle assemblies, where magnetic fields from an external stator act on the laminated steel stack to create high angular velocity for machining centers and other CNC equipment. By supplying only the rotor, the product supports direct integration into the spindle housing and removes the need for belt or gear transmissions in suitable machine layouts.

With a frame size of 140, the rotor matches the outer diameter envelope used by corresponding stator laminations in the same motor family. An inside bore of 45 mm leaves clearance for drawbars, tool-release shafts, or through-spindle coolant lines. The unit tolerates continuous operation up to 23,000 rpm, a mechanical limit based on the stress capacity of the steel, the shrunk hub, and the balancing grade. Acceleration behavior is influenced by a mass moment of inertia of 0.0044 kg·m², which helps keep drive torque demand moderate while still damping speed ripple. For mechanical coupling, the journal is machined with a step interference fit, so the rotor grips the spindle shaft through thermal expansion without relying on keys.

Overall mass is limited to 3.3 kg, which helps reduce bearing load while still providing useful kinetic energy for cutting stability after rapid speed changes. The outer surface arrives completely processed, so no additional grinding or balancing is required before installation, and the concentricity set during production is maintained. Length code B indicates an axial stack size suited to medium power density in high-speed spindles. In this configuration, the component serves as a Rotor for 1MB Frameless Spindle Motor and is intended for direct installation within the spindle assembly.