Product Description:

The 1MR240B-A087 rotor is produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. It serves as the rotating core of a frameless spindle package, pairing with a separate stator to create the torque required for milling, drilling, and grinding heads used in automated machining centers. Its geometry, threads, and interference features are tailored for compact housings where high rotational speed and precise balance are critical.

This rotor is built on Frame Size 240 with Motor Length Code B, two dimensional markers that let machine designers select a matching stator and housing depth. The outside diameter is machined to 163.9 mm with a –0.05 mm tolerance, ensuring consistent interference against the spindle sleeve. A center relief diameter of 88 mm removes excess mass while keeping the hub rigid. Dynamic capacity reaches 11000 rpm, giving the spindle sufficient surface speed for aluminum and composite cutting. A balancing ring thread of M8 accepts correction screws, and a pressure-port thread of M4 × 0.5 admits oil–air lubrication; both threaded points streamline assembly and maintenance. The rotor’s stepped interference-fit design further locks the hub in place during rapid acceleration cycles.

The mounting interface is completed by a main bore of 87 mm, an end bore of 87.2 mm, and a secondary bore of 86.8 mm; the graduated diameters enable progressive seating on the spindle shaft without tensile overstress. Final trim balancing occurs at thread M8, keeping vibration within ISO limits once the unit is coupled to the stator. Together, the bore geometry, balance provisions, and interference steps maintain predictable radial runout, thermal growth, and centrifugal loading, supporting closed-loop control of spindle position and desired surface finish quality in continuous production environments.