Product Description:

The 1MR241D-A098 rotor is supplied by Bosch Rexroth Indramat as a component of the 1MB High-Speed Asynchronous Motors series. It is a rotor for 1MB frameless spindle motors, intended to be built directly into machine tool spindles where high circumferential speeds and compact envelopes are required. Within an automation line, this rotating element couples with a stator to generate torque for milling, drilling, or grinding heads, allowing the host CNC system to maintain precise speed control during rapid material removal. Because it is a frameless rotor, the surrounding spindle structure provides the bearing support and enclosure.

Its frame designation of 241 establishes the overall radial envelope and aligns with standardized stator laminations in the same series. An outer rotor diameter of 180.9 mm sets the working air gap, while an inside diameter of 98 mm accommodates the spindle shaft and thermal expansion sleeves. The internal bore tolerance is specified as H6, supporting concentric mounting without excessive clearance. A rotor body length of 205 mm provides an extended magnetic path for higher power density. The design uses a step interference fit that locks the rotor core to the 127 mm shaft seat, and the 24.7 kg mass must be considered during handling and assembly.

A balancing ring thread of M8 permits attachment of correction weights to fine-tune residual imbalance. A pressure-oil connection thread of M6 supports hydraulic mounting or removal procedures that ease service work. The rotor’s mass moment of inertia is 0.135 kg·m², and it affects acceleration times and drive controller tuning. With a protection rating of IP00, the part offers no inherent guarding, so it must operate inside a fully enclosed spindle housing that supplies coolant flow, environmental sealing, and protection against accidental contact.