Product Description:

The 1MR310F-A118 is a rotor component engineered by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As a rotor for a frameless spindle motor, it converts electromagnetic torque from the stator into mechanical rotation that drives milling, drilling, or grinding tools in automated machining centers. The rotor is manufactured with a stepped interference fit so it seats tightly on the spindle shaft, preserves concentricity under high surface speeds, and reduces micro-slip that can cause vibration during continuous production service.

For motor frame size 310 with length code F, the rotor interfaces to the drive shaft through a bore machined to 118 mm H6, while the mating spindle lands at 118 mm s6 to maintain a controlled interference band. A balancing ring thread of M10 at the outer hub allows correction screws to be installed for residual imbalance adjustment after assembly. The inner fit length of 312 mm spans the stator stack so magnetic flux is fully used, and the overall rotor diameter reaches 228.7 mm, giving a large polar section for torque generation. Dynamic response is influenced by a moment of inertia of 0.723 kg·m², which the drive controller must overcome during rapid acceleration and deceleration.

The axial interface to the machining spindle uses a mating length of 315 mm, and the spindle must project at least 408 mm to prevent contact between the shaft nut and the stator end windings. Radial clearance is controlled by an outer diameter tolerance of -0.05 mm, which helps limit chatter at service speeds. The rotor weighs 95 kg, so lifting devices are required for safe handling. Lubrication oil is supplied through a pressure port threaded M6, and the stepped interference fit keeps the rotor locked without keys while maintaining runout accuracy during sustained high-speed duty.