Product Description:

The 1MR310B-A120 is a rotor supplied by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As a dedicated rotor for 1MB frameless spindle motors, it forms the rotating element that couples to the stator to generate torque in high-speed machining spindles used throughout automated production lines. The component is delivered as a bare rotor so that machine builders can integrate it into custom housings and balance it to the specific dynamic requirements of their spindle designs.

The rotor has a frame size of 310 and an inside rotor bore of 120 mm, dimensions that govern the shaft diameter and the allowable bearing arrangement inside the spindle. The laminated core has 3 magnetic pole pairs, which influence synchronous speed and drive-side frequency selection. With a rotational inertia of 0.477 kg·m², the rotor stores moderate kinetic energy, enabling rapid acceleration without excessive load on the inverter. A stepped interference fit is used, and motor length code B corresponds to the active core length within the 1MB series. Lubrication during installation is supported by floating oil with a viscosity of 300 mm²/s, and two pressure-oil ports simplify delivery of the lubricant to the joint during assembly.

During thermal mounting, a seating force limit of 500 N protects the shaft and bore surfaces, while the shrink-fit window ranges from 180 °C to 200 °C to establish the correct interference without distorting the laminations. After service life, removal oil with a viscosity of 900 mm²/s can be injected to release the joint before extraction from the shaft seat. The complete rotor weighs 54.2 kg, so handling equipment must be sized accordingly. Its open construction carries an IP00 protection code, so it must be enclosed by the spindle housing during operation.