Product Description:

The 1MR313F-A112 is a dedicated rotor component produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. Supplied as an insertable kit element, it forms the rotating core of a frameless spindle motor that drives high-speed milling, grinding, or turning spindles in automated machine tools. By combining low inertia with a continuous magnetic path, the rotor converts stator field energy into mechanical torque while allowing end users to build ultra-compact spindles directly into the machine headstock.

Its mechanical outline uses the 313 frame size, giving a large outer diameter that supports high pullout torque without extra flywheel mass. The inner rotor bore is 112 mm, a dimension selected to slide over the spindle shaft while still providing sufficient wall thickness for the embedded conductor bars. Motor length code F sets the axial stack height, balancing torque production with axial space inside the spindle cartridge. Because the rotor belongs to an open kit motor arrangement, there is no exterior housing, so cooling and enclosure are provided by the machine builder. A degree of protection of IP00 confirms that the kit is delivered completely open to ambient air and requires enclosure by the host machine.

The rotor is machined with a step interference fit so that the outer lamination stack locks tightly into the mating stator can without adhesives. Two axial retention points are provided by 2 set screws for the pressure-oil seal, preventing movement during high-speed rotation. A single 1 O-ring sits in the step-fit groove to stop lubricant from bypassing the oil seal and reaching the motor cavity. Listed as a rotor for a 1MB frameless spindle motor, the component completes the electromagnetic circuit once assembled with the matching stator and supports precise, high-speed spindle operation.