Product Description:

The MRS203C-C085-NN is a rotor supplied by Bosch Rexroth Indramat for the MRS Synchronous IndraDyn H Motors series. As the rotating element of a spindle-class synchronous motor, it couples with a stator kit to generate the torque needed for high-speed machining centers and other precision automation equipment. The product uses an open kit design, allowing machine builders to mount the magnetic core directly on their shaft and integrate custom cooling and bearing structures without the constraints of a fully enclosed housing.

This rotor has a frame size of 203, giving it an outside geometry compatible with large-diameter stators while keeping inertia moderate for fast acceleration. The lamination stack has a bore measuring 85 mm, allowing installation on thick motor shafts or drawbar assemblies used in spindle heads. Magnetic coupling produces an axial attractive force of 460 N, so the spindle thrust bearings must accommodate this load during operation. A radial attractive force of 621 N acts toward the stator yoke and influences bearing preload in the radial direction. The component has a protection rating of IP00, indicating that it has no integral enclosure and requires machine-level safeguards against contact and contamination.

The permitted ambient temperature range is 0–40 °C, so additional cooling is required if the spindle chamber exceeds this range during continuous operation. Installation is limited to elevations up to 1000 m above sea level because thinner air at higher elevations reduces heat transfer from the rotor surface. Windings used with this rotor require Class F insulation to withstand the expected temperature rise. Electrical excitation is supplied through a three-phase synchronous drive, which produces the rotating magnetic field needed for controlled rotor motion. The C-length frame provides the stack depth needed to calculate torque, magnetic pull, and drivetrain dynamics for the integrated spindle assembly.