Product Description:

The 1MS140B-4A-A1 is a stator module engineered for frameless high-speed spindle assemblies in industrial automation. It belongs to the 1MB High-Speed Asynchronous Motors series manufactured by Bosch Rexroth Indramat. Acting as the stationary field generator, the stator produces the rotating magnetic flux that drives a matched rotor when installed in a machine-tool spindle. By separating the active magnetic components from the mechanical shaft and bearings, the frameless design supports compact, low-inertia spindles used for precision milling, drilling, and grinding.

Heat generated by the windings is removed by liquid cooling through an integrated aluminum cooling jacket that surrounds the stator laminations. The connection cable is supplied as a 1.5 m loom and exits through the stator end, which helps simplify installation inside a spindle housing and reduces stress on the leads. With frame size 140, the outer dimensions match standardized rotor cores used in modular motor assemblies. This cooling method supports higher continuous power density because coolant moves directly across the jacket surface, helping limit thermal expansion and maintain coil insulation during sustained high-speed operation.

The unit uses motor length code B, which indicates the active stack height and affects the torque available for a given current level. Its winding variant 4A sets the conductor layout and turn count so the completed motor can operate within the voltage and frequency range used by high-speed inverters. As a stator for a 1MB frameless spindle motor, it can be combined with a matching rotor, bearing system, chuck, and sensor package in a custom spindle assembly. This arrangement gives machine builders flexibility in the mechanical design while keeping the magnetic section aligned with the established 1MB platform.