Product Description:

Bosch Rexroth Indramat manufactures the 1MS240F-4A-A1 stator as part of the 1MB High-Speed Asynchronous Motors series. Designed as the fixed electromagnetic element for a frameless spindle motor, this component is integrated directly into machine-tool spindles to generate the rotating field that drives the paired rotor. By supplying self-contained cooling and cabling, the stator simplifies high-speed spindle construction and supports continuous duty cycles in industrial metal-cutting and composite machining centers.

The stator uses liquid cooling, circulated through an internal jacket, to remove loss heat while the magnetic field is energized at high frequency. The jacket is an aluminum cooling jacket, a material choice that combines thermal conductivity with low mass. Its dimensional classification uses frame size 240, which matches the outside diameter and mounting register to compatible rotor and housing hardware. Axial stack growth reaches motor length code F, so the active iron supports a torque envelope suited for large-diameter spindles. Copper conductors use winding variant 4A, which sets the slot fill, wire gauge, and current density for the intended speed range. Power leads exit through a pre-terminated 1.5 m harness, and the cable is supplied as a loom routed through the stator end so assembly does not disturb insulation integrity.

In operation, the stator couples tightly to the machine spindle housing. This frameless integration concept minimizes radial runout and allows the fluid manifold interface to align with the machine's coolant network without external hoses. Because coolant passes directly over the jacket, thermal gradients remain small, which helps preserve winding resistance stability and avoid derating during continuous power operation. The cable length also allows drive terminations to be placed outside the rotating envelope, which helps reduce electromagnetic interference inside the headstock cavity.