Product Description:

The 1MS240D-4A-A1 is a stator assembly supplied by Bosch Rexroth Indramat for integration with the 1MB High-Speed Asynchronous Motors series. Acting as the stationary electromagnetic core of a frameless spindle motor, it converts incoming three-phase current into a rotating magnetic field that interacts with a matching rotor. Within machine tools and other high-speed machining centers, the stator provides the torque-producing field while leaving flexibility for custom spindle layouts. This arrangement is useful where the motor must be integrated directly into the machine structure instead of packaged in a conventional motor housing.

It ships with a 1.5 m connection loom that is routed through the stator end, letting the winding leads reach the terminal area without external junctions. Dimensional classification follows Frame Size 240, giving an outside diameter suitable for mid-power spindles while maintaining a compact radial package. Axial depth follows Motor Length Code D, which sets the active stack height and affects continuous output capability. These dimensions also help determine how the stator fits around the rotor and how much installation space is required inside the spindle assembly.

Thermal regulation relies on liquid cooling, a closed circuit that removes copper and iron losses directly from the laminated core. The coil set uses Winding Variant 4A, which sets the turns count and conductor cross section for the intended electrical operating range. Heat passes through an aluminum cooling jacket, whose high thermal conductivity supports efficient transfer to the coolant path. Supplied as a stator for 1MB frameless spindle motor, the unit uses a frameless design that allows installation in custom housings and helps keep overall spindle diameter low. This layout also leaves access to coolant connections and electrical leads without requiring a separate external motor frame.