Product Description:

The 1MS240H-4B-A1 is supplied by Bosch Rexroth Indramat and belongs to the 1MB High-Speed Asynchronous Motors series. It is not a complete motor, but a stator subassembly intended for integration into a frameless spindle motor, where it forms the stationary electromagnetic field system around a separate rotor. In machine tools and other high-speed automation equipment, this part provides the magnetic drive component that produces torque after it is paired with the matching rotor and drive electronics.

Electrical terminals are pre-wired to a 1.5 m loom that exits through the non-drive side stator end, so connections can be made without opening the winding package. Heat generated by copper losses is removed through liquid cooling, with coolant circulating directly around the lamination stack to support continuous spindle duty at high power density. The stator belongs to frame size 240, giving it an outer diameter suited to large-format milling or grinding spindles. Its motor length code H indicates an extended axial core that increases total slot area for higher output without increasing the radial envelope. The winding pitch and insulation system align with the drive parameters used across this high-speed spindle platform.

The active iron is enclosed by an aluminum cooling jacket that forms the liquid passages and provides a rigid mounting flange. Within the laminated core, the phase set follows the 4B winding variant, which sets the number of turns per coil and matches the impedance expected by matching inverters. When combined with a rotor, encoder, and balancing hardware, the assembly fits directly into the 1MB High-Speed Asynchronous Motors platform. As a frameless stator, it allows bearing placement to be set by the machine design while still using factory-produced electromagnetic components.