Product Description:

The 1MS270C-4B-A1/S040 is a rotating-field stator section produced by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. Serving as the stationary electromagnetic core of a frameless spindle package, it creates the three-phase magnetic field that drives a companion rotor in high-speed machine-tool, grinding, or routing spindles. By shipping the active lamination stack without bearings or end bells, the unit can be fitted directly into a machine-specific housing. This approach helps reduce overall spindle length and leaves the surrounding structure free to accommodate sealing, bearing support, and the cooling passages required for continuous operation.

In terms of physical envelope, frame size 270 sets the outside diameter and mounting circle suited to midsize machining centers, while length code C gives the stator an axial stack intended for moderate torque and quick acceleration. The electromagnetic layout follows winding variant 4B, which matches the electrical characteristics expected by compatible spindle inverters. Thermal loads are removed by liquid cooling, and coolant passes in close contact with an aluminum cooling jacket that surrounds the lamination stack. This arrangement supports high current density and helps maintain stable winding temperature during long operating periods at elevated spindle speed.

Electrical integration is simplified by a pre-terminated 1.5 m loom that exits the non-drive stator end for direct connection to the drive cabinet. The component is delivered as a stator for a 1MB frameless spindle motor, so its mounting surfaces and sensor pockets match standard 1MB rotor kits. Its frameless design allows the spindle builder to choose separate bearing sets and shaft dimensions for the final assembly. A dedicated liquid circuit runs through the jacket to support close thermal control when the spindle operates near maximum continuous current.