Product Description:

The 1MS140B-4B-A1 is a stationary motor element manufactured by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. Supplied as the electromagnetic core of a high-speed spindle assembly, it produces the rotating field that drives the matching rotor in CNC milling, grinding, and drilling centers. Integrating this field-producing section directly inside the machine spindle housing allows builders to reach elevated peripheral speeds, minimize drivetrain mass, and maintain a compact envelope suitable for high-demand metal-cutting environments.

This model relies on liquid cooling, so heat is removed through an external circuit instead of ambient airflow, keeping stator winding temperatures stable during continuous high-frequency operation. It follows the dimensional envelope assigned to frame size 140, giving a 140 mm lamination diameter that suits the spindle bore it can occupy. The active length corresponds to motor length code B, indicating a medium axial stack height that balances torque output against installation depth. Thermal transfer is enhanced by the integrally cast aluminum cooling jacket, which routes coolant around the outside of the laminations. Magnetic characteristics are tailored by winding variant 4B, a coil configuration selected to match the voltage, frequency, and power targets of high-speed drives.

Electrical interfacing is handled through a 1.5 m loom that exits as a pre-terminated connection cable. Routing it through the stator end keeps the external profile smooth and reduces snag points inside the spindle sleeve. Because it is delivered as a complete stator for a 1MB frameless spindle motor, the unit can be pressed into a bearing cartridge and paired with a rotor without additional machining. This cable orientation simplifies routing through the machine column, keeps wiring orderly inside the spindle housing, and permits final winding tests before the spindle assembly enters the production line.