Product Description:

The 1MS312C-4C-A1 stator is supplied by Bosch Rexroth Indramat for use in the 1MB High-Speed Asynchronous Motors series. As a frameless component, it integrates directly into spindle housings where limited space and high rotational speeds are required for CNC milling, drilling, or grinding. The stator provides the electromagnetic field needed for torque generation while allowing machine builders to customize the rotor, bearings, and encoder around it for high-speed spindle construction in automated production lines.

This model relies on liquid cooling circulated through its external jacket to extract heat, allowing continuous operation at elevated spindle speeds without thermal derating. The electrical system is configured for three-phase excitation, which delivers balanced current and helps minimize torque ripple in precision machining tasks. A connection strand diameter of 22 mm sets the passage size required through the machine frame for the bundled stator leads, while the power conductors use a 16 mm² cross-section to handle high RMS currents with acceptable temperature rise. Because the unit has an ingress protection rating of IP00, the surrounding spindle housing must provide complete environmental protection.

The stator uses an open kit motor design, so it ships without end bells or bearing seats and is intended to be clamped against a single front mounting face inside the spindle shell. A pre-terminated 1.5 m loom routed through the stator end simplifies routing toward the inverter cabinet, where open cable ends allow custom connector selection. Heat is transferred directly into the spindle housing through a sleeve with an aluminum cooling jacket, which improves thermal conductivity to the coolant circuit. The dedicated winding code 4C identifies the voltage constant and resistance values expected by matched 1MB drives.