Product Description:

The 1MS243F-4Y-N1 is a stator assembly supplied by Bosch Rexroth Indramat for the 1MB High-Speed Asynchronous Motors series. As a stator for 1MB frameless spindle motors, it forms the stationary electromagnetic field that drives high-speed machine tool spindles and other precision automation axes. The component is delivered without end bells or housing so that integrators can embed it directly in a custom spindle frame, minimizing inertia while keeping the drive package compact.

The stator is liquid-cooled, and a closed circuit using water removes heat from the laminations and windings, allowing continuous operation at high surface losses. Its enclosure rating of IP00 means the installation must provide its own mechanical guarding and contamination control. Power and sensor conductors arrive in a 1.5 m loom that exits through the drive end of the stator, reducing junction points inside the spindle. The mechanical size corresponds to length code F, which sets the stack height and magnetic surface area within the 243 frame. Thermal endurance follows class 155 (F), so insulation remains stable up to 155 °C. Electrical termination is implemented as wires with open ends, enabling direct soldered, crimped, or terminal-block connections to the drive cabinet.

The internal cabling follows the bundle pattern of 3x power, 4x KTY, 4x NTC, 4x bimetallic leads, supplying three-phase stator current and several temperature-monitoring paths. Ambient operating limits span 0 °C to 40 °C, and installation altitudes are permitted up to 1000 m without output derating, which matches common factory conditions. Bosch Rexroth seals the windings with a protective varnish that resists moisture ingress and vibration, but the open construction still requires a cooled spindle housing to shield the active laminations. This format suits machine designs that place the motor’s active parts directly inside the spindle structure.