Product Description:

The MST290B-0018-FT-N0CN-NNNN is a frameless stator assembly in the MST Synchronous Torque Motors series manufactured by Bosch Rexroth Indramat. As a low-speed, high-torque synchronous motor component, it is intended for direct-drive rotary tables, extruders, and similar automation axes where gearboxes can be eliminated. The stator pairs with a matching rotor to generate precise constant torque at very low speeds, delivering smooth motion for closed-loop servo control in packaging, printing, and material-forming equipment. Because the assembly is frameless, it is meant to be integrated directly into the host machine, which helps reduce backlash sources and other mechanical transmission parts that can affect positioning smoothness.

At its continuous operating point, the stator develops a 220 Nm rated torque while turning at a 180 rpm rated speed, translating into 4.10 kW of power at the shaft. Supplying this load requires a 14.8 A rated current, and each ampere contributes nearly constant torque because of the 14.90 Nm/A torque constant measured at 20 °C. Electromagnetic behavior also depends on a 34.8 mH phase inductance and 6.6 Ω phase resistance, which influence current rise time and thermal losses. The laminated stack has a 105 mm axial length, an inner diameter of 200 mm that fits around large spindle bearings, and an outer diameter of 310 mm. A mass of 13.5 kg supports installation in compact direct-drive housings without adding unnecessary bulk.

Transient demands are handled through a 460 Nm maximum torque that becomes available when the converter supplies a 60.0 A maximum current. When motion pauses, the active windings hold position with a 245 Nm standstill torque, which helps resist drift during indexing and dwell periods. Continuous thermal stability is maintained by circulating coolant at a 5.0 l/min coolant flow, removing copper losses and supporting repeated overloads without exceeding insulation limits. This cooling arrangement is useful on rotary tables and other high-inertia axes that spend long periods producing torque at low speed, where natural airflow would not remove heat effectively.