Product Description:

Bosch Rexroth Indramat manufactures the MST290B-0018-FT-N0RN-NNNN as part of its MST Synchronous Torque Motors series. This frameless torque motor is intended for direct-drive rotary tables, indexing heads, or printing cylinders where slow, high-torque motion is required without mechanical gear reduction. By mounting the stator to the machine bed and the rotor to the load shaft, the unit delivers controlled continuous torque for precise positioning tasks in industrial automation.

Under nominal operating conditions the motor supplies a 220 Nm continuous shaft torque at a rated speed of 180 rpm, producing 4.1 kW of mechanical power directly at the load. To reach that operating point the windings draw a rated phase current of 14.8 A; the torque generation is dictated by the torque constant of 14.9 Nm/A, while the induced back-EMF follows a voltage constant of 1.64 V per rpm. The magnetic circuit presents an inductance of 35.3 mH and a DC resistance of 6.3 Ω, figures that influence current ripple and drive sizing. A discharge capacity of 8.41 nF and a minimum cable cross-section of 1.5 mm² complete the electrical connection data. The laminated stator package weighs 13.5 kg, facilitating compact machine integration.

For short acceleration or indexing moves the drive can deliver a peak torque of 460 Nm when the inverter supplies up to 60 A per phase. With 3.3 min of thermal time constant, the stator temperature follows current changes quickly, so duty-cycle calculations must consider heat accumulation during successive peaks. The electromagnetic design uses 30 pole pairs, explaining the high torque density at low rotor speed and the need for high-resolution position feedback. Combined, these overload, thermal, and pole-count characteristics enable precise direct-drive motion without mechanical reducers while keeping wiring and inverter ratings within practical industrial limits.