Product Description:

The MST291C-0018-FT-N0CN-D303 is a frameless permanent-magnet torque motor built by Bosch Rexroth Indramat and supplied within the MST Synchronous Torque Motors series. As a direct-drive component, it mounts inside rotary tables or indexing heads and provides high stall torque at very low speed, eliminating gearboxes in industrial positioning systems. The motor couples directly to the load, so precise angular control is achieved through the connected drive electronics. Its electromagnetic design relies on multiple pole pairs to produce smooth, ripple-free rotation during process cycles.

Under continuous duty, the motor delivers 6.74 kW of mechanical power while turning at 230 rpm. At that speed, it provides 280 Nm of shaft torque and draws 16.9 A from the drive amplifier. The torque generated per ampere is given by a constant of 16.57 Nm/A, which assists the controller in precise current regulation. With fifteen pole pairs, the machine synchronizes to low electrical frequency, enabling high resolution in feedback systems. Its copper windings exhibit a resistance of 3.9 Ω at 20 °C, and the rotor can sustain 295 Nm in standstill to keep fixtures locked between indexing moves.

Intermittent process peaks are handled by a ceiling torque of 620 Nm and by supply capability up to 42.2 A. A short thermal time constant of 5.0 min means the stator temperature follows load changes quickly, so drive software can apply time-weighted overload curves for protection. The phase inductance of 34.3 mH slows the current rise enough to filter inverter switching edges, reducing bearing currents. Installation is eased by an M5 fastening thread that is 11 mm deep in the housing. Power conductors use 2.5 mm² cable, while AWG 12 leads connect to the field supply and 0.5 mm² conductors carry control signals without requiring external junction boxes.