Product Description:

The MST290D-0004-FH-N0PU-NNNN torque motor is produced by Bosch Rexroth Indramat as part of the MST Synchronous Torque Motors series. This frameless permanent-magnet unit is intended for direct-drive rotary stages where slow, smooth motion and high positioning accuracy are required in industrial automation. Its frameless design allows direct integration into the machine structure, which helps reduce backlash, coupling losses, and maintenance linked to mechanical transmissions. This layout is well suited to applications that need stable torque at low speed without relying on a gearbox.

At its continuous operating point, the motor delivers 350 Nm while turning at 45 rpm, producing 1.65 kW of mechanical power. This output is obtained with a phase current of 10.4 A, so drive sizing matches inverter capacity. The electromagnetic conversion follows a torque constant of 33.70 Nm/A, so each additional ampere raises shaft torque by that amount at a winding temperature of 20 °C. Back electromotive force develops according to a voltage constant of 2.190 V/rpm, establishing the voltage the drive must supply for a given speed. Thermal and electrical dynamics are influenced by 75.1 mH phase inductance and 13.9 Ω winding resistance, values that smooth current ripple and limit heating. Liquid cooling removes heat, and the rotatable power connector accepts 1.0 mm² conductors, simplifying cabinet routing.

For dynamic peaks, the winding can accept 30.0 A to reach a maximum torque of 700 Nm without magnetic saturation. The 20.0 kg stator assembly bolts to the machine through a housing jacket with a flange mount, giving a rigid interface that tolerates high process forces. A sealed coolant jacket keeps stator temperature within limits so overload intervals do not compromise insulation. Because the motor is supplied without an encoder, designers must add external feedback or operate in sensorless mode if the application permits. With all components enclosed, the motor forms a compact, gearless source of high torque for mixers, winders, and rotary positioning platforms.