Product Description:

The MST531L-0009-FT-N0SN-D303 stator belongs to the MST Synchronous Torque Motors series manufactured by Bosch Rexroth Indramat. As a liquid-cooled, permanent-magnet torque motor component, it is intended for direct-drive positioning axes where high continuous torque at very low rotational speed is required, eliminating gearboxes and minimizing mechanical backlash in automated machines such as rotary tables, plastic-processing screws, and printing cylinders. The unit is supplied without a motor encoder and pairs with an external feedback device selected by the machine builder.

Under continuous duty the stator delivers a rated torque of 5000 Nm at a shaft speed of 90 rpm. That operating point corresponds to a mechanical output of 47.10 kW, drawn from a phase current of 98.0 A. The windings present 0.53 Ω of resistance and 8 mH of inductance, so the drive amplifier must provide a smooth sinusoidal waveform to control current rise times. A back-EMF constant of 3.080 V min⁻¹ assists closed-loop voltage control. Liquid cooling removes copper and iron losses; to keep the stator below its thermal limit the circuit must circulate 16.5 l/min of coolant through the jacket. Electrical terminations accept 2 × 16 mm² signal conductors and a minimum 35 mm² power supply cable.

The application margin is defined by a peak torque ceiling of 12000 Nm, allowing brief acceleration phases without exceeding the magnetic loading of the laminated stack. With a torque constant of 51.00 Nm/A, the motor builds considerable torque per ampere, which simplifies inverter sizing. Magnetic energy is stored in an inductance of 8 mH, supporting stable current loops during high-load reversals. Thermal encapsulation improves heat transfer into the cooling jacket, and the stator mass is 158.0 kg, a factor for handling fixtures during installation.