Product Description:

The MST290E-0004-FT-N0CN-D303 stator is a synchronous torque motor component produced by Bosch Rexroth Indramat within the MST Synchronous Torque Motors series. As a direct-drive element, it mounts inside rotary tables, indexing heads, or winders to supply high torque at crawl speeds, eliminating mechanical gearboxes and improving position accuracy in automated assembly, forming, and test equipment. Its frameless construction allows the motor to become part of the machine structure, which helps reduce compliance in rotary axes.

At its continuous operating point, the stator produces 575 Nm while rotating at 40 min⁻¹, a combination that delivers 2.40 kW of mechanical output for slow but forceful motion. The windings draw 12.5 A during this duty point, yet the inverter may apply up to 50.0 A for short periods to overcome static friction or accelerate payloads. Each ampere adds torque according to the constant of 46.00 Nm/A, which simplifies current-based control algorithms. Heat generated by 8.2 Ω of winding resistance and core losses is carried away by a cooling circuit that must supply 9.0 L/min of fluid. Electrical design considerations include 21.0 nF of leakage capacitance that limits common-mode displacement currents, and a 49.5 mH inductance that damps high-frequency switching so the current loop remains stable.

Transient capability and thermal behavior set the remaining limits. The assembly can reach 1150 Nm of peak torque for indexing strokes, and it sustains 610 Nm at standstill without cogging. With a thermal time constant of 3.3 min, overloads of a few minutes are possible before the stator approaches its allowable winding temperature. The magnetic circuit incorporates 30 pole pairs, which enables precise commutation at the electronic speed ceiling of 145 min⁻¹ and keeps torque ripple low. A voltage constant of 3.620 V min⁻¹ couples with the back-EMF, so the drive must provide adequate bus voltage during startup and at standstill.