Product Description:

The TBMS-7631-A is a frameless torque motor set manufactured by Kollmorgen and supplied under the TBM Frameless Motors series. Because the stator and rotor are delivered without an outer housing or bearings, the assembly is pressed directly into a customer-designed structure. This configuration allows compact rotary axes that eliminate belts or gears, lower reflected inertia, and improve position accuracy in automation tasks such as articulated robots, gimbals, and semiconductor handling stages.

For continuous operation, the motor can hold 1.65 N-m of stall torque while drawing 8.9 Arms, a combination matched to moderate-load servo joints. Its nominal shaft speed is 2300 rpm, obtained when the winding is driven from a 48 V DC bus and kept within rated thermal limits. The system voltage is 48 VDC, and the phase-to-phase resistance is 0.398 Ω while the inductance is 0.6 mH, which affect current ripple and drive selection. A back electromotive force constant of 11.56 Vrms/kRPM indicates the generated voltage per speed unit and supports encoderless velocity estimation. The electromagnetic design also yields a torque constant of 0.191 N-m/Arms, providing a direct conversion factor between commanded current and mechanical output. Static friction is limited to 0.05 N-m, and viscous damping is 0.016 N-m/kRPM, which supports smooth low-speed motion.

During rapid acceleration or shock loads, the motor tolerates a peak stall torque of 5.37 N-m while momentarily accepting 29.4 Arms from the drive. Thermal loading is controlled so that the winding can deliver a continuous mechanical output of 307 W at rated speed. Dynamic response is aided by a rotor inertia of only 0.0000564 kg-m², allowing fast servo loops without excessive gain. The motor has 12 electromagnetic poles, which set the electrical frequency relationship and contribute to a smooth sinusoidal torque profile required in precision motion platforms.