Product Description:

The TBM-7615-A is a frameless brushless motor core manufactured by Kollmorgen as part of the TBM Frameless Motors series. It is supplied as separate rotor and stator components so integrators can mount the magnetic assembly directly into a custom housing, gearbox, or robotic joint. Doing so removes the extra mass of a traditional motor frame, which helps automation systems achieve lower inertia and tighter envelopes in articulated arms, gimbals, and spindle heads. By positioning feedback devices and load couplings close to the electromagnetic air gap, the motor also improves torsional stiffness and positioning accuracy in high-speed, closed-loop motion platforms.

The motor has a back-electromotive force constant of 6.85 Vrms/kRPM, which links mechanical speed to the generated phase voltage and helps with drive sizing. A torque constant of 0.113 N-m/Arms means that each ampere of sinusoidal current produces 0.113 newton-meters, making current control a direct torque command. When driven at its application point of 258 W, the motor can sustain rated mechanical output while spinning at 3930 RPM. Under continuous stall conditions, it resists load with 0.939 N-m of torque, with performance limited by winding temperature rise, phase resistance of 0.37 ohms, and inductance of 0.4 mH. Twelve poles help minimize cogging torque, while viscous damping of 0.00605 N-m/kRPM and static friction of 0.032 N-m affect speed regulation at low velocities.

For intermittent peaks, the electromagnetic circuit delivers 3.04 N-m of stall torque, allowing short bursts during acceleration or shock loading. The rotor carries only 0.0000304 kg-m² of inertia, so it responds rapidly to torque commands and minimizes servo lag. Total mass is limited to 0.435 kg, supporting lightweight end effectors where payload is at a premium. Supplied from a nominal bus of 48 VDC, the motor reaches its rated speed without exceeding typical low-voltage limits.