Product Description:

The 103H8221-5044 is a two-phase stepping motor produced by Sanyo Denki for the StepSyn Stepping Motors series. It uses a permanent-magnet rotor and sequential winding excitation to advance the shaft in fixed increments, providing precise open-loop motion control without an encoder. Integrators use this motor in feeders, small gantries, and metering pumps where repeatable positioning and low-speed torque are needed from a compact electromechanical actuator.

At full energization, the motor develops 2.74 N·m of holding torque, so the axis resists back-driving when the controller commands standstill. The mechanical resolution is set by the 1.8° per step pitch, which divides one revolution into 200 distinct positions and simplifies gear ratio calculations. Coil temperature rise is managed through a rated phase current of 2 A, which allows suitable drive transistors and power supplies to be selected for continuous operation. Dynamic response is influenced by the coil’s electrical characteristics. A phase inductance of 14 mH limits current slew during rapid step sequences, while the winding’s phase resistance of 2.3 Ω determines copper losses and voltage requirements. These electrical values affect the available speed and torque during microstepping or full-step excitation.

The NEMA 34-style frame measures 86 mm across and has four drilled mounting holes for direct attachment to brackets or gearheads. The single-shaft configuration simplifies the connection of pulleys, lead screws, or feedback devices on the driven end while keeping the opposite face closed. The motor has a total mass of 1.5 kg, which provides enough weight to help damp vibration without placing an excessive load on cantilevered mounts. Its rotor inertia is 1.45 × 10⁻⁴ kg·m², which should be matched to the load inertia so acceleration commands remain within the available pull-out torque during rapid indexing. Proper load matching also helps reduce missed steps when the motor starts, stops, or changes direction quickly.