Product Description:

The PX-MBF250J-15TB-A is a permanent-magnet servo motor built by Okuma and positioned within the PREX Servo Motors series. As a servo actuator, it delivers closed-loop rotary motion to machine axes, enabling accurate position and speed control in CNC machining centers and automated material-handling stations. Its construction pairs stator windings with a rotor-mounted magnet set and a high-resolution encoder that returns shaft position to the drive for precise corrective commands.

At rated conditions, the motor delivers 2.8 kW of continuous mechanical power to the driven load. The stator is wound for a 3-phase supply, which keeps torque production balanced at every 120-degree interval. The rotor carries 6 magnetic poles, so each mechanical revolution spans three electrical cycles, a factor that influences controller resolution. When the windings are energized at 77 V, shaft speed stabilizes at 1500 rpm, enabling direct coupling to mid-speed machinery without external gearing. This operating point suits machine axes that require steady continuous output.

Control electronics must supply 32.6 A of running current while maintaining the stator frequency at 75 Hz to sustain the electromagnetic field that synchronizes rotor motion. Position feedback is provided by the ER-JG-7200D incremental encoder, giving the drive a consistent stream of angular data for tight velocity regulation and quick settling after command changes. This feedback, combined with the pole arrangement, supports smooth commutation across the operating range. The drive should stay within these current and frequency limits to avoid excessive thermal rise or demagnetization. Proper installation clearances, cable impedance, and cooling airflow help the motor operate within its electrical load limits over extended duty cycles.