Product Description:

The BL-120E-20 is a brushless motor produced by Okuma for the BL Servo Motors series. Intended for CNC cells, this motor couples to the ball screw or belt pulley that governs the machine’s vertical slide. By translating electrical drive commands into precise shaft torque, it positions the Z axis so that cutting depths, tool clearances, or stacking heights stay within tolerance across repeated cycles. Its compact frame, matched windings, and feedback package allow tight positional loops without extra sensors, making the unit a common actuator in machining centers and palletizers.

For vertical duty, the motor is assigned the axis role of Z-axis drive, allowing the control logic to apply gravity compensation and regenerative braking profiles for downward motion. The stator receives up to 153 V DC from the inverter, and the thermal design permits a continuous phase draw of 12.1 A. Startup surges are handled by the associated BLd-A amplifier, which is rated at 50 A, so brief acceleration bursts do not trigger overcurrent faults. Rotor position is returned through a Type E incremental encoder mounted on the rear shaft extension. The motor is a servo unit, so electronic commutation remains in a closed loop during operation.

When commanded to its rated speed of 2000 RPM, the drive maintains sinusoidal commutation and continues to sample signals from the integrated encoder to correct load-induced drift. Motion control algorithms from Okuma keep this actuator synchronized with the other axes in the machine so coordinated cutting and rapid-traverse moves remain phase-aligned. This helps the Z axis stay consistent during feed moves, retracts, and repeated positioning cycles. As part of the BL Servo Motors family, the motor uses the same general feedback and cooling approach used throughout the series.