Product Description:

Bosch Rexroth Indramat’s SF-A4.0125.015-04.000 is an AC servo motor in the SF Servo Motors series. Built for precision motion loops, it converts controlled current from a drive into controlled mechanical rotation for gantries, indexing tables, and automated tooling. The unit weighs 17.7 kg, is 324 mm long, and uses a 24 mm diameter by 50 mm shaft with a keyway and feather key so that torque is transferred without slip. This shaft arrangement suits direct coupling to machine elements that need repeatable torque transfer during starts, stops, and short indexing moves. A single-turn absolute STG encoder is mounted on the rear end to report position within one revolution, allowing the controller to recover the shaft angle after a power cycle.

The holding brake is sized for stationary load control and can apply 18 Nm of holding torque. It is released with 24 VDC supplied by the drive, and its release time is 50 ms. Brake current is only 0.7 A, which helps limit heat while the brake circuit is energized. The brake adds 3.1 × 10⁻⁴ kg·m² of inertia on the rotor side, which helps keep reflected mass low during axis motion. This combination is useful on axes that must remain in place when commanded motion stops or when the load applies a static force to the shaft.

For dynamic starts, the stator can deliver 14.5 Nm of locked-rotor torque while current is limited to 5.2 A, providing a controlled surge at the start of motion. After acceleration, the motor can run continuously at 1500 rpm, a moderate operating speed that balances throughput and bearing life. The electromagnetic design produces torque in proportion to current with a constant of 2.8 Nm/A, which helps the drive predict load response accurately. Combined inertia is 30 × 10⁻⁴ kg·m², and the 17.7 kg housing helps the motor maintain stable motion in repeatable servo applications.