290 W three-phase servo with holding brake — SH3 series fit
The SH30551P01F1000 is a three-phase servo motor from the SH3 series, rated 290 W continuous power with an integrated holding brake (0.8 N.m holding torque). Nominal speed depends on supply: 2000 rpm at 115 V single-phase, 4000 rpm at 230 V single-phase, and 8000 rpm at 400 V or 480 V three-phase — the 8000 rpm ceiling makes this a high-speed spindle or light-axis motor, not a direct-drive low-speed torque motor. The absolute single-turn SinCos Hiperface encoder gives position feedback on power-up without a homing cycle — critical for applications where the machine must resume from the last known position after a power loss or emergency stop.
Mounting and shaft — 55 mm flange, smooth shaft
Motor flange size is 55 mm with a 40 mm centring collar and 2 mm collar depth — mounts to the international standard flange pattern (IEC 60034). Smooth shaft, 9 mm diameter, 20 mm shaft length — no keyway, so the coupling or pulley must be clamped or use a set-screw hub. The smooth shaft simplifies balancing at high speed but requires a positive-lock coupling to prevent slip under the 1.5 N.m peak stall torque. IP protection is IP54 at the shaft bushing without the seal ring, IP65 on the motor body and with the shaft seal ring installed — the seal ring is the difference between a dry-machine fit and washdown-capable mounting.
Torque and thermal limits — what the numbers mean for the drive tune
Nominal torque is 0.5 N.m on single-phase supplies, dropping to 0.35 N.m on three-phase 400/480 V — the motor delivers less sustained torque at higher voltage because the winding current limit (2.9 A) is the same, but the back EMF at 8000 rpm reduces the available current for torque production. Continuous stall torque is 0.42 N.m across all supply voltages — this is the torque the motor can hold at zero speed indefinitely without overheating, limited by natural convection cooling. Peak stall torque reaches 1.5 N.m for acceleration or short overloads. Torque constant is 0.58 N.m/A at 120°C copper temperature — the drive's current loop must be tuned to this value. Stator resistance is 41.8 Ohm and inductance 37.13 mH, which sets the electrical time constant and the minimum PWM frequency for smooth current regulation.
Radial and axial load limits — bearing life at speed
Maximum radial force derates with speed: 340 N at 1000 rpm, dropping to 170 N at 8000 rpm — a belt-driven load must be sized against the 8000 rpm limit, not the static rating, or the bearing will fail prematurely. Maximum axial force is 40 N — this is a light axial load rating; any thrust load from a helical gear or fan must be verified against this ceiling.