Shaft Power from Torque and Speed
Shaft Power from Torque and Speed
Rotating machinery is rated by power, which is the product of torque and angular speed. This is the bridge between a motor’s nameplate and the torque a shaft must carry.
Rotational power is P = T·ω. where T is the torque and ω the angular velocity in radians per second.
Inputs
T := 150 N·m=150 Nm
omega := 157 rad/s=157 Hz
Multiply torque by angular velocity to get power.
P := T·omega=23550 W
Results
The result is the transmitted power. For a fixed power, torque and speed trade off inversely — which is exactly what a gearbox exploits.
Assumptions & limitations
- Steady-state rotation, constant torque.
- No transmission losses.
- Angular speed expressed in rad/s.