rotors

A rotor is the rotating part of a machine that interacts with stationary components to transfer energy, produce torque, or convert energy between forms. Rotors appear in a wide range of devices, including electric machines, turbomachinery, rotorcraft, and centrifuges.

In electric machines such as motors and generators, the rotor is the moving element inside the stator. It may carry windings in wound-rotor designs or consist of laminated conductive bars in squirrel-cage rotors. The rotor is typically separated from the stator by an air gap and must be precisely supported by bearings and cooled as it turns. In induction machines the rotor speed differs from the stator field by slip, while in synchronous machines the rotor carries a direct current excitation or permanent magnets. Laminations reduce eddy currents and improve efficiency.

In turbomachinery and drive systems, rotors are shafts with blades or vanes that impart energy to or extract energy from a fluid. Turbomachine rotors operate at high speeds and require careful balancing, vibration control, and thermal management. Turbines, compressors, and pumps rely on rotor assemblies to function correctly.

In rotorcraft, the main rotor provides lift by acting as a rotating wing, while auxiliary rotors such as a tail rotor or fenestron counteract torque and contribute to yaw control. Blade pitch and rotor speeds are actively controlled to manage thrust, stability, and maneuverability.

Other applications include centrifuges, flywheels, and spindle motors, where rotor design emphasizes rigidity, durability, and reliability. Rotor health is monitored for balance, cracks, and bearing wear to maintain performance and safety.