Rotor refers to a rotating body supported by a bearing. An object such as an optical disc that does not have a rotating shaft itself can be regarded as a rotor when it is rigidly connected or attached.
Typical rotors include turbine mechanical rotors, motor rotors, rotors for various pumps, and rotors for turbo compressors. When the rotor rotates at certain speeds, it will deform greatly and cause resonance. The speed at which resonance occurs is called the critical speed of the rotor.
In engineering, a rotor whose working speed is lower than the first-order critical speed is called a rigid rotor, and a rotor larger than the first-order critical speed is called a flexible rotor.
Since the rotor performs a high-speed rotational motion, balance is required. Static balance is mainly used to balance the inertial force of the disc rotor. The dynamic balance of the rigid rotor can balance the inertial force and the inertial force couple through a universal balancing machine, eliminating the vibration of the rotor on the elastic support.
The dynamic balance of the flexible rotor is more complicated, and it is distinguished from the principle by the vibration mode balance method and the influence coefficient method.
