In large high-speed motors, asymmetric heating of the shaft often occurs due to the loose fit between the rotor core and shaft, leading to unstable vibration. Therefore, a hot sleeve fit should be used between the rotor core and shaft of this type of motor, and a shaft with higher stiffness should be used as much as possible. Flexible rotors with operating speeds higher than the first or second critical speeds are particularly sensitive to thermal imbalance and require supplementary balancing during assembly.
Subcritical speed vibration
During the starting process of a horizontal motor, severe vibration may also occur when the rotor speed reaches half of its critical speed, which is due to the occurrence of the so-called subcritical speed. The difference in radial stiffness between two perpendicular rotors, such as the large teeth and wire grooves on the body of a bipolar turbogenerator rotor, and the keyways milled on the shafts of DC and AC motors to fix the iron core, commutator, and fan, are the reasons for the above phenomenon.
Vibration caused by ellipses
The ellipticity of the journal, like the difference in stiffness of the shaft in two mutually perpendicular directions, can cause vibration at twice the rotational speed frequency. In large high-speed motors, if rolling bearings are used and the journal diameter is above 100-120 millimeters, the ovality of the journal has a particularly significant impact on rotor vibration
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Product Overview:
Motor: microsecond motor
Motor series: G series
Voltage: 220V
Inertia: medium inertia
Frame size: 60 frames
Rated power: 400W
Rated speed: 3000rpm
Encoder type: 23 bit single turn absolute encoder
Brakes: without brakes
Shaft extension specification: straight shaft with key-IP65
Outgoing method: aerial insertion