Shaft current of high temperature bearing shaft current is what what's the harm?
Shaft voltage and shaft current voltage are the two high temperature motor shaft impact bearing side or motor through a shaft and the high temperature lead to bearing, generated by the voltage between ac asynchronous motor is running under sinusoidal alternating voltage, the rotor of the motor is running in the sinusoidal alternating magnetic field.
When motor stator be dead on the direction of the circumference of unbalanced magnetic resistance attack, occurs with axis chain of alternating magnetic flux, which can produce alternating voltage, when the motor work to produce a rotating magnetic pole direction, through the magnetic pole of the magnetic flux attack some of the changes, and then the flux of fellowship with shaft chain.
Alternating with the axis of the magnetic flux cross change the rotation of the pole, it generates an electrical finale.
The voltage produced by axial extension, if with a closed circuit on direct contact with high temperature bearing on both sides of the shaft, the shaft of the electric current.
On the other hand, during the motor work on rotating parts produced by friction static charges of fluid load operation, can produce a buildup in the charge of shaft voltage.
By this kind of situation, and through the agency of shaft voltage alternating axis voltage is different.
Static charges of shaft voltage is intermittent, and can be periodically, its size and operation condition, relationship between the state of the fluid elements such as there is a big.
Shaft voltage under ordinary living conditions as long as 0.
5 ~ 2 v or so, but because of the current control loop impedance effect is very small, so we will have a very big by producing shaft current, high temperature of motor bearing endangers a lot.
The harm of shaft current generated under normal circumstances, between shaft and high temperature bearing has a smooth film, have the effect of insulation.
About the shaft voltage, this film of lubricating oil can still maintain its insulation, do not produce the shaft current.
When the shaft voltage rise to a certain value, especially the motor starts, smooth in the high temperature bearing oil film instability, will break through the oil film shaft voltage and discharge, shaping circuit, causing various harmful accident.
It can be seen that the axial voltage is internal components, analysis of the axial current is the key to distinguish between the axial voltage.
In the process of the motor running, if high temperature bearing roller at both ends and high temperature between the bearing ring or between the motor shaft and high temperature bearing axial current, can greatly shorten the service life of high temperature bearing.
Fine can run thousands of hours, serious can only for a period of a few hours or less, has a great influence on site safety consumption.
Low melting point alloy blow molding sliding bearing temperature shaft current us from a high temperature will affect the bearing and shaft metal contact management, because the metal contact point is very small, so for the current density of the point, suddenly produce a kind of high temperature, the high temperature lead to bearing parts burning-out, burned the high temperature of melt and bearing under the action of ground pressure and its alloy splash, so in the high temperature burn out small pits or protect the bearing inner appearance appearance is pressed out of the strip in high temperature bearing arc scars.
2 high temperature rolling bearing lock or apart rolling table in vitro and high temperature affect the bearing ring raceway appearance of shaft current ablation, light fever, temperature anomalies, lock each other or apart, the person that weigh can trigger over current maintenance system downtime, and eventually cause burning a motor.
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