First of all, understand the phenomenon and characteristics of bearing paint rust:
Paint rust mainly appears in closed motor or closed packaging storage motor.This
is mainly because the paint rust of the closed motor is not easy to
escape. The characteristics of the paint rust phenomenon are mainly as
1. Location: Usually in the south with high temperature and humidity and the coastal areas with high humidity.
Occurrence time: Usually in the sultry season, the proportion of the
motor entering the warehouse in April, May and June is the highest,
because the motor entering the warehouse at this time is prone to
condensation due to the change of climate.
3, motor type: usually closed motor or closed storage.
4. The paint rust of the bearing has obvious directivity. It is more serious near one end of the rotor than the other end.
The bearing grease where paint rust occurs has a special taste of paint
rust, which is similar to the smell of insulating paint.
the occurrence of paint rust phenomenon mostly occurs in the case of
solvent-based insulating paint, sometimes the use of no solvent-based
paint will also occur (drying time is insufficient).
Under the understanding: paint rust mechanism
production of bearing paint rust is affected by internal and external
comprehensive factors: motor bearing paint rust is caused by the
reaction caused by the acid molecules volatilizing from the insulating
paint of the motor stator and the moisture being absorbed by the grease
together.It is related to the type of insulating paint, the drying process of stator and the storage environment of the motor.When
using amino or phenolic base kind of insulating varnish, varnish is
extremely unstable in the molecular chain in sclerosis process to be
able to have low molecular material to escape.Such
as formaldehyde, when the temperature and humidity are appropriate,
formaldehyde reacts with water molecules in the weather to produce
formic acid, which will hydrolyze the grease and corrode the bearing to
produce paint rust.
infrared spectrum analyzer is used to analyze the taste of paint rust.
It can be seen that there is a unique absorption spectrum line of paint
rust, which is the same as iron formate pair (characteristic absorption
peak). It can be considered that rust is caused by formic acid.
Understand again, the cause of Qiu Xiu
induced by bearing paint rust refer to that, in the process of bearing
paint rust test, it is found that the severity of bearing paint rust is
closely related to humidity. It is generally believed that in the
environment of 70%RH, paint rust is easy to occur, which is consistent
with the imagination that the vast majority of paint rust occurs in the
southern or coastal rainy season every year.
1, climate environment: high temperature and high humidity
2, the stator drying is not complete;
3. Motor bearings are sealed and packaged in storage;
4, the severity of paint rust mainly depends on the composition of the paint base.
5, paint rust prevention (bearing seal and rust prevention, grease type)
Again, understand the characteristics of lacquer rust bearing:
bearing with paint rust is generally on the one side of the inner side
of the motor, and it will rust seriously. The oil near the edge of the
inner and outer ring will deteriorate first, which is generally
Finally, understand the bearing paint rust prevention countermeasures
sum up, the prevention of bearing paint rust must be considered in
terms of its mechanism, from the design and manufacturing of motor,
insulation and bearings. We will sort out the preventive measures as
1, avoid complete sealing, as far as possible to open pores;
The manufacture of traditional Chinese medicine must ensure the drying
time of insulating paint. It is best to place it in the ventilated place
after the drying of the stator to ventilate naturally so that the paint
gas can be completely released.
In the storage process of the warehouse, not close to the walls and
corners, with pallets on the ground to ensure ventilation, humidity
should be less than 70%RH.
the use of low molecular acid does not escape the stable type of
insulation paint (such as epoxy non-solvent insulation paint), and
strictly in accordance with the production process requirements.
5, in the selection of grease, grease with mineral oil as the base oil.
6, the use of sealed bearings.