Question 1

Why we use electrically insulated bearings

Accepted Answer

Motor bearings play an important role in the efficient operation of motors. Even with strict production control during motor manufacturing, it is difficult to completely avoid the magnetic asymmetry of the armature and rotor. This asymmetry generates a voltage between the stators. The current through the bearings is even worse, especially in AC motors. This current produces corrosion pits, fusion marks, galvanic corrosion marks, discolouration, abrasion and other damage on the bearing raceways and rolling element surfaces. Of course, motors with inverter and 0-converter technology also produce this phenomenon. In order to block the current flowing through the bearings, it is necessary to cut off the electrical circuit, so insulated bearings and insulated bearing housings are created.

Question 2

Where are electrically insulated bearings used?

Accepted Answer

1. Electric power industry: Insulated cylindrical roller bearings for generators, wind turbines, hydroelectric generators, and thermal generators. They are suitable for motors and generators, especially for variable frequency motors.

2. Railway industry: Insulated cylindrical roller bearings for diesel locomotive traction motors: used in locomotives, etc.

3. Machinery and metallurgical industry: Insulated bearings for high-power variable frequency motors: used in cranes, textile machinery, printing machinery, iron-making equipment, steel-making equipment, steel rolling equipment, cutting equipment, coking equipment, complete sets of smelting equipment, etc.

4. Mining machinery industry: Insulated bearings for high-power high-voltage motors, suitable for mining machinery, coal preparation machines, coal washers, crushers, ball mills, grinders, and sand mills

5. Petrochemical industry: Insulated bearings for high-power explosion-proof motors: used in compressors, etc.

Categories

Electrically Insulated Bearings

SKF bearing designation

FAG Germany Concrete Mixer Truck Bearing 801806

Original Japan 22208CAE4 spherical roller bearing 22208 Bearing

Cylindrical Roller Bearing NJ304

Good NSK 22205CE4C3 Spherical Roller Bearing 22205

High speed 22316 China Bearing Spherical roller bearing

Good China 24040 Spherical roller bearing for Fan

Good 71802 angular Contact Ball Bearing for Bike

Japan NTN 6205ZZ Deep Groove Ball Bearing Size Chart