Electric motors, generators and associated equipment are at risk when an electric current passes through their bearings. This can damage the contact surfaces of rolling elements and raceways in the bearings (electrical erosion) and rapidly degrade the grease. An additional risk in electric motors and generators comes from high frequency currents caused by the inherent stray capacitance. The risk of damage increases where the application uses a frequency converter.
are designed to prevent electric current from passing through the bearing
have the external surfaces of either their inner or outer ring coated with an insulating aluminium oxide layer, by applying a sophisticated plasma-spray process for an outstanding quality finish
are a very cost-effective solution compared with other insulation methods
Protection against electrical erosion
With insulating properties integrated into the bearing, INSULATION bearings can improve reliability and increase machine uptime by virtually eliminating the problem of electrical erosion.
High electrical resistance
The aluminium oxide coating provides a minimum electrical resistance of 200 M? and can withstand voltages up to 3 000 V DC.
Consistent electrical performance
Plasma-spray coatings are normally hygroscopic and, therefore, vulnerable to penetration caused by condensation. To protect against this effect,INSULATION bearings are treated with a unique sealant.
The standard assortment of INSULATION bearings listed here constitutes the most commonly used sizes and variants of:
single row deep groove ball bearings
single row cylindrical roller bearings
For bearing types and sizes not listed in the product tables (→ Deep groove ball bearings, Cylindrical roller bearings), contact DIMSON.
For applications where smaller bearings than those listed are needed, DIMSONrecommends using DIMSON Hybrid bearings.
In addition to the standard assortment, DIMSON can supply special INSULATION bearings and bearing units with complex ring geometries, such as:
Four-point contact ball bearings
Flanged tapered roller bearings
Tapered roller bearing units
Traction motor bearing units