6320/C3VL0241 SKF INSOCOAT Deep Groove Ball Bearing 100x215x47mm

Prevention of electric erosion in bearings

SKF electrically insulated bearings, called INSOCOAT, are designed to protect a bearing against electric current passage. By inte - grating the insulating properties into the bearing, INSOCOAT bearings can improve reliability and increase machine uptime by virtually eliminating the damaging effect of electrical erosion in applications including:

Industrial electric motors
Traction motors
Generators

The effects of stray electric current
Electric current passing through the bearing can cause micro-cratering on the raceways of the inner and outer rings and on the roll - ing element surfaces. Heat generated by the electrical discharges causes local melting that creates micro craters and changes in the structure of the metal, which can be recognized as a dull grey discolora - tion of the raceways. If such a bearing continuous to be operated, further a wash - boarding pattern may develop as a secondary damage. Local high temperatures cause the additives in the lubricant to char or burn the base oil. This causes the additives to be consumed more quickly. In the case of grease lubrication, the grease turns black and hard. This signiicantly shortens grease life, leading to shorter bearing service life. Once bearing damage from electric erosion has progressed, increased noise levels, reduced effectiveness of the lubricant, increased heat and inally excessive vibration can all contribute to signiicantly decreased bearing service life.

A cost-effective solution
INSOCOAT bearings are a very cost effective solution for protecting bearings against damage or failure due to passage of electric current through the rolling contacts. The total cost of INSOCOAT bearings is lower than shaft or housing insulation

INSOCOAT bearing designs
INSOCOAT bearings have an aluminumoxide coating on the external surfaces of the outer ring or the inner ring. The coating is sealed with a resin to provide stable electrical properties in humid environments. Bearings with an electrically insulting coating provide enhanced protection against electric current damage. The enhanced protection results from the increased impedance due to the smaller coated surface area. The basic coating is tested to withstand voltages of at least 1 000 V DC. Coating variants with the capability to withstand higher voltages can be supplied on request. The standard range of INSOCOAT bearings in the most frequently used sizes and variants are available from stock

INSOCOAT bearings with coated outer ring
Bearings with an electrically insulating coating on the external surfaces of the outer ring are the most common INSOCOAT bearings.
Bearings with a coated outer ring are identiied by the sufix VL0241.
Outer ring coated INSOCOAT bearings are recommended for medium-size motors, that use bearing sizes smaller than 6226, 6324.
INSOCOAT bearings with an outer ring coating are suitable for all types of housings.
Outer ring coating can be applied to bearings with an outside diameter > 80 mm.

INSOCOAT bearings with coated inner ring
Bearings with an electrically insulating coating on the external surfaces of the inner ring provide enhanced protection against electric current damage. The enhanced protection results from the increased impedance due to the smaller coated surface area.
Bearings with a coated inner ring are identiied by the sufix VL2071.
Inner ring coated INSOCOAT bearings are recommended for larger-size motors, that use bearing sizes from 6226, 6324 or other applications where the bearings risk being subjected to high shaft voltages.
Inner ring coating can be applied to bearings with a bore diameter > 70 mm.

Principal dimensions
d: 100mm
D: 215mm
B: 47mm

Basic load ratings
Dynamic: 174 kN
Static: 140 kN

Fatigue load limit: 4.75 kN

Speed ratings
Reference speed: 6700 r/min
Limiting speed: 4300 r/min

Mass: 7.00 kg