What happens if an electrical current flows through the bearing?

What happens if an electrical current flows through the bearing?

When an electric current passes through a rolling bearing, electrical discharges take place through the lubricant between the raceways of inner and outer ring and the rolling elements. The heat, which is generated by the discharge, causes local melting of the bearing metal surface.

Why do electric motor bearings fail?

Corrosion. The finely finished surfaces of your motor bearing components are all subject to corrosion by water, acids, and other agents, which leads to the development of a deep seated rust along surfaces and ultimately motor failure.

What causes electrical fluting in bearings?

Electrical fluting occurs when a current is passed through the motor bearing instead of a grounded source. PWM (Pulse Width Modulated) drive switching frequencies result in undesirable motor shaft currents, a side effect that causes bearing damage within the motor through pitting and fluting.

What is current bearing?

Bearing currents occur when there is an induced voltage on the motor shaft that is high enough to over- come the breakdown voltage on the bearing lubricant.

What is bearing fluting?

What is Fluting? Fluting is a form of electrical damage suffered by electric motor bearings when alternating (AC) or direct (DC) current actually passes through the metal bearing. As the currents pass through the bearings, they can leave behind surface damage that results in premature bearing failure.

How do bearing get damaged?

The majority of bearing failures occur because of improper lubrication. Lubrication failure can occur if the wrong lubricant is used, if not enough lubricant is applied, or if the bearing has been exposed to excessive temperatures that have caused the lubricant to degrade. Corrosion & Contamination.

What causes bearing damage?

How do I know if my electric motor bearings are bad?

Ball bearings in motors can wear out without lubrication. Check for mechanical binding or seized bearings. If you feel resistance or hear rasping or scraping sounds when you rotate the shaft by hand, the bearings may be worn or seized.

What is fluting damage?

What is electrical pitting?

Electrical discharges in bearings may occur in shaft lines equipped with electrical machines. This effect, known as electrical pitting, consists of the removal of material from the pad surface; this can lead to bearing pad failure mainly because of overheating and reduced load capacity.