High Quality Grease is Key to Preventing Rolling Element Bearing Failure

Because electric motors are invaluable to the daily operation of industrial facilities, failures of any kind can be disastrous.  Proper lubrication of rolling element bearings is essential to prevent bearing failure That can take motors out of commission and increase repair expenses and downtime.  According to Machinery Lubrication, the following are common causes of bearing failure:

Loss of Lubricant

Equipment failure caused by loss of bearing lubrication occurs when bearings are not regreased at proper intervals with the appropriate level of grease or when overheating causes the oil to separate from the base thickener.

Grease Incompatibility

Because not all grease are compatible, it is a good practice to ensure new grease is compatible with grease already in use.

Incorrect Grease

Ensure the proper grease is being used for the application.  Some bearing designs require extreme pressure (EP) greases to ensure optimum protection.

Grease Degradation

Grease hardening, chemical breakdown and oil separation are common types of grease degradation that seriously compromise protection.

Excess Lubrication

A problem seen primarily with open face bearings, too much grease churning in the bearing can lead to dramatic temperature increases.  Excess grease can also be pushed into the windings of the motor and lead to overheating and damage of electrical insulation.

                                Proper Lubrication of Rolling Element Bearings is Essential

                                to Prevent Bearing Failure That Can Take Motors Out of

                                Commission and Increase Repair Expenses and Downtime.

The following regreasing steps help ensure optimal bearing performance while minimizing failures:

1.) Because grease is less viscous under operating conditions, regrease bearings while the motor is running and hot or after the motor is removed from service (before the grease cools).

2.) Be sure the proper lubricant is in the grease gun.

3.) Thoroughly clean the areas surrounding the fill and drain fittings to ensure contaminants are kept out of the bearing cavity.

4.) Remove the drain fitting to allow excess grease to leave the bearing.

5.) Leave the drain plug out for the entire regreasing procedure.

6.) When the motor is running at normal operating temperature, add the proper quantity of grease or add it slowly until it starts to move into the relief tube.

7.) After excessive grease has been purged, reinstall the drain plug and clean any extra grease from the drain area.

When regreasing is completed, check motor noise and vibration to establish a baseline and measure them again at regular intervals.  Inspect lubrication upon any sudden or significant change. Monitor and trend motor bearing temperatures.  Increasing temperatures could indicate a problem with a bearing, an over greasing issue or a need to renew the grease.  high frequency noise output or vibration levels are also signs of a bearing lubrication problem.

AMSOIL Synthetic Multi-Purpose Grease

Composed of premium quality synthetic base oils and lithium complex thickeners, AMSOIL SYNTHETIC Multi-Purpose Grease is ideal for rolling element bearings, providing superior film strength, shear resistance, adhesion properties and mechanical stability.  It excels in temperature extremes and is compatible with many other types of grease. NLGI #2 (Part #GLC) is recommended for regular to hot temperatures, while NLGI #1 (GLB) is recommended for colder temperatures, some centralized lubrication systems or high speed bearings.