Electric Motor Bearing Grease Selection

Another crucial factor for electric motors is energy efficiency.

Electric motor bearing grease selection. 3 c p load ratio where c basic dynamic load rating kn and p equivalent dynamic bearing load kn. When applied correctly the right grease will protect your electric motor s bearing against damaging corrosion reduce wear caused by friction and act as a seal against contaminants. This too is highly influenced by bearing selection. Regularly greasing your electric motor bearing is an important part of electric motor maintenance.

This will help to insure maximum. While most would not use an ep 220 gear oil for an oil lubricated electric motor bearing many people will use a grease containing that same oil for an identical grease lubricated bearing. With the motor running pump fresh grease into the bearing while observing the old grease that is being forced out of the grease drain. When the purged grease looks fresh stop pumping.

And since 40 to 70 of motor failures are related to bearings it s no surprise that high quality bearings are key for reliable motors. Grease relubrication intervals for normal operating conditions can be read as a function of bearing speed. If motor manufacturer instructions are not available determine the appropriate grease relubrication intervals for motors under normal operating conditions using figure 1 which is based on information provided by nsk bearing corp. Nlgi 2 is about the consistency of peanut butter.

Mineral oil based grease derived from petroleum is more economical than synthetic oil. Combined with safety issues proper lubrication can maintain the electric motor reliability. These include incorrect lubricant selection contamination loss of lubricant and overgreasing this article discusses several effective strategies to minimize the likelihood of these failure modes. Nlgi viscosity grade is a rating of a grease s consistency.

But choosing the right bearings alone isn t enough. Choosing the right electric motor grease important grease characteristics for electric motor bearings the following criteria may be used as typical indicators of a good electric motor grease. Nlgi 3 is about the consistency of vegetable shortening. Able to handle light to moderate loads at high speeds this grease is often used on electric motor bearings for fans pumps and dryers.

Viscosity oil viscosity should be appropriate for the load and speed of the application at operating tempera ture. Because the majority of grease lubricated applications are element bearings one should consider viscosity selection for those applications. 2 for ball bearings spherical roller bearings tapered roller bearings and carb bearings rotational speed up to 210 000 and for cylindrical roller bearings rotational speed up to 270 000. 1 rotational speed rotational speed r min x 0 5 d d mm.

Electric motor bearing greasing requires the motor to be de energized during the procedure.