TECHNI-TIP: Lubrication of Electric Motors

CUSTOMER TESTIMONIAL: Cadillac Overall Supply - Detroit


FEATURED ARTICLE: Compatibility     

Proper lubrication is critical to the efficiency of a process and the life of the equipment. For electric motor bearings, the right grease in the right amount must be applied at the right time. Under-lubrication results in bearing failure from excess friction and wear, and over-lubrication can resist part motion and have pressure buildup. Greases are made up of base oil, additives, and a thickener which acts like a sponge holding all the components together. The chemical makeup of greases differs depending on the intended application.

The table below should be used as a reference for thickener compatibility. When a new grease is mixed with an old grease and the thickeners are incompatible, they react negatively and could lead to a weakened structure incapable of holding the base oil.

                             Figure 1 - Grease Compatibility

Charts are available for base oil and additive compatibility as well, and these should also be considered. The best way of determining compatibility, however, is to perform a test.

For more information or if you have any concerns, please contact us at info@lubeng.com or 1-800-465-8237 and we would be happy to help.


TECHNI-TIP: Lubrication of Electric Motors

The frequency of re-greasing antifriction bearings of electric motors is affected by the following factors:

- Quality of grease used, especially as to its service life

- Severity of service, including operating temperatures

- Cleanliness of surroundings

- Presence of water

- Continuity of service (may range from infrequent operation to 24-hour-a-day operation)

- Bearing size

- Speed and housing design

In many applications, motor bearings are greased once a year during routine inspection and maintenance work. In general, large electric motors (greater than 40 hp) should be greased more frequently, such as every six months. Small motors operating under non-severe conditions and using high-quality grease may not require re-greasing for periods of up to several years.

Re-Lubrication Volume Formula

The amount of grease needed depends on bearing size. You must know the size of the bearing as well as how much each pump of the gun delivers. Grease guns come in a variety of pump sizes, typically dispensing 1 to 3 gm (0.03 to 0.1 oz) per stroke. We suggest you pump grease into a small container of known volume and count the number of strokes to fill it. From this, you can figure the volume per stroke of the gun.

For formulas and changeover procedures specific to each type of motor bearing, please click here.

CUSTOMER TESTIMONIAL: Cadillac Overall Supply - Detroit


Customer Profile

Cadillac Overall Supply is an industrial laundry that serves the Detroit area. They have been in business since 1953.


The following equipment is used in this laundry operation: WX washers; Norman dryers and Unipress presses. The WX washers are powered by 50 hp electric motors, and the Norman dryers are equipped with 30 hp electric motors.

While using a commercial grade grease, Don Gordon, Chief Engineer found that the grease would not stay in the bearings. As the temperature of the machine would rise, the grease would run out of the bearings.

LE Solution

In June of 1989 the local LE Representative recommended LE's 1275 ALMAPLEX Industrial Lubricant for this application. LE's 1275 is an excellent general purpose EP lubricant for industrial or fleet use. It contains ALMASOL, LE's exclusive wear reducing additive. It is very effective in severe operations caused by moisture and high temperatures. LE's 1275 seals out dirt and water and prevents corrosive wear. It is excellent for electric motors.

Customer Cost Savings

 Cadillac Overall Supply estimates that since they began using LE's 1275 ALMAPLEX Industrial Lubricant, they have saved over $10,000 in bearings and $6,000 in labor. Lubricant consumption has also been cut dramatically. With the commercial grade grease they had to re-lubricate every week. After switching to LE's 1275, they only had to re-lubricate once a month.  

For a copy of the testimonial, please click here.

Click here to view previous newsletters from Lubrication Engineers.