470 likes | 920 Views
Eli Lilly Study . Primary causes of failure: Misalignment of sheaves and couplings Over/under lubrication of bearings Improper tension in belted systems Temperature: Readings taken on the drive-end bell housing within 1 in. of the drive shaft closely approximate the internal winding and bearin
E N D
1. Basic Electric Motor Maintenance
Ed Robinson
Regional Service Manger
erobinson@weg.net
2. Eli Lilly Study Primary causes of failure:
Misalignment of sheaves and couplings
Over/under lubrication of bearings
Improper tension in belted systems
Temperature: Readings taken on the drive-end bell housing within 1 in. of the drive shaft closely approximate the internal winding and bearing temperatures
3. Basic Maintenance Bearing & Lubrication Maintenance
Coupling Maintenance
Electrical Inspection
4. Bearing Failures Bearing Failures are the #1 cause of motor failures. Over 60% of all motor failures are attributed to the bearings. However, many external factors contribute to the actual failure of the bearings. The bearing itself is not usually the culprit.
So, lets start by talking about the original design and what affect that has on the life.
5. Bearing Design Shape Deep Groove Radial Ball Bearings are used for general purpose applications. They work with both radial and axial type loading.
6. 200 SeriesBall Bearing
7. Its very easy to see the difference in the 300 series bearing on the left, and the 200 series on the right.
8. Bearing Design Load and Speed. Those are the two determining factors in designing a bearing for a particular application and the life expected from that bearing in that application.
The size of the bearing will help determine how much load, and for how long the bearing can handle that load. The size and type of the rolling element also plays an important part in the load rating.
Since you cant change the design characteristics or the size of the bearings in your motors, it is a good idea to include these things in your analysis for selecting a new motor, in the beginning.
9. Bearing Design Life L10 Life
10. Bearing Design LifeL50 Life
11. Bearing Design LifeL10 Life L50 allows them to downsize the bearing and save money. But who really pays?
12. Bearing MaintenanceBasic Inspection Shaft Feel, without the motor running
Turn the shaft by hand
Before 1st use to distribute grease.
Does it turn easily ?
Feel for flat spots, rubbing, stiffness, etc
Bearing Noise while running (unloaded)
Listen to the motor bearings
Listen for abnormal sounds, squealing, squeaking, grinding, etc
Unloaded roller bearings will definitely make a rattling noise..
13. RTD Thermal Analysis