An anti-friction bearing race unexpectedly cracked on your electric motor, leading to a catastrophic failure, emergency shutdown, downtime, and lost productivity — not to mention the expensive repairs involved. Is there a way to detect impending failures before they happen?
Yes! Using regular vibration analysis can help you avoid costly electric motor repairs such as this.
What is Vibration Analysis?
Vibration analysis monitors mechanical vibration levels and patterns in machinery and structures. When used as a part of condition monitoring and predictive maintenance (PdM), vibration analysis can reveal changes in machine behavior that could be related to impending failure. If the issues detected warrant it, failure can be prevented by maintenance or repair.
Keep in mind that vibration analysis is more than just raw vibration data. The data needs to be processed and studied by a certified vibration analyst using time and frequency domain methods. This type of analysis is necessary to extract useful information about the performance and condition of your motors. And to determine abnormal vibration results, you need to establish a baseline, which requires data collected over a significant period.
What is Vibration Analysis Capable of Doing?
When vibration analysis is done correctly as part of a PdM plan, it allows your team to be alerted and address potential issues before they lead to costly repairs and excessive downtime. And beyond PdM, vibration data also supports technicians and repair professionals as they attempt to troubleshoot why an electric motor failed in the first place. Vibration analysis also serves as an invaluable tool in root cause analysis to ensure the actual motor issue, and not just the systems, is addressed. Finally, data can be used by technicians to verify that certain repairs and maintenance tasks have been performed correctly which in turn increases the confidence you have in your electric motors.
Protecting Your Motors
The truth is that electric motors can reveal quite a bit about their operation and condition through vibration testing. Let’s look at what vibration analysis can tell you about an electric motor:
- Worn bearings
- Rotor imbalance
- Bent or cracked shafts
- Coupling and bearing misalignment
- Structural resonance
- Mechanical looseness (e.g., loose fasteners)
- Defective mountings (e.g., soft foot)
So how does this protect your motors? Let’s look at some examples. Anti-friction bearings reduce friction and support the motor shaft. When the bearings wear, the friction will reduce the efficiency of your motor, even more importantly, can lead to misalignment and imbalances that can generate other issues.
Cracked shafts can start as a tiny crack on the surface but can expand to catastrophic failure levels literally at the speed of sound. The aftermath of a significant shaft failure will wreck other (expensive) components in your electric motor. When ignored, loose fasteners and defective mountings can be disastrous to your motor and anything that the motor powers.
However, regular vibration analysis can catch these problems before more damage occurs.
What is Regular Vibration Analysis?
Regular vibration analysis means that one or more technicians follow a route for gathering vibration data, going to specific machines in an orderly manner. This process is also called route-based vibration monitoring and technicians use handheld vibration equipment to gather data in predetermined positions and locations on the machinery. Data is then transmitted to the cloud or a hard drive to await processing and analysis.
In some instances, vibration sensors may be placed permanently on certain components within an electric motor to support remote condition monitoring. In such instances, the vibration data is regularly uploaded to the cloud so that key personnel can access it for viewing or analysis.
Correctly gathered and analyzed vibration data can provide you with warning flags that something is off with your equipment. A skilled analyst can study the data to determine the most likely source of the problem and let your maintenance team know. You and your maintenance team can decide whether to follow up on the information.
Benefits of Vibration Analysis
We’ve already talked about how routine vibration analysis can reduce the frequency of costly motor repairs and unexpected downtime. It also enhances the reliability of your electric motor and the other equipment that depends on it while improving the consistency of your facility’s productivity.
That reliability also leads to higher customer satisfaction and a better reputation for your company. And depending on what other equipment is involved, vibration analysis can also lead to better safety, not just for your employees, but your equipment as well.
Following up on the red flags revealed by vibration analysis allows you to schedule when the maintenance/repair will be performed. You have control over when the shutdown occurs, allowing you to choose a time when it will have minimum impact on productivity. This also reduces the costs associated with downtime.
Regular vibration analysis also provides a massive amount of data that can be converted into information that helps you make important decisions about your equipment. Data-driven decisions can help you get the most value from your electric motors.
Conclusion
By making regular vibration analysis a part of your maintenance program, you can protect the electric motors you are responsible for — and reap the benefits of route-based vibration analysis.
