Blog

Ingression can be defined as going in or entering,  a right or permission to enter, or a means or place of entering. It is important to understand, recognize, detect and reduce the effects of particle ingression. Doing so will have a very positive effect on your maintenance and reliability efforts.

Dirt is often the root cause leading to bearing damage and reduced equipment reliability. If not monitored correctly, ingression can lead to unexpected failures resulting in high maintenance and inventory costs.
When measured in the Moh’s Hardness scale, dirt is typically more abrasive than the bearing material. This leads to pitting and other damage to the bearing that reduces the life of the equipment. It’s really quite simple: under great load, something has to give and it’s usually the bearings, gears, pump impellers, etc. Our goal should be to remove contaminants from the lubricant to our target cleanliness before placing it in our equipment. Doing so will increase our equipment reliability.

Guest post by Kasey McClain,  Mechanical Engineer at Pioneer Engineering

Everyone knows that lubrication is crucial to the life of a bearing. Two common types of bearing lubrication are grease and oil.  I commonly see oil bath lubrication and oil mist along with grease lubrication.  One of the biggest problems that I have encountered with greased bearings is over greasing.  When installing a new bearing assembly, it is important to note whether the bearings are pre-greased by the manufacturer.  Over greasing will not allow the heat to dissipate from the bearing which will cause the bearing to expand and cause a tolerance stack-up which may then show bearing defects.  This may also cause an existing defect to progress, decreasing the life of the bearing.  With an oil bath lubrication system, too much oil can be just as detrimental as too little oil.

With too little oil, the slinger ring, or whichever component carries the oil, will not be submerged in the oil and will not be able to lubricate the necessary components.  With too much oil, some of the components may not get the lubrication necessary.  Oil mist systems have been shown to eliminate the issue of too much or too little oil.

However, running the mist system low on oil will cause the components to not be lubricated.  Also, the oil misters can become clogged which would lead to a lack of necessary lubrication.  This is why regular lubrication monitoring is necessary to keep equipment running smoothly for as long as possible. Attention to detail is essential in all aspects of machinery maintenance.

The Finger as a Sensor and Other Things That Are Of Utmost Importance!

Toyota did a study to find out why some equipment failed prematurely. They found that something like 80% of premature equipment failures could all be traced to three rather simple causes; causes that could have been prevented or remediated before they led to equipment breakdown. What were the three culprits?
a. Looseness
b. Improper Lubrication
c. Contamination

All three of these can be addressed by the vibration analyst during collection and analysis.

Looseness can be detected with a vibration analyzer. When you see looseness,  use your finger as a sensor and run it around the interfaces of the bearing pedestals, housings, and foundations. It is surprising how sensitive one can be to the phase difference of shaking parts that have become loose. See that it is remedied before it causes catastrophic failure.

Inadequate lubrication can be detected by Shock Pulse. If you are taking high-frequency acceleration readings it will cause a raised noise floor. This one is best avoided altogether by a well-planned and supported lubrication program. Often, by the time-poor lubrication is detected, a considerable amount of damage has already been done. An electric motor’s winding insulation breakdown rate is doubled for every 18° F rise over 165° F. This is why motor cooling fins are actually for cooling and not for holding dust, grime, or whatever. Contamination is an important condition to monitor via a manual input point for each machine area. Add it to your route. Report equipment covered in whatever foreign matter your plant has lots of so it can be properly cleaned before damage is created.

Focusing attention on the three areas above will definitely create value for your company.

Combine vibration monitoring and ultrasound for more cost-effective predictive maintenance
The best overall machinery monitoring program is one that utilizes multiple,  integrated monitoring technologies.
In brief:

• The best overall machinery monitoring program is one that utilizes multiple, integrated monitoring technologies that are well-suited to detect expected failure modes.
• One goal of PdM is to determine how much time is left before a machine will fail, so plans can be made to minimize downtime and damage while still getting the most useful life from the machine.
• An application where ultrasound and vibration work well together is a mechanical inspection.

Reliability-centered maintenance programs are most effective and most profitable when a variety of appropriate technologies and tools are used to complement one another. Vibration analysis and ultrasound are as complementary as two sides of the same coin. Ultrasound is a useful monitoring tool, capable of detecting failing rolling element bearings and over-and under-lubrication conditions. The best overall machinery monitoring program is one that utilizes multiple, integrated monitoring technologies that are well-suited to detect expected failure modes. For low-risk machines, vibration analysis can be performed by a mechanic or operator using a vibration data collector or vibration meter. For machines of higher criticality, a certified vibration analyst should use advanced vibration data collection and analysis hardware and software.

Read my comments in this valuable PLANT SERVICES article.

The Hibbing Taconite Company,  managed by Cliffs Natural Resources of Hibbing,  MN, won UPTIME Magazine’s Best Lubrication Program award. At the heart of their condition monitoring efforts is the Oil Analysis component of their lubrication program, key to helping them identify problems at an early stage of failure.
During the first phase of the program, which they called “First Evolution”, reliability engineers were trained as Level I Machine Lubrication Technicians (MLT1). Thereafter, dedicated lubrication mechanics were assigned to the plants to monitor the condition of the oil. They engaged with their vendors to identify needed parts and reviewed their planning, scheduling, and work execution. They selected critical equipment on which to prove the concept.

During Phase 2, MLT1 training continued, including lubrication mechanics and supervisors. Critical equipment underwent lubrication upgrades with the addition of desiccant breathers, sight tubes, sample ports, and quick couplers for filtering, allowing for safer filter changes and reducing cross-contamination risk.
Today, 80 employees have been MLT1 trained on machinery lubrication and basic oil analysis. Employees are fully engaged and enjoy wholehearted management support as significant consumption reduction was realized. Management views the program as an investment.

During their presentation at the IMC-2012 International Maintenance Conference, Reliability Engineer Dan Lerick shared that in certain applications, they have proved a 3.5% energy reduction by switching to synthetic gear oil, which also extended oil drains from 5 to 15 years. Another positive was the switch to synthetic engine oil where they observed a reduction in fuel usage and fueling time, with an extension in engine life and extended drain and maintenance intervals.  Overall ROI was under 1 year!

In addition to their award-winning Lubrication Program and as part of their reliability efforts, the company uses CMMS software and other Predictive Maintenance technologies such as Ultrasonic examination, Laser Alignment with ROTALIGN ULTRA, etc. Learn more.
Congratulations to Dan Lerick and his team for this award and a job well done!

Program Highlights
1) Fluid Analysis consolidated across all Cliff operations. They now use a single oil lab after carefully ranking and comparing sample results from eight different labs. The benefit was consistency and the ability to review and compare data.
2) For Fluid Sampling, they developed sample standards per equipment specs, installed sample ports, and trained personnel on how to collect samples. Their CMMS system controls their sample frequency.
3) The use of Grease Systems and Grease Routes wherever possible along with ultrasonic technology on motors.
4) Implementation of condition monitoring (CM) via oil moisture sensors and CM sensors for real-time monitoring. The immediate benefit was a reduction in overall site oil consumption by removing water contamination.
5) Cleaner and safer fluid changes with the use of dedicated Lube Carts to eliminate drips and spills.
6) All machines were tagged with machine identification and lubrication information to reduce mixing and cross-contamination.