Vibration
Matters
The Vibration Analyst’s NewsletterSeries 3, Issue 4 – April 2016
FEATURED LESSON
Rolling Element Bearings – Condition Monitoring
Part 2
In our last issue of Vibration Matters, we began looking at incipient bearing faults, paying attention to their root cause and how we can minimize their reoccurrence. We identified cocked bearings, looseness, lubrication and rotating element skidding. In this issue, we will continue by looking at installation issues, excessive clearance and rotating looseness. If you missed the last issue, you can download it here.
Installation errors
If the bearing is cocked on the shaft, we expect to see increased amplitude at 1X, 2X and/or 3X. The key indicator is phase – take measurements on all four sides of the shaft. If the bearing is cocked on the shaft, we will see a 180 degree phase shift left to right and top to bottom – it is rotating. If the bearing is cocked in the housing, there will be a 180 phase change from one side to the other, however you
will need to find the axis of the angle of the bearing. If it was cocked vertically (i.e. the top pushed in and the bottom pulled out) then the 180 degree phase difference will be from top to bottom.
Clearance
Excessive clearance can lead to looseness if there is a driving force and to skidding if there is low load or an incorrect lubricant. If the bearing is skidding, there will not be a periodic frequency; instead high frequency noise is generated. This is
ISO/IEC 17024 and ISO 18463-1 accredited with training centers in 50 countries.
RELIABILITY IMPROVEMENT VIBRATION ANALYSIS
CERTIFICATION PER ISO 18436 PRECISION MAINTENANCE
www.mobiusinstitute.com
In this issue: Featured Lesson:
Rolling Element Bearings – Condition Monitoring – Part 2
page 1
- - -
Featured Training Video: Bearing Failure Analysis
page 2
- - -
Mobius Conference Listing 2016
page 3
- - -
Mobius Presentations at the Reliability Conference in Las Vegas
page 3
- - -
Upcoming Global Vibration Analyst Certification Courses
Page 5
- - -
Mobius Institute North America complete listing of courses:
>Click to learn more
because there is a rubbing rather than an impacting.
If bearings are skidding they can heat up and even catch on fire as you will see in the following example.
The figure above shows the burnt up bearing from a condensate extraction pump motor. The motor had run for 24 years without problems. Recently the motor was rewound, the rotor was balanced, new bearings were installed (cylindrical roller DE) and the unit was laser aligned. Three months later, the motor DE bearing over heated and the motor stopped. Another overhaul was completed, the rotor was balanced and aligned again and new bearings were installed.
Six months later a loud explosion rocked the whole station. When someone went to investigate they found the DE bearing on fire and they shut the machine down. Both coolers had been blown off the motor. One of them flew 3 meters away and just missed a hydrogen carrying pipe. The whole motor was scrapped.
The cause
The roller bearings in the motor require 30% of their design load to operate correctly. When the load is removed, the rollers skid and cause heating. When the machine was balanced and aligned, the loads were greatly reduced, the bearing skidded causing the grease to vaporize and finally ignite. In order to resolve the problem a new motor was installed with deep groove bearings on the drive end.
Rotating looseness
Rotating looseness may be the result of the shaft loose in the bearing or the bearing loose in the housing. Either way, rotating looseness results in a series of high 1x harmonics in the spectrum, often out to 10x. This may be accompanied by a raised noise floor as the result of random vibration or random impacting. If phase measurements are collected you will notice that the phase readings do not remain steady. This is because the phase reference on the shaft is not remaining steady because it is loose. In any case, an unstable phase reading is another indication of rotating looseness.
Bearing loose in housing or slipping on shaft
A bearing loose in its housing may result in a high 4x peak and a bearing slipping on the shaft may result in a high 3x peak. *Case study and photos are courtesy of Simon Hurricks, Genesis Energy, NZ. Thanks Simon!
FEATURED TRAINING VIDEO:
Vibration Analysis:
Bearing Failure
Analysis
This presentation explains why bearings fail, how to detect the defects and how to extend the life of rolling element bearings. This topic is relevant to our featured topic; condition monitoring of rolling element bearings, and one we would recommend that you see.
Length: 47 min
www.mobiusinstitute.com
Mobius at the Reliability Conference
in Las Vegas
Mobius Institute’s Jason Tranter is conducting Learning Labs at the Reliability Conference in Las Vegas this week. Topics include:
Condition Monitoring is Not Enough: You Can’t Monitor Your Way to Improved Reliability
In plants around the world, condition monitoring programs are established to improve plant reliability. The trouble is, in the
majority of those plants, those programs don’t actually improve reliability at all. In this presentation we will explore (briefly) how the condition monitoring does benefit the plant (even if it does not improve reliability), and propose how the condition monitoring skills and technologies can be used to actually improve reliability.
• Learn why most condition monitoring programs do not improve reliability • Learn about the benefits delivered by those programs.
• Learn how the condition monitoring technologies can be applied to make substantial improvements in plant reliability.
An Animated Introduction to Vibration Analysis
Vibration analysis provides an extremely powerful opportunity to learn about the condition of rotating machinery – but only if you understand it and can use it properly. This highly graphical and animated presentation will explain the origin of the vibration frequencies, amplitudes and motion, and introduce the spectrum, time waveform and phase. You will be amazed how much you can learn in such a short time!
• How does vibration analysis provide a key insight into the health of rotating machinery.
• Where does the spectrum come from, and what do those peaks mean.
• What does the time waveform and phase readings tell you that you cannot learn from the spectrum alone.
What Every Reliability Engineer Needs to Know About Improving Reliability
While you could focus on condition monitoring and improvements in maintenance practices, you will achieve far greater results by taking a holistic approach to reliability improvement. We have to start with the design process and work our way through every phase to ensure that we do not introduce the “defects” that reduce our reliability and thus increase the cost of ownership. This interactive short course will provide you with a “roadmap” so that you have a clear understanding of what changes need to be made, and the benefits of each of those changes. This is a proactive approach; getting ahead of the problems before they cause downtime or cause safety incidents. It is also a proven, practical approach that does not require engineering degrees or months of analysis. We explain the technology but we emphasize the need to develop the reliability culture.
• Why you should take a proactive “defect elimination” approach instead of a reactive condition monitoring + RCFA approach.
• How to develop the reliability culture in everyone from senior management down to the plant floor.
• A “roadmap” that will provide guidance and help overcome the most common challenges.
Meet Mobius in 2016!
Reliability Conference
April 11-16, 2016 Las Vegas, NV, USA
http://reliabilityconference.com Learning Lab & Exhibition Booth
SIRF Condition Monitoring, Lubrication & Reliability National Forum 2016
April 19-20, 2016 Surfers Paradise, QLD, AUS
http://www.sirfrt.com.au/calendar/event_detail /4315
Presentation & Exhibition Booth
Vibrations Association of New Zealand Conference 2016
May 10-12, 2016 Queenstown, NZ http://vanz.org.nz
Presentation & Exhibition Booth
Uhre & Nybæk Vibration Analysis Seminar May 26-27, 2016 Denmark http://www.uhrenybaek.dk/?page_id=238 Presentation Euromaintenance 2016 May 30 - June 1, 2016 Athens, Greece http://www.euromaintenance2016.org Presentation & Exhibition Booth
Lubrication, Maintenance & Tribology (lubmat) 2016
June 7-8, 2016 Bilbao, Spain
http://www.lubmat.org Presentation & Exhibition Booth
SMRP Conference 2016
October 17-19, 2016 Jacksonville, FL, USA
http://www.smrp.org/i4a/pages/index.cfm?pag eID=3831
Presentation & Exhibition Booth
2016 IMVAC - Orlando
October 31-November 2, 2016 Orlando, FL, USA
http://www.vibrationconference.com Presentations & Exhibition Booth
International Maintenance Conference 2016
December 12-16, 2016 Bonita Springs, FL, USA
http://reliabilityweb.com/events/event/imc-2016
Upcoming Vibration Analyst Certification Courses
Vibration Analysis ISO Category I: Basic Lima, PE 4/13/2016 3 days
Vibration Analysis ISO Category II: Intermediate Cairo - Nasr City, EG 4/17/2016 4 days
Vibration Analysis ISO Category III: Advanced Beijing, CN 4/18/2016 5 days
Vibration Analysis ISO Category II: Intermediate shanghai, CN 4/18/2016 5 days
Vibration Analysis ISO Category II: Intermediate Jakarta, ID 4/18/2016 4.5 days
Vibration Analysis ISO Category I: Basic Bandung, ID 4/18/2016 4 days
Vibration Analysis ISO Category II: Intermediate Bandung, ID 4/18/2016 5 days
Vibration Analysis ISO Category I: Basic Dungun, MY 4/18/2016 3.5 days
Vibration Analysis ISO Category II: Intermediate Lima, PE 4/18/2016 4 days
Vibration Analysis ISO Category II: Intermediate Lisboa, PT 4/18/2016 5 days
Vibration Analysis ISO Category II: Intermediate Strängnäs, SE 4/18/2016 5 days
Vibration Analysis ISO Category II: Intermediate Solwezi, ZM 4/18/2016 5 days
Vibration Analysis ISO Category II: Intermediate Lahore, PK 4/20/2016 4 days
Vibration Analysis ISO Category II: Intermediate Edmonton, AB, CA 4/25/2016 4.5 days
Vibration Analysis ISO Category III: Advanced Bucaramanga, CO 4/25/2016 6 days
Vibration Analysis ISO Category I: Basic Ismaning, DE 4/25/2016 4 days
Vibration Analysis ISO Category I: Basic Montreal, QC, CA 5/2/2016 3.5 days
Vibration Analysis ISO Category II: Intermediate Bucaramanga, CO 5/2/2016 6 days
Vibration Analysis ISO Category III: Advanced Antwerpen, BE 5/9/2016 5 days
Vibration Analysis ISO Category I: Basic Madrid, ES 5/9/2016 5 days
Vibration Analysis ISO Category II: Intermediate Maynooth Near Dublin,
Vibration Analysis ISO Category I: Basic Monterrey, MX 5/9/2016 4 days
Vibration Analysis ISO Category I: Basic Miri, MY 5/9/2016 4 days
Vibration Analysis ISO Category I: Basic ISTANBUL, TR 5/9/2016 3.5 days
Vibration Analysis ISO Category II: Intermediate Point Lisas, TT 5/9/2016 5 days
In Field Balancing May 2016 Johannesburg, ZA 5/9/2016 2 days
Vibration Analysis ISO Category I: Basic Dallas, TX, US 5/10/2016 3.5 days
Vibration Analysis ISO Category I: Basic Bucaramanga, CO 5/11/2016 4 days
Shaft Alignment May 2016 Johannesburg, ZA 5/11/2016 2 days
Vibration Analysis ISO Category II: Intermediate Dungun, MY 5/15/2016 4.5 days
Vibration Analysis ISO Category I: Basic DUBAI, AE 5/16/2016 4 days
Vibration Analysis ISO Category II: Intermediate Montreal, QC, CA 5/16/2016 4.5 days
Vibration Analysis ISO Category II: Intermediate Kuala Lumpur, MY 5/16/2016 4.5 days
Vibration Analysis ISO Category I: Basic Muntinlupa, PH 5/16/2016 4.5 days
Vibration Analysis ISO Category II: Intermediate Singapore, SG 5/16/2016 4.5 days
Vibration Analysis ISO Category II: Intermediate Knoxville, TN, US 5/16/2016 4.5 days
Vibration Analysis ISO Category I: Basic Johannesburg, ZA 5/16/2016 5 days
Vibration Analysis ISO Category I: Basic Perth, AU 5/17/2016 3.5 days
Vibration Analysis ISO Category I: Basic Toronto, ON, CA 5/17/2016 3.5 days
Vibration Analysis ISO Category I: Basic Strängnäs, SE 5/17/2016 4 days
Vibration Analysis ISO Category I: Basic Kidatu, TZ 5/20/2016 1 days
Vibration Analysis ISO Category I: Basic Cairo - Nasr City, EG 5/22/2016 4 days
Vibration Analysis ISO Category II: Intermediate Perth, AU 5/23/2016 4.5 days
Vibration Analysis ISO Category II: Intermediate Madrid, ES 5/23/2016 5 days
Vibration Analysis ISO Category I: Basic Jakarta, ID 5/23/2016 4.5 days
Vibration Analysis ISO Category II: Intermediate Pattaya - Chonburi, TH 5/23/2016 5 days
Vibration Analysis ISO Category II: Intermediate Johannesburg, ZA 5/23/2016 5 days
Vibration Analysis ISO Category I: Basic Espoo, FI 5/24/2016 3 days
Vibration Analysis ISO Category I: Basic Jakarta, ID 5/24/2016 4 days
Vibration Analysis ISO Category II: Intermediate Middelfart, DK 5/30/2016 5 days
Vibration Analysis ISO Category II: Intermediate Wrocław, PL 5/30/2016 5 days
Vibration Analysis ISO Category III: Advanced Strängnäs, SE 5/30/2016 5 days
Vibration Analysis ISO Category II: Intermediate Sydney, AU 6/6/2016 4.5 days
Vibration Analysis ISO Category I: Basic Hyderabad, IN 6/6/2016 4 days
Vibration Analysis ISO Category II: Intermediate Lahore, PK 6/6/2016 5 days
Vibration Analysis ISO Category I: Basic Wilmington, DE, US 6/7/2016 3.5 days
Vibration Analysis ISO Category I: Basic Seattle, WA, US 6/7/2016 3.5 days
Vibration Analysis ISO Category II: Intermediate Senlis, FR 6/13/2016 5 days
Vibration Analysis ISO Category I: Basic Alabang, Muntinlupa
City, PH 6/13/2016 3.5 days
Vibration Analysis ISO Category I: Basic FABRIANO (AN), IT 6/14/2016 4 days
