Ludlum Presentation
- 1. Matthew Kaminski Supervisors: Tom Thayer & Brian Gilchrist August 11, 2010
- 2. Introduction Machine Background Vibration Analysis & Reliability Centered Maintenace (RCM) Plan Do Check Act (PDCA) Evaluating My Experience 2
- 3. Graduated in 2008 from Bethel Park High School Entering junior year at the University of Pittsburgh Studying Mechanical Engineering 3
- 4. Worked with the maintenance group with a team responsible for performing a RCA (Root Cause Analysis) and a FMEA (Failure Mode and Effects Analysis) for the Pangborn blast machine Identify machine failure modes and potential causes Goal is to eliminate these problems and increase machine reliability 4
- 5. SIDE VIEW ENTRANCE VIEW 5
- 6. OPERATOR STAND EXIT VIEW 6
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- 8. Wear detection is an important problem associated with high speed rotating machinery A damage not detected in time can result in severe damage to machinery, injuries and financial losses The abrasive shot wears the vanes, impeller and impeller case Creates an uneven distribution of mass on the blast head poor blast pattern or unbalance 8
- 9. New Impeller New Vane New Impeller Case Damaged Impeller Case Damaged Impeller Damaged Vane 9
- 12. A predictive maintenance technique that uses instruments to monitor and analyze machine vibrations to determine if the machine is working properly Operation of a machine can cause it to vibrate. Transducers and diagnostic electronic equipment can translate these vibrations into a frequency spectrum graph A vibration analysis allows one to analyze the graphs to monitor and trend the overall condition of the machine over time. 12
- 14. Develop a procedure to ensure that the company’s assets will continue to run in their desired manner RCM is a process used to determine the maintenance requirements of any physical asset in its operating context Maintenance is typically categorized into three separate categories: reactive, preventative, and predictive maintenance 14
- 15. Plan Identify the Problem Understand how the Pangborn machine operates Speak with maintenace workers about current maintenace procedures and problems Familiarize myself with vibration analysis Set my objectives Order and install the necessary equipment Perform the analysis and interpret the results 15
- 16. Determined the mounting technique, location, and position of accelerometers, diagnostic electronic, and power source Mounted accelerometers in horizontal position of the spindle on each of the three top blast heads using a mounting pad and adhesive Diagnostic electronics and power source were placed in protective housing Electricians helped to draw necessary power to wire up the accelerometers, diagnostic module, power source, and interface my computer with the equipment Learned how to operate the software and determine necessary parameters to analyze the vibration signals Calculated speed (RPM) of spindle shaft using strobescope 16
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- 19. Head #1 Close Up of Head #1 19
- 20. Head #2 Head #3 20
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- 22. Acquired baseline values These are readings that correspond with equipment operating correctly without any faults Had to make sure all equipment was up to par before gathering data All subsequent readings were compared to the baseline values in order to diagnose the problems on the machine Used to set warning and alarm levels 22
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- 25. Achieve better baseline values Have all new equipment/parts installed prior to gathering baseline values Account for variable speed of motors with a switching output Connect diagnostic electronics to PLC to provide more advanced warnings & alarms for operators Train employees to interpret the data and anticipate faults before they occur Employ SDCA: Suggest standardizing PdM procedures for critical machinery at the plant 25
- 26. Safety is #1! Must keep in mind the person who must fix the equipment when designing something Good communication is essential between different members of the team (planners, maintenance crew, operators, engineers) Learn about all the new technology in school; in reality, most is very old and primitive At school, the only one holding you back is yourself, at work it can be anyone 26
- 27. Questions? 27
Editor's Notes
- #2: Thank you for the introduction. My name is Matthew Kaminski and I worked as part of the maintenance team at the Washington Plant. If anybody has any questions along the way, please don’t hesitate to ask
- #3: I’ll just start with a agenda of the topics I will cover today.
- #5: After first bullet point: As a member of this team, we met for about 6 hours every week. Assigned to gather relevant drawings, engage in the discussions, developing excel spreadsheets, present updates on my project
- #6: Before I get ahead of myself, I’ll give you a brief background on the machine. Blasting creates proper surface preparation for further operations by using abrasive shot to remove surface contaminants and smoothing the surface. This machine is considered a bottleneck at the plant due to the fact that nearly every plate that enters the plant must eventually go through the blast and the blast is slow and always has maintenance issues (it literally is a self-destructive machine). Here are some pictures of the actual machine.
- #7: Here are a few more pictures
- #8: Here is a brief clip of how the Blast heads operate. (Play video here) Obviously this is not the entire machine (there are a total of 6 heads-3 that blast the bottom of material and 3 that blast the top) but it is the section that I focused on. I should point out that this machine is direct driven whereas the machine at Washington is belt driven. Point out the parts of the machine here.
- #9: Unbalance can ultimately lead to failures in other parts of the machine
- #14: Transducer Output: Accelerometer vibrates with the machinery and converts this vibration into an analog signal (voltage) Signal conditioning: Voltage signal is read and amplified Data filtering: Filters out noise, eliminates discontinuties in the signal, and modifies the signal for further processing FFT: Transforms vibration signals from the time domain into the frequency domain. We rarely use the time domain because the time waveform pattern is often very complex, making difficult to identify faults. Extraction: Focus on frequency range we want to evaluate and store this data history to analyze trend data Fault Diagnosis: By analyzing frequency spectrum, we can diagnose faults associated with unbalance, misalignment, damaged bearings, shafts, gears or motor electrical faults
- #15: Before first bullet point: Motivation behind the assignment is to improve the reliability of the Pangborn Blast. Therefore, using the RCM approach, I can address this problem After first bullet: There is currently an A3 out for the blast which details making RCM (reliability centered maintenance) improvements through predictive maintenace and a vibration analysis falls under this category. With this in mind, I can give a brief background about RCM After third bullet point: Reactive: Reactive maintenance is the “run until it breaks and then fix it” practice. Preventitive: a schedule of planned maintenance actions (down days at the Blast) aimed at the prevention of breakdowns and failures. maintenance activities include equipment checks, oil changes, lubrication, etc… Predictive: measurements that detect the onset of a degradation mechanism, thereby allowing causal stressors to be eliminated or controlled prior to any significant deterioration in the component physical state. differs from preventative maintenance because it bases maintenance on the actual condition of the machine rather than on some preset schedule. Examples: infrared analysis, oil analysis, vibration analysis
- #16: Before first bullet: I needed to determine a method for completing my summer project: PDCA Problem: I mentioned earlier about the wearing in the vanes, impeller, which cause imbalance, misalignment, and machine failure Operation of Machine: Look over blueprints and read abridged operator’s manual. Familiarize myself with analysis: Read about how a vibration analysis is performed and what the necessary equipment is. Read case studies to get a better understanding of what I should expect to see Objective/Goals: Essentially, the goal is to move from reactive and preventative maintenance to practicing predictive maintenance. The vibration analysis should provide us with information which will allow us to continuously monitor the machine and predict when various parts of the machine will need to be fixed or replaced before they fail. Ultimately, it is desired that this will establish safe levels of maintenance and will increase productivity and machine uptime. Therefore, machine damage, power consumption, machine unavailability, delayed shipments, unnecessary maintenance and quality problems will all be minimized
- #17: Before first bullet: after performing my literature review on vibration analysis, talking with the maintenace crew and RCM specialists at the company, and inspecting the equipment firsthand, I was able to determine the equipment that was necessary for my project (also had to make sure all equipment was compatible and the necessary power could be drawn). After first Bullet: accelerometer-converts vibration into electrical signal-looked at things like device bandwidth, senstivity, After first bullet: Technique-whether to use magnets, epoxies, studs (certain techniques will provide more accurate readings). Position-confined space and maintenance crew must be able to get in and replace parts without hindering their movements. Also there are grease fittings for greasing the bearings which also take up valuable space, must consider what axis to mount in on (different axis will diagnose different problems) After second bullet point: Had to clean the surface in order to mount and I got help from the machine shop to prepare the surface After fifth bullet: determine how the resolution, bandwidth, sampling frequency, etc… After sixth bullet: Decided that blueprint RPM is only for ideal conditions where there is not misalignments, belt slippage
- #20: There are 6 Rotoblast heads; 3 on the top and 3 on the bottom. This is a picture of the first Rotoblast head on the top of the machine (inside the doghouse). You can see the motor which drives the belts (under the cover), which drive the shaft connected to the Rotoblast head. I mounted my accelerometers in the horizontal radial direction as close as possible to the bearings and Rotoblast head
- #21: These are heads 2 and 3
- #23: After last bullet: For example, if I got baseline vibration readings of .2 in/sec, I would set my early warning alarm to .4 in/sec and the main alarm to .6 in/sec
- #25: A branch of study known as frequency spectrum diagnostics can be applied to match the machine fault with its frequency spectrum. Charts and tables exist that assist with the diagnosis, however, often times there are multiple machine faults occuring simultaneously on one piece of equipment thereby complicating the diagnosis procedure. In addition, frequency spectrums are rarely as clean as they appear on the diagnosis charts. Nevertheless, I was able to perform predicitive maintenance and alert the crew before parts began to fail. This case showed some misalignment. We went to number 3 head and saw the grease feed line from the auto lube system was caught in the belts and the motor wasn’t aligned properly
- #27: After first bullet: Attended a safety huddle meeting everyday for the entire summer Safety was always the first and last thing talked about at all maintenance meetings. Its important to be aware of your surroundings and maintain a constant respect for your environment Also important to be able to freely communicate and not be intimidated if the plant manager sits in on a meeting After last bullet: If I was ready to work on something, I had to wait for everyone else or a down day. Have to have patience