Maintenance Achievements 2000-2003


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Examples of industrial maintenance improvments in manufacturing environment while at Federal Mogul Corp.

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Maintenance Achievements 2000-2003

  1. 1. The New Maintenance Plan: Short Term Goals • All PMs will be updated and be generated by the new maintenance management system, MP2 software. 9/1/00 • 25% of all work orders will be generated from PMs and scheduled ahead of time. 12/1/00 • Improve mold press availability (up time) by 50%. 1/1/01 • Warehouse inventory will be databased and maintained accurately using MP2 maintenance management software.
  2. 2. How We Will Reach Our Short Term Goals • We will establish a dedicated PM crew. Approximately 2 persons. • We will establish a scheduled amount of work for another crew. Approximately 2 persons. • The remainder of the maintenance work force will continue with our current emergency, breakdown work load. • Over time as our PMs become more effective people working on the emergency crew will slowly begin being scheduled. • Scheduled work orders will be generated from our PM system. • Our PM focus will be mold presses and plant critical equipment, i.e. mix mill, ionic, Barwell, etc. • Warehouse inventory will be limited and under lock and key, inventory will be controlled by the scheduler using MP2 software.
  3. 3. The New Maintenance Plan: Long Term Goals • Overall maintenance skill level will improve 30%, based on WorkKeys testing. 06/01/01 • Average time between failures will decrease by 50%. 06/01/02 • 75% of all work orders will be generated from PMs and scheduled. 06/01/05 • We will provide our customers with “World Class” service and professionalism. ASAP
  4. 4. How We Will Achieve Our Long Term Goals • We will stay focused on scheduling work and working towards our common goals. • We will increase training opportunities for the maintenance department. • We will provide PLC troubleshooting computer and supplies. • We will work and function in a clutter-free, clean work environment. • We will live by the PM philosophy. • We will continue to build our database of equipment documentation, prints, and keep accurate usable equipment history. • We will continue to bench mark our progress in developing the skill level of the maintenance department using different types of testing methods.
  5. 5. Hydraulic Oil Contamination Control (with Autonomous Maintenance): Bipel Press Kidney Loop • Problem: The Bipel press group consists of six mold presses, two of which have been completely rebuilt. The four older mold presses lack sufficient filtration and oil cooling capabilities. No signal to replace the hydraulic oil filters or excessive oil temperature existed. • Corrective Action: To correct this problem an additional pump, motor, 3- micron filter, and shell and tube heat exchanger were installed. The improvement provided an additional 20 gallons per minute filtration and improved cooling over the original equipment. The standard breather filter was discarded for the same 3-micron type used on the Wabash and Hydro press groups. Temperature of the oil was dropped from 155 0F to 125 0F. Indicator lights were installed on the machine to warn personnel of excessive oil temperature and needed filter change s. Shell and tube heat exchanger and Vickers 3- micron hydraulic oil filter flow 20 gallons of oil per minute.
  6. 6. Contamination Control: Hand Transported Lubricants Each container is labeled to prevent lubricant mixing and has leak tight caps for contamination control. Cart has a specified storage location for each lubricant type. Problem: Many lubricants and oil need to be transferred from a larger container to a smaller one for transportation to the machine waiting on the factor floor. Before lubricant specific containers were available, any container would serve duty to transport various types of oil throughout the plant. This led to lubricants being mixed and contaminated with dirt and other debris. Corrective Action: A cart was specifically built to store the various types of lubricants used throughout the plant. New containers and funnels with built in strainers were purchased and labeled for lubricant specific use only. Containers are required to have caps and lids installed at all times unless transferring lubricant. One maintenance person is solely responsible for the condition and maintenance of the lubricant cart to help ensure effective contamination control.
  7. 7. Contamination Control: Controlling Partials at the Source Problem: Hydraulic oil used for all hydraulic systems use oil from storage tanks located outside the plant. While implementing predictive maintenance oil analysis techniques, it was discovered that the new or recycled hydraulic oil entering the plant contained an unacceptable level of contamination. Corrective Action: A ½-micron pressure filter was installed between the outside storage tanks and the plant-wide oil replenishment system. This improvement was completed free of charge from Dilmar Oil Company, our Texaco oil supplier and recycler. Hydraulic pressure filter is 48” tall and filters partials down to ½ micron in size. All hydraulic oil entering the plant is transferred through this filter before use. This moisture absorbing tank breather was also installed by our supplier to keep moisture and contaminates from entering the outside storage tanks. Since installation, moisture in the hydraulic oil has been non-existent.
  8. 8. Contamination Control: Hydro Mold Presses Problem: Nine mold presses operate from a single hydraulic power unit. Nominal oil temperature was 140 0F and on an average day the system leaked about 150 gallons. Within one year 10 hydraulic pumps were replaced on the 5-pump power unit. (Average pump life was 6 months!) The pump manufacturer would not honor the warranty due to the dirty condition of the oil. We were replacing nearly one directional valve per day that could be directly related to dirty oil. Background: This system was in the worst condition at the beginning of the Preventive Maintenance program initiated in July of 2000. Many reservoirs were open with missing lids, no breather elements, and many other areas where contaminates could enter the system. Oil filtration was limited to 70 gallons per minute through a 25-micron filter for the entire 3000-gallon system. Most of the hydraulic hoses on this system were in need of replacement as well as much of the hydraulic piping. Corrective Action: We began by closing all openings and installing breather elements on the central and remote reservoirs. Oil replenishment plumbing was installed to allow the central reservoirs to be filled without having to remove a cap and introduce contamination. Outside contractors were hired to replace much of the aging hydraulic plumbing that was notorious for springing leaks and showering everything with hot hydraulic oil. A representative from Vickers was brought in to determine how much filtration would be needed to effectively control contamination and new pressure filters were installed at each pump. The kidney loop filter was upgraded from a single 25 micron to a four element, 3-micron filter to remove smaller partials from the oil. A second, 135 gallon per minute kidney loop was installed with two more heat exchangers and four more 3-micron filter elements. With both kidney loops, pressure filters at each pump, and four chilled water heat exchangers installed, the oil was being filtered at 385 gallons per minute and the oil temperature was down to 100 0F. Within a couple of months, the advantages of clean oil were obvious. Hydraulic valve problems quickly disappeared. After the first year of completion, pump failures were reduced by 70 percent. Cylinder and valve wear has also been reduced. Oil leaks were much improved due to the cooler (thicker) hydraulic oil. The hydraulic filters are checked every shift to ensure they are changed as needed to keep the filtration system performing effectively. 3-Micron reservoir breather filters used on the central hydraulic unit as well as the individual press reservoirs Individual 3-micron pressure filters for each pump on the central hydraulic power unit
  9. 9. Contamination Control: Hydro Mold Presses (Cont) Kidney loop number one with four, single pass 3-micron, hydraulic oil filters. Notice the filter bypass circuit that allows the filters to be changed without having to shut the system down. Kidney loop number two, 135 gallons per minute with four 3-micron filter elements and two shell and tube heat exchangers. New hydraulic plumbing with support bracing to prevent pipes from excessive movement and cracking welds.
  10. 10. Contamination Control: Wabash Mold Presses Problem: Based on oil analysis data, an effort to reduce contaminates in the hydraulic oil of the Wabash mold presses was needed. If a pump failure occurred, the manufacturer would not honor the warranty due to contaminates found in the hydraulic oil. Background: This press group consisted of ten mold presses that were five years old or newer. They were equipped with a single kidney loop with a single pass 10-micron filter, 10-micron reservoir breather filter, and shell and tube heat exchanger. Proper oil temperature was maintained but particle count analysis indicated the amount of filtration was inadequate to maintain the required 16/14/12 ISO cleanliness code. Oil servicing of these machines was typically done manually, using a “bucket” to transfer oil from storage to the press reservoir. This method introduced foreign contaminates into the system and was very labor intensive. An alternative for servicing this equipment was needed. Corrective Action: First action taken was to plumb the new oil supply directly to each press. This allowed the press to be serviced with oil without the need of a container. Since the oil supply was plumbed directly into the reservoir, the reservoir cap did not need to be removed each time to add oil. Simply start the oil supply pump, open the valve, and fill the press with contamination free hydraulic oil. The oil line is plumbed directly into the hydraulic reservoir Clean oil supply plumbed in from outside storage tanks directly to the press.
  11. 11. Contamination Control: Wabash Mold Presses (Cont) The easiest contamination control measure taken was to reduce hydraulic filter sizes from 10- micron to 3-micron. When changing filter sizes, the reservoir breather element must also be changed accordingly. With a 3-micron filter element and breather filter, contaminants within the oil were greatly reduced but were still not clean enough. Additional measures were needed to obtain the 16/14/12 ISO cleanliness code target. 3-Micron Filter Element 3-Micron Breather Filter To ensure the filter elements were 3 – Micron breather elements were changed as needed, a daily schedule placed in stock and are changed (every 8 hours) was established and during the quarterly preventive followed to check each hydraulic maintenance inspection. filter with a visual indicator. This schedule ensures prompt element replacement.
  12. 12. Ionic Hydraulic System Contamination Control: Improved Filtration and Oil Replenishment Procedure Changes Filtration: Problem: Hydraulic oil filtration on the ionic barrel rotation system was very inadequate. The system had to be shutoff to change the oil filter and the filter was obsolete and did not have an indicator to signal when the element needs changing. The only element that was available for the housing was from Napa and only available in a 25 micron size. Corrective Action: This project was given as a Multi-Skill evaluation to Billy Parker. Billy was provided a sketch of the hydraulic filtration improvement circuit and tasked to build and install the system. The circuit provides oil filtration on both the pressure and return lines. Filters selected used the same elements as those on the Hydro press reservoir, eliminating the need to stock another type of element in the supply crib. Three-micron filtration was also accomplished by using the currently stocked filter elements. The circuit provides the ability to change elements without shutting down ionic by utilizing a three-way ball valve to re-direct the flow around the filters. Ionic Filtration Before Upgrade - Single 25-micron pressure filter. Filter had no indicator to alert anyone that it needed changing. Return line filter removed any contaminates returning from the hydraulic motors on the ionic line. Three-way ball valve to re-direct the flow around the filter to allow the filter to be changed without shutting the machine down. Three-micron pressure filters to clean all oil leaving the pump going to the hydraulic motors on the ionic line.
  13. 13. Ionic Hydraulic System Contamination Control: Improved Filtration and Oil Replenishment Procedure Changes Oil Replenishment, Procedure Change: Problem: When oil needed to be added to the ionic hydraulic system it had to be carried to the tank manually. Before oil contamination control measures were in place, an open quot;jugquot; was used to refill the hydraulic tank. This introduced the mixing of oils, and dirt into the hydraulic system. Corrective Action: To prevent this contamination from occurring, a dedicated oil line directly from the outside storage tank was plumbed to the ionic hydraulic reservoir. This eliminates the need to obtain a container, fill it with oil, and carry it to the reservoir. Now all that is required is to start the pump and hold the spring loaded valve open as the clean oil is pumped directly from the outside storage tanks into the hydraulic reservoir. Replenishment oil line plumbed directly from the storage tanks to the ionic hydraulic reservoir. Fill valve with spring loaded handle. Spring-loaded handle on fill valve prevents the valve from being opened and forgotten resulting in the tank from being overfilled. The mechanic must stand and hold the valve while filling reservoir.
  14. 14. Hydraulic Oil Temperature Control – Bipel Press Group Problem: After the installation of the additional filtering and cooling kidney loop, the temperature of the hydraulic oil was lower than before but still unacceptable. Some valves were operating as high as 160 0F. Ideal temperatures should not exceed 120 0F. An analysis of the problem reveled inadequate cooling water flow through the heat exchangers. A flow of only 2.5 gallons per minute was measured. Background: A noticeable problem with the Bipel press group has been the numerous hydraulic oil leaks. A major cause of this problem has been high oil temperature. The hot oil causes the rubber o-rings and seals to become hard and brittle causing them to form leaks. As the leak develops, more heat is generated and the problems grow worse unless corrective action to reduce oil temperature is taken. Kidney loops were added to the hydraulic reservoirs of each press for additional filtration and cooling capacity. The loops improved the filtration and cooling but not enough heat was removed from the oil to keep the system at optimum temperature. An investigation determined the chiller that supplies cooling water to the press was not being loaded as was expected. If enough cooling water at the right temperature were supplied to the press it would control the hydraulic oil temperature. A flow meter was installed at the press to measure the amount of cooling water delivered to the press. The heat exchanger should have 10 - 12 gallons per minute of cooling water for optimum heat removal. A flow of only 2.5 gpm was measured. The cooling pipes were traced throughout the plant and the Bipel press group was located at the end of the plumbing system. We were only able to remove about 1.5 hp of heat under these conditions. Our heat exchanger is capable of 20 hp under optimum conditions. There was simply not enough water flow reaching the press group to keep them temperatures low. Corrective Action: Immediately after the plumbing was suspected of being inadequate, two contractors were called to quote corrections to identified plumbing problems. After the plumbing modifications were made, the temperature of the hydraulic oil was considerably better. Average temperature on the hydraulic reservoir dropped 20 degrees from 120 0F to 100 0F . Shell and tube heat exchanger and Vickers 3- micron hydraulic oil filter flow 20 gallons of oil per minute.
  15. 15. Predictive Maintenance: Vibration Analysis Failure Prevention 40 Hp Motor Bearings On November 26th, 2001 motor bearings from vacuum pump four were replaced based on information from our fledgling predictive maintenance program. When beginning vibration data collection, a baseline signature was taken by collecting readings from vacuum pumps. The vibration signature should be similar between all like machines, providing all the machines are in good condition. If one machine’s vibration signature is significantly different than the rest of the group, further investigation may be warranted. With the motor bearings on vacuum pump four, this was the case. Once we determined there maybe a problem, the vacuum pump was monitored more frequently until a shutdown was scheduled. Over the Thanksgiving shutdown the decision was made to replace the motor bearings before a failure could occur. After installation the overall noise level around the vacuum pump was very noticeable. The bearings were sent to the manufacturer for a through inspection and report on the findings. Shaft End Motor Bearing Vacuum Pump #4 40 Horsepower Electric Motor Non-Shaft End Motor Bearing
  16. 16. Electric Motor Balancing to Cure Excessive Vibration McNeil Mold Presses: Excessive Vibration of the Drive Motor Problem: Excessive vibration of the main drive motor on McNeil mold presses. Background: The next step to improve the availability of the McNeil mold presses is to remove the amount of vibration occurring within these machines. When the motors change from low to high speed the vibration can shake the machine apart. After several months of investigation, a number of items leading to excessive vibration were identified. Motor shaft run out was found to be as much as 0.020” and the fit between the rotor and the shaft was 0.040” over sized. The proper fit between the shaft and rotor should be no more than + 0.005”. It was found that when the rotor (with 0.040” oversize) was placed onto the shaft, the centerline of the shaft did not lineup with the centerline of the rotor. This condition caused an imbalance within the motor that caused excessive vibration during operation. The McNeil motors have a pneumatic activated friction brake on the top of the motor that mounts to the 52” motor shaft. Excessive run out on this shaft caused severe vibration, shaft wear, worn keyways, and motor brake problems. To compound both of these problems, motor windings and rotors were mixed and matched over the years and were never balanced before assembly. Sending the complete motor and shaft assembly out for repairs and re-balancing would have caused pro-longed production disruptions. Corrective Action: In October of 2001, one of the McNeil mold presses was scraped. The motor winding, rotor, and shaft were salvaged and used as a spare. The winding and rotor were completely rebuilt but special attention was paid to repairing the shaft. The new motor shaft was repaired and re-machined to align both centerlines of the shaft and rotor. The newly repaired shaft had a total run out of only 0.003” of an inch. The shaft, rotor, and brake assembly were dynamically balanced as a complete unit. With a complete spare motor, rebuild and balanced, the installation was completed within eight hours. When the new motor was installed an improvement in smoothness of operation and noise was obvious. Each time a motor is changed, the remaining shaft and rotor are sent out for machining and balancing. This process is repeated each time a motor is vibrating excessively or needs replacing.
  17. 17. Electric Motor Balancing (Cont.) McNeil rotor with 0.040” oversized inner diameter McNeil motor shaft before re-work Motor shaft and rotor before machining, disassembled. Motor shaft and rotor assembly worm gear side of shaft. Weights were added to balance the rotating assembly. Rotor and shaft are machined to utilize a split coupling to align both centerlines and attach the rotor to the shaft securely. Split coupling and balancing weight.
  18. 18. Electric Motor Balancing (Cont.) Additional Pictures of Modifications
  19. 19. Post Cure Ovens: Forklift Guarding Problem: Over several years of use, the post cure ovens were showing signs of abuse from collisions with forklifts. The damage was not only cosmetic, damaged air circulation plenums caused temperature distribution problems within the oven and produced under cured parts that will cause premature oil seal failure. Damage to doors and door seals produced “cold spots” within the oven also resulting in under cured parts or low microhardness. Corrective Action: Most of the damage on all of the six ovens was on the inside. The thin sheet metal flooring was replaced with ¼” thick plate steel. All damage to the air circulation plenums was hammered back into shape and patched using new sheet metal. To protect the newly repaired plenums, a railing fabricated from angle and channel iron was installed. Metal around the door sealing area was repaired and new seals were installed. Two of the ovens use swing open style doors and required hinge adjustments to get the doors to seal properly. Holding the door closed was also improved by installing new heavy-duty door latches. Three weeks after work began, all six ovens were repaired and protected with heavy duty steel guarding and temperature distribution was greatly improved. Heavy duty door hinges installed on ovens with swing-out doors. Double sealed doors with heavy-duty door latches and plenum protecting guardrails.
  20. 20. Excessive Vibration: Oven #2, Circulation Fan Motor Problem: Excessive vibration Background: Past history of bearing failures and guards vibrating loose indicated that a root cause analysis was needed to better understand the nature of the problem. Using a stroboscope, we discovered the motor cooling fan had damaged and missing blades causing the motor base to vibrate excessively. We also discovered that a drive belt that was slipping on the sheave, possibly due to poor misalignment or improper belt tension. Before corrective action was initiated the following vibration readings were taken at each of the seven points of interest. Points 1 and 2 were on the motor in the vertical direction. Points 3 and 4 were on the motor in the horizontal direction. Measurement point 6 was on the motor base near the back of the oven. Point 7 was also on the motor base on a diagonal from point 6. Measurement point 5 is on the motor in the axial (parallel to the motor shaft). The data collected is listed below. Point 1 - 0.30 in/s Point 2 – 0.34 in/s Point 3 – 0.25 in/s Point 4 – 0.37 in/s Point 5 – 0.20 in/s Point 6 –0.20 in/s Point 7 – 0.33 in/s Corrective Action Taken: A new motor was ordered along with new belts to allow very little oven down time. The motor base was leveled and the new motor was installed. The motor was shimmed as needed to provide equal belt tension. A straight edge was used to align the sheaves and provide an even running surface for the belts to transmit power to the blower wheel. The motor base height was adjusted to provide proper belt tension. The guards were reinstalled and the vibration measurements were re-taken. The improvements are illustrated in the vibration readings below. Point 1 - 0. in/s Point 2 – 0. in/s Point 3 – 0. in/s Point 4 – 0. in/s Point 5 – 0. in/s Point 6 –0. in/s Point 7 – 0. in/s
  21. 21. Autonomous Maintenance: Excessive Operating Temperature Causing Pre-mature Motor Failure Problem: Electric motors that power McNeil mold presses operate under extreme conditions and require an external cooling source for longevity. Prior to installing this new high volume blower, we were replacing or repairing cooling fans approximately one per day. Motor temperatures ranged from 120 0F to 140 0F. Back Ground: It seemed that constantly we were installing new motor windings on the “high speed” McNeil motor presses. The motors are two-speed, 80 hp, Louis-Allis motors that have a custom, single piece worm gear shaft. Windings for these motors are obsolete and must be rebuilt and re-wound. Replacement of a burnt out McNeil motor winding required two men for 8 hours of lost production time, not to mention the $1700 for the winding repair. In an effort to keep these motors from getting too hot, a check to verify the cooling fans were still working was performed at the beginning of every shift. At least daily, blower wheels or housings were being replaced. A heavy-duty high-speed blower with better durability and increased cooling capacity was badly needed. Corrective Action: A cast aluminum blower housing attached to a 3200 rpm Baldor, 1/3 hp motor was chosen as an improvement over the older cooling blowers. The new blowers moved three times more air through the large motor windings than before, lowering the normal operating temperature by 30 degrees. This greatly improved the durability of the McNeil motor windings. After 10 months after the installation of the heavy-duty blowers, not one motor winding has been lost due to excessive heat or insulation winding breakdown. As a visual indicator, temperature sensitive patches were installed on the outside of the motors. The patches would change color, providing a quick indication to the mechanic making his daily rounds of excessive heat or cooling fan failure. On Going and Future Improvements: To further enhance the motor cooling system, ducting to import fresh clean air from outside the mold shroud is being installed. Mold spray and oil mist are plentiful within the mold shroud, both of which are enemies of electric motors. To ensure McNeil motors are not continuing to operate while overheating, temperature monitoring, using the presses’ PLC will prevent the press from operating and “shut down” before expensive damage is done. This will be the ultimate preventive measure for getting the most out of the older McNeil mold presses. New improved McNeil motor cooling fan without fresh air duct attachment.
  22. 22. Autonomous Maintenance: Excessive Operating Temperature Causing Pre-mature Motor Failure (Cont.) Improved McNeil motor Temperature Fresh air ducting brings in cool cooling fan with fresh air indicator changes clean air from outside the mold ducting and temperature color when motor shroud to keep mold spray, oil, indicator. temperature rises and other debris from entering above 1200 F the motor windings. McNeil low speed motor with thermocouple installed into motor winding. Temperature indicator pilot light activates when motor temperature is above 125 0F Example of thermocouple installed into a high speed McNeil Motor. The thermocouple is wired directly to an open input into the PLC for temperature monitoring. Shuts motor down when temperature exceeds 1250F.
  23. 23. Autonomous Maintenance: Warm-up Mill Out of Grease Safety Shutoff Problem: In July 2001 the warm up rubber mill was allowed to operate with the lubrication pump out of grease. Operating the mill without grease destroyed the 14” diameter main roller bushings. To replace the bushings cost $7000 parts and labor, plus lost production time. Lubrication assignments belong to the maintenance helpers. Due to the many duties placed on the helpers, some tasks are forgotten or simply never completed. A startup checklist by the production personnel would have prevented this situation also but using a “human dependant” system is never as dependable as an automatic system. Corrective Action: A proxy switch was installed on top the grease pump. The switch senses a plunger rod that extends from the top of the grease pump. When the grease gets too low, the rod travels below the switch and shuts the mill off before damage can be done. The mill will not restart until the grease pump is re-filled with grease. Safety “shut off” proxy switch will prevent the warm-up mill from operating if the lubrication system runs out of grease. Warm-up Mill “Out of Grease” Safety Shutdown Indicator Pilot Light
  24. 24. Autonomous Maintenance: Centralized Vacuum Pump System Oil and Temperature Safety Shutoff • Problem: A PLC controlled four-pump vacuum system was used to provide vacuum to all mold presses. All four vacuum pumps are equipped with a low oil sensor and a temperature sensor to shut the pump off in the event the temperature becomes too high or the oil level is too low. Neither of these safety features were being utilized because three of the four pumps were operating in “manual mode”. • Background: It was discovered in July 2000, the system was designed to progressively activate a pump as needed. If the vacuum demand was low, the control system would start one pump. If the demand increased, another pump would be started, and so on. This centralized control feature would save machine wear as well as conserve electricity if it were being utilized. It was also discovered that when the pumps were allowed to operate in the “manual mode” the temperature and low oil level sensors were not being used! This could have lead to severe damage to any of the vacuum pumps if allowed to operate without these safeguards. The system had been suffering from several years of neglect. • Corrective Action: All temperature and oil level sensors were replaced, the old sensors were found to be bad. Indicator lights were mounted on the control panel to indicate when a pump was running and if a temperate or oil level fault had occurred. The PLC program was modified to allow the temperature and oil level safeguards to be functional even during the “manual mode”. By operating the vacuum system in “automatic mode”, energy is conserved and vacuum pump life is extended while continuing to provide the proper level of vacuum to production processes. Pump Run Time Indicator Lights Pump Fault Indicator Lights, Low Oil or High Temperature Faults
  25. 25. Autonomous Maintenance: Boiler Blow Down Problem: Boiler makeup water chemical composition was out of specification causing steam traps, strainers, and piping to clog with scale and rust. This resulted in low quality steam thus causing temperature problems within the phoscoating line. Background: Federal Mogul, Summerton has an annual contract with the Metro Group Inc. to maintain the chemical composition of the ionic boiler. The proper chemical concentration is critical to maintaining an efficient boiler / steam system. The chemical keeps scale and rust from building up within the plumbing system and heater coils. Every month the results of the report were the same, the system was out of control. Metro Group technicians would make adjustments and recommendations and leave to return the following month. The boiler was required to be “blown down” on a regular basis to help remove scale and balance conductivity. Since the blow down needed to be performed three times per day, it was often forgotten due to other maintenance requirements. Corrective Action: To be sure the boiler was being blown down regularly, a small PLC was added to the boiler to control two automatic ball valves. One valve controls the bottom blow down, responsible for removing trash that settles on the bottom of the boiler. The top blow down valve controls the boiler water conductivity. A manual conductivity meter was purchased to monitor the boiler water and fine-tune the blow down time and frequency for optimum system performance. Since the modifications, the boiler has been able to maintain the proper chemical levels, reduced the amount of scale and rust, and resulted on less maintenance and downtime.
  26. 26. Bipel 408 & 409 Design Deficiency Front Guard Safety Switch Repetitive Failure Resolution Problem Documentation: When Bipel presses 408 and 409 were rebuilt, the vendors installed “keyed” safety switches. When the guard closes, a key attached to the bottom inserts into a safety switch signaling the press it is closed and safe for operation. The switches used were made of plastic and were breaking about once every three weeks. Reasons for failure were loose rubber flash from the mold getting into the switch mechanism and the gate slamming down too hard. Since these two presses were the only place these switches were used, replacement switches were not stocked in the supply crib. A failure could keep a press down for one to two days until another was ordered and installed. This was the number one reason for downtime on both rebuilt Bipel presses. Corrective Action: To permanently solve this re-occurring problem, a “non-contact” safety switch was purchased and installed. The non-contact switch uses a receiver mounted to the press and an emitter mounted to the guard. The emitter is detected when it comes within 18 mm of the receiver, when the guard is down. Since the two never come in contact, it will not become worn or broken because of normal opening and closing of the guard. Receiver “Keyed” type safety switch. Typically these switches are used Non-contact safety switches do on a guard that is used for not use moving parts and do not maintenance purposes, not for fail due to wear. normal machine cycle.
  27. 27. Bipel 408 & 409 Design Deficiency Front Guard Safety Switch Repetitive Failure Resolution (cont) Emitter Receiver This is the new non-contact safety Old “keyed” safety switch with the top switch arrangement. The emitter is broken off. mounted to the moving gate and does not require wiring. The receiver is mounted below to sense when the gate is closed and safe for operation.
  28. 28. Ionic Barrel Improvements (Metals Treatment Barrels) Old Bushing Design New Bushing Design Problem: Due to normal wear and tear the journals and stubs on the ionic barrels were out of round causing excessive clearance around the Teflon bushings. The chemicals used in the ionic line would flow into the large clearance of the bushing journal and harden preventing the barrel from rotating. When a barrel does not rotate, the metals are not coated properly and will produce scrap (if allowed to proceed to the molding department) or will need to be re-coated. Also, when the bushings are changed each journal and barrel stub must be measured individually and the bushing made custom for each side. Because of this, a routine bushing change took about 24 hours. The door on the barrel had it’s own bushing that was also changed due to the same problems. This bushing allowed the door to hinge open and the metals to be loaded and unloaded. Corrective Action: The bushing journals and barrel stubs were re-designed using thicker material that would not easily become deformed. New door hinges were fabricated with thicker materials to prevent breakage. All components were fabricated and machined on the CNC mill after welding to ensure tight tolerance. A single Teflon bushing was designed to take the place of the two individual bushings, one for the barrel to rotate, the other to allow the door to hinge open. This makes for a simpler design and ensures the smaller, hard to reach, door hinge bushing is changed regularly. Once all the barrels were upgraded with a standard bushing size, a spare set of bushings can be produced ahead of time and installed in approximately two hours. With the bushing surfaces perfectly round, the barrel could be rotated with minimum effort. The tight tolerance of the new components keeps the chemicals from entering the bushing area and hardening. This will allow the barrel to spend many more months in service before a bushing change is required.
  29. 29. Ionic Barrel Improvements (Metals Treatment Barrels) cont. Problem: Most of the ionic barrels that process metals through the phoscoat line are in need of major repair. Many frames were bent so badly they would not function properly. Many of the lids were bent and falling off because of poor quality hinges. The bearings on the drive shaft that rotates the barrels were 20 years old and were in need of changing. Corrective Action: The barrel refurbishing was completed one at a time. As each barrel was returned from cleaning, the frames were straightened and reinforced to prevent future bending. New 1/8” stainless steel was used to construct new heavy- duty lids and was attached using heavy duty hinges. New bearings were installed on each barrel with the grease fittings oriented to allow for easy lubrication. Newly designed bushings, journals, door hinges, and barrel stubs were also installed to allow the barrel to rotate easily. Barrel with Light Weight Bent Up Lid Barrel with New Drive Shaft Bushings Barrel with New Heavy Duty Lid and Highly Visible Numbers
  30. 30. Employee Development: Ionic Barrel Rotation Gearbox Rebuild Program Problem: Barrel rotation gearbox failure is fairly common in the harsh conditions of the ionic line. We were replacing as many as three gearboxes per month at a cost of nearly $1500 each. Background: Since the barrel rotation gearbox is on the critical item list in the supply crib, we always have a replacement in stock. Many times the old gearbox was simply discarded because the supply crib did not stock replacement parts and there never seemed to be “extra time” to perform a rebuild. Corrective Action: With an abundance of old gearboxes, new bearings, gaskets, seals, and shaft repair sleeves were ordered to begin a rebuild program. Blake Weathersbee, first shift maintenance helper, was selected to head up the rebuild program. Blake was trained to repair the worn shafts, install bearings, seals and adjust the lash in the gear set. Within the first four months of gearbox rebuild program, it has saved the plant approximately $2000 in replacement boxes. It has also been a valuable training tool for the helpers within the maintenance department. To identify the gearbox as a rebuild, they are painted blue as opposed to the factory color gray. Note - At the beginning of this program, it was discovered that the gear ratio of the gearbox was 18:1, which is a special order ratio. Since the output speed of the gearbox was throttled down when installed on the line anyway, the ratio of new gearboxes ordered was changed to a standard 20:1 ratio. By simply ordering a standard ratio box, the initial cost of a new gearbox was reduced by $500. Gearbox Before Rebuild Gearbox After Rebuild
  31. 31. Redicoat Paint Booth Mandrel Spinner Mechanism Re-design Problem: The mechanism that spins stacks of oil seals in front of a paint gun has a chronic problem of throwing belts off the pulley, shearing keys, destroying bearings and eating shaft couplings. Bearing blocks were attached “back to back” and would not withstand the belt tension load and wore out quickly. Framework of the mechanism was poorly supported and allowed the belt pulleys to tip causing the belt to jump off the pulley system. Corrective Action: To correct the many problems of the mandrel spinner mechanism a complete redesign was necessary. Starting with a strong framework built from a ¼” thick steel weldment, the bearing flanges were spaced apart to carry the belt tension load. The mechanism incorporates a spring loaded belt tensioner, eliminating the need for a mechanic to periodically adjust belt tension. The gearbox used to drive the mechanism was turned 180 0 to position the drive motor directly under the mechanism for a smaller overall package. Due to the extra weight of the new mechanism, jacklegs were added for proper support. Bearings were positioned too close together causing the pulley to “tip” in towards each other due to belt tension. The front bracket was not properly supported and deflected causing the belt to jump off the two pulleys. In an attempt to keep the pulleys from becoming misaligned the lower bearing blocks were positioned away from the upper bearings. Original position of the lower bearing was on the opposite side of the steel plate. A standard key would not reliably function on this poorly designed system. Notice the grade 8 bolt through the shaft.
  32. 32. Redicoat Paint Booth Mandrel Spinner Mechanism Re-design (cont.) The QD style tapered bushings provide a tighter fit on the shafts that the setscrews used on the older system. A spring-loaded belt-tensioning idler provides proper belt tension at all times The newly designed mechanism positioned the bearings apart to properly support the belt tension. A ridged heavy-duty base prevents any deflection or movement that would cause the belt to jump off the pulleys or cause mis-alignment. Two support legs were needed to support the added weight of the new mechanism.
  33. 33. Repair / Replacement Parts Logistics Repair Parts Staging Area Problem: Many times during a PM inspection, a mechanic will find an item that should be repaired but our supply crib does not stock the necessary parts. The mechanic will submit a parts request and several weeks later the part will arrive. Many times the parts were ordered with good intentions but were never installed due to various reasons. This lead to wasted money, missing parts, and machines continuing to operate with failing or faulty parts. Corrective Action: When a parts request is submitted, a job card is staged with the open work order with the card on the yellow “Hold” side. This visual system indicates to everyone within the department that parts are ordered to complete this work order. When all necessary parts are received, the job card is staged with the green “Ready” side out. Indicating that the repair and work order are ready to be scheduled and completed. This system signals the scheduler when work orders requiring parts are ready and provides tasks for leadmen to assign when the work load is light. Job cards are matched with open work orders when repair parts are ordered. When the parts are received the jobs are ready to be scheduled for completion. These cards are all green indicating that the necessary repair parts have been received and are awaiting installation.