PREVENTATIVE MAINTENANCE:
POWER FILE, SERIES 2000

Overview:

The Power File, series 2000 (aka: PF2000, rotary file, carousel, lektriever, etc) uses a conveyor/load chain type mechanical assemblies to rotate vertically up or down via the top sprockets with internal bearings and lower sprockets (attached via a solid torque shaft connected to the motor assembly). This load chain holds the pan assemblies (aka: shelves, tubs, etc) with which all types of material is stored. The load chain is rotated similar to a theme park ferris wheel via a motor, gear box and motor chain. The 120 VDC motor is run via an electronic control system that handles the conversion of AC to DC power. Furthermore the controls monitor the stopping position, safety circuits and over current draw from load deviation in the Power File. Like any other mechanical device similar to an automobile, the Power File 2000 requires periodic maintenance, based on: age, usage, and weight load. Assuming the unit has been installed properly, i.e. shimmed, leveled and plumbed the moving parts as well as the electronic parts require periodic attention, A.K.A. - Preventative Maintenance.

Conveyor Chain:

• The load chains similar to a bicycle chain (only on a large scale) will “wear in” (a.k.a. stretch) and become loose. Age, usage, and weight load has a great bearing on the amount of wear the load chain can incur.
  
• The scissors arms are suspended upon and share an extended pin on the load chains, which have load chain guide rollers attached to them to allow uniform travel up and down the internal vertical chain tracks. The scissors arms can wear at the point of attachment on the pin if the chain becomes loose or rigid.
  
• Trunnion plate scissors arm assemblies have the pans attached to them on both sides. These trunnion plate assemblies include stabilizing (cam) arms with rollers. This roller is used as a guide to maintain stability and levelness of the pans as they are rotated throughout the tracking system.
  

Motor Chain:

• Connects the gear reducer drive sprocket to the driven sprocket on the torque shaft.
  
• Will become loose over time.
  

Lower and Upper Curved Stabilizing Tracks:

• Located at the top and bottom on both the left and right sides, allowing the cam arms to travel smoothly throughout it's rotation.

Chain Track:

• Guides the load chain guide rollers on the extended pins to ride smoothly up and down in a vertical path.
  

Upper Load Chain Sprocket Bearing Assembly:

• Permits the load chains to rotate smoothly in a vertical path.
  

Torque Shaft Bearings:

Allows the torque shaft and load chain assemblies to rotate uniformly in a vertical path. The set screws on the bearings must be inspected.

Product Protect / Access Safeties:

Require periodic inspection for the safe operation of the Power File.

Possible Failures Due to Lack of Maintenance:

When the load chains wear/stretch, all other components are affected. The cam arms cannot move smoothly through and around the curved stabilizing tracks. The load chain guide rollers cannot effectively pass through the chain tracks. The upper sprockets bearings will prematurely wear and possibly fail. The motor chain will wear/stretch and become inefficient. When the load chains stretch the cam arm rollers as well as the load chain guide rollers are “forced” through the tracking system, no longer riding smoothly.

• The cam arm rollers will soon bust out at the bottom of one or both of the lower curved tracks. When this happens the rollers will constantly get caught on the broken area(s) and eventually cause the pan to flip shutting down the machine. This may cause damage to numerous parts. The cam arm rollers can also wear irregularly and possibly fall off. The loose roller or remaining attachment stud can get caught on internal parts potentially crashing the machine.
  
• With the cam arm rollers being forced through the curved tracks, the load chains will over wrap the lower sprockets causing the guide rollers to buckle, eventually breaking the vertical guide track(s). Over time the rollers can get caught on the damaged vertical guide tracks and break the extended pin(s). When this happens the scissors arms will fall and the pan will flip at the top or get stuck/flip at the bottom on the floor, and shut the machine down. If the pan flips it may become damaged as well as other components requiring replacement.
  
• The attachment point or hole of the scissors arms where they fit over the extended pins on the load chains will “egg out”, a.k.a. - become oval and loose. If this happens the trunnion plates and pans will rock as they travel through the curved tracks. This will cause disruption of the continuous flow of the conveyor system and cause failure to the other above mentioned components.
  
• The motor chain as it wears will become slack. With the weight distribution and erratic condition of the worn load chains and associated parts, can possibly skip over the drive sprocket on the motors gear box. This can cause a safety concern as when the chain skips the pans will not stop properly and will drift until the chain catches again. The slackened motor chain may also break and get caught on internal parts, allowing the pans to free wheel damaging other parts as well.
  
• Lack of lubrication will cause stiffness in all moving parts, premature wear and eventual failure.
  
• The cam arm rollers as well as the load chain guide rollers being forced through the the tracking system will become worn and loose over time, therefore possible getting caught on the tracking system. If they get caught and stuck, the system will shut down and potentially flip a pan damaging numerous part.
  
• With loosened load chains and other fatigued components, product may creep out of the pan(s) and get caught, causing further damage and down time.
  
• If the set screws on the lower torque shaft bearings come loose, the torque shaft can shift to the side causing unnecessary wear and fatigue. This will allow the load chain guide rollers to travel improperly possibly causing broken chain pins and down time.

Preventative/Corrective Maintenance:

1. Visually and audibly observe the operation of the machine.
   
2. Check the upper sprockets for wear.
   
3. Remove pans if required for 4, 5, 6 and 7.
   
4. Re-torque the load chains to factory specifications if required.
   
5. Adjust lower curve tracks to factory specifications in order for the stabilizing cam arm rollers as well as the guide rollers to track properly, if necessary.
   
6. Inspect lower and upper curved stabilizing tracks for wear/damage. Repair (weld) or replace as necessary.
   
7. Check the set screws on the torque shaft bearings, and lower sprockets. Tighten if loose.
   
8. Inspect the vertical guide tracks for wear, and repair as necessary. Welding may be required
   
9. Check for level and plumb.
   
10. Inspect the load chain guide rollers and replace as necessary.
    
11. Inspect cam arms and cam arm rollers for looseness. Replace as necessary.
    
12. Inspect sample scissors arms for wear. May require all to be replaced if wear is shown.
    
13. Tighten the motor drive chain if necessary.
    
14. Lubricate all wear points, chains etc.
    
15. Inspect/test all product protect/access safeties, and wiring. Repair, replace, re-secure as required.
    
16. Adjust motor control voltage and current output as necessary.
    
17. Inspect the floor where the pan mustache passes for clearance. Re-shim/level if too close.
    
18. Replace all removed pans and test run.
    
19. Inspect any options, peripherals, etc. added to the Power File. Adjust, clean, etc. as necessary.
    
20. Clean any debris and lubricants from the floor inside the machine. This will allow observation of wear during the next regularly scheduled maintenance.

Follow Up Maintenance:

The Power File has not been produced for close to 10 years, making most machines decades old. Based on: age, usage, and weight load a maintenance program should be in effect to promote the longevity of the Power File with minimal down time. Machines with long term neglect will benefit greatly from a comprehensive PM to extend the life of the Power File with a regularly scheduled maintenance program. Less down time and properly working Power Files will improve product picking and improved efficiency in other areas as well. Regularly scheduled maintenance permits “scheduled” down time for the maintenance. Always schedule follow up maintenance after completing a regularly scheduled maintenance. Always have failing or weak components replaced as soon as reported, especially the product protect/access safeties.

This document or any of its contents may not be copied or reproduced in any way without the written consent from:
Logic Level Technologies, Inc.