Now is the time to Inspect your combine
Written by admin on August 6, 2009 – 12:11 pm -Few people appreciate the value of planned preventive maintenance more than Earl Knuth. Years of field experience and a desire to maintain combines at peak operating performance have led Knuth to refine the process of detecting breakdowns before they occur.
The fleet of harvesters he manages for MachineryLink serves as an ideal planned preventive-maintenance proving grounds for combines.
Preseason repair interrogation
Knuth and his expert team of combine technicians have put together a preseason inspection plan for your harvester.
"An invaluable inspection guide can be found in your combine's bible -- the owner's manual," Knuth says. "Interrogate it prior to harvest to create your own inspection plan."
Knuth strongly urges you to "become good friends with your dealer's combine technician. You can learn a lot and develop a relationship that comes in very handy when you're trying to troubleshoot a problem in the shop or field."
Knuth offers one last bit of invaluable advice about cleanliness.
"You can never spend too much time cleaning a combine," he contends. "Beyond the effect it has on keeping your combine's threshing, separating, and cleaning activities at peak capacity, the process of cleaning can reveal a potential breakdown in the making and is invaluable at preventing a combine fire."
20-point inspection checklist
1. Header height control
Beyond discovering broken and worn parts, focus your inspection on the mechanical aspects of a height-control system. Problems in this area can result in sluggish and inconsistent height control. Check cutter bar movement, suspension springs, and support runners on platforms. Recon feeler paddles and wands, adjusting as necessary.
2. Header auger
After checking auger flighting for wear, take the time to open the auger finger cover (on cutting platforms) and inspect the fingers, being sure to lubricate nylon bearings.
3. Feederhouse components
Often taken for granted, the feederhouse has a huge influence on threshing in how well it presents the crop in an even stream, Knuth explains. Check that all slats are operating parallel to each other and are in good repair. Inspect the drive chains for wear and proper tension.
"A lot of operators miss inspecting the keepers on connecting links to make sure they are secure," Knuth says. "While you're at it, scan the top drive sprockets and the bearing of the front drum." Finally, examine the chain guides and replace if worn.
4. Feederhouse drive system
Completely disassemble and inspect the variable-speed drive pulley (sheave) assembly (if your combine is so equipped) on an annual basis, Knuth recommends. "It's not easily taken apart but not something to be scared of," he says. "And it will reveal problems with the cams that can greatly affect the speed adjustment operation of the feederhouse and header reverser." When greasing the variable drive (on a daily basis), make sure your zerks are located in the 12 o'clock and 2 o'clock positions so grease flows through ports to the drive's internal cams. Next, start up the combine and exercise the drive, speeding it up and down three times to completely distribute grease on surfaces of the cams.
5. Feederhouse belts
Unlike typical V-belts, the belts powering the feederhouse are of a special design and are engineered to transfer a lot of power. Much of the work they do requires power to be transferred strictly on the sides of the belts. As such, closely examine the belts for burnt spots, grooves in their sides, missing pieces, and for separation, Knuth urges. Replace worn belts instead of relying on dressing to extend their life. After inspection, adjust belt tension accor-ding to the owner's manual.
6. Threshing elements, rasp bars
Such components require scrutiny to detect excessive wear, missing hard surfacing, and damage to serrations. Chips on these components can increase grain damage, retard threshing, and boost threshing power requirements. Also scan the paddles on the transition cone for wear and replacement. Worn paddles and impellers affect how crop is presented to the cylinder or rotor.
7. Concaves
Remove the concaves to perform a thorough inspection, Knuth says. Look for rounded bars, missing wires, foreign objects, and residue buildup. Clean the concaves and reinstall them, making sure the units are level. Finally, check to see that the seals on covers are intact so they don't leak crop during threshing.
8. Separation tines
Tines and related crop-engaging devices can wear. "Once the hard surfacing is gone, it doesn't take long for the base metal to erode rapidly," Knuth says. "Worn tines retard crop flow and allow poor separation of grain."
9. Separator vanes
Survey the directional vanes mounted on the separation housing(s) for wear and damage. Replace as needed.
10. Chaffer, sieve elements
Key recon points include missing wires, misshaped elements, and damaged high-crop dividers.
11. Chaffer, sieve frames
Pay attention to frames for deterioration. "We've seen situations where a corner of the chaffer dropped into the shoe," Knuth says. "The shaking mechanism pounds the frame, eventually destroying it and damaging the shoe."
12. Cleaning shoe
Inspect the pan for holes and the mounting frame (for the chaffer and sieve assembly) for stress cracks.
13. Cleaning shoe fan
Scrutinize all the vanes for damage. "Today's fans turn at a high rate of speed," Knuth says. "A piece of residue sucked into the fan can bend a vane, jeopardizing its operating balance, which will eventually destroy a fan."
14. Cleaning shoe augers
Adjust augers to operate level as opposed to bowed. Examine the bearings and drive gears for damage.
15. Shaker arm
As stout as it appears, the arm assembly that propels the chaffer and sieve can bend. "This sets up a fierce vibration in the cleaning shoe, which leads to premature bearing failure, for starters, and can even damage the chaffer and sieve," Knuth warns.
16. Chopper mountings, belts
Recon the hinge points for stress cracks. Cracking indicates excessive vibration or imbalanced operation. Examine the belt for wear.
17. Chopper knives
Balance is key to long chopper life, Knuth stresses. Missing knives, or failure to replace knives in matched sets can set up vibration that could cause a chopper to self-destruct.
18. Tailboard vanes, spreaders
Often overlooked, worn vanes can be damaged. When that happens, the distribution of residue is compromised. Rotate traditional spreaders by hand to see that they operate smoothly (do not wobble) and check for wear on their distribution vanes.
19. Tailings, grain elevators
Beyond scanning for worn chains and paddles (particularly paddles with rounded corners), adjust the tension on these conveyors so that their paddles don't sag backwards in operation. "This is called backlegging (grain cascading back down the elevator), which severely limits the capacity of the elevators and can cause the cleaning shoe to overload," Knuth points out.
20. Clean grain auger
All augers wear in time, and the massive flighting filling the clean grain tank is no exception. Look for edges that are rolled back and sharp.
Tags: Farm Economy
Posted in Farm Implements, News | No Comments »