25 August 1995

Maintenance

– a time saver

Maintenance and adjustment are the key elements in getting the best from a sugar beet harvester, reckons James de Havilland

"LUBRICATE and adjust" is a good maxim. In a busy campaign, that may seem a costly waste of time. But regular attention can save breakdowns, especially on older machines, which wear fast if adjustments are neglected.

Different makes of harvester need specific care. But the basics apply to most machines including self-propelled units.

Thorough cleaning is a key initial task. This will help reveal damaged components and make servicing easier.

Always lubricate after cleaning. Moisture in cleaned bearings and chains causes corrosion.

Drives

The most important aspect regarding hydraulics is the oil. It must be in good condition. Emulsified, dirty oil is the cause of most problems. Always keep the tank topped up to prevent condensation.

Change filters at least once a year, regardless of machine use.

Check for leaks to hydraulic drive motors, cracking or ageing in hydraulic pipes and rams. Rams left extended in store may have rusted and become pitted. This will wear seals.

Remove drive guards, checking the drive line for play in shafts, slack and wear in drive chains and loose belts. Belts running deep in V-pulleys may be too slack or worn. Pull them around to check the whole wearing area. Threads showing usually indicate time for replacement.

Check for uneven wear, cracking and "burnishing". This can cause, and be caused by, belt slip. Examine pulleys and idlers – play indicates excessive wear that can lead to failure in the field. Keep belts slack in storage and re-tighten before use.

Drive chains are best checked off the machine. Wear on the chain side rails and rollers shows up as polishing and mottling, wear in the pins as play in the chain itself. Examine chain split links and clips. If clips are bent or do not spring back tightly on links, renew.

Sprockets and idlers must be checked at the same time. Badly worn sprockets accelerate chain wear and can lead to jamming.

Use a straight edge to check alignment of pulleys and sprockets, and use shims if needed to restore a straight drive path. If reusable, chains should be cleaned with a wire brush and lubricated.

Where shafts are used, check for play and damage. Make sure shafts are straight – slight kinks speed wear and set up vibrations than can cause fatigue cracks.

Gearboxes

Oil level is critical. Also check for shaft movement. This can be taken up with shims on some designs or by fitting new bearings. Oil leaks may indicate other faults. Replace seals to prevent lubricant loss.

Ensure guards are replaced and that they fit without touching moving parts. Remove dents. Where gaskets are used make sure they are replaced or renewed as appropriate. Pay particular attention to safety guards and fixings.

Cleaning and transfer webs, cyclones and conveyors

Different designs make it difficult to generalise. But whatever type of machine is being prepared, wear and damage must be corrected to ensure in-field reliability.

Bent bars are more easily dealt with if the web is removed, but this calls for a link to be unhooked. If this is impractical ensure the whole web run is checked. This is easier to do if drive chains are left off. Where rubber is used in the construction check its condition.

Pay particular attention to play in sprockets and idlers. If this cannot be accommodated by some form of adjustment, replacement may be necessary. Ensure bearings can be greased.

Work through the machine to the discharge elevator, seeing web-tensioning idlers are not seized and can be adjusted. Adjustments will be easier and more likely to be made if fastenings can be readily undone and re-tightened.

Toppers

These should provide a clean cut and, according to design, distribute cut leaves away from rows to be lifted. Poor cutting can be caused by incorrect alignment, blunt blades and poor setting. Drive problems also cause erratic topping.

Scalpers

Ensure blades are sharp and correctly aligned. Wheel toppers need teeth in good order to give a clean cut. Check the drive system – wear is accelerated if settings are not checked regularly.

Lifting shares

Check for wear and freedom of movement. Wheel play will adversely affect lifting efficiency. Adjust with shims or by tightening bearings. Dismantle lifter wheel bearings annually, clean and repack with grease. Replace worn bearings.

Adjustments

Basic adjustment in the workshop will save time setting up in the field. Invest in new fasteners and fittings to save grazed knuckles and poor setting later. Make sure correct sized spanners are left with the machine so adjustments can be made quickly without "rounding off" nuts.

Avoid setting pre-toppers too aggressively as this will affect final topping. Make sure they are correctly aligned and run horizontally.

With feeler wheel toppers, set the knife just back from the wheels centre, setting the depth to give the desired level of top. Check knife is horizontal to give a flat cut. Slight adjustments may be needed to suit knife position in relation to forward speed. Be prepared to alter setting during harvest to accommodate wear, a bent knife or changing conditions.

Settings with a knife and comb follow a similar pattern, self-compensating designs being less critical. Refrain from adjusting all elements at once on the initial run.

Lifting

Look at your sample and see if it is what you want. Much depends on soil type, size of beet, conditions, operating speeds and the balance between getting as clean and complete a sample as possible and time available. Accept share settings may need changing not only bet-ween fields and varieties but also as conditions change within a field.

With thanks to Neville Lawrence and Philip Germany of Standen Engineering and Alan Winter at Standen-Reflex. &#42

From the biggest to the smallest, beet harvesters need maintenance and setting for optimum results.