Maintenance and energy

Inspection schedule

Increase the frequency for dusty, hot, wet or shock-loaded drives, and for drives where a stop costs a lot.

What to look for

• Belt dust under the drive: some is normal; a lot means slip or misalignment.
• Temperature: after a stop (isolated), belts should be warm, not too hot to hold. Hot belts mean slip or overload.
• Cracks, glazing, swelling, frayed covers, cords showing: see wear patterns.
• Belt position in groove: sinking lower over time means groove wear.
• Take-up left on the motor base: no more adjustment means it's time for a new set (and a look at why they stretched).

When to replace

• Any belt with cracks into the cords, exposed cords, a missing section or severe glazing.
• When the belts can no longer be tensioned within the base adjustment.
• Multi-belt drives: replace the whole set, never one belt.
• Pulleys: when the groove gauge shows wear (see gauging), and always with a new set on a drive that has been eating belts.

Storing belts

• Cool, dry and out of direct sunlight: ideally below about 30 °C and away from heat sources.
• Away from ozone sources (electric motors, welding plant, switchgear, fluorescent lighting transformers) and from oils, solvents and chemicals.
• Hang belts on wide saddles or lay them flat. Don't hang them on a nail or small peg (it kinks them), and don't stack heavy weights on them.
• Never crimp timing belts. Store them flat or on wide saddles in their original packaging.
• First in, first out. Rubber ages on the shelf; check older stock for surface cracking before fitting.

Critical spares and breakdown kits

Every hour a critical drive waits for a belt costs production. A breakdown kit is a box per machine (or per line) with a full matched set of belts for each critical drive, labelled with the machine, drive and belt size. When one is used, it's replaced.

1. List every belt drive on the site: machine, drive, belt section and length, number of belts, pulley sizes. A drive survey is the fastest way.
2. Rank them by cost of downtime and how long a belt takes to get.
3. Stock full sets for the critical ones. Use the breakdown cost calculator to justify the stock.
4. Review twice a year and before the season.

Ask us to build a breakdown kit

Drive records

A one-line record per drive saves hours at every breakdown: machine · motor kW and rpm · driver and driven pulley (section, grooves, datum Ø, bush) · belt (section, length, quantity) · centre distance · tension setting · date fitted. Stick a label inside the guard as well.

Energy efficiency

The US Department of Energy's motor systems guidance (Tip Sheet #5) gives a useful frame:

• Standard V-belt drives can reach about 95 % or more efficiency when new and correctly tensioned, but efficiency falls as belts wear and slip, by as much as 5 % if they are not re-tensioned.
• Cogged (notched) belts run cooler, last longer and are about 2 % more efficient than standard V-belts, on the same pulleys.
• Synchronous (timing) belts hold about 98 % across their life and the load range.

Run your numbers: energy savings calculator.

The cheapest energy saving is still correct tension: a slipping belt wastes power as heat and wears itself out.

Shutdown planning

Most process and agricultural industries have a predictable quiet period: the sugar mills' off-crop, packhouses and macadamia crackers after their season, sawmills at year-end. Plan the belt and pulley work for it:

1. Survey and gauge every drive 6 to 8 weeks before the shutdown.
2. Order belts and pulleys early, especially custom-made and non-stock items.
3. Replace on condition, align, tension, record.
4. Re-tension after the first day of the new season.