A conveyor rarely breaks down without warning. In most cases, it gives signs several days or several weeks beforehand. Spotting them in time lets you plan the repair instead of suffering it in the middle of production.

Important: any close inspection or adjustment must be done on a conveyor that is stopped and locked out (RSST, s. 188.1 to 188.13).

1. A new noise

A squeal, a regular clacking or a whistling that wasn't there before. It often comes from a bearing that lacks grease or is starting to fail, a seized roller or a chain skipping on a worn tooth. Note where and when the noise occurs: it helps the diagnosis a lot.

2. Increasing vibration

Vibration that grows over time often points to misalignment, a bent shaft, a damaged bearing or a loose fastener. Vibration measurements taken at regular intervals let you see the trend, for example by following the criteria in the ISO 20816 series of standards.

3. A belt that drifts

A belt that shifts to one side, rubs against the frame or has frayed edges signals a pulley or roller alignment problem, uneven tension, or material stuck to a drum. Left as is, the belt wears quickly and can tear.

4. Abnormal heat

A bearing, motor or gearbox running hotter than usual is working too hard: lack of lubrication, overload or the start of a failure. An infrared thermometer or thermal camera lets you compare temperatures from one week to the next. An increase in motor current for the same load is another sign to watch.

5. Visible wear

• Stretched chain: most manufacturers recommend replacing a roller chain at around 3% elongation.
• Sprocket teeth that are pointed or hook-shaped.
• Cracked belt, splice coming apart, rollers that no longer turn.
• Metal or rubber dust under the conveyor.

What to do when you see one of these signs?

Note it, measure it if possible, and plan the work for the next shutdown rather than waiting for the breakdown. A preventive maintenance program, with regular inspections and a log of interventions, lets you catch these signs before they become an emergency.

If the conveyor has already stopped, our emergency service answers 24 hours a day at 438-357-8800.

Sources

1. Regulation respecting occupational health and safety (RSST), CQLR, c. S-2.1, r. 13 — lockout, s. 188.1 to 188.13
2. ISO 20816 — Mechanical vibration: measurement and evaluation of machine vibration
3. Roller chain manufacturers' maintenance guides (replacement criterion at about 3% elongation)

Photo: Unsplash. This article provides general information; it does not replace the manufacturer's requirements or your facility's risk assessment.