Vibrating mechanisms may be mechanical, pneumatic, or electromagnetic. The latter two are always packaged modular units, which can be quickly replaced when they malfunction.
Mechanical vibrators, whether integral with the structure or externally mounted modules, comprise one or more rotating shafts mounted in anti-friction bearings. Impending failures almost always are signaled by the gradual development of noise and/ or vibration in one or more bearings. Both are symptoms of fatigue spalling, or pitting, in the bearing races and/or rollers. If neglected, these symptoms will invariably lead to an eventual seizure within the bearing.
The only remedy is to replace the bearing, after a thorough investigation to isolate the cause of the failure.
If the two parallel rotors in a vibrator unit are gear-coupled, the gears normally will generate some noise, but without vibration. Excessive backlash in the gearset, or damage from lubricant contamination with foreign material, may result in an increasing noise level, but with little or no vibration.
A few simple rules can reduce the probability for premature bearing failure in well designed mechanisms:
For grease lubrication:
- Observe the manufacturer’s recommended intervals for grease replenishment and replacement, and don’t over grease.
- Open purge ports (if provided) when adding grease, to expel old grease from the bearing housing.
- Wipe grease fittings clean before connecting the grease gun.
- Guard against contamination of grease supplies with moisture or foreign material.
For oil lubrication:
- Maintain the oil level within the manufacturers’ recommended limits;
- Use the manufacturers’ recommended oil, or approved substitutes;
- Use a strainer to guard against introducing contamination when adding makeup or changing oil.
- When changing oil at the manufacturers’ recommended intervals, drain while the oil is hot. Clean magnetic drain plugs, if provided.
- Inspect vent filters periodically, more often in very dusty environments, and replace when clogged. Don’t substitute automotive oil filters.
If symptoms of impending failure are detected:
Follow the manufacturer’s instructions when repairing or rebuilding vibrator mechanisms(like shale shaker). Whenever possible, move enclosed vibrator modules to a clean shop environment before opening up the enclosure. For best results, send the module to the factory for rebuild, and replace with a spare.