Selecting Bearings for Vibrating & Shock-Load Equipment

The challenge of vibrating equipment

Vibrating screens, crushers, hammer mills and impact conveyors subject bearings to high, constantly reversing loads and frequent shock. The wrong bearing fails quickly from fatigue, cage fracture or lubrication breakdown. Getting the selection right is critical for uptime.

Bearing type selection

Spherical roller bearings

The primary choice for vibrating screens and heavy vibratory equipment. They handle:

• High radial and axial loads in both directions.
• Shaft misalignment — critical in vibrating equipment where the shaft deflects.
• Heavy shock loads — the barrel-shaped rollers distribute load well.

Use the 22200 or 23300 series with brass cages for vibrating screen applications.

Cylindrical roller bearings

For pure radial loads at high speed. They handle heavy radial loads but not axial loads, so they are typically used in pairs or with an angular contact bearing for axial location.

Tapered roller bearings

For combined radial and axial loads in crushers and gearboxes. Use in matched pairs for vibrating equipment to manage loads in both directions.

Clearance

Vibration generates heat from the constant load reversal. Use C4 clearance (greater than C3) to ensure the bearing does not run tight as it heats up. For very high-speed vibration, C5 may be needed.

Cage design

Brass or steel cages only. Nylon cages crack from vibration fatigue and are unsuitable for this service. Machined brass cages are preferred for heavy-duty vibrating equipment — they are stronger and more resistant to shock.

Lubrication

• Use EP (extreme pressure) grease — the shock loads require higher film strength.
• Frequent relubrication — vibration churns grease out of the bearing. Plan for relubrication intervals 2-3 times more frequent than normal.
• Oil bath lubrication — for very high-speed vibrating equipment, oil provides better cooling and lubrication than grease.

Common applications and recommendations

| Application | Recommended bearing | Key features | |---|---|---| | Vibrating screens | Spherical roller 22200/23300, C4 | Misalignment, shock, brass cage | | Jaw crushers | Spherical roller, heavy series | High shock, heavy load | | Hammer mills | Spherical or cylindrical, C4 | High speed + impact | | Impact conveyors | Spherical roller, sealed | Vibration + contamination |

Practical tips

• Mount with the correct interference fit — loose fits allow the bearing to creep on the shaft under vibration.
• Check housing bore wear regularly — vibration can fret the housing bore oversize.
• Monitor temperature — a sudden rise means the bearing is failing or running tight.
• Keep spares — vibrating equipment bearings fail without warning and are often not next-day available.