Journal bearings and rolling element bearings are two types of bearings used in pumps. The main differences between them are as follows:
1. Contact Type - Journal bearings have sliding contact between the shaft and the bearing surface, whereas rolling element bearings have rolling contact between the shaft and the bearing surface.
2. Load Capacity - Rolling element bearings have higher load capacities as compared to journal bearings.
3. Friction - Journal bearings have a higher coefficient of friction, resulting in more energy loss due to heat generation. Rolling element bearings have lower frictional forces and hence, lower heat generation and longer life.
4. Lubrication - Journal bearings are generally oil-lubricated, whereas, rolling element bearings can be grease or oil lubricated. Oil lubrication is preferred in journal bearings as it helps in dissipating heat generated during operation.
5. Noise and Vibration - Rolling element bearings generate lower noise and vibrations as compared to journal bearings due to their rolling contact design.
6. Maintenance - Journal bearings require more frequent maintenance as compared to rolling element bearings. This is because oil has to be replenished or changed regularly in journal bearings, whereas, rolling element bearings generally have longer life and require less maintenance.
Overall, the choice between journal bearings and rolling element bearings depends on various factors such as load capacity, speed, lubrication, and maintenance requirements of the pump application.
