Concept
It refers to every mechanical part, regardless of its shape and material, that uses self-lubrication or rolling character (ball, roller) to deliver power to different kinds of motion such as rotation, reciprocation, thrust, and angular pitching motion.
Type and characteristics
Rolling bearing
Its speed and load resistance are the most excellent in general condition.
1. Ball Bearings
(Used in high speed applications through point-contact motion)
2. Roller Bearings
(Used in high load parts through line-contact motion.)
- Spherical Roller (
) - Tapered Roller (
) - Cylindrical Roller (
) - Needle Roller (
)
3. Thrust Bearings
(Thrust motion)
- Ball Thrust
- Tapered Roller Thrust
Sliding bearing
It directly operates with shaft or sliding surface without rolling character and it requires gap when working. It is more suitable than ball & roller bearing for coping with impact and vibration in small size and light weight.
- 1) Oilless bearings (used without lubrication)
- 2) Simple lubricatiing sliding bearings (oil or grease lubrication)
Comparative Characteristics
| Item | Oilless bearing | General sliding bearing | Rolling bearing |
|---|---|---|---|
| Lubrication | Can be used without lubrication | Requires lubrication | Requires general lubrication |
| Impact resistance | Excellent | Slightly excellent | Weak |
| Heat resistance | Can be used in high temperature | Slightly excellent | Weak (cannot be used in high temperature) |
| Corrosion resistance | Excellent | Slightly weak | Slightly weak |
| Reciprocation | Excellent | Slightly weak | Slightly weak |
| Oscillation | Excellent | Slightly excellent | Weak |