Additional lubrication with grease or oil can reduce friction heat and abrasion compared to dry lubrication status. Also, it can discharge worn particles abrasion and prevent foreign substance from flowing in (seal effect), and rust from occurring, which can improve bearing performance and life cycle. Also, if initial lubricant is applied on internal diameter where it requires no lubrication, it can reduce rapid initial wear amount that is occurred in starting and achieve soft operation effect.
Lubricant can be used effectively as below depending on the using condition.
| Using condition | Lubricant |
|---|---|
| low-load, high-speed | Spindle oil having low viscosity of < 8~17cst (30˚C) |
| medium-load, medium-speed | Motor oil and turbine oil having viscosity of < 7~15cst (98.9˚C) |
| high-load, low-speed | Gear oil and cylinder oil having high viscosity of 100~1,000 cst (37˚C) (oil containing MoS2 is effective) |
▶ For using on high-load and resistance to abrasion and heat, grease containing molybdenum disulfide (MoS2) is most effective, which is recommended for improving performance and life cycle.
Oil impregnation method
When using solid lubricant dispersed bearing, Develon by purchasing the material and machining or grinding, be sure to apply oil impregnation. There are heating type and vacuum type in impregnation method. Heating method contains processed product in the container with lubricant (motor oil) and gradually heats to 100 ~ 110˚C and keep the temperature 1 to 2 hours until bubble does not occur. Cut the heat source and let it cool down to the room temperature and takes products out of the bath. If oil impregnation by heating is not available, leave the products in the oil bath for 24 hours or more. Also, vacuum impregnation can be available on request.
oil groove
Design can be applied evenly on the internal diameter surface based on the maximum load point. Length of oil groove should be 80 % more or less of bearing length. All edges should be chamfered. In case of injecting oil from outside of the housing, it is very effective to make the rotation groove on the housing internal diameter or bearing external diameter surface in order to avoid inadequate lubrication from clogged oil hole caused by shifiting of the oil hole from the housing oil groove.
oil hole
Normally, 1 oil hole is made to the direction where load is not applied. In case of rotational motion, 2 oil holes are made to both direction based on the maximum load point. Also, when bearing length is long, 2 oil holes are made to length direction.
oil hole and oil groove
Cross sectional
co nfiguration of oil groove
| ID | R | r | H | Q'ty |
|---|---|---|---|---|
| 30 or below | 1.5 | 1.5 | 1.2 | 1~2 |
| 30~50 | 2 | 2 | 1.8 | 3 |
| 50~80 | 3 | 3 | 2.5 | 3 |
| 80~120 | 3.5 | 3.5 | 3.5 | 4 |
| 120~180 | 4 | 4 | 5 | 4 |
| 180~250 | 5 | 5 | 6 | 5 |
| 250~315 | 6 | 6 | 7 | 6 |
| 315~400 | 7 | 7 | 8 | 8 |
| 400~500 | 8 | 8 | 8 | 8 |