Relubrication interval adjustments
| Operating condition /
bearing type |
Description | Recommended adjustment of tf | Reason for adjustment |
| Operating temperature | For every 15 °C (27 °F) above 70 °C (160 °F) up to the high temperature performance limit (HTPL) | Halve the interval.
|
To account for the accelerated ageing of grease at higher temperatures |
| For 15 °C (27 °F) under 70 °C (160 °F) | Double the interval
(maximum once)1). |
To account for the reduced risk of ageing of grease at lower temperatures | |
| Shaft orientation | Bearings mounted on a vertical shaft | Halve the interval.
|
The grease tends to leak out due to gravity |
| Vibration | High vibration or acceleration levels | Reduce the interval.
|
Interval reduced depending on machine specific instructions (e.g. vibrating screen) |
| Outer ring rotation | Outer ring rotation or eccentric shaft weight | Calculate the speed as nD rather than ndm |
The grease has a shorter grease life under these conditions |
| Contamination | Contamination or presence of fluid contaminants | 1. Low contamination level
There will be no or only slight ingress of contamination. No need to adjust the interval. 2. Medium contamination level Some contaminants may enter the bearing. Some additional relubrication is required to remove contaminants. Halve the interval. 3. High contamination level There is a clear risk that contaminants will enter the bearing. Relubrication is required to remove aged grease and to remove contaminants. Reduce the interval by a factor 0,2. 4. Severe contamination level Relubrication is primarily needed to flush the bearing and remove contaminants. Use continuous lubrication. |
To reduce the damaging effects caused by contaminants |
| Bearing size | Bearings with a bore diameter d > 300 mm | Reduce the interval by a factor 0,5 initially. If grease samples taken before relubrication are found to be satisfactory, the relubrication interval can be increased gradually.
|
These are typically critical arrangements, which require strict, frequent relubrication programmes |
| Cylindrical roller bearings | Bearings fitted with J, JA, JB, MA, MB, ML, MP and PHA cages2) | Halve the interval.
|
These cage designs require higher oil bleeding from the grease |
- 1) For full complement and thrust bearings, do not extend the interval.
- 2) For P, PH, M and MR cages, there is no need for adjustment.
