[Usage Report Summary]
Based on your report, the usage conditions are as follows:
- Filled approximately 30% of bearing clearance volume with “No.0” grease
- Angular contact bearing (Inner diameter: φ40)
- Rotation speed: 10,000 rpm
- Ambient temperature: 140°C
- Operating time: 100 hours
Thank you for your detailed report regarding the loss of thickener under these conditions.
■ Heat Resistance and Operating Limit of LS Grease
LS Bell Hammer Grease specifications:
- No.0: Dropping Point 215°C
- No.2: Dropping Point 217°C
Please note that the dropping point is the temperature at which the grease begins to soften and liquefy, and not the recommended continuous operating temperature.
In general, the practical operating temperature is about 60–70% of the dropping point, which suggests a safe range of approximately 130–150°C for a grease with a 215°C dropping point.
Given the 140°C ambient temperature and the additional internal heat from 10,000 rpm, it's likely the actual internal temperature exceeded this range.
Additionally, No.0 has a lower consistency (softer), making it more prone to:
- Oil separation due to centrifugal force
- Thermal degradation, oxidation, and carbonization of thickener
- Apparent disappearance of the grease
These effects are plausible under the reported conditions.
■ Switching to No.2
No.2 is a stiffer formulation than No.0 and has better grease retention under high-temperature and high-speed conditions. Your decision to switch to No.2 is appropriate.
However, the thermal limitations remain similar, so we recommend continued monitoring and regular inspection.
■ Effectiveness of Bell Hammer Metal Grease for Heat Resistance
Bell Hammer Metal Grease features:
- Contains solid lubricants (copper powder, graphite, zinc oxide, molybdenum)
- Forms a lubricating film on metal surfaces
- Provides anti-wear protection under extreme pressure
- Offers emergency lubrication even when the oil film breaks down
Usable temperature range: −26°C to 800°C
Unlike LS Bell Hammer products which rely on chemical reaction lubrication, this product is optimized for rolling contact under high heat and load.
It is expected to provide superior lubrication and durability under high-temperature, high-speed, and long-duration conditions.
Note: Due to solid lubricants like graphite, the grease may appear dirty (black) in appearance. Please consider this if aesthetics are a concern.
■ Additional Note: Use of LS Bell Hammer GOLD Base Oil
If the thickener has broken down, lubrication might not be completely lost. Supplementing with a small amount of LS Bell Hammer GOLD base oil may help maintain lubrication and protect the metal surface.
This product retains effectiveness up to approx. 198°C and can be used to supplement or partially replace grease under these conditions.