Pump Bearing Grease Quantity Calculator

G = 0.005 × D × B grams. The defaults model a 6311 pump thrust bearing (OD 120 mm, width 29 mm → 17.4 g) — measure or look up your bearing's OD and width and the tool recomputes instantly. This is the replenishment charge, not the initial fill (which is 30–50% of the free space for most speeds).

The nameplate and manual, always: an oil-bath housing has no grease relief geometry, so grease packs solid, overheats, and starves the bearing of the oil circulation it was designed for — the failure arrives months later and gets misdiagnosed. Restore the constant-level oiler, drain the grease, flush the housing, and label the pump. The reverse error (oil in a grease design) leaks away harmlessly but lubricates nothing for long. Standardise per pump model and audit the lube routes yearly.

The rolling elements churn through excess grease, temperature climbs sharply (often 10–30 °C), the thickener shears down and bleeds oil, and pressure can lip the seals open — after which contaminants walk in. Electric motors suffer the extra failure mode of grease forced into the windings. If you see grease purging from seals and a temperature spike after lubing, you found the cause.

Interval depends on speed factor (n·dm), temperature, load and orientation — use the OEM's table or SKF's relubrication chart as your starting point, then halve it for every 15 °C the bearing runs above 70 °C, for vertical shafts, or for wet/dusty service. Enter that interval here and pair this tool with a bearing-temperature trend to validate it.