From those photos, which you provided, we can see there are slight oil leakage in both inner and outer bearing seats. After careful checking, we found main leakage location are in the connection surface between upper&lower bearing seat and near fastening bolts.
Normally, during motor running, the negetive pressure of bearing inner side is bigger than bearing outer side, which causes inner side oil leakage is more than outer side. However, we didn't see any leakage between inner bearing cover and bearing, which proved the seal between bearing and its cover is workable to prevent oil leakage.
We analyzed that possible reasons for oil leakage are as follows:
1, Fastening bolts were not tightened, which caused bad seal result and oil leakage after long time running.
2, Sealant was not painted in good condition, which caused leakage if bearing oil pressure is bigger.
3, Oil in bearing house is too much.
4, The pressure difference between oil station and outlet pipe is too small or outletpipe is jammed.
5, The breathe pipe on bearing seat is obstructed, which will increase the air pressure difference between inside bearing house and outside and cause oil leakage.
Accordingly, we give you following suggestion to check:
1, Repaint sealant between upper and lower bearing seats.
2, Add oil-resistant rubber at all connecting bolts which are oil leaked or paint sealant.
3, If temperature of bearing tile is not high, lower the oil inlet pressure a little bit.
4, Check breathe pipe is obstructed or not and make sure there is no foreign things and jammed.
5, If temperature of bearing tile is not high, lower the oil level of bearing house. Keeping the oil level at 1/3 of oil level sight glass is OK.
All above suggestion will improve the oil leakage situation.