Abstract
An internal pressurized lubrication system of a radial support bearing assembly includes oil passages within a bearing housing that comprise a charge-retaining section bounded by vertical or upward-sloping passages and configured to retain an oil charge therein during a shutdown. A vent bleeds air into the suction side of the passages during a shutdown, thereby preventing syphoning of the oil charge from the charge-retaining section. In embodiments, a rear cover plug is doubly sealed to the bearing housing body, and air is substantially unable to enter the oil passages via the bearing or via the vent during a shutdown, such that the passages remain oil-filled and the pump prime is retained for an extended time period. The bearing assembly can further include a thrust bearing, and/or an axial displacement measurement probe parallel with the shaft-driven oil pump. The radial support bearing can be a journal bearing.