Abstract: A system for lubricating bearings on a vertical rotatable shaft within a bearing housing, is comprised of an annular lower lubricant sump at a lower portion of the bearing housing; an annular upper lubricant reservoir at an upper portion of the bearing housing; and a conduit providing fluid communication between the lower lubricant sump and the upper lubricant reservoir. Provision is made for metering a flow of lubricant from the upper lubricant reservoir into upper bearings. The lubricant is pumped from the lower lubricant sump, through the conduit, to the upper lubricant reservoir at a rate exceeding the rate of metered flow into the upper bearings. A constant head of lubricant above the metering orifice is provided in the upper lubricant reservoir, as well as an outlet for shunting excess lubricant back to the lower lubricant sump.