Lubricant feed system for use in the journal of a crankshaft

Abstract

There is disclosed a lubricant feed system for use in a journal of a crankshaft comprising first bearing supporting portions formed in a cylinder block, each having a peripheral surface, second bearing supporting portions formed in caps, each having a peripheral surface, first bearings in the form of half shells arranged on the peripheral surfaces of the first bearing supporting portions, second bearings in the form of half shells arranged on the peripheral surfaces of the second bearing supporting portions and an oil main gallery. In this arrangement, annular grooves are formed on the peripheral surfaces of the first and second bearing supporting portions and oil grooves are circumferentially formed at the inner peripheral surfaces of the first bearings. Apertures are formed at the first bearings to communicate the annular grooves with the oil grooves. The inner peripheral surfaces of the second bearings are made flat. Further, a bridge is mounted on the undersides of the bearing caps and the oil main gallery is provided in the bridge. The oil main gallery is communicated with the annular grooves in the second bearing supporting portions. Oil in the oil main gallery is fed to the annular grooves to directly cool the second bearings to which explosive loads are applied.

Dependencies are inferred from the claim text.