US 6,029,638 AGranted

Internal combustion engine with dry sump lubricating system

AssigneeHonda Giken Kogyo Kabushiki Kaisha

InventorsHiroshi Funai, Hideo Shigedomi, Yasushi Fujita

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Abstract

An internal combustion engine with dry sump lubricating system includes a feed pump which supplies lubricating oil from a lubricating oil tank disposed outside an engine body to all moving parts in the engine. After circulating through the engine, the lubricating oil drops down into a crank chamber and is immediately picked up from the crank chamber and sent back into the lubricating oil tank by a recovery pump. Since the lubricating oil tank is attached to an end of the engine body from which a crankshaft project, it does not increase the overall width (dimension in the direction perpendicular to the axis of the crankshaft) and height of the engine. Even when the engine has inclined cylinders, the lubricating oil tank can avail a high degree of design freedom because the end face is not influenced by inclination of the cylinders as greatly as side surfaces of the engine body. The engine also includes a breather system so designed as to prevent an operation failure of the engine which would otherwise be caused due to inflow of the lubricating oil into an intake system of the engine.

Claims15

Dependent claims

An internal combustion engine having an intake system, comprising:

(a) an engine body including a crankshaft rotatably mounted therein with one end projecting from an end face of said engine body, a head cover at the top of said engine body and defining a valve chamber, and a crankcase at the bottom of said engine body and defining a crank chamber;
(b) a dry sump lubricating system for lubricating moving parts in said engine with a lubricating oil, said lubricating system including
(i) an oil sump at the bottom of said crank chamber for temporarily holding therein the lubricating oil that has dripped from the moving parts down into said crank chamber,
(ii) an oil tank attached to said end face of said engine body for holding therein the lubricating oil,
(iii) a feed pump driven by said crankshaft for supplying the lubricating oil from said oil tank to the moving parts of said engine body, and
(iv) a recovery pump driven by said crankshaft for sending the lubricating oil from said oil sump back into said oil tank;
and
(c) a breather system connecting said crank chamber and said oil tank to the intake system of the engine to circulate blowby gas and oil vapors from said crank chamber and said oil tank to the intake system.

5 more elements

Dependencies are inferred from the claim text.