Internal combustion engine including splash-resistant oil storage structure

An internal combustion engine, comprising:

• a crankcase;
• a crankshaft rotatably retained in the crankcase;
• an oil pump;
• an oil storage chamber provided in the crankcase and disposed at a lower portion of the internal combustion engine;
• and
• an oil supply pipe having a pickup port disposed proximate the bottom of the oil storage chamber for drawing in oil stored in the oil storage chamber using the oil pump;
• wherein the oil storage chamber comprises a first subchamber having an opening on top thereof for receiving the oil supply pipe, and a second subchamber disposed adjacent the first subchamber so as to communicate therewith at the side thereof;
• wherein the second subchamber comprises a ceiling wall located below a full oil level of the first subchamber;
• wherein the crankcase comprises a crank chamber for storing the crankshaft;
• and a communicating portion is provided between the crank chamber and the second subchamber for permitting fluid communication therebetween;
• and
• wherein a check valve is provided at the communicating portion for allowing oil to flow in one direction therethrough from the crank chamber to the second subchamber.

An internal combustion engine, comprising:

• a crankcase having a crank chamber formed therein for housing a crankshaft, said crankcase having an oil storage chamber defined therein at a lower portion of said engine, and an internal partition wall substantially separating the crank chamber from the oil storage chamber;
• a crankshaft rotatably disposed in said crank chamber;
• an oil pump for drawing oil out of the crankcase;
• and
• an oil supply pipe having a pickup port disposed proximate the bottom of the oil storage chamber for drawing in oil stored in the oil storage chamber using the oil pump;
• wherein the oil storage chamber comprises:
• a first subchamber having an opening formed therein for receiving the oil supply pipe, said first subchamber having a full oil level therein;
• and
• a second subchamber disposed in abutting relation adjacent the first subchamber so as to communicate therewith at the side thereof;
• and
• wherein the crankcase comprises a ceiling wall located above the second subchamber and
• below the full oil level of the first subchamber;
• and
• wherein a communicating portion is provided between the crank chamber and the second subchamber for permitting fluid communication therebetween.

An internal combustion engine, comprising:

• an oil storage chamber having a first subchamber and a second subchamber disposed adjacent the first subchamber so as to communicate therewith at the side thereof;
• an oil pump for supplying oil to the engine for lubrication thereof;
• and
• an oil supply pipe having a pickup port disposed proximate the bottom of the first subchamber for drawing in oil stored therein using the oil pump;
• wherein
• said oil storage chamber disposed at a lower portion of the engine;
• the second subchamber comprises a ceiling wall located below a full oil level of the first subchamber;
• and
• a cross sectional area of the first subchamber along a horizontal plane is narrower than a cross sectional area of the second subchamber along a horizontal plane, whereby the pickup port remains immersed in oil during engine operation irrespective of oil surface fluctuation;
• wherein the crankcase comprises a crank chamber for storing a crankshaft;
• and a communicating portion is provided between the crank chamber and the second subchamber for permitting fluid communication therebetween;
• and
• wherein a check valve is provided at the communicating portion for allowing oil to flow in one direction therethrough from the crank chamber to the second subchamber.

An internal combustion engine, comprising:

• a crankcase having a crank chamber and a internal partition wall;
• an oil pump;
• an oil storage chamber provided in the crankcase and disposed at a lower portion of the internal combustion engine;
• and
• an oil supply pipe having a pickup port disposed proximate the bottom of the oil storage chamber for drawing in oil stored in the oil storage chamber using the oil pump;
• wherein
• the oil storage chamber comprises a first subchamber having an opening on top thereof for receiving the oil supply pipe, and a second subchamber disposed adjacent the first subchamber so as to communicate therewith at the side thereof;
• a partitioning wall is provided between the first subchamber and the second subchamber, said partitioning wall comprising a portion extending substantially vertically and having an open and unobstructed communicating port formed in a rear portion thereof for establishing communication therebetween the first subchamber and the second subchamber;
• the second subchamber comprises a ceiling wall located below a full oil level of the first subchamber;
• and
• the internal partition wall separates the crank chamber from the first subchamber whereby forming a barrier to prevent the crankshaft from splashing oil contained in the first subchamber.