Lubricating device for internal combustion engine

A combination comprising:

• a vehicle;
• and
• an internal combustion engine including:
• a crankcase;
• an oil tank formed inside said crankcase;
• an oil pump including a feed pump and a scavenge pump, said feed pump for supplying lubricating oil inside said oil tank to respective components of the internal combustion engine, and said scavenge pump for returning lubricating oil that has accumulated in a bottom of said crankcase to said oil tank;
• a crankshaft disposed in said crankcase, with said crankshaft extending in a direction parallel to a direction of travel of said vehicle;
• a transmission chamber disposed in said crankcase to one side of said crankshaft;
• a transmission including a main shaft, a counter shaft, and an output shaft disposed in said transmission chamber, wherein said oil tank is disposed on a side of said transmission chamber opposite said crankshaft, and wherein said oil tank has an approximately crescent shaped cross section, with a lower end of said cross section extending under at least one of said main shaft, said counter shaft and said output shaft;
• and
• a drain hole formed in said crankcase, said drain hole communicating with said oil tank and with said transmission chamber.

An internal combustion engine comprising:

• a crankcase;
• an oil tank formed inside said crankcase;
• an oil pump including a feed pump and a scavenge pump, said feed pump for supplying lubricating oil inside said oil tank to respective components of the internal combustion engine, and said scavenge pump for returning lubricating oil that has accumulated in a bottom of said crankcase to said oil tank;
• a crankshaft disposed in said crankcase;
• a transmission chamber disposed in said crankcase to one side of said crankshaft;
• a transmission including a main shaft, a counter shaft, and an output shaft disposed in said transmission chamber, wherein said oil tank is disposed on a side of said transmission chamber opposite said crankshaft, and wherein said oil tank has an approximately crescent shaped cross section, with a lower end of said cross section extending under at least one of said main shaft, said counter shaft, and said output shaft;
• a bulkhead partitioning said oil tank from said transmission chamber, wherein said bulkhead extends from a top of said crankcase to said bottom of said crankcase;
• and
• a cutout formed in an upper portion of said bulkhead for allowing, when said oil tank is filled with oil, excess oil to overflow into said transmission chamber.

An internal combustion engine comprising:

• a crankcase;
• an oil tank formed inside said crankcase;
• an oil pump including a feed pump and a scavenge pump, said feed pump for supplying lubricating oil inside said oil tank to respective components of the internal combustion engine, and said scavenge pump for returning lubricating oil that has accumulated in a bottom of said crankcase to said oil tank;
• a crankshaft disposed in said crankcase;
• a transmission chamber disposed in said crankcase to one side of said crankshaft;
• and
• a transmission including a main shaft, a counter shaft, and an output shaft disposed in said transmission chamber, wherein said main shaft is elevated relative to said counter shaft and said counter shaft is elevated relative to said output shaft, wherein said oil tank is disposed on a side of said transmission chamber opposite said crankshaft, and wherein said oil tank has an approximately crescent shaped cross section, with a lower end of said cross section extending under said output shaft.

A combination comprising:

• a vehicle;
• and
• an internal combustion engine including:
• a crankcase;
• an oil tank formed inside said crankcase;
• an oil pump including a feed pump and a scavenge pump, said feed pump for supplying lubricating oil inside said oil tank to respective components of the internal combustion engine, and said scavenge pump for returning lubricating oil that has accumulated in a bottom of said crankcase to said oil tank;
• a crankshaft disposed in said crankcase, with said crankshaft extending in a direction parallel to a direction of travel of said vehicle;
• a transmission chamber disposed in said crankcase to one side of said crankshaft;
• and
• a transmission including a main shaft, a counter shaft, and an output shaft disposed in said transmission chamber, wherein said main shaft is elevated relative to said counter shaft and said counter shaft is elevated relative to said output shaft, wherein said oil tank is disposed on a side of said transmission chamber opposite said crankshaft, and wherein said oil tank has an approximately crescent shaped cross section, with a lower end of said cross section extending under said output shaft.