Internal combustion engine oil tank arrangement

1. An internal combustion engine comprising:

a crankcase;

a crankshaft disposed in the crankcase, the crankshaft defining a crankshaft axis;

a cylinder block disposed on the crankcase, the cylinder block having at least one cylinder, the at least one cylinder defining a cylinder axis;

at least one piston disposed in the at least one cylinder, the at least one piston being operatively connected to the crankshaft;

a cylinder head assembly connected to the cylinder block;

a plurality of oil passages disposed in at least one of the crankcase, the cylinder block, and the cylinder head assembly;

an oil tank fluidly connected to at least one of the oil passages, the oil tank having a first side and a second side opposite the first side;

an oil outlet disposed in the oil tank, the oil outlet fluidly communicating the oil tank with at least one of the oil passages for supplying oil from the oil tank to the oil passages; and

an oil inlet disposed in the first side of the oil tank, the oil inlet fluidly communicating with at least one of the plurality of oil passages for returning a mixture of oil and blow-by gases from the at least one of the plurality of oil passages to the oil tank, an angled portion of the second side of the oil tank generally facing the oil inlet being angled relative to a plane defined by the crankshaft axis and the cylinder axis such that the mixture of oil and blow-by gases exiting the oil inlet flow over the angled portion, the angled portion being angled relative to the oil inlet, the angled portion being spaced from a bottom of the oil tank, and the angled portion extending away from the plane as the angled portion extends upwardly, an angle between the angled portion of the second side of the oil tank and the plane is between 45 degrees and 80 degrees.

2. The engine of claim 1 , further comprising a blow-by gas outlet fluidly communicating the oil tank with an exterior of the engine.

3. The engine of claim 1 , wherein the first side of the oil tank is at least in part an outer wall of the crankcase; and

wherein the second side of the oil tank is an oil tank enclosure connected to the crankcase.

4. An internal combustion engine comprising:

a crankcase;

a crankshaft disposed in the crankcase, the crankshaft defining a crankshaft axis;

a cylinder block disposed on the crankcase, the cylinder block having at least one cylinder, the at least one cylinder defining a cylinder axis;

at least one piston disposed in the at least one cylinder, the at least one piston being operatively connected to the crankshaft;

a cylinder head assembly connected to the cylinder block;

a plurality of oil passages disposed in at least one of the crankcase, the cylinder block, and the cylinder head assembly;

an oil tank fluidly connected to at least one of the oil passages, the oil tank having a first end portion and a second end portion opposite the first end portion, the first end portion being closer to the cylinder head assembly than the second end portion;

an oil outlet disposed in the second end portion of the oil tank for supplying oil from the oil tank to at least one of the crankcase, the cylinder block, and the cylinder head assembly;

an oil inlet disposed in the oil tank for returning oil from at least one of the crankcase, the cylinder block, and the cylinder head assembly to the oil tank;

a blow-by gas outlet disposed in the first end portion of the oil tank; and

a blow-by gas passage fluidly communicating the blow-by gas outlet with an exterior of the engine,

a first portion of the blow-by gas passage extending from the blow-by gas outlet in a direction generally away from the cylinder head assembly,

a second portion of the blow-by gas passage extending from the first portion of the blow-by gas passage in a direction generally towards the cylinder head assembly,

such that when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow sequentially from the oil tank to the blow-by gas outlet, to the first portion of the blow-by gas passage, to the second portion of the blow-by gas passage, and to the exterior of the engine, and

the oil inlet being arranged in the oil tank such that when the first end portion of the oil tank is disposed generally vertically below the second end portion of the oil tank, blow-by gases in the oil tank flow sequentially from the oil tank to the oil inlet, and to the exterior of the engine.

5. The engine of claim 4 , wherein the blow-by gas outlet is disposed generally at a center of a length of the first end portion of the oil tank;

wherein the length of the first end portion of the oil tank is generally parallel to the crankshaft axis.

6. The engine of claim 4 , wherein the oil inlet returns oil from the cylinder head assembly; and

wherein when the first end portion of the oil tank is disposed generally vertically below the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine.

7. The engine of claim 4 , wherein the oil inlet is a first oil inlet;

the engine further comprising a second oil inlet in the oil tank for returning oil from at least one other of the crankcase, the cylinder block, and the cylinder head assembly to the oil tank;

wherein the first and second oil inlets are disposed between the blow-by gas outlet and the oil outlet in a direction generally parallel to the cylinder axis; and

wherein the first oil inlet is disposed closer than the second oil inlet to the blow-by gas outlet.

8. The engine of claim 7 , further comprising at least one oil pump, the at least one oil pump pumping oil from at least one of the crankcase and the cylinder block to the oil tank;

wherein the first oil inlet returns oil from the at least one oil pump; and

wherein the second oil inlet returns oil from the cylinder head assembly.

9. The engine of claim 4 , wherein the first portion of the blow-by gas passage extends in the crankcase;

wherein the second portion of the blow-by gas passage is a timing chain case of the engine fluidly communicating with the cylinder head assembly; and

wherein when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine.

10. The engine of claim 4 , wherein when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine; and

the engine further comprising a blow-by gas separator disposed in the cylinder head assembly for separating oil from the blow-by gases prior to the blow-by gases flowing to the exterior of the engine.

11. The engine of claim 4 , wherein the oil tank is formed by an outer wall of the crankcase and by an oil tank enclosure connected to the crankcase.

12. An internal combustion engine comprising:

a crankcase;

a crankshaft disposed in the crankcase, the crankshaft defining a crankshaft axis;

a cylinder block disposed on the crankcase, the cylinder block having at least one cylinder, the at least one cylinder defining a cylinder axis;

at least one piston disposed in the at least one cylinder, the at least one piston being operatively connected to the crankshaft;

a cylinder head assembly connected to the cylinder block;

a plurality of oil passages disposed in at least one of the crankcase, the cylinder block, and the cylinder head assembly;

an oil tank fluidly connected to at least one of the oil passages, the oil tank having a first end portion and a second end portion opposite the first end portion, the first end portion being closer to the cylinder head assembly than the second end portion;

an oil outlet disposed in the second end portion of the oil tank for supplying oil from the oil tank to at least one of the crankcase, the cylinder block, and the cylinder head assembly;

a first oil inlet disposed in the oil tank for returning oil from at least one of the crankcase, the cylinder block, and the cylinder head assembly to the oil tank;

a second oil inlet in the oil tank for returning oil from at least one other of the crankcase, the cylinder block, and the cylinder head assembly to the oil tank;

a blow-by gas outlet disposed in the first end portion of the oil tank, the first and second oil inlets being disposed between the blow-by gas outlet and the oil outlet in a direction generally parallel to the cylinder axis; and

a blow-by gas passage fluidly communicating the blow-by gas outlet with an exterior of the engine,

a first portion of the blow-by gas passage extending from the blow-by gas outlet in a direction generally away from the cylinder head assembly,

a second portion of the blow-by gas passage extending from the first portion of the blow-by gas passage in a direction generally towards the cylinder head assembly,

such that when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow sequentially from the oil tank to the blow-by gas outlet, to the first portion of the blow-by gas passage, to the second portion of the blow-by gas passage, and to the exterior of the engine.

13. The engine of claim 12 , wherein the blow-by gas outlet is disposed generally at a center of a length of the first end portion of the oil tank;

wherein the length of the first end portion of the oil tank is generally parallel to the crankshaft axis.

14. The engine of claim 12 , wherein the second oil inlet is arranged in the oil tank such that when the first end portion of the oil tank is disposed generally vertically below the second end portion of the oil tank, blow-by gases in the oil tank flow sequentially from the oil tank to the second oil inlet, and to the exterior of the engine.

15. The engine of claim 14 , wherein the second oil inlet returns oil from the cylinder head assembly; and

wherein when the first end portion of the oil tank is disposed generally vertically below the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine.

16. The engine of claim 12 , wherein the first oil inlet is disposed closer than the second oil inlet to the blow-by gas outlet.

17. The engine of claim 16 , further comprising at least one oil pump, the at least one oil pump pumping oil from at least one of the crankcase and the cylinder block to the oil tank;

wherein the first oil inlet returns oil from the at least one oil pump; and

wherein the second oil inlet returns oil from the cylinder head assembly.

18. The engine of claim 12 , wherein the first portion of the blow-by gas passage extends in the crankcase;

wherein the second portion of the blow-by gas passage is a timing chain case of the engine fluidly communicating with the cylinder head assembly; and

wherein when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine.

19. The engine of claim 12 , wherein when the first end portion of the oil tank is disposed generally vertically above the second end portion of the oil tank, blow-by gases in the oil tank flow to the cylinder head assembly prior to flowing to the exterior of the engine; and

the engine further comprising a blow-by gas separator disposed in the cylinder head assembly for separating oil from the blow-by gases prior to the blow-by gases flowing to the exterior of the engine.

20. The engine of claim 12 , wherein the oil tank is formed by an outer wall of the crankcase and by an oil tank enclosure connected to the crankcase.