Internal combustion engine
View Patent ↗A twin cylinder engine, includes a pair of cylinder members mounted to mounting surfaces of a crankcase, and cylinder heads mounted to the cylinder members. The cylinder members are modular components, which may be pre-assembled with components of the valve train as packaged units before the cylinder members are attached to the crankcase. Each cylinder member rotatably supports a cam gear which extends into the crankcase for driving engagement with the crankshaft. The cylinder members may be configured for either side valve-type (“L-head”), or overhead valve-type (“OHV”) engines, and the cylinder members may also be used in single cylinder engines.
1. A twin cylinder internal combustion engine, comprising:
a crankcase;
a crankshaft rotatably disposed within said crankcase, said crankshaft having a drive gear mounted thereto;
a pair of cylinder members mounted to said crankcase, said cylinder members and said crankcase being separate components; and
a valve train, comprising:
a pair of cam gears respectively rotatably mounted to said cylinder members, said cam gears in meshing engagement with said drive gear;
at least one cam lobe associated with each said cam gear; and
at least one lifter pivotally mounted within each said cylinder member, each said lifter in engagement with a respective said cam lobe.
2. The internal combustion engine of claim 1 , wherein each said cylinder member includes a pair of said lifters, and each said cam gear includes a pair of said cam lobes, each said cam lobe actuating a respective said lifter.
3. The internal combustion engine of claim 2 , wherein each said cylinder member includes an intake valve and an exhaust valve in respective engagement with said lifters.
4. The internal combustion engine of claim 3 , wherein each said cylinder member comprises a cylinder bore therein and said intake and exhaust valves are disposed radially adjacent said cylinder bore in each said cylinder member.
5. The internal combustion engine of claim 3 , wherein each said cylinder member further comprises a valve seat for each of said intake and exhaust valves.
6. The internal combustion engine of claim 2 , wherein each said cylinder member further comprises:
an intake valve in engagement with one of said lifters;
an intake port communicating with said intake valve;
an exhaust valve in engagement with the other of said lifters; and
an exhaust port communicating with said exhaust valve.
7. The internal combustion engine of claim 1 , further comprising a cylinder head attached to each said cylinder member, each said cylinder member and cylinder head defining a combustion chamber therebetween.
8. The internal combustion engine of claim 1 , wherein at least a portion of each said cam gear extends into said crankcase for engagement with said drive gear.
9. The internal combustion engine of claim 2 , wherein said valve train further comprises a pair of push rods carried in each said cylinder member, said push rods actuated by respective said lifters.
10. The internal combustion engine of claim 9 , wherein each said cylinder member comprises a cylinder bore therein, and said push rods are disposed radially adjacent said cylinder bore in each said cylinder member.
11. The internal combustion engine of claim 9 , wherein each said cylinder member further comprises a cylinder head, each said cylinder head comprising:
an intake valve;
an exhaust valve; and
a pair of rocker arms for respectively actuating said intake and exhaust valves in response to movement of said push rods.
12. A twin cylinder internal combustion engine, comprising:
a crankcase having a crankshaft rotatably disposed therein
a pair of cylinder members mounted to said crankcase, said cylinder members and said crankcase being separate components; and
a valve train, comprising:
a pair of cam gears respective rotatably mounted to said cylinder members, at least a portion of each said cam gear extending into said crankcase for driving engagement with said crankshaft;
a pair of cam lobes associated with each said cam gear; and
a pair of lifters pivotally mounted to each said cylinder member, each said lifter in engagement with a respective said cam lobe.
13. The internal combustion engine of claim 12 , further comprising a drive gear mounted to said crankshaft, said drive gear in meshing engagement with each of said cam gears.
14. The internal combustion engine of claim 12 , wherein said valve train further comprises an intake valve and an exhaust valve carried in each said cylinder member, each said intake and exhaust valve actuated by a respective said lifter.
15. The internal combustion engine of claim 14 , wherein each said cylinder member comprises a cylinder bore therein, and said intake and exhaust valves are disposed radially adjacent said cylinder bore in each said cylinder member.
16. The internal combustion engine of claim 12 , wherein each said cylinder member further comprises a cylinder head, each said cylinder member and cylinder head defining a combustion chamber therebetween.
17. The internal combustion engine of claim 16 , wherein said valve train further comprises a pair of push rods carried in each said cylinder member for actuating valves within said cylinder heads, each said push rod actuated by a respective said lifter.
18. A twin cylinder internal combustion engine, comprising:
a crankcase;
a pair of cylinder members mounted to said crankcase, said cylinder members and said crankcase being separate components;
a cam gear and lobe assembly rotatably mounted to each said cylinder member, one of said cam gear and lobe assemblies facing in a first direction, and the other of said cam gear and lobe assemblies facing in a second direction opposite said first direction.
19. The internal combustion engine of claim 18 , further comprising:
a crankshaft rotatably disposed within said crankcase; and
a drive gear mounted on said crankshaft, said drive gear in driving engagement with each said cam gear and lobe assemblies.
20. The internal combustion engine of claim 18 , wherein each said cam gear and cam assembly includes a cam gear and a pair of cam lobes.
21. The internal combustion engine of claim 18 , wherein each said cylinder member includes a pair of lifters rotatably mounted thereto, each said cam lobe actuating a respective said lifter.
22. The internal combustion engine of claim 21 , further comprising a pair of valves carried in each said cylinder member, each said valve actuated by a respective said lifter.
23. The internal combustion engine of claim 21 , further comprising a pair of push rods carried in each said cylinder member, each said push rod actuated by a respective said lifter.