Supercharged engine
View Patent ↗A supercharged internal combustion engine is disclosed which includes a supercharger operatively connected to the crankshaft via a clutch supported by an intermediate shaft such that torque variations are partially absorbed by the clutch.
1. A supercharged internal combustion engine, comprising:
a crankcase having a crankshaft rotatably mounted therein;
a cylinder block connected to the crankcase;
a cylinder head connected to the cylinder block wherein the cylinder block and the cylinder head form at least one combustion chamber;
at least one air intake passageway operatively coupled to the combustion chambers;
an air intake manifold connected to the cylinder head and operatively connected to the at least one air intake passageway;
a supercharger for boosting air to the air intake manifold, the supercharger having a driven shaft operatively connected to the crankshaft via a friction clutch supported by an intermediate shaft; and
an electric starter having a drive gear,
the intermediate shaft comprising a reduction gear operatively connected to the starter drive gear wherein in a starting operation, the electric starter rotates the crankshaft via the reduction gear of the intermediate shaft.
2. A supercharged internal combustion engine as defined in claim 1 , wherein the crankshaft rotates at a first speed, the driven shaft of the supercharger rotates at a second speed and the intermediate shaft rotates at a third speed intermediate the first speed and the second speed.
3. A supercharged internal combustion engine as defined in claim 2 , wherein when the crankshaft rotates at the first speed and the friction clutch is engaged, the second speed is higher than the first speed.
4. A supercharged internal combustion engine as defined in claim 3 , wherein the intermediate shaft is connected to the driven shaft of the supercharger via gears and the intermediate shaft rotates at a lower speed than the driven shaft of the supercharger through gear reduction.
5. A supercharged internal combustion engine as defined in claim 1 , wherein the driven shaft of the supercharger is decoupled from the intermediate shaft by the friction clutch such that the friction clutch absorbs a portion of variation of engine torque.
6. A supercharged internal combustion engine as defined in claim 5 , wherein the maximum torque transmitted by the friction clutch is 120% to 350% of an average torque at the driven shaft of the supercharger at maximum engine power.
7. A supercharged internal combustion engine as defined in claim 6 , wherein the maximum torque transmitted by the friction clutch is 150% to 250% of an average torque at the driven shaft of the supercharger at maximum engine power.
8. A supercharged internal combustion engine as defined in claim 1 , wherein the reduction gear is connected to the intermediate shaft through a one-way clutch.
9. A supercharged internal combustion engine as defined in claim 1 , further comprising an elastomeric damper supported by the intermediate shaft, the driven shaft being operatively connected to the crankshaft via the elastomeric damper.
10. A personal watercraft, comprising:
a hull;
a deck disposed on the hull;
an engine compartment defined between the hull and the deck; and
a supercharged internal combustion engine comprising:
a crankcase having a crankshaft rotatably mounted therein;
a cylinder block connected to the crankcase;
a cylinder head connected to the cylinder block wherein the cylinder block and the cylinder head form at least one combustion chamber;
at least one air intake passageway operatively coupled to the combustion chambers;
an air intake manifold connected to the cylinder head and operatively connected to the at least one air intake passageway;
a supercharger for boosting air to the air intake manifold, the supercharger having a driven shaft operatively connected to the crankshaft via a friction clutch supported by an intermediate shaft; and
an electric starter having a drive gear,
the intermediate shaft comprising a reduction gear operatively connected to the starter drive gear wherein in a starting operation, the electric starter rotates the crankshaft via the reduction gear of the intermediate shaft.
11. A personal watercraft as defined in claim 10 , wherein the driven shaft of the supercharger is decoupled from the intermediate shaft by the friction clutch such that the friction clutch absorbs a portion of variations of engine torque.
12. A personal watercraft as defined in claim 10 , wherein the reduction gear is connected to the intermediate shaft through a one-way clutch.
13. A personal watercraft as defined in claim 10 , further comprising an elastomeric damper supported by the intermediate shaft, the driven shaft being operatively connected to the crankshaft via the elastomeric damper.