Method and system to provide engine torque
An exemplary method of providing torque-assist to a crankshaft of an internal combustion engine includes, among other things, assisting a rotation of the crankshaft using an electric machine during the transition between stages of a multi-stage forced induction system.
1. A method of providing torque-assist to a crankshaft of an internal combustion engine, the method comprising:
assisting a rotation of the crankshaft using an electric machine during the transition between stages of a multi-stage forced induction system.
2. The method of claim 1 , further comprising activating the electric machine when a first stage of the forced induction system reaches a peak performance level.
3. The method of claim 2 , further comprising deactivating the electric machine when a second stage of the forced induction system reaches a peak performance level.
4. The method of claim 1 , further comprising activating the electric machine when a second stage of the forced induction system is activated.
5. The method of claim 4 , further comprising deactivating the electric machine when a first stage of the forced induction system is deactivated.
6. The method of claim 1 , further comprising deactivating the electric machine when a second stage of the forced induction system reaches a peak performance level.
7. The method of claim 1 , further comprising deactivating the electric machine when a first stage of the forced induction system is deactivated.
8. The method of claim 1 , further comprising assisting the rotation of the crankshaft during only a middle portion of the speed range of the engine.
9. The method of claim 1 , further comprising assisting the rotation of the crankshaft only when more than one stage of the forced induction system is activated.
10. A torque-assist system for an internal combustion engine, the torque-assist system comprising:
a multi-stage forced induction system;
an electric machine coupled to a crankshaft of the engine; and
a controller configured to activate the electric machine during transition between the stages of a multi-stage forced induction system to assist the rotation of the crankshaft.
11. The torque-assist system of claim 10 , wherein the multi-stage forced induction system comprises at least one turbocharger.
12. The torque-assist system of claim 10 , wherein the electric machine is coupled to the crankshaft of the engine by virtue of one or more intermediary members.
13. The torque-assist system of claim 12 , wherein the multi-stage forced induction system comprises at least one turbocharger.
14. The torque-assist system of claim 13 , wherein the electric machine is coupled to the crankshaft at a front end of the engine.
15. The torque-assist system of claim 10 , wherein the electric machine is coupled to the crankshaft at a front end of the engine.
16. An engine comprising the torque-assist system of claim 8 .
17. The torque-assist system of claim 10 , wherein the controller is further configured to deactivate the electric machine when a second stage of the multi stage forced induction system reaches a peak performance level.
18. The torque-assist system of claim 10 , wherein the controller is further configured to activate the electric machine when a second stage of the multi stage forced induction system is activated.
19. The torque-assist system of claim 10 , wherein the controller is further configured to deactivate the electric machine when a first stage of the multi stage forced induction system is deactivated.
20. The method of claim 1 , further comprising using a controller to control the electric machine when the electric machine is assisting of the rotation of the crankshaft.