Patent ID: 7395803
Filing Date: 2008-07-08
Classification: B60K,B60W,Y02T

Abstract:
1. A hybrid electric vehicle powertrain comprising an engine and an electric vehicle traction motor defining in part separate power flow paths to vehicle traction wheels; an engine lubrication oil pump in fluid communication with a lubrication oil flow circuit for the engine; the lubrication oil pump having a lubrication oil pressure supply line communicating with the lubrication oil flow circuit for the engine; an oil reservoir for the lubrication oil pump; a low pressure lubrication oil return communicating with the lubrication oil pump; an electric oil pump drive motor drivably connected to the lubrication oil pump; and a powertrain control module and a vehicle system controller in electrical communication with the pump drive motor, the vehicle system controller being configured to develop engine power commands to the powertrain control module in response to system operating input variables and driver power demand whereby the engine is turned off during vehicle operation using solely traction motor power and the engine is turned on during a demand for engine power; the powertrain control module being configured to start the pump drive motor during a transition from an engine-off state to an engine-on state whereby the lubrication oil flow circuit is pressurized prior to engine acceleration to its steady-state speed, the powertrain control module being configured also to command a modification of oil flow rate from the lubrication oil pump to the engine as a function of at least one engine operating variable, including engine speed, engine power demand and engine oil temperature.