The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 2012
Filed:
Apr. 15, 2009
Oliver Gloge, Friedrichshafen, DE;
Oliver Gloge, Friedrichshafen, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A method of operating a motor vehicle drivetrain having, along a power flow, an internal combustion engine, a clutch, an electric motor, a transmission and a drive output. The transmission is associated with a main and auxiliary hydraulic pumps, and an internal or an external starting element. When the engine is at rest and the clutch and starting element are both disengaged, to start with the electric motor, with the brake pedal actuated, the auxiliary hydraulic pump is operated at a first power level to supply the transmission with pressure for maintaining a defined gear. Then, upon recognizing a desire to start, the auxiliary hydraulic pump is changed from a first to a second power level to supply pressure to the transmission to produce starting torque and, only after lapse of a time interval, is the speed of the motor increased to produce the desired starting power or torque.