Drive train and method for operating a drive train

Patent metadata

Field	Value
Publication number	US-2016236561-A1
Application number	US-201615019179-A
Country	US
Kind code	A1
Filing date	Feb 9, 2016
Priority date	Feb 12, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

A drive train ( 10 ) for driving a motor vehicle has a combustion engine ( 12 ) for providing purely mechanical drive for the motor vehicle. A transmission ( 16 ) can be coupled to the combustion engine ( 12 ) via a shaft unit ( 14 ) for transmitting torque between the motor vehicle transmission ( 16 ) and the combustion engine ( 12 ). A reserve volume ( 18 ) is between the combustion engine ( 12 ) and the motor vehicle transmission ( 16 ) and is penetrated by the shaft unit ( 14 ). The reserve volume ( 18 ) can accommodate a high-voltage electric machine for purely electric drive of the motor vehicle or a low-voltage electric machine ( 32 ) for applying an electrically generated assistance torque to the motor vehicle transmission ( 16 ). As a result, a hybrid functionality can be made available to an at least limited degree, with the result that a cost-effective drive train ( 10 ) configured for a hybrid motor vehicle is made possible.

First claim

What is claimed is:

1 . A drive train for driving a motor vehicle, comprising:
a combustion engine for providing purely mechanical drive for the motor vehicle; a motor vehicle transmission for converting the rotational speed, the motor vehicle transmission being configured to be coupled to the combustion engine via a shaft unit for transmitting torque between the motor vehicle transmission and the combustion engine; a reserve volume between the combustion engine and the motor vehicle transmission and penetrated by the shaft unit for positioning a high-voltage electric machine for providing purely electric drive for the motor vehicle; and a low-voltage electric machine arranged in the reserve volume for applying an electrically generated assistance torque to the motor vehicle transmission.

2 . The drive train of claim 1 , wherein the low-voltage electric machine has a rated operating voltage U below a direct contact limit, in particular of U<60 V.

3 . The drive train of claim 1 , wherein the reserve volume is bounded in the axial direction on the engine side or transmission side by a torsional vibrational damper for damping torsional irregularities in the torque generated by the combustion engine.

4 . The drive train of claim 3 , wherein the reserve volume is bounded in the radial direction by a clutch case that is attached to the combustion engine and to the motor vehicle transmission.

5 . The drive train of claim 1 , wherein the low-voltage electric machine is a three-phase current machine.

6 . The drive train of claim 5 , wherein the low-voltage electric machine is a three-phase current machine and power electronics assigned to the low-voltage electric machine are arranged in the reserve volume.

7 . The drive train of claim 1 , wherein the low-voltage electric machine is connected electrically to a motor vehicle battery to also make available an on-board power system voltage.

8 . The drive train of claim 1 , wherein the combustion engine can be uncoupled from the drive train by a switchable disconnecting element.

9 . A method for operating the drive train of claim 1 , comprising using the low-voltage electric machine for providing purely electric drive for the motor vehicle in a power range below the rated maximum power of the combustion engine and for starting the combustion engine.

Assignees

• Porsche Ag

Inventors

• Stache Immo
• Spiegel Leo
• Schrage Henrik

Classifications

• Y10S903/907

  Electricity storage, e.g. battery, capacitor · CPC title

• B60K6/24 Primary

  characterised by the combustion engines · CPC title

• B60K6/28 Primary

  characterised by the electric energy storing means, e.g. batteries or capacitors · CPC title

• Y10S903/905

  Combustion engine · CPC title

• Y10S903/906

  Motor or generator · CPC title