Hybrid propulsion system for a motor vehicle and a method of operating the hybrid propulsion system

US5698905A · kind A · utility

Assignee

• Fichtel & Sachs · DE

Inventors

• Alfred Ruthlein · Schweinfurt, DE
• Erich Karg · Zeitlofs, DE

Key dates

• Filing date: Oct 4, 1995
• Grant date: Dec 16, 1997
• Expiry date: Oct 4, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/72
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A hybrid propulsion system for a motor vehicle, in which electric motors corresponding to the wheels of the motor vehicle are supplied by a generator, which generator is driven by an internal combustion engine, in particular via a direct current intermediate circuit. To be able to start the internal combustion engine, in the event of the failure of the battery provided for starting the internal combustion engine, by pushing or towing the vehicle or rolling it downhill, the electric motors can be switched over to operate as generators, and the generator can be switched over to operate as a motor, during an emergency starting phase, once the speed of travel of the vehicle exceeds a specified speed threshold. The emergency starting attempt can be initiated by the driver by means of a control mechanism, e.g. a manually actuated control switch or the accelerator pedal. If necessary, the speed threshold can be measured by means of a speed sensor. A voltage monitoring device can essentially guarantee that before the emergency starting attempt takes place, there is sufficient operating voltage available for the control systems which correspond to the electric motors and the generator.