Fuel pump for a motor vehicle

Abstract

The invention relates to a fuel pump ( 3 ) that is mounted in a fuel tank ( 1 ) of a motor vehicle. Said pump has a preliminary phase ( 6 ) and a principal phase ( 7 ), which are driven by an electromotor ( 5 ). The principal phase ( 7 ) lies directly in front of a flow pipe ( 17 ) to the internal combustion engine. The fuel that is transported by the principal phase ( 7 ) is taken in from a component ( 2, 21 ), into which the fuel of the preliminary phase ( 6 ) has been transported. As the principal phase ( 7 ) is located downstream of the electromotor ( 5 ), an impermissible heating of said electromotor is prevented. The fuel pump ( 3 ) also allows the starting times of the internal combustion engine to be extremely short.

1 . Fuel pump for a motor vehicle, having a preliminary stage delivering into a component, preferably a surge chamber or a filter, having a main stage for delivering fuel via a forward-flow line to an internal combustion engine and an electric motor for driving the preliminary stage and main stage, characterized in that the main stage ( 7 ) sucks in fuel from the component ( 2 ,  21 ), and in that the main stage ( 7 ) is arranged directly upstream of the forward-flow line ( 17 ) to the internal combustion engine.  
     
     
         2 . Fuel pump according to  claim 1 , characterized in that the main stage ( 7 ) is arranged on a side of the electric motor ( 5 ) which lies opposite the preliminary stage ( 6 ).  
     
     
         3 . Fuel pump according to either of claims  1  and  2 , characterized in that a discharge line ( 15 ) of the preliminary stage ( 6 ) opens into the surge chamber ( 2 ) in the region of the main stage ( 7 ).  
     
     
         4 . Fuel pump according to  claim 3 , characterized in that the discharge line ( 15 ) of the preliminary stage ( 6 ) opens into the surge chamber ( 2 ) above the suction branch ( 18 ) of the main stage ( 7 ).  
     
     
         5 . Fuel pump according to at least one of  claims 1  to  4 , characterized in that the main stage ( 7 ) has a suction line ( 19 ) which is guided outside the electric motor ( 5 ) into the bottom region of the surge chamber ( 2 ).  
     
     
         6 . Fuel pump according to at least one of  claims 1  to  5 , characterized in that a discharge branch ( 16 ) and a suction branch ( 18 ) are arranged on the main stage ( 7 ), on its side facing away from the electric motor ( 5 ), preferably on a flange.  
     
     
         7 . Fuel pump according to at least one of  claims 1  to  6 , characterized in that the discharge line ( 15 ) of the preliminary stage ( 6 ) is guided through the electric motor ( 5 ).