Oil pump that can be driven by means of an electric motor

Abstract

An electrically operated crescent pump of a hybrid drive train conducts entrapped oil emerging from the oil pump to windings of the stator in order to cool the electric motor of the pump.

1 . An oil pump for supplying a gearbox having a housing with working pressure, comprising: 
 an electric motor connected to the pump for driving the pump; and    a sealing gap in the pump through which an oil stream is fed to windings of the electric motor for cooling purposes.    
   
   
       2 . The oil pump according to  claim 1 , wherein the pump and motor are configured so that the oil stream is directed by centrifugal force along a rotor of the motor to a stator of the motor which lies radially outside the rotor and is fitted with the windings.  
   
   
       3 . The oil pump according to  claim 2 , wherein the windings of the stator overlap the rotor at least in a partial region, and wherein at least one rotor bore lies in said overlapping region and extends through the rotor, and wherein the oil stream is guided through said rotor bore.  
   
   
       4 . The oil pump according to  claim 1 , further comprising a gearbox housing part which is fitted with the stator radially on an outside of the stator, said housing part having cutouts, wherein an additional oil stream can be fed to the stator through a first one of the cutouts and an oil stream can be carried away through a second one of the cutouts.  
   
   
       5 . The oil pump according to  claim 3 , wherein the rotor is fitted with permanent magnets which are secured radially on an outside of the rotor by means of banding, and wherein a duct, through which the oil stream coming from the oil pump is carried, extends around a circumference between two of the permanent magnets.  
   
   
       6 . The oil pump according to  claim 1 , wherein the rotor is supported by at least one roller bearing with respect to a gearbox housing wall which lies in the oil stream from the oil pump to the windings.  
   
   
       7 . The oil pump according to  claim 6 , wherein at least a part of the housing wall bears against part of the oil pump so that the oil stream is directed along said housing wall.  
   
   
       8 . The oil pump according to  claim 5 , wherein the banding has a cutout.  
   
   
       9 . The oil pump according to  claim 1 , wherein the oil pump lies within an oil or air space in the gearbox housing.  
   
   
       10 . The oil pump according to  claim 1 , wherein the oil pump supplies actuating elements of the gearbox with working pressure.  
   
   
       11 . The oil pump according to  claim 2 , wherein stator is composed of a laminated steel core which is pressed so as to be rotationally fixed and axially nondisplaceable with a gearbox housing part which is composed of a nonlight metal containing a large amount of iron, and wherein the gearbox housing part is connected by flanges in a fixed fashion to a gearbox housing which is composed of a light metal and is fitted with transmission means of the gearbox.