Vane pump and method for the operation thereof

Abstract

A vane cell pump comprises a contour ring having an inner peripheral face and a rotatable rotor which has a plurality of conveying elements displaceable radially relative to a rotation axis. The inner peripheral face includes a plurality of pump portions each constructed with an intake region and a pressure region which are passed through by the conveying elements during rotation of the rotor. A narrow location at which the conveying elements are displaced radially inward toward the rotation axis to a greatest extent, is located between a pressure region and a subsequent intake region. By applying a part-stroke, an auxiliary start contour which is arranged between the rotation axis and the inner peripheral face radially inside the conveying elements in the region of at least one pump portion displaces the conveying elements to the greatest extent radially inwardly.

1 . A vane cell pump ( 01 ) comprising a hollow-cylindrical contour ring ( 10 ) which is arranged between two side plates ( 11 ,  12 ) and which has an inner peripheral face ( 100 ) and a rotor ( 22 ) which is rotatably supported about a rotation axis ( 21 ) which extends parallel with the cylinder axis of the contour ring ( 10 ) and which has a plurality of conveying elements ( 20 ) which can be displaced radially relative to the rotation axis ( 21 ) and which are urged against the inner peripheral face ( 100 ) during a rotation of the rotor ( 22 ), wherein:
 the inner peripheral face ( 100 ) is formed in such a manner that a number corresponding to the number of flows of the vane cell pump ( 01 ) in respect of conveying chambers ( 03 ) which each form a pump portion ( 31 ,  32 ) are each constructed with an intake region ( 33 ) and a pressure region ( 34 ) which are passed through by the conveying elements ( 22 ) during a rotation of the rotor ( 22 ),   within a pump portion ( 31 ,  32 ), the radial spacing between the rotation axis ( 21 ) and the inner peripheral face ( 100 ) increases when viewed in the working rotation direction (P) of the rotor ( 22 ) over the intake region ( 33 ) in order subsequently to decrease toward the end of the pressure region ( 34 ) again,   a narrow location ( 30 ), during the passage through which the conveying elements ( 20 ) are displaced radially inward toward the rotation axis ( 21 ) to the greatest extent, is located between a pressure region ( 34 ) and a subsequent intake region ( 33 ) when viewed in the working rotation direction (P), and   the rotor ( 22 ) has, radially inside the conveying elements ( 20 ), expulsion regions ( 200 ) which are at least partially connected to at least one pressure region ( 34 ) via a fluid path ( 35 ) in order to expel the conveying elements ( 20 ) against the inner peripheral face ( 100 ),   
       characterized by an auxiliary start contour ( 04 ) which is arranged between the rotation axis ( 21 ) and the inner peripheral face ( 100 ) radially inside the conveying elements ( 20 ) in the region of at least one pump portion ( 31 ,  32 ) and which displaces the conveying element ( 20 ) by applying only a part-stroke into the pump portion ( 31 ,  32 ) as a result of a maximum of temporary contact with a conveying element ( 20 ) which is previously displaced at a narrow location ( 30 ) to the greatest extent radially inwardly toward the rotation axis ( 21 ). 
     
     
         2 . The vane cell pump as claimed in  claim 1 , wherein the auxiliary start contour ( 04 ) moves into contact with the conveying element ( 20 ) only when it is already located in the pump portion ( 31 ,  32 ) and is still completely moved in, whereas a conveying element ( 20 ) which is displaced against the inner peripheral face ( 100 ) is free from contact with the auxiliary start contour ( 04 ) in principle. 
     
     
         3 . The vane cell pump as claimed in  claim 1  or  2 , wherein the contact between the auxiliary start contour ( 04 ) which is provided radially inside the conveying elements ( 20 ) and a conveying element ( 20 ) takes place at a side of the conveying element ( 20 ) facing the rotation axis ( 21 ). 
     
     
         4 . The vane cell pump as claimed in  claim 1 ,  2  or  3 , wherein the auxiliary start contour ( 04 ) is constructed on an outer peripheral face ( 41 ) of an auxiliary start ring ( 40 ) which is arranged radially within the conveying elements ( 20 ) so as to be non-rotatable relative to the contour ring ( 10 ) and/or is included thereby and/or includes it. 
     
     
         5 . The vane cell pump as claimed in one of the preceding claims, wherein the auxiliary start contour ( 04 ) is similar to the inner peripheral face ( 100 ) in a mathematical sense, wherein the same spacing is present between the auxiliary start contour ( 04 ) and the inner peripheral face ( 100 ) at any rotational angle of the rotor ( 22 ) when viewed from the rotation axis ( 21 ) toward the inner peripheral face ( 100 ). 
     
     
         6 . The vane cell pump as claimed in one of  claims 1  to  4 , wherein there is per pump portion ( 31 ,  32 ) a maximum of two rotational angles, at which the same spacing between the auxiliary start contour ( 04 ) and the inner peripheral face ( 100 ) is present when viewed from the rotation axis ( 21 ) toward the inner peripheral face ( 100 ). 
     
     
         7 . The vane cell pump as claimed in  claim 6 , wherein the auxiliary start contour ( 04 ) is provided on or in at least one side plate ( 11 ,  12 ). 
     
     
         8 . A method for operating a vane cell pump ( 01 ), which provides for at least the conveying elements ( 20 ) which are still completely moved in during a rotation of the rotor ( 22 ) after the introduction thereof into a pump portion ( 31 ,  32 ) in order to forcibly redirect a part-stroke in the direction toward the inner peripheral face ( 100 ) of the contour ring ( 10 ). 
     
     
         9 . The method as claimed in  claim 8 , wherein only at most the conveying elements ( 20 ) which are not yet displaced against the inner peripheral face ( 100 ) within a pump portion ( 31 ,  32 ) are forcibly redirected, whereas a conveying element ( 20 ) which is displaced against the inner peripheral face ( 100 ) is in principle free from forced redirection. 
     
     
         10 . The method as claimed in  claim 8  or  9  for operating a vane cell pump ( 01 ) as claimed in one of  claims 1  to  7 . 
     
     
         11 . The method as claimed in  claim 10 , wherein the mechanically forced movement of the conveying elements ( 20 ) is carried out during the start while the operation of the pump is carried out in a completely hydraulic manner.