Vane pump

Abstract

A vane pump includes a rotor; a plurality of slits that are formed in the rotor, the plurality of vanes being respectively inserted into the plurality of slits in a slidable manner; a cam ring that has a cam face on which tip-ends of the vanes slide by the rotation of the rotor; and pump chambers that are defined by the rotor, the cam ring, and an adjacent pair of the vanes. The plurality of vanes have a plurality of first vanes that are formed by applying a DLC coating on a base material and second vanes that are formed such that the base material is exposed, the first vanes being respectively inserted into at least two adjacent slits of the plurality of slits.

1 . A vane pump comprising:
 a rotor linked to a driving shaft;   a plurality of slits formed in the rotor in a radiating pattern to open in an outer circumference of the rotor;   a plurality of vanes respectively inserted into the plurality of slits in a slidable manner;   a cam ring having an inner circumferential surface on which tip-ends of the vanes slide by rotation of the rotor;   pump chambers defined by the rotor, the cam ring, and the pair of adjacent vanes,   wherein the plurality of vanes have:   a plurality of first vanes formed by applying DLC coating on a base material; and   a second vane formed such that the base material is exposed, and   the first vanes are respectively inserted into at least two adjacent slits of the plurality of slits.   
     
     
         2 . The vane pump according to  claim 1 , further comprising
 back pressure chambers into which working fluid discharged from the pump chamber is guided, the back pressure chambers being defined in the slits by base-end portions of the vanes.   
     
     
         3 . The vane pump according to  claim 1 , wherein
 the plurality of vanes have the two first vanes.   
     
     
         4 . The vane pump according to  claim 1 , wherein
 the plurality of vanes have the three first vanes, and   the three first vanes are arranged side by side in a consecutive manner.   
     
     
         5 . The vane pump according to  claim 1 , wherein
 the plurality of vanes have the four first vanes, and   the four first vanes are arranged such that pairs of the adjacent first vanes face against each other with a center of the rotor located therebetween.