Gear wheel having an improved profile

A gear wheel for a hydraulic apparatus, comprising a plurality of teeth and arranged to be rotatable about an axis of rotation, said teeth having a sectional profile and being adapted to mesh with respective teeth of another gear wheel during a rotational motion about the axis of rotation, wherein at least one tooth is shaped so as to have at least one cutting edge configured to remove material from a body which is contacted by said at least one cutting edge during the rotation of said gear wheel, characterized in that said at least one cutting edge is defined by at least one groove which is lowered, with respect to a rounded starting profile, by an amount from 0.2% to 5% of the height of said tooth, said at least one groove decreasing away from the at least one cutting edge along the sectional profile, wherein the sectional profile corresponds to the rounded starting profile except for the at least one groove;

• wherein the at least one groove forms a projection which protrudes with respect to a rounded profile of the tooth by an amount from 0.01 mm to 1 mm;
• wherein the projection has a width from 0.01 mm to 1 mm.