Patent ID: 8556609

Claim:
An improved geared hydraulic apparatus, comprising a pair of meshing gearwheels, mounted reciprocally rotatable in a casing, the gearwheels having helical toothing, said casing having an inlet and an outlet for the passage of a fluid which flows in a direction transverse to the axes of rotation of the gearwheels, the fluid flowing substantially transversally alone the meshing gearwheels when said gearwheels rotate, the meshing gearwheels presenting, during their reciprocal rotation, different meshing configurations, wherein in at least one of said meshing configurations, a closed fluid entrapment area between two meshing teeth of the meshing gearwheels is formed, said closed fluid entrapment area being entirely cancelled out in one of a progressive meshing configurations, so that in the latter meshing configuration an absence of any area entrapping fluid between a tooth head of one gearwheel and a tooth bottom of the other gearwheel is achieved.