Patent ID: 7878781

Claim:
A gear pump for operating with reduced likelihood of cavitation occurrences in the fluid being pumped thereby, the pump comprising: a pair of gears each supported on a corresponding one of a pair of gear shafts between shaft ends thereof with each gear shaft having a corresponding gear shaft axis of symmetry intersecting the shaft ends thereof substantially parallel to one another, and each gear intersecting a common gear plane substantially perpendicular to the gear shaft axes of symmetry with spaced apart teeth provided in each gear that mesh with at least one tooth of the other when such teeth have been rotated into a meshing region in the common gear plane, and with one of the gear shafts being rotatably connectable to a motor; bearing structures rotatably supporting corresponding ones of each of the pair of gear shafts on either side of that one of the pair of gears supported thereby, and with the bearing structures having bearing surfaces adjacent those gear sides each primarily in a corresponding bearing plane, the bearing surface of the bearing structure on at least one side of the pair of gears having an entry mesh recess across from where the pair of gears rotate to enter the meshing region and an exit mesh recess across from where the pair of gears rotate to exit the meshing region with the entry and exit mesh recesses each beginning at a corresponding beginning location separated from one another by a separation space that is intersected by an alignment axis in the bearing plane thereof intersecting the gear shaft axes of symmetry and from there each of the entry and exit mesh recesses extend in opposite directions at least in part perpendicular to that bearing plane axis; and a pressurized fluid passageway in at least one of the bearing structures across from the meshing region and extending between surface openings at the bearing surface of that bearing structure that are positioned on opposite sides of the alignment axis across from paths followed by the teeth of the pair of gears during rotations thereof, and with one of the surface openings being positioned in the exit mesh recess to have a concurrent flow of the fluid through both surface openings when the remaining surface opening is across from a space between successive ones of the gear teeth of one of the pair of gears.