Gear pumps have two sliding-contact areas (sealing areas): at the periphery as well as the two sides of the gear wheels, i.e. in the axial direction.
The pressure-controlled leakage that occurs here can be reduced if the clearance gap at the side is reduced with increasing pressure. The axial compensation is undertaken by springs that press the bearing bush or thrust washer against the gearwheels (Figure A 29).
Figure A 29: Axial gap reduction