If a net load on shaft bearings of pump is balanced then the pump is balanced vane pump.

Explanation with sketch

A balanced vane pump is a very versatile design . The basic design principle is shown in Fig. The rotor and vanes are contained within a double eccentric cam ring and there are two inlet segments and two outlet segments during each revolution. This double pumping action not only gives a compact design, but also leads to another important advantage: although pressure forces acting on the rotor in the outlet area are high, the forces at the two outlet areas are equal and opposite, completely canceling each other.