This series gear pump applies to delivering non-corrosive lubricating-oil or equivalent liquid without solid particles and fibres at temperature below 80 centigrade and with the viscosity of 5*10-6-1.5*10-3m2/s(5-1500cst). It applies to hydraulic system, too. And it can give performance as transferpump or booster pump in oil delivery system. And a fuel pump for delivery, pressurization and injection in fuel supply system. It can be also applied as hydraulic pump supplying hydraulic power in hydraulic system and in all industry fields as lubricating pump.