PURPOSE: To prevent any thermal deterioration due to seizure in bearing portions or residence of liquid to be transported by making a discharge pressure uniform with variation of gaps between the intermediate bearings and gears in the case of occurrence of a difference in discharge pressure between the gears.

CONSTITUTION: A gear pump 1 for transporting high viscous fluid is used for transportation of high molecular melt such as polyester. A pair of fluid transportation passages are constituted of a space surrounded by an outer peripheral surface of teeth of gears 3-6, an inner circumferential surface of a case main body 7, and side surfaces of bearings 23-28. Fluid is sucked through a suction path 11 with rotation of the driving gears 3, 5, to be discharged from discharge paths 12, 13. If a difference in discharge pressure between the discharge paths 12, 13 occurs caused by a machining error of the gears 3-6 and a difference in pressure loss in a pipeline, intermediate bearings 25, 28 are moved in the axial direction due to the difference in pressure. Therefore, gaps between the intermediate bearings 25, 28 and the other pair of gears 5, 6 are different from each other so that the gap on a side where the discharge pressure is higher becomes large, and consequently, a leakage quantity is increased, thus making the discharge pressure uniform.