PURPOSE: To keep pump vibration and out-of-balance from being transmitted to the pump housing of a fuel tank supporting body by mounting one end of a rotary pump shaft on one end of a flexible spindle and accommodating the spindle in an enclosure surrounding the spindle.

CONSTITUTION: A pump assembly includes an inlet housing 20 on one end and an outlet housing 22 on the other end. A bearing shaft 40 provided on the upper end of an armature 30 extends into a hollow chamber 42. A flexible finger 50 is integrated with the end wall of the housing 22 inside the chamber 42. The finger 50 has sufficient rigidity to support the shaft 40 in the radial direction and also includes elasticity to move correspondingly to the eccentric 'run out' of the shaft 40. Thus transmission of out-of-balance or vibration from the pump to the surround mounting portions or a fuel tank can be reduced.