PUMP DEVICE

PROBLEM TO BE SOLVED: To suppress the expansion and contraction of a film itself caused by the deformation of a balloon with the reciprocation of a diaphragm, to improve efficiency by achieving low energy, and to elongate a life, in a pump device which sends and supplies fluid by changing a capacity of a pump chamber by using the diaphragm which reciprocates.SOLUTION: In a constitution for supporting the diaphragm 3 which changes the capacity of the pump chamber by reciprocating via the hollow balloon 13, slope angles α of slopes 11b, 12b of a housing 4, the circumferential length L and the radial dimension (height σ) of the balloon 13, and the radius t of the diaphragm 3 become minimum in their warpage values defined by the following expression in the range of the reciprocation of the diaphragm 3. The expression is ε={(v-v)/v}×100. Here, ε denotes warpage (%), v denotes a distance from a central position of the diaphragm 3 to a prescribed position in the circumferential direction of the balloon 13, and Vis v when the diaphragm 3 is in the central position of the range of the reciprocation.