Micro pump

Abstract

A micro pump includes: a vibrating membrane on which a piezoelectric element is stacked; an upper space provided in contact with an upper surface of the vibrating membrane; and a lower space provided in contact with a lower surface of the vibrating membrane, wherein by displacing the vibrating membrane toward the upper space, a fluid flows out from the upper space to an outside and flows in from the outside to the lower space, and wherein by displacing the vibrating membrane toward the lower space, the fluid flows out from the lower space to the outside and flows in from the outside to the upper space.

What is claimed is: 
     
         1 . A micro pump comprising:
 a vibrating membrane on which a piezoelectric element is stacked;   an upper space provided in contact with an upper surface of the vibrating membrane; and   a lower space provided in contact with a lower surface of the vibrating membrane,   wherein by displacing the vibrating membrane toward the upper space, a fluid flows out from the upper space to an outside and flows in from the outside to the lower space, and   wherein by displacing the vibrating membrane toward the lower space, the fluid flows out from the lower space to the outside and flows in from the outside to the upper space.   
     
     
         2 . The micro pump of  claim 1 , wherein an upper inflow port, which is provided on a side surface of the upper space and configured to allow the fluid to flow in from the outside to the upper space, and a lower inflow port, which is provided on a side of the lower space and configured to allow the fluid to flow in from the outside to the lower space, are disposed at positions where the upper inflow port and the lower inflow port do not overlap with each other in a film thickness direction of the vibrating membrane. 
     
     
         3 . The micro pump of  claim 2 , wherein an upper inflow path connecting the upper inflow port and the outside has a shape in which the upper inflow path gradually widens from the outside toward the upper inflow port, when viewed from the film thickness direction of the vibrating membrane, and
 wherein a lower inflow path connecting the lower inflow port and the outside has a shape in which the lower inflow path gradually widens from the outside toward the lower inflow port, when viewed from the film thickness direction of the vibrating membrane.   
     
     
         4 . The micro pump of  claim 1 , wherein an upper outflow port, which is provided on a side surface of the upper space and configured to allow the fluid to flow out from the upper space to the outside, and a lower outflow port, which is provided on a side surface of the lower space and configured to allow the fluid to flow out from the lower space to the outside, are disposed at positions where the upper outflow port and the lower outflow port do not overlap with each other in a film thickness direction of the vibrating membrane. 
     
     
         5 . The micro pump of  claim 4 , wherein an upper outflow path connecting the upper outflow port and the outside and a lower outflow path connecting the lower outflow port and the outside are disposed at positions where at least portions of the upper outflow path and the lower outflow path overlap with each other in the film thickness direction of the vibrating membrane, and merge into a single path at the overlapping position. 
     
     
         6 . The micro pump of  claim 4 , wherein an upper inflow path connecting the upper outflow port and the outside has a shape in which the upper outflow path gradually widens from the upper outflow port toward the outside, when viewed from the film thickness direction of the vibrating membrane, and
 wherein a lower outflow path connecting the lower outflow port and the outside has a shape in which the lower outflow path gradually widens from the lower outflow port toward the outside, when viewed from the film thickness direction of the vibrating membrane.   
     
     
         7 . The micro pump of  claim 1 , wherein the vibrating membrane is formed on a lower member in which the lower space is formed,
 wherein the upper space and the lower space have a circular shape when viewed from a film thickness direction of the vibrating membrane, and   wherein a diameter of the lower space is smaller than a diameter of the upper space.   
     
     
         8 . The micro pump of  claim 1 , wherein each of an upper member in which the upper space is formed and a lower member in which the lower space is formed has a quadrangular shape when viewed from a film thickness direction of the vibrating membrane,
 wherein an upper inflow path configured to inflow the fluid from the outside into the upper space and an upper outflow path configured to outflow the fluid from the upper space to the outside are disposed on non-opposite side surfaces of the upper member, and   wherein a lower inflow path configured to inflow the fluid from the outside into the lower space and a lower outflow path configured to outflow the fluid from the lower space to the outside are disposed on non-opposite side surfaces of the lower member.