Ultrasonic piezoelectric pump

Abstract

Disclosed is an ultrasonic piezoelectric pump in which a piezoelectric pump is integrated with a fluid pipe without a check valve so that the structure can be simplified. The pump includes a fluid pipe having a hollow part formed therein to permit a fluid to flow from a fluid source, a piezoelectric actuator inserted into the hollow part and including a piezoelectric device and a plurality of fluid holes, a controller connected to a lead wire to apply a driving power to the piezoelectric device, and a tapered nozzle inserted into the hollow part in front of the piezoelectric actuator and tapered forward and downwardly.

1 . An ultrasonic piezoelectric pump comprising:
 a fluid pipe having a hollow part formed therein to permit a fluid to flow from a fluid source;   a piezoelectric actuator inserted into the hollow part and including a piezoelectric device and a plurality of fluid holes;   a controller connected to a lead wire to apply a driving power to the piezoelectric device; and   a tapered nozzle inserted into the hollow part in front of the piezoelectric actuator and tapered forward and downwardly.   
   
   
       2 . The ultrasonic piezoelectric pump according to  claim 1 , wherein the piezoelectric actuator comprises:
 a case having a through-hole formed at the center thereof;   a frame, inserted into the through-hole, to which the piezoelectric device is installed; and   the fluid holes formed in the vicinity of the frame to penetrate the front side to the rear side of the case.   
   
   
       3 . The ultrasonic piezoelectric pump according to  claim 2 , wherein the piezoelectric device comprises a unimorph comprising:
 a thin plate; and   a piezoelectric ceramic contacting a side of the thin plate.   
   
   
       4 . The ultrasonic piezoelectric pump according to  claim 2 , wherein the piezoelectric device comprises a unimorph comprising:
 a thin plate; and   a piezoelectric ceramic contacting sides of the thin plate.   
   
   
       5 . The ultrasonic piezoelectric pump according to  claim 2 , wherein the piezoelectric device comprises a multi-layer piezoelectric disc having a plurality of thin piezoelectric ceramics and resonating in the thickness direction. 
   
   
       6 . The ultrasonic piezoelectric pump according to  claim 1 , wherein the piezoelectric device comprises:
 a case having a through-hole formed at the center thereof;   a pipe-shaped cylinder inserted into the through-hole;   a rear plate fixed to the rear side of the cylinder to close the rear side of the cylinder;   a front plate contacting an inner wall of the cylinder and used as a piston;   the piezoelectric device, provided to connect the rear plate to the front plate, in which a plurality of piezoelectric ceramics are laminated; and   the fluid holes formed in the vicinity of the cylinder to penetrate the front side to the rear side of the case.   
   
   
       7 . The ultrasonic piezoelectric pump according to  claim 6 , wherein the front plate further comprises a circular rubber ring to seal the case and to prevent the fluid from entering. 
   
   
       8 . The ultrasonic piezoelectric pump according to  claim 1 , wherein the piezoelectric actuator comprises:
 a case having a through-hole formed at the center thereof;   a frame inserted into the through-hole;   a piezoelectric ceramic provided in the frame to generate a deflection in the radial direction;   an elastic member contacting the front side of the piezoelectric ceramic, a part of the elastic member inserted into the frame and another part of the elastic member protruding from the front side of the frame, and the protruded part having a smaller diameter than that of the part inserted into the frame and vibrating due to ultrasonic waves applied to the piezoelectric device;   a fixed body to fix the elastic member to the frame, and through which the elastic member penetrates; and   the fluid holes formed in the vicinity of the frame to penetrate the front side to the rear side of the case.   
   
   
       9 . The ultrasonic piezoelectric pump according to any one of  claims 1  to  8 , further comprising a distance adjusting circular ring provided in the fluid pipe to adjust a distance between the piezoelectric actuator and the tapered nozzle.