Actuator and pump device

Abstract

An actuator includes a fixed body and a movable body. The fixed body includes a first yoke, a pair of drive magnets overlapped so as to interpose the first yoke therebetween with their same polarities being directed to the first yoke, and a second yoke which faces an outer peripheral end face of the first yoke and is superposed on respective end faces positioned on the outer sides of the pair of drive magnets. The movable body includes a coil disposed so as to surround around the outer peripheral end face of the first yoke between the first yoke and the second yoke and the coil is displaced in an axial direction by energization of the coil. The actuator may be preferably applied to a pump device.

1 . An actuator comprising: 
 a fixed body including; 
 a first yoke;  
 a pair of drive magnets which are overlapped so as to interpose the first yoke therebetween with their same polarities being directed to the first yoke; and  
 a second yoke which faces an outer peripheral end face of the first yoke and is superposed on respective end faces positioned on outer sides of the pair of drive magnets; and  
   a movable body including, 
 a coil which is disposed so as to surround around the outer peripheral end face of the first yoke between the first yoke and the second yoke, the coil being displaced in an axial direction by energization of the coil.  
   
     
     
         2 . The actuator according to  claim 1 , wherein the second yoke is provided with a ring-shaped protruding part which protrudes so as to face the outer peripheral end face of the first yoke.  
     
     
         3 . The actuator according to  claim 1 , further comprising: 
 a pair of yoke members included in the second yoke which are formed in a bottomed cylinder shape and capable of being divided in the axial direction, the pair of yoke members being disposed such that respective cylindrical body parts of the pair of yoke members are butted with each other and bottom plate portions of the pair of yoke members being overlapped on the respective end faces of the pair of drive magnets, and    a space which is formed by the second yoke and the first yoke and the pair of the drive magnets for allowing the movable body to move in the axial direction.    
     
     
         4 . The actuator according to  claim 1 , further comprising: 
 a coil bobbin around which the coil is wound; and    a guide member which is disposed in a space which is formed by the second yoke and the first yoke and the pair of drive magnets;    wherein the coil bobbin is provided with a guide part which engages with the guide member for performing a guide operation to the movement of the movable body.    
     
     
         5 . The actuator according to  claim 1 , further comprising a sheet-shaped elastic member which supports the coil disposed between the first yoke and the second yoke such that the coil is capable of moving in the axial direction.  
     
     
         6 . A pump device comprising: 
 an actuator comprising; 
 a fixed body including; 
 a first yoke;  
 a pair of drive magnets which are overlapped so as to interpose the first yoke therebetween with their same polarities being directed to the first yoke; and  
 a second yoke which faces an outer peripheral end face of the first yoke and is superposed on respective end faces positioned on outer sides of the pair of the drive magnets; and  
 
 a movable body including; 
 a coil which is disposed so as to surround around the outer peripheral end face of the first yoke between the first yoke and the second yoke, the coil being displaced in an axial direction by energization of the coil; and  
 
   a pump chamber in which suction of fluid and discharge of the fluid are performed by movement of the movable body.    
     
     
         7 . The pump device according to  claim 6 , further comprising: 
 a first pump chamber disposed on one side of the movable body in the axial direction in a space which is formed by the second yoke;    a second pump chamber disposed on the other side of the movable body in the axial direction in the space which is formed by the second yoke; and    a piston which is formed by the movable body.    
     
     
         8 . The pump device according to  claim 7 , wherein the first pump chamber and the second pump chamber are in communication with a common fluid inlet port and a common fluid outlet port.  
     
     
         9 . The pump device according to  claim 7 , further comprising: 
 a first fluid inlet port which is in communication with the first pump chamber;    a second fluid inlet port which is in communication with the second pump chamber;    a first fluid outlet port which is in communication with the first pump chamber; and    a second fluid outlet port which is in communication with the second pump chamber.    
     
     
         10 . The pump device according to  claim 6 , further comprising: 
 a first pump chamber disposed on one side of the movable body in the axial direction in a space which is formed by the second yoke;    a second pump chamber disposed on the other side of the movable body in the axial direction in the space which is formed with the second yoke; and    a diaphragm which is formed by the movable body.    
     
     
         11 . The pump device according to  claim 10 , wherein the first pump chamber and the second pump chamber are in communication with a common fluid inlet port and a common fluid outlet port.  
     
     
         12 . The pump device according to  claim 10 , further comprising: 
 a first fluid inlet port which is in communication with the first pump chamber;    a second fluid inlet port which is in communication with the second pump chamber;    a first fluid outlet port which is in communication with the first pump chamber; and    a second fluid outlet port which is in communication with the second pump chamber.    
     
     
         13 . The pump device according to  claim 10 , wherein the diaphragm includes the coil and a sheet-shaped elastic member which supports the coil disposed between the first yoke and the second yoke such that the coil is capable of moving in the axial direction.