Linear motor and linear compressor having the same

Abstract

A linear compressor comprising a linear motor. The linear motor comprises an outer core fixed to a cylinder block in such a fashion that it is spaced apart from a piston to surround it, a coil for producing a magnetic field by receiving electric power, and an inner core assembly fixed to an outer circumference of the piston. The inner core assembly has a hollow cylindrical shape, and includes an inner core, a magnet fixed to an outer circumference of the inner core 51 , and a molded material obtained through injection molding for fixing the inner core and the magnet to each other.

1 . A linear compressor comprising: 
 a piston reciprocating inside a compression chamber for compressing a refrigerant;    an outer core spaced apart from the piston to surround it, and having a coil wound therein for producing a magnetic field; and    an inner core assembly fixed to an outer circumference of the piston,    wherein the inner core assembly includes:    an inner core serving as a propagation passage of the magnetic field produced inside the outer core; and    a permanent magnet for reciprocating the piston through electromagnetic interaction with the inner and outer cores.    
   
   
       2 . The compressor according to  claim 1 , wherein the permanent magnet is provided at an outer circumference of the inner core.  
   
   
       3 . The compressor according to  claim 1 , wherein the inner core assembly further includes a molded material obtained through injection molding, the molded material serving to fix the inner core and the permanent magnet to each other.  
   
   
       4 . The compressor according to  claim 3 , wherein the inner core assembly further includes an insulation member disposed between the inner core and the magnet for the electrical insulation therebetween.  
   
   
       5 . The compressor according to  claim 1 , wherein the piston has first and second support portions formed at the outer circumference thereof for axially supporting both ends of the inner core assembly, respectively.  
   
   
       6 . The compressor according to  claim 5 , wherein the piston is dividable into a first piston member formed with the first support portion, and a second piston member formed with the second support portion.  
   
   
       7 . The compressor according to  claim 6 , wherein, for the coupling of the first and second piston members, one of the piston members is formed with a coupling protrusion, and the other one of the piston members is formed with a coupling recess, into which the coupling protrusion will be inserted.  
   
   
       8 . A linear motor comprising: 
 an outer core spaced apart from an output shaft to surround it, and serving to drive the output shaft, the outer core having a coil wound therein for producing a magnetic field; and    an inner core assembly fixed to an outer circumference of the output shaft,    wherein the inner core assembly includes:    an inner core serving as a propagation passage of the magnetic field produced inside the outer core; and    a permanent magnet for reciprocating the output shaft through electromagnetic interaction with the inner and outer cores.    
   
   
       9 . The motor according to  claim 8 , wherein the inner core assembly further includes a molded material obtained through injection molding, the molded material serving to fix the inner core and the permanent magnet to each other.