Stroke-regulated linear compressor

Abstract

A linear compressor having an electromagnet; an oscillating body movably guided in an oscillating fashion in the alternating field of the electromagnet; a cylinder; a piston connected to the oscillating body and movable back and forth inside the cylinder; a power supply circuit to supply the electromagnet with an alternating current; a proximity sensor to detect whether a distance between the piston and the end face of the cylinder falls below a predetermined threshold value; and a control circuit to detect a time period in which the distance between the piston and the end face of the cylinder falls below the threshold value and to regulate an amplitude and/or a phase of the alternating current if the time period deviates from a positive setpoint value.

1 - 8 . (canceled) 
   
   
       9 . A linear compressor, comprising:
 an electromagnet having an alternating field;   an oscillating body movably guided in an oscillating fashion in the alternating field of the electromagnet;   a cylinder having an end face;   a piston connected to the oscillating body and movable back and forth inside the cylinder;   a power supply circuit to supply the electromagnet with an alternating current;   a proximity sensor to detect whether a distance between the piston and the end face of the cylinder falls below a predetermined threshold value; and   a control circuit to detect a time period in which the distance between the piston and the end face of the cylinder falls below the predetermined threshold value and to regulate at least one of an amplitude and a phase of the alternating current if the time period deviates from a positive setpoint value.   
   
   
       10 . The linear compressor of  claim 9 , wherein the setpoint value is smaller than 
     
       
         
           
             
               
                 T 
                 π 
               
                
               
                 cos 
                 
                   - 
                   1 
                 
               
                
               
                 
                   2 
                    
                   
                     ( 
                     
                       L 
                       - 
                       ɛ 
                     
                     ) 
                   
                 
                 L 
               
             
             , 
           
         
       
     
     wherein ε is the predetermined threshold value, T is an oscillation period of the piston and L is the distance between the end face of the cylinder and the piston in a rest position of the piston. 
   
   
       11 . The linear compressor of  claim 10 , wherein the setpoint value is smaller than 0.15 T. 
   
   
       12 . The linear compressor of  claim 10 , wherein the setpoint value is greater than 0.02 T. 
   
   
       13 . The linear compressor of  claim 9 , wherein the predetermined threshold value is smaller than a tenth of the distance between the end face of the cylinder and the piston in a rest position of the piston. 
   
   
       14 . The linear compressor of  claim 9 , wherein the predetermined threshold value is greater than a fiftieth of the distance between the end face and the piston in a rest position of the piston. 
   
   
       15 . The linear compressor of  claim 9 , wherein the proximity sensor is a contactless sensor. 
   
   
       16 . The linear compressor as claimed in  claim 15 , wherein the proximity sensor is an inductive switch.