Sealed compressor and refrigeration device

Abstract

A sealed compressor includes sealed container that contains electric element, and compression element driven by electric element. Compression element includes shaft that includes main shaft portion, and eccentric shaft portion integrally movable with main shaft portion, and bearing portion that supports main shaft portion of shaft to constitute a cantilever bearing. Compression element further includes cylinder that compresses gas, piston reciprocatively inserted into cylinder, and connecting rod that connects eccentric shaft portion with piston.

1 . A sealed compressor comprising a sealed container that contains an electric element, and a compression element driven by the electric element, wherein
 the compression element includes:
 a shaft that includes a main shaft portion, and an eccentric shaft portion integrally movable with the main shaft portion, 
 a bearing portion that supports the main shaft portion of the shaft to constitute a cantilever bearing, 
 a cylinder that compresses gas, 
 a piston reciprocatively inserted into the cylinder, and 
 a connecting rod that connects the eccentric shaft portion with the piston, 
   an angle a 1  formed by a first center line indicating a shaft center of the bearing portion, and a second center line indicating a shaft center of the cylinder, and an absolute value c 1  of an angle of a tilt of the shaft with respect to the bearing portion satisfy equation (1):
     a 1=π/2 +c 1  (1), and
 
   an outer circumferential surface of the piston includes:
 a seal portion producing a clearance from an inner circumferential surface of the cylinder, and forming a sliding surface, 
 an extension portion disposed in a rear of the seal portion, and forming a sliding surface, and 
 a non-sliding portion disposed in the rear of the seal portion, and not forming a sliding surface. 
   
     
     
         2 . The sealed compressor according to  claim 1 , wherein the extension portion has a radius same as a radius of the seal portion, and forms the sliding surface that supports side pressure. 
     
     
         3 . The sealed compressor according to  claim 1 , wherein the electric element is driven at a plurality of rotation speeds by an inverter circuit. 
     
     
         4 . A refrigeration device comprising the sealed compressor according to  claim 1  in a freezing cycle.