SEALED COMPRESSOR AND REFRIGERATION DEVICE

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.