SEALED COMPRESSOR AND REFRIGERATOR INCLUDING SEALED COMPRESSOR

1 . A sealed compressor comprising:

an electric component including a stator and a rotor which is rotatable with respect to the stator;

a compression component activated by the electric component; and

a sealed container accommodating the electric component and the compression component;

wherein the compression component includes:

a shaft including a main shaft fastened to the rotor, an eccentric shaft which is eccentric with respect to the main shaft, and a flange connecting the main shaft and the eccentric shaft to each other;

a cylinder block including a main bearing supporting the main shaft such that the main shaft is rotatable, and a cylinder having a compression chamber inside thereof;

a piston which is coupled to the eccentric shaft and is reciprocatable within the compression chamber; and

a ball bearing placed between the flange and a thrust surface of the main bearing;

wherein the ball bearing includes:

a cage;

a plurality of rolling elements held in the cage;

a first race and a second race which sandwich the rolling elements therebetween; and

an elastic support member placed between the second race and the thrust surface of the main bearing; and

wherein when a mass of a shaft assembly including the rotor and the shaft is M, a spring constant of the support member is K, and a maximum rotational frequency of the shaft assembly is F, a relationship of F<(1/4π)*(K/M) − 0.5 is satisfied.

2 . The sealed compressor according to claim 1 ,

wherein the support member is an annular wave washer; and Pe

wherein the wave washer is configured to include a plurality of convex portions protruding in a thickness direction toward the second race and a plurality of convex portions protruding in the thickness direction toward the thrust surface of the main bearing such that the convex portion protruding toward the second race and the convex portion protruding toward the thrust surface are arranged alternately.

3 . The sealed compressor according to claim 2 ,

wherein the wave washer is formed of a spring steel; and

wherein when a diameter of the main shaft is d and a thickness of the wave washer is t, 0.1 d<t<0.3 d is satisfied.

4 . The sealed compressor according to claim 1 ,

wherein the electric component is activated by one of a plurality of operation frequencies using an inverter power supply which adjusts a frequency of electric power supplied to the electric component.

5 . A refrigerator comprising the sealed compressor as recited in claim 1 .