Patent ID: 7028512

Claim:
A washing machine comprising: an outer tub for storage of washing water; a washing tub mounted in the outer tub; an impeller rotatably fitted in a lower part of an inside of the washing tub for pumping the washing water in a space between the washing tub and the outer tub; a driving motor under the outer tub; and a power transmission connected to the driving motor for transmitting a rotation power of the driving motor to the impeller with a reduced speed, the power transmission comprising; a lower washing shaft for receiving the rotation power of the driving motor and being rotated by the rotation power, a cylindrical housing coupled under the washing tub having a bottom surface the lower washing shaft is fitted thereto to pass therethrough, and an inside circumference of a lower part gear teeth are formed therein, a sun gear coupled to a top end of the lower washing shaft, a plurality of planetary gears engaged both with the sun gear and the gear teeth in the inside circumference of the housing for making rotation and revolution when the lower washing shaft rotates, and a hollow cylindrical upper washing shaft fitted to top of the planetary gears, to pass through an upper surface of the housing, and provided with the impeller in an upper part thereof for rotating with the revolution of cams to rotate the impeller.