Washing machine

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 washing plate up and down movably fitted inside of the washing 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, and transmitting a rotation power of the driving motor to the washing plate with the rotation power converted into up and down direction power, 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,
• cylindrical cams each having a guide groove in an outside surface thereof for up and down movement of a follower body, coupled to top of the planetary gear for making rotation and revolution together with the planetary gear,
• a hollow cylindrical upper washing shaft fitted to top of the cams, 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,
• an elevating shaft up and down movably fitted inside of the upper washing shaft and provided with the washing plate to top thereof for making up and down movement together with the washing plate when the cams rotate, and
• rolling members provided to a lower part of the elevating shaft by moving along the guide grooves in the cams when the cams rotate for moving the elevating shaft in up and down directions.

A washing machine comprising:

• an outer tub for storage of washing water;
• a washing tub mounted in the outer tub;
• a washing plate up and down movably fitted inside of the washing 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 washing plate with the rotation power converted into up and down direction power, 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,
• cylindrical cams each having a guide groove in an outside surface thereof for up and down movement of a follower body coupled to top of the planetary gear for making rotation and revolution together with the planetary gear,
• a hollow cylindrical upper washing shaft fitted to top of the cams to pass through an upper surface of the housing,
• an elevating shaft up and down movably fitted inside of the upper washing shaft and provided with the washing plate to top thereof for making up and down movement together with the washing plate when the cams rotate, and
• rolling members provided to a lower part of the elevating shaft by moving along the guide grooves in the cams when the cams rotate for moving the elevating shaft in up and down directions.