Patent ID: RE39687

Claim:
A tray driving apparatus of a microwave oven, comprising: a driving source for rotating a tray disposed in a cooking chamber of said microwave oven; a driving shaft rotated by the driving source; a driven shaft connected to the tray and rotated together with the tray; and speed changing means for changing the rotational speed of the tray by changing the ratio of the rotational speed transmitted from the driving shaft to the driven shaft; said speed changing means including comprising : a driving gear unit having a plurality of driving gears, and mounted to on the driving shaft; and a driven gear unit having a plurality of driven gears corresponding to respective driving gears of the driving , ear gear unit, and mounted to on the driven shaft; wherein gears of any one of the driving rear gear unit and the driven gear unit are portion gears which are gears having gear teeth on respective portions of outer peripheries thereof, so that, upon a rotation of the driving shaft, each portion gear of any one of the driving gear unit and the driven gear unit are alternately meshed with a corresponding gear of the other one of the driving gear unit and the driven gear unit, to thereby change the rotational speed of the tray.