Abstract: A transmission mechanism including a first shaft and a second shaft extending rotatably through a first positioning plate and a second positioning plate. The second positioning plate is spaced apart from the first positioning plate. A first gear is mounted on the first shaft between the first positioning plate and the second positioning plate, and has a first helical tooth portion. A second gear is mounted on the second shaft between the first positioning plate and the second positioning plate, and has a second helical tooth portion having a same tooth profile and helix angle as the first helical tooth portion. A middle gear is located between the first gear and the second gear and has a transmitting helical tooth portion engaging the first helical tooth portion and the second helical tooth portion. The middle gear rotates about an axis perpendicular with the first shaft and the second shaft.

Abstract: A transmission mechanism includes a first shaft connected to a first mounting plate; a second shaft connected to a second mounting plate; a first positioning plate through which the first shaft and the second shaft extend rotatably; a second positioning plate, through which the first shaft and the second shaft extend rotatably, spaced from the first positioning plate by a distance; a first gear mounted on the first shaft, disposed between the first positioning plate and the second positioning plate and having a first helical tooth portion; a second gear mounted on the second shaft, disposed between the first positioning plate and the second positioning plate and having a second helical tooth portion having the same tooth profile and helix angle with the first helical tooth portion ; and a middle gear disposed between the first gear and the second gear and having a transmitting helical tooth portion engaging the first helical tooth portion and the second helical tooth portion, wherein the middle gear rotates a