GEAR TYPE VARIABLE SPEED DEVICE

PROBLEM TO BE SOLVED: To reduce manhours and to constantly maintain sealing performance by making working fluid work in an engaging space between an external tooth gear and an internal tooth gear and providing a working fluid suction part on an axial direction one side end part of both of the gears and a discharge part on the other side end part. SOLUTION: An external tooth gear 4 of an axially supporting part 17 made of a cam decentered only by (e) from a shaft center by rotation of a driving rotation axis 2 is engaged with an internal tooth gear 3 by autorotating and revolving. Working fluid in an oil tank sucked from a suction pipe 18 enters an engaging space 40 of the gears 3, 4 from a comma-shaped suction hole of a rotating disc 5. Thereafter, working fluid flows in the axial direction and returns to an oil tank through a pressure chamber 20 and a discharge pipe 19 from a comma-shaped discharge hole of a rotating disc 6. When opening of a discharge pressure control valve is reduced, discharge pressure rises, torque of the gear 4 is transmitted to the gear 3, and a rotation axis 1 on the output side is converted in speed. The disc 5 and the gear 4 and the gear 3 and the disc 6 are free to slightly move in the axial direction, slide on each other without making an excessive clearance by working fluid pressure and it is possible to maintain sealing performance. Additionally, assembly and adjustment are facilitated.