ROCKING GEAR DEVICE

PROBLEM TO BE SOLVED: To provide a rocking gear device that makes compatible both the durability and the engaging accuracy of engaging teeth, and is high in the freedom of machining accuracy and positioning accuracy. SOLUTION: In a so-called the rocking gear device formed of four bevel gears, a first gear and a fourth gear among first to fourth gears are formed in projecting teeth of equal heights with recessed grooves of semi-circles in cross sections arranged at equal intervals on a pitch cone and radially extending from the center of the gear and columnar rollers rollingly disposed in the recessed grooves. A second gear and a third gear meshing with the first gear and the fourth gear, respectively, are formed in recessed teeth formed in prescribed arc shapes to mesh with the projecting teeth. The recessed grooves constituting the protruding teeth include an enlarged part with its opening enlarged toward a tooth trace direction with a reference pitch circle diameter as a base point. COPYRIGHT: (C)2009,JPO&INPIT