Fishing-reel power transmission device

A spinning reel, comprising:

• a handle;
• a reel unit that rotatably supports said handle;
• a rotor rotatably supported at a front of said reel unit;
• a spool arranged at a front of said rotor, said rotor winding a fishing line on an outer periphery of said spool;
• an oscillating mechanism that has a threaded shaft and reciprocates said spool back and forth in response to a rotation of said handle with a spool shaft that is coupled to said threaded shaft;
• a power transmission mechanism which transmits the rotation of said handle to said oscillating mechanism, said power transmission mechanism including
• a pinion gear that rotates in cooperation with said handle;
• a dual-stepped gear having a first gear portion and a second gear portion, said first gear portion having a helical-tooth gear and meshing with said drive gear, said second gear portion being arranged coaxially with said first gear portion, said first gear portion and said second gear portion being formed as a one-piece unitary member, said second gear portion having one of a straight-tooth gear and a helical-tooth gear whose orientation is substantially the same as an orientation of said first gear portion;
• and
• a driven gear that meshes with said second gear portion of said dual-stepped gear to rotate one of said rotor and said oscillating mechanism.