| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of fallout of a key and looseness at the time of transmission of rotation without increasing work costs by forming engaging grooves deeply closer to fitting-in holes, forming those bottom surface slantly, and arranging the key so as to fit to the engaging groove in both power transmitting wheels. SOLUTION: Engaging grooves 13, 14 are formed deeply closer to fitting-in holes 7c, 9c, bottom surfaces 13a, 14a extending to radial direction in the engaging grooves 13, 14 are inclined for an angle θ from an axis in an installing shaft part 4. A key 15 is installed on a part extended over both sides of a sprocket 7 and a boss part 9 in a pulley 8, and is engaged with A key groove 16 slit on the shaft part 4. The key 15 is engaged with the engaging groove 13 in the sprocket 7 and the engaging groove 14 in the boss part 9 of the pulley 8. It is thus possible to surely obstruct the key 15 from falling out from the key groove 16 by inclined bottom surfaces 13a, 14a. |
