| 摘要 |
<p>A speed change gear mechanism for lathes includes a driving shaft (10) having a number of first gears (A,B) securely mounted thereon to rotate therewith, a driven shaft including a number of second gears (C,D,E,F) each rotatably mounted thereon via a bearing (21), and a chuck shaft (30) including a number of third gears (G,H) securely mounted thereon to rotate herewith. The number of the second gears (C,D,E.F) is a sum of the number of the first gears (A,B) and the number of the third gears (G,H). Each second gear (C,D,E,F) is meshed with a corresponding one of the first gears (A,B) and the third gears (G,H). A camshaft (40) includes a cam (41) formed thereon, the cam having a number of angular positions that correspond to different speeds of the chuck shaft (30). A clutch device (L) has a first end selectively engaged with two of the second gears (C,D) that respectively meshed with an associated first gear (A,B) and an associated third gear (G,H) to thereby determine a rotational speed of the chuck shaft (30). <IMAGE></p> |
