| 摘要 |
<p>A crank mechanism has a crank arm (4) disposed transversely on a drive crankshaft (2) and a crankpin (5) which projects from the crank arm and is arranged to be connected to a member to be driven. A device for automatically varying the stroke of the crank mechanism includes a slide guide (7,8) in which the crankpin (5) is guided. A screw spindle (11) is disposed parallel to and to be rotatable with the crank arm (4) and is arranged to adjust the crankpin in the slide guide radially relative to the crankshaft (2). The end of the screw spindle (11) facing the crankshaft is rotationally fixed to a first bevel gear (12) which meshes with a second bevel gear (24) mounted for free rotation on the crankshaft. The second bevel gear (24) is driven by the crankshaft (2) through a transmission train (13,14, 22,23) at a speed different from that of the crankshaft (2). <IMAGE></p> |
