| 摘要 |
<p>A power-transmission mechanism of the present invention comprises a large ring gear (15) (circular gear) having teeth on the inner circumference, an annular gear (17) having teeth on both the inner and outer circumferences, and a small gear (12) having the same axis as the large ring gear (15). The difference between the number of teeth of the ring gear (15) and the numer of teeth on the outer circumference of the annular gear (17) is set very small, for example just one, for the meshing engagement of the gears. Likewise, the difference between the number of teeth of the small gear (12) and the number of teeth on the inner circumference of the annular gear (17) is also set very small, and the annular gear (17) and the small gear (12) are in meshing engagement with each other opposite to the meshing position of the above ring gear (15) and the annular gear (17). The annular gear (17) functions as the input gear and revolves eccentrically rather than concentrically. The ring gear (15) that rotates while meshing with the annular gear (17) functions as the first driven gear, and the small gear (12) functions as the second driven gear. The power-transmission mechanism comprising a minimum combination of gears that reduce a high speed revolution directly taken out of a power source such as an engine (2). A mowing machine of the present invention using the power-transmission mechanism mentioned above employs two blade wheels (5, 6) that rotate in opposite directions to mow grass by shearing. Therefore grass and shrubs can be surely and cleanly mowed. Moreover, one drive shaft (9) drives a combination of only three gears (12, 15, 17) which are reduced by large reduction ratios and rotate in opposite directions to one another. Therefore the revolution of a high-speed running engine (2) can be directly used without a speed reducing device, and as a result, it is possible to make a compact and light mowing machine. <IMAGE></p> |
