| 摘要 |
A system of gearing that allows gears to be designed that are smaller than standard involute gears of corresponding torque capacity. This reduction in size is made possible by increasing the angle through which the teeth are engaged. The wider angle of engagement is achieved by adding to the path of contact two segments: (1) the path portion closest to the pinion is extended by adding on a slightly curved segment lying outside the circle that is the locus of interference points for involute gearing; and (2), the path portion closest to the gear is extended by adding a segment that is produced by the use of an exceptionally long pinion addendum. The reduced size of the gears made possible by the wider engagement angle obtained from addition of these two path segments not only reduces mass and pitch line velocity, but the wider engagement angle itself also affords an increased profile contact ratio that reduces transmission error. The wider angle of engagement thus reduces noise excitation in two ways. In addition, a third way may be added if proportions are used that reduce or eliminate mesh stiffness variation. |
