确定凸轮机构基本尺寸的新方法

New Method for Determining the Dimentional Parameters of a Cam Mechanism

文章讨论了设计直动从动件盘形凸轮机构时如何确定机构基本尺寸——圆半径和偏距的方法。通过分析,得出了推程压力角的两个约束极大值一个在推程的起点,另一个在推程加速段内或加速段终了处出现的结论。并在此基础上,进一步提出了按许用压力角确定最小基圆半径和偏距以及按给定的基圆半径确定能使最大压力角达到最小的最佳偏距的方法。文中还指出,当从动件推程运动规律为等速运动时,若将偏距取为升程与推程运动角的比值,则无论基圆半径为多大,均可使推程压力角恒为0°,机构的传力性能达到最佳状态。

It is important to determine the basic dimension of an object—the radius of the base circle and the offset when designing a disk cam mechanism with reciprocating follower. This paper first drew a conclusion that one of the two bound maximums of pressure angle in actual travel appears at the start and the other in the middle or at the end of the accelerating travel. Based on the conclusion, some methods to are put forward settle the smallest radius of the base circle and the offset according to the allowable pressure angle and the to determine best offset making the largest pressure angie reaching the smallest according to the given radius of the base circle. It is also pointed out if the motion of the actuating travel of the follower adheres to the law of constant velocity motion and when the offset is the radio of the lift to the cam angle during actuating travel, the pressure angle of actuating always constantly is equal to 0° and the transmission of a object is at its best no matter how large the radius of the base circle is.