《KISSsoft 和有限元分析的比较》.pdfVIP

Calculation of the Path of Contact under Load Whenever a machine is designed, there are parts which need to be engineered precisely for strength, accuracy, and reliability. This means that stresses in this part must be calculated. There are two different approaches to solve this problem, the very general finite element method (FEM), and the d a specific classical methods available for most of the common machine parts. The classical methods are o tailored to one specific type of part only, e.g. bolts, gears or bearings. The advantage of these methods L is their fast and easy application. r e In many cases no classical method is available, for instance for housings. In these cases the application d of FEM is the only possibility. In other cases the application of FEM would be much to expensive, like n for a key and key way on a shaft. This paper will examine a problem for which it is not apparent which u t of the two methods is superior: The calculation of the stress in the root area and in the flank of a c cylindrical gear. a t To calculate the stress in the tooth of gear during meshing, the contact path under load is calculated. n o This means a contact problem must be solved: The number of tooth pairs in contact varies by one C during the meshing, most often it changes from one pair to two pairs in contact. This effect causes the f total stiffness in the engagement to change periodically (see figure 1). The teeth themselves are o deflected due to the torque applied. This shifts the point of change from one to two pairs in contact a h t small amount and leads to a premature contact. a P Formulae for all values must be derived for a classical method. For the calculation of the stiffness, a model according to Peterson is used. This model covers the deflection of the teeth, the bending of the e h