Projektieren der zykloidenverzahnungen hydraulischer verdrängermaschinen

Abstract

Cycloidal gears are of great importance in the design of positive displacements machines. They are frequently called gerotor gears, without the design technique, gearing type or gear profile being differentiated. There are, however, different types of these gears with different gear profiles. Thus general design techniques for these types of gears may be determined. There are two methods of cycloidal gear design: the external envelope technique and the internal enveloped technique, with the first one usually being applied. With this technique, the external gearing of the base gear first and then according to it, the internal gearing of the mating gear are determined. The most beneficial solution is the one shown in Fig. 5, where the external gearing of the base gear is designed on the basis of being equidistant to the curtailed epicycloid and the internal mating gearing has the form of circles (rollers). This type of gear is employed, by Danfoss among others in orbit motors (low-speed orbitrary motors) and control modules for the steering systems of traction vehicles. The internal envelope technique is, as a matter of fact, the inversion of the external envelope technique. First, the internal basic gearing and then, the external mating are formed. This technique is used rarely and is regarded as the complementary one except for a special case of the hypocycloidal gears in which the internal base gear is formed in accordance with the curtailed hypocycloid and the external mating gearing has the form of circles (rollers). This special case is shown in Fig. 9. This type of gearing is applied by Rexroth in its MZ type low-speed motors.