A study on the development of a kinematic scheme of a planetary mechanism with an opening kinematic circuit for driving the working body of mixing machines is presented. The main purpose of the study is to create two kinematic cycles in the planetary mechanism, in which, during one revolution, the satellite drivers consistently perform movements of the epicyclic trajectory of hypocyclic motion. To achieve this goal, braking devices for damping the kinematic energy of satellites and synchronizer devices were used in the transition zones between two segments of different names, for smooth entry of the satellite gear into the gear engagement of these gears. The oscillatory process of the synchronizer at the entrance of the tooth of the satellite gear with the front teeth of the synchronizer is considered. Practical significance includes ensuring the possibility of assembling a planetary mechanism, taking into account the choice of the angle of rotation of the synchronizer around the axis of the support. The discussion makes recommendations for further improvement of the developed biplanetary mechanism for driving mixing machines.