The cam mechanism of periodic rotation contains a body, a drive shaft with a main cam mounted on it, a main gear connected to the driven link shaft, rollers mounted on it that interact with the main cam, an elastic link and two additional gears interacting with the main gear, wherein the elastic link is connected to eccentrically mounted pins on the additional gears, and the working profile of the cam is made open along the minimum radius vectors. The mechanism additionally includes gears fixed in the housing, an additional sector fixed on the drive shaft and interacting with the rollers at the initial moment of rotation of the driven shaft, which are mounted on the main gear.