Abstract <p>An important task in the theory of mechanisms and machines is to reduce the nonuniformity of rotation of the input link of cyclic machines. A traditional method for solving this problem is the installation of a flywheel; however, for equipment with large peak values of cyclic loads, the moment of inertia of the flywheel can become very high, which leads to an increase in the size and weight characteristics of the machine. This paper investigates, using the example of a piston compressor, the possibility of reducing speed fluctuations of the input link by means of a pair of noncircular gears installed between the engine shaft and the input shaft of the cyclic mechanism. These gears enable nonlinear torque transmission, increasing torque during the working stroke and decreasing it during the idle stroke of the machine. The dynamics of the piston compressor are analyzed, and the noncircular gears are synthesized based on the law of motion of the crank link. A comparative analysis is conducted on the reduction of speed fluctuations of the initial link achieved by installing either a flywheel or the designed noncircular gears.</p>