FIELD: mechanical engineering. SUBSTANCE: crank mechanism of a piston machine has shaft with a crank coupled with the piston through a flexible link made up as a screw spring which may be conical. The end of less diameter of the conical spring is secured to the piston whereas the end of greater diameter is secured to the crank. In addition the joint between the piston and spring may be made up as a ball with a central opening flanged into the piston. The opening receives the end of the spring. The second end of the spring is secured in the opening in the crank. EFFECT: improved design. 5 cl, 2 dwg
