A cam mechanism for converting a swiveling movement of a drive-side shaft into a linear output movement. A cam disk is attached to the drive-side shaft, a slider is shiftable in a linear guide, and a cam follower is applied against the circumferential surface of the cam disk. Swiveling movement of the cam disk leads to a linear output movement of the slider in the linear guide. The circumference of the cam disk is spiral-shaped at least in sections, and the radius of the cam disk increases monotonically in the spiral-shaped section from a start radius to an end radius along a swiveling direction. By selecting two reversal points within the spiral-shaped section, the setting of a variable stroke can occur. A piston pump is provided with the cam mechanism and a method is provided for using the cam mechanism and the piston pump.