Abstract: An eccentrically cycloidal gear engagement of tooth profiles having curvilinear teeth is disclosed. One of the engaging profiles represents a gearwheel with at least two helical teeth. The flanks of each tooth of the first tooth profile are outlined, in a principal cross-section of the gearwheel, by corresponding arcs of circular curves, eccentrically shifted from a center of rotation of the gearwheel. The second tooth profile, which is conjugated with the first tooth profile, has helical cycloidal teeth. The teeth of the second tooth profile are outlined, in the same cross-section, by segments of front edges of intersecting cycloidal curves. Tips and troughs between teeth can have any shape, not intersecting with the gearwheel teeth.

Abstract: The invention relates to mechanical transmissions for transforming the rotational motion to the rotational or reciprocal one, applying the toothed engagement of gears and it can find its application in cylindrical, bevel or planetary gearboxes and rack gears. One of the engaging profiles represents the gearwheel with at least two helical teeth. Operating segments of each tooth flank of this gearwheel are outlined in principal cross-sections by arcs of the circumference, eccentrically shifted with respect to the center of the gearwheel rotation. Conjugating helical teeth of the second profile are outlined in the same cross-section by segments of cycloidal curves. Tips and troughs between teeth can have any shape, not intersecting with the gearwheel teeth.