Tricycle transmission device for going ahead and back

The utility model relates to a tricycle transmission device for going ahead and back. The tricycle transmission device for going ahead and back is characterized in that when forward running, an operating handle is positioned at a disengaging position; a ratchet wheel and ratchet pawls are positioned at constant engagement; an input chain wheel with the ratchet wheel drives an output chain wheel to rotate at the same direction by the ratchet pawls, a stopping disk, and a cross axle; when reverse running, the operating handle drives the ratchet pawls and the ratchet wheel to disengage from the engagement, which forces the stopping disk and the cross axle to stop rotating; the input chain wheel drives the output chain wheel to oppositely rotate by the mutual engagement of a big bevel gear and a small bevel gear. Thereby, reverse running transmission is realized. The utility model has the advantages of simple operation, flexible action, reliable work, less investment, and easy mass production.