Carbon-free self-propelled trolley with reversing function

The invention discloses a carbon-free self-propelled trolley with a reversing function. A four-connecting-rod mechanism and a joint bearing part are used to accurately control swing of a guide wheel fork so as to realize turning of a guide wheel, small torque and abrasion and accurate swing are achieved. Four rail rods are used to limit swing of a counter weight, so that tilting of the trolley during turning and coming up and down a slope can be avoided effectively. The carbon-free self-propelled trolley is driven to move by converting gravitational potential energy into kinetic energy, no fuel or electric energy is needed, no greenhouse effect gases such as carbon dioxide are emitted, and the carbon-free self-propelled trolley is low-carbon, environmental friendly, and simple to use. An operator can reverse a trolley drive wheel to hang a heavy object, namely converting mechanical energy into gravitational potential energy. The carbon-free self-propelled trolley can be used as physics demonstration experiment equipment for primary schools and middle schools, and students are allowed to better understand experiment energy conversion and application through specific instances.