Reciprocating mechanism, bicycle, and method of achieving reciprocating motion

A bicycle, comprising:

• a frame comprising a frame tube;
• a reciprocating mechanism mounted on the frame and comprising:
• a first connecting element;
• a crankshaft comprising:
• a rotation shaft;
• a first following element pivotally disposed on one side of the rotation shaft and movably coupled to the first connecting element;
• and
• a second following element pivotally disposed on the other side of the rotation shaft, wherein one end of the second following element is pivotally connected to the rotation shaft, and a first angle is formed between the first following element and the second following element;
• and
• a second connecting element movably coupled to the other end of the second following element, wherein a second angle is formed between the second connecting element and the second following element;
• a seat cushion, wherein a rear end of the seat cushion is pivotally connected to the first connecting element, and a front end of the seat cushion is pivotally connected to one end of the frame tube;
• a gear sleeved on the rotation shaft;
• a bracket, wherein the second connecting element is pivotally connected to one side of the bracket;
• a first tire mounted on the frame;
• and
• a belt body wound around the gear and movably coupled to the first tire;
• wherein the first following element and the second following element are configured to rotate around the rotation shaft so as to be movably coupled to and cause each of the first connecting element and the second connecting element to reciprocate and cyclically pivot along an arc-shaped trajectory, so as to drive the bracket and the seat cushion to reciprocate and cyclically pivot, thereby the belt body is movably coupled to and causes the first tire to simultaneously rotate via the gear being driven to rotate by the rotation shaft.

A method of achieving a reciprocating motion, comprising:

• providing a crankshaft, wherein the crankshaft comprises a rotation shaft, a first following element and a second following element, one end of the second following element is pivotally connected to the rotation shaft, and the first following element and the second following element are able to relatively rotate around the rotation shaft;
• providing a first connecting element, causing the first connecting element to be movably coupled to the first following element;
• providing a second connecting element, causing the second connecting element to be movably coupled to the other end of the second following element;
• causing the first following element and the second following element to rotate around the rotation shaft so as to be movably coupled to and cause each of the first connecting element and the second connecting element to reciprocate and cyclically pivot along an arc-shaped trajectory.