The movement principle of the York connecting rod is a mechanism that connects components to each other by means of hinges and slides to realize movement transformation and power transmission. The York connecting rod can be used to achieve the requirements of a variety of motion trajectories; it can realize the transformation between a variety of motion forms. York connecting rod mechanism is widely used in various machinery, instruments and various electromechanical products.

When designing the movement of the York connecting rod, it takes into account the requirements of some aspects of movement characteristics and force transmission characteristics, such as the requirements of the entire rotation pair, the requirements of the pressure angle or the transmission angle, and the requirements of the mechanism occupying space. In addition, the design result should also meet the requirements of continuity of motion, that is, when the active part moves continuously, the follower can continuously occupy the predetermined positions without dislocation or order.

The motion design of York connecting rod can generally be summarized into the following three types of basic problems:

1) To achieve a given position of a component, that is, a York connecting rod is required to guide a certain component to pass through a number of given positions accurately or approximately in a prescribed order.

2) Realize the known motion law, that is, the master and follower are required to meet several known sets of corresponding position relationships, including meeting certain requirements for quick-return characteristics, or when the motion law of the master is certain, the follower can be accurate or approximate The ground moves according to a given law.

3) Achieve a known motion trajectory, that is, a certain point on the component that is required to move in a plane in the York connecting rod to accurately or approximately move along a given trajectory.

York connecting rod motion design methods are mainly geometric methods and analytical methods, in addition to atlas methods and model experiments. The geometric method uses the geometric relationship between the positions of the motion pairs during the movement of the mechanism, and obtains the related motion dimensions through drawing. Therefore, the geometric method is intuitive and the geometric relationship is clear. It is effective and quick to deal with some simple design problems. Due to the existence of drawing errors, the design accuracy is low.