Universal coupling is a kind of transmission device widely used in mechanical transmission system. In recent years, the development and application of universal coupling, especially constant angular speed universal coupling, has brought great economic benefits to the development of machinery industry. With the view of modern design methodology, the parameter design system established by JAVA is used to synthesize various schemes, and a new structure is formed by evaluating the optimal schemes. 1 Parameter design system The parameter design system contains valuable models, graphics and parameter design dimensions of equiangular velocity universal coupling design selected from a large number of existing data, organized by category and can be continuously added and improved. The basic requirement of equiangular velocity universal coupling design is to find a coupling device for two intersecting axes at a certain Angle in space, which can transmit torque, the angular velocity transmission between the input axis and the output axis is uniform, and the Angle between the two axes can also change within a certain range. It mainly includes a moving chain, a transmission element and its supporting structure. The design catalog takes physical effects and geometric elements as the basic units respectively. Due to its simple and intuitive search and synthesis methods, precedents can be fully applied and elements of precedents can be innovated. The parameter design of constant angular velocity universal coupling includes the determination of function and effective geometric elements, and then the scheme is selected according to the selection principle and evaluation method.

1 Function to determine the step design constant angular speed universal coupling, according to the isometric function, many combinations can achieve the physical effect of the function. For example: solid cohesion, lever effect and wedge effect, and hydraulic static propagation, etc., while various physical effects can be designed according to JAVA parameters to determine a variety of effective geometric elements.

2 Determining effective geometric elements Determine effective geometric elements to move efficiently. The distribution of the freedom of effective motion and the transformation of the freedom of the universal coupling composed of different components and the change of the effective curve. There are many schemes for the distribution of degrees of freedom and the combination of kinematic chains. When selecting the scheme, according to the conclusion reached, the instantaneous rotating sliding shaft is located in the bisection Angle plane composed of the input and output axes or parallel to the bisection Angle plane composed of the two axes, then the coupling can transmit the isometric velocity motion. In this way, the basic conditions of constant angular speed transmission universal coupling can be met. The effective motion is expressed as a vector, and the above basic conditions are taken into account in the process of vector synthesis. According to the view of modern mechanical design methodology, the research work of designing constant angular velocity universal coupling by means of JVA design catalog and parameter library has been carried out for a long time. All kinds of constant angular velocity universal coupling designed, especially non-centering constant angular velocity universal coupling, have been applied in steel rolling industry and other fields, which fully embodies the simple manufacturing cost and excellent performance (for example, the bearing capacity varies little with the deflection Angle) and other significant advantages.