In the process of helicall gear design, CAD / CAM / CAE integrated software UG is adopted. Combining the three-dimensional parametric modeling function of UG, expression processing and free-form surface scanning, a general three-dimensional design method of helical gear is proposed, which is called scanning forming method. The idea of this method is to first complete the profile of the end face helical gear, then obtain the normal profile through the projection relationship, scan the normal profile along the helix to obtain the helical gear profile, use the face entity for cutting operation to generate a single tooth, and finally obtain the complete tooth through Boolean operation. Practice shows that this method has high precision, simplicity, directness and high design efficiency.
In the process of helical gear modeling, the main problems to be solved include the accurate drawing of helical gear profile of end face gear, the relationship between end face and normal helical gear profile, the generation of spiral line, the generation of single tooth and the generation of the whole helical gear.
Taking involute helical gear as an example, the design of helical cylindrical gear is a general method. The use of tools combined with analytical method reduces the programming workload and ensures the calculation accuracy. The matrix transformation improves the accuracy of symmetrical contour design. The operation of single tooth array reduces the amount of calculation and generates a relatively small part file. The established equation can generate a new curve only by changing some parameters, which has a high reuse rate and further improves the design efficiency. That is the case with involute equation.