In this paper,calculation method for profile error of modified ZI worm hob #is studied Factors that design parameters and relieving technical parameters affect profile error are analyzed theoretically, a new relieving technique called "changing hight of wheel center"is proposed,This creates a new way for the increase of qualified length of hob gear profile.

In this paper, the test plan of profile errors for modified ZI worm hob re-ground section is studied.

Mathematical descriptions of worm and worm gear and the means of accurate accomplish based on Pro/E are introduced, parametric design is accomplished by the second development, mechanical simulation is carried out,the working case is dynamic observated.

This paper takes the worm and worm gear as an object,discusses a define of character and parameter and the research of worm and worm gear,which could be used in similar hardware,introduces the theory and method of the redevelopment approachor UG with Visual C++.

Research of Designing Exact Non-involute Spur Gear Hob Worm;

Modeling Studying of TI Worm in the Environment of ANSYS;

Parametrization design of worm based on Pro/E;