A Study On Quasi TI Worm

Quasi TI worm drive, namely involute enveloping hourglass worm drive, is a novel hourglass worm drive, which is formed by new hourglass worm and its enveloping worm gear, and the new hourglass worm is grinded by the wheel with a section profile of involute. Since the shape of this worm pair is close to that of TI worm drive, and the grinding method of this worm pair is easier than that of TI worm drive, this new worm drive is called quasi TI worm drive for short, namely Q-TI worm drive. This worm has the characteristic of hourglass worm drive, that is, perfect condition of lubrication and loading and easy grinding. Study on this drive will have great theatrical significance and application value on development of worm reducer with simple grinding, high efficiency and heavy load. The content is as follows:Base on the theories of differential geometry and gear meshing, meshing system of the single-enveloping TI worm drive and the double-enveloping one under an ideal state is established by kinematics method. Meshing function, meshing equation, tooth surface equations and so on are also deduced.Single-enveloping quasi TI worm drive is simulated and further analysis on its meshing performance is carried out. Numerical analysis on this worm drive is performed based on theatrical system. At the same time, boundary condition on the worm surface is derived in imitation of TI worm drive, and influence of design parameters on Q-TI worm drive is emphasized. The optimized method of selecting design parameters under perfect meshing condition is obtained.Numerical analysis on distribution feature of contact lines of double-enveloping Q-TI worm gearing is studied. Meshing performance is also obtained. Influence of design parameters on the transmission performance of double-enveloping Q-TI worm is developed. Simultaneously, difference between the influence of design parameters on tooth surface of single-enveloping Q-TI worm drive and that of double-enveloping are obtained by further comparison.3D modeling study of Q-TI worm drive is developed. Base on those, difference between tooth shape of worm wheel of this worm drive and that of helical gear with the same parameters is compared, and then modification method of this worm wheel is presented.