For a new non-backlash double-roller enveloping hourglass worm

the tooth profile and contact curve equation

which involves several errors of worm parameters

was established to investigate the effects of the errors on the worm tooth profile. Technology of three-dimensional modeling was chosen to analyze the influence law of the errors. The influences of the setover error of roller

the error of axial float of worm

the centre distance error

the error of axial movement

the angular pitch error and the error of shaft angle on the tooth profile were discussed

the contact curve was analyzed

and the kinematic simulation was carried out. The results show that the axial movement error

the angular pitch error and the error of shaft angle reaching 0.5° exert clear influence on the tooth profile of worm; especially

when the error of shaft angle gets 0.5° the tooth profile of worm is heavily deformed and the axis cross-section becomes ellipse; however

the other errors have lighter influence on the tooth profile of worm as the values are limited within 1.0 mm.