Self-locking dual worm gear and the tools needed to produce it

摘要

A self-locking dual worm gear with parallel axes and linear contact for the worms with involute herringbone gears is characterized by the fact that the cross sections for curvature radii pnm1 and pnm2 and the longitudinal sections for curvature radii pxm1 and pxm2 of the worm profile are always determined at the point of contact M for the teeth and with the following equations: pnm1=ptm1/cos beta B1; pnm2=ptm2/cos beta B2 pxm1=pnm1xsin beta B1=ptm1xg beta B1; pxm2=pnm2xsin beta B2=ptm2xtg beta B2 wherein ptm1 and ptm2 represent the curvature radii of an involute profile in the cross section at contact point M and beta B1 and beta B2 are the tooth edge inclinations for the worms with <IMAGE> wherein rm1 and rm2 represent the operational radii for the circles, which run through contact point M and rB1 and rB2 are the basic circle radii for the worms. One tool for manufacturing the worm profiles for the self-locking dual worm gear has turning tools with rounded cutting edges and curvature radii R1 and R2 which are determined with the following formulas: <IMAGE> <IMAGE>