H4-SH-13-D flender kupplung n eupex Helical gear Reduction Boxes H4

Flender/Flender Gear Units/Helical gear Reduction Boxes H4

eviations may thenoccur on the work piece. Modern gear making machines include device tocompensate for manufacturing deviations of this kind (see Sect. 6.5.5.2 ). Apart from radial run-out and pitch deviations, bevel gears also exhibit topog- raphy deviations. These are caused by incorrect settings of the gear cutting machineor geometry deviations of the machine axes. Such errors can, however, be com-pensated using corrective programs (see Sect. 7.1.5 ). In addition to systematic topography deviations, there may also be stochastic deviations. These include, for example, deviations caused by wear-induced changesin the form of the tool. Topographic deviations appear mainly in the form of angularand crowning deviations of the tooth ank and in bias. Micro geometry deviations in the ank form also occur, for instance in the form of excessive surface structures and roughness. Among other causes, surface structures or waviness of the toothanks may be caused by excessive generating feed during gear tooth cutting, alsoreferred to as cutter ats. Machine vibrations may produce chatter marks, which arelikewise categorized as surface structures. Gear grinding may generate grooves inthe tooth ank surface because of the presence of grinding wheel structures orwrong selections in the dressing parameters; this is no longer classied as rough-ness but as waviness. The last category in gear tooth deviations is damage, usually caused around the edges by incorrect transportation of the gear sets after soft machining. Radial Run-Out and Pitch Deviations Radial run-out and cumulative pitch errors cause long term transmission errors, and may therefore be considered together. The cumulative pitch error of gear usually appears in sinusoidal form. pitch deviation leads to shift in the relative position of following tooth ank topogra-phies. If the tooth is otherwise free of deviations, transmission error curve of thekind shown in the top-left half of Fig. 5.2 results. It is evident that in