Abstract:
A slewing drive actuator is a power / torque transmission mechanism that gives controlled power / torque output for rotation in desired axis while safely carrying radial & axial loading. These are mainly used for regulating & controlling precise motion in control applications. Applications may include heavy hydraulic machinery, drilling equipment, retraction / extension mechanism, helicopter transmission etc. Slewing actuators function with worm drive technology. The rotation of the worm turns the gear about an axis normal to the axis of the worm decreasing the speed of the gear and increasing its torque. For increased loading requirements including working arrangements with shock loads, smoother operation & higher efficiency, globoid (double-enveloping) worm drive may be used. Globoid worm gear sets have both members throated; the worm is also curved longitudinally to fit the curvature of wheel. The current research study deals with a single axis slew drive lift actuator, whose desired operational data is known & the emphasis is to design the globoid worm gear drive which will satisfactorily perform the desired function. The load rating (load carrying capacity & efficiency) of globoid worm gear pair is calculated by applying mathematical and analytical approach. The calculation of gear tooth geometry & gearing parameters necessary for manufacturing & analysis are determined by following the AGMA gear standards. Parametric modeling of globoid worm gear drive is done in Pro-E Wildfire 4.0 using gear parameters & relations and the motion actuator assembly is modeled in Solid Edge ST3. Computer-Aided Finite Element Model is developed in Ansys Workbench 13.0 and models of bending stress and non-linear contact stress with static deformation mode are analyzed.
