This paper presents a study regarding the gear hob’s rake face grinding possibilities and its consequences. A simple theoretical lined surface is considered. The mathematical model of the reciprocate meshing of surfaces was applied. It was proven that the proposed form of the rake face cannot be obtained because an undercut of inacceptable extent occurs. It is also proven and sustained by CAD modeling that using a simplified, flat grinding disk, the undercut is avoided, but the phenomenon of transection appears.
The most simple and robust construction of the monolithic gear hobs present a common helical rake face for a given line of teeth, whose generatrix is a straight-line segment perpendicular to the hob’s axis while its directory is a helix, perpendicular to the pitch helix. As a consequence, constructive rake angles are zero on all edges. Total curvatures of such a surface are negative. Thus, it can be grinded only using the conical surface of a platter type grinding wheel, or a grinding bit. Despite this, some industry practices, possibly for reasons of simplicity and cost lowering, involve the plain grinding surface, supposed to a helical motion. This paper deals with the CAD-simulation of the grinding process using the plain wheel surface, and it shows the differences between the theoretical and rake face and the real obtained helical surface.
The electrospinning procedure is a relatively simple and fast way of producing polymer fibers with diameters in the micrometer range. The one needle setup is commonly used due to its flexible design and effectiveness; however, this procedure has one major shortcoming; it has low productivity. The disk electrospinning design presented here combines the advantages of the corona and needleless electrospinning setups, namely the small solution surface area and high productivity. We used 33 wt% polyvinylpyrrolidone (PVP) solution to produce PVP fibers with the new design. The average fiber diameter of the produced PVP fibers was d = 446±116 nm, which is ~25 % larger compared to fibers produced with the one needle method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.