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The paper presents a construction design and results of laboratory tests of so-called mechanical stress detectors, which can be used to detect the deformation of the steel structure of a crane and to amplify the mechanical signal from the effect of the so-called crane skewing, which is included among occasional loads acting on the crane. The values of the relative elongation of the detectors corresponding to the magnitude of the instantaneous tensile force were obtained by conducting experimental mechanical tests. Detectors of a known extent of deformation were installed on a two-girder overhead crane bridge, where they measured axial forces generated during the controlled deformation of the crane bridge. In practice, the instantaneous values of the axial forces recorded by the individual detectors make it possible to regulate the speed of the crane drive wheels and thus eliminate, in a relatively short time, the undesirable effects of deforming the crane bridge and friction of the crane wheels on the sides of the rail heads.

In this paper, root stress, manufacturing possibilities and limitations of standard and nonstandard tooth root fillet of spur gears are examined. Nowadays, standard trochoidal root fillet is used the most as an economical trade-off between tooth strength and manufacturing complexity. A disadvantage of the trochoidal root fillet, especially in spur gears with less than 17 teeth, is undercutting which minimises strength of tooth root, introduces stress concentration, and deteriorates meshing conditions. This study focuses on different root designs, namely elliptical and novel cycloidal root fillets. Root stress in gears with different root designs is analysed by FEM and compared with analytical equations according to ISO. The possibility of producing nonstandard root fillet gears by hobbing and limitations of surface finishing are considered as well. Analysis reveals stress differences between each of the root fillet shapes and their relative advantages and disadvantages.

Shrnutí Članek se zabyva navrhem dimenzovani ozubeni pro různe typy automobilnich diferencialů a děličů momentů. V navrženem postupu jsou použity nejnovějši vypočtove postupy podle norem ISO a DIN. Do vypočtu jsou aplikovana hypoteticka spektra provozniho zatiženi, ktera jsou odvozena od vlastnich měřeni.

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