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.
The article describes the creation of the normal cycloidal curve by rotation of the point about the normal of the circle on the spherical surface and binormal cycloidal curve created by rotation of ...the point about the binormal of the previous cycloidal curve. Cycloidal cyclical surfaces are created by moving circles along the curves lying in the normal plane of the curves. Described cycloidal cyclical surfaces are projected on the spherical surface. Varying parameters of the curves are generated different ornaments on the spherical surface.
Članak predstavlja porodicu cikloidnih kružnih ploha koje nastaju gibanjem kružnice duž posebne prostorne cikloide, pri čemu kružnica leži u normalnoj ravnini te krivulje, a središte joj je na ...krivulji. Prostorna cikloida može nastati istodobnom rotacijom točke oko tri različte osi 1^o, 2^o, 3^o, u prostoru. Oblik prostorne cikloide, isto kao i oblik cikloidne kružne plohe, ovisi o međusobnom položaju rotacijskih osi, kratnosti kutnih brzina i orijentacijama pojedinih rotacija. Izvedena je analitička reprezentacija tih ploha, njihova klasifikacija te neka od geometrijskih svojstava.
The global steel industry is rapidly transitioning towards energy decarbonization to address the climate crisis. Sintering is one of the main sources of greenhouse gas emissions from steel mills. ...Traditional sintering processes use straight inclined chutes to feed raw materials into the sinter machine. However, this design suffers from insufficient horizontal momentum, resulting in poor segregation of the layered materials. This study proposes an improved charging chute design profile that uses a cycloid curve and rolls to enhance segregation, thus reducing coal consumption and increasing productivity. To achieve this, we first modeled a charging chute using the cycloid curve. Secondly, building upon the cycloid concept, we created a roll-type chute by strategically placing rollers along the cycloid trajectory. Finally, the cycloid roll-type charging chute, integrating the cycloid trajectory with the roll-shaped charging chute, was simulated. Pilot tests comparing the cycloid roll-type and straight chute models demonstrated a significant increase in dispersion for the cycloid roll-type design, with a 65% improvement in the Strand-ward segregation (Sw) index compared to the straight chute. Furthermore, actual filed implementation in a sintering process achieved a 2.9% increase in operational productivity and a 6% reduction in fuel consumption. This study is significant not only for proposing an optimal chute design, but also for successfully implementing it in a full-scale steel mill, contributing to a reduction in fuel consumption and carbon reduction in steel mills.
Many studies have been conducted to reduce the cogging torque of electric power steering motors. However, in the mass production of such motors, it is essential to enhance performance robustness in ...relation to tolerances. For such motors, this work analyzes performance robustness in relation to tolerances by applying a cycloid curve to the surface magnet of the rotor. Applying a cycloid curve to the magnet surface of the rotor is one of several ways to reduce cogging torque. To evaluate the performance of the cycloid curve, we compare it with an eccentric curve. The two curves are compared for the same specifications and evaluated using the indicator, tolerance insensitivity rate, which is used to assess performance robustness in relation to tolerances. The cycloid curve was evaluated to be more robust in relation to tolerances, as compared with the eccentric curve. Finally, an experiment was conducted to validate the robustness of the cycloid curve.
A low cogging torque and torque ripple are the most important qualities for electric power steering (EPS) motors. Therefore, various design methods are employed to obtain EPS motors with these ...qualities. In this study, a novel design method for the pole shape was developed by adopting a cycloid curve to realize the desired qualities of EPS motors without reducing the torque. An evaluation index (δq) was used to design the pole shape of the magnet and to compare the pole shape between the proposed method and the conventional method. The proposed and conventional methods were applied to existing machine designs, and their performances were compared using a finite-element analysis (FEA). The results of the FEA and prototype tests indicated an improved motor performance for the proposed method.
When we heat materials such as coffee beans or sesame over a fire, we usually stir them to get uniform heating. But it is not easy to do it in microwave applicator. If there is a stirring mechanism, ...unexpected sparks or discharges caused by microwave energy are generated around the mechanism. They are the loss of the energy and may damage both materials and applicator.This is a new microwave heating mixer without stirring mechanism, and it can heat materials uniformly and efficiently with no sparks or discharges.
PDF
