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Gear Machining
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
Skiving is a hard finishing process in which the gear is recut after heat treatment to remove distortions [1, 16, 136–138]. For cylindrical gears, the skiving process is sometimes called skive hobbing [136] or hard carbide rehobbing [139, 140]. Analogous hard recutting methods are used for bevel gears [84]. The gears are first machined in the soft state, heat treated, and then recut in the hardened state, generally using the same process employed for rough machining but with a modified tool with a stronger edge geometry. Skiving may be performed as a finishing process or for high accuracy cylindrical gears as a pre-finishing process prior to honing or a light final grinding operation [1]. Hard broaching, an analogous hard recutting process for broached gears, is discussed in Section 17.3.1.
Analysis of the influence of tool radius on mechanical state of monocrystalline silicon during nano-cutting
Published in Mechanics of Advanced Materials and Structures, 2022
Lai Lianfeng, Niu Qinchuan, Li Minglin
The above researches [13–20] mostly used two-dimensional or quasi-three-dimensional tool models when MD methods were used to study the mechanism of NC, but the 3D tool models that are closer to the reality are not considered. The previous research is helpful to understand the NC process. However, they mainly research the effect of cutting tool rake angle and skiving edge radius on the removal mechanism during material removal. However, there is no systematic research on the influence of NC tool radius and other tool geometric parameters on the deformation of workpiece material. In this work, we will consider the influence of the tool radius and conduct a series of large-scale MD simulations on the nanoscale cutting of single crystal silicon with diamond tools. In addition, this chapter establishes a SCS NC model with tool fillet, and investigates the SCS NC process from the perspectives of workpiece morphology change, cutting force, and energy evolution, so as to study the mechanism of tool fillet NC of SCS impact.
A Review of the EMI Effect on Natural Convection Heatsinks
Published in IETE Journal of Research, 2023
Abdullah Genc, Habib Dogan, Ibrahim Bahadır Basyigit, Selcuk Helhel
Heatsinks can be classified as active heatsinks that use air forced convection and passive heatsinks that use natural convection methods [4, 5]. Active heatsinks usually include the flow pulsation, vibration, electrostatic field, and variable roughness structure. In addition to energy usage, heatsinks are also classified according to their fins structures such as plate-fin, parabole-plate fin, square-pin fin, and circular-pin fin. Fin structures help heat dissipation between the base of heatsink and the ambient and can be different shapes such as cylindrical, parabolic, square, and rectangular. Square fins are more advantageous than other fin types in terms of total surface area. The total surface area increases as the number of fin increases. There is a limitation that air circulation will decrease as the gap between the fins decreases [6]. For this reason, there is a trade-off between the number of fins and the performance of heat dissipation. To overcome that, the optimization of heatsink parameters (fin types, number of fins, space between two fins and heatsink dimension) should be made for the best performance. Moreover, they can also be classified according to the manufacturing methods as machining, extrusion, skiving, etc. The machining is a final process that is obtained by cutting material of a certain size from raw material with a controlled process that is made via a CNC machine [7]. The extrusion is the most common method a process used to create objects with a constant cross-section profile by heating the metals and pushing them towards a certain mold. The skiving is also a method in which a blade slices a part of the single metal and then pushes the part upwards.