A review of some of the recent work on the mechanism of rolling contact fatigue (RCF) is presented. Topics covered include the appearance and classification of RCF and the processes of stra...

The Mechanism of Rolling Contact Fatigue: An Update

Gear finishing by abrasive processes

Joining with friction welding of high-speed steel and medium-carbon steel

Fatigue behaviour of friction welded medium carbon steel and austenitic stainless steel dissimilar joints

Friction welding is a solid state joining process used extensively currently owing to its advantages such as low heat input, high production efficiency, ease of manufacture, and environment friendliness. Materials difficult to be welded by fusion welding processes can be successfully welded by friction welding. An attempt was made to develop an empirical relationship to predict the tensile strength of friction welded AISI 1040 grade medium carbon steel and AISI 304 austenitic stainless steel, incorporating the process parameters such as friction pressure, forging pressure, friction time and forging time, which have great influence on strength of the joints. Response surface methodology was applied to optimize the friction welding process parameters to attain maximum tensile strength of the joint. The maximum tensile strength of 543 MPa could be obtained for the joints fabricated under the welding conditions of friction pressure of 90 MPa, forging pressure of 90 MPa, friction time of 6 s and forging time of 6 s.

Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel

In order to obtain adequate friction-welding conditions for high alloy steels, an austenitic stainless steel (SUS304), a martensitic stainless steel (SUS440C), a high-speed steel (SKH9) and a 0.45% carbon steel (S45C) were used as test materials. The adequate welding conditions under which friction welded joints with sufficient strength in both static and cyclic loading could be obtained were established and shown in terms of the friction coefficient μ^^(SUB) at the rubbing surfaces just before upsetting. The limit of the adequate welding conditions was μ^^(SUB)≤0.08 for material combinations of (SUS304-S45C), (SUS440C-S45C), (SKH9-S45C) and (SUS304-SUS304) in the case of round bars with diameters in the range of 13 to 20mm. Two kinds of welded joints with and without sufficient strength were examined using an X-ray micro-analyzer with a scanning electron microscope, and the distributions of the alloy elements at and near the weld interface were compared. It was clearly shown that the distributions closely related to the welding conditions, and that the adequate welding conditions shown in terms of the friction coefficient are very effective in practice.

Studies on Friction Welding of Carbon and Alloy Steels : 3rd Report : Adequate Welding Conditions for High Alloy Steels and Distributions of Alloy Elements near Weld Interface

The authors introduced a new method (element removal method) for calculating the profiles of the tools (hob, form grinding wheel, etc.) used for finishing gears with an arbitrary tooth profile. Because this method simulates exactly the metal removing process in the gear tooth profile generation, it is possible to calculate the generated tooth profile when interference occurs between the cutting edge and the finished tooth profile. Using this method, the authors calculated the exact wheel profile which can produce and involute tooth profile with a tip relief at a transverse section of the involute helical gears. The wheel profile was generated by a single point diamond dresser using a universal NC milling machine with an attachment made by the authors. The tooth flank and root of test gears were ground at the same time to prevent a step (notch), which is apt to be produced at the boundary of ground and unground surfaces. The accuracy of the form ground test gears was in the zero class of JIS and the surface roughness was in the range of 0.5 to 1.0 μm Rmax.

Design and Manufacture of Gear Cutting Tools and Gears with an Arbitrary Profile : Vibration, Control Engineering, Engineering for Industry

Remarkable effects of running-in upon surface durability of steel and bronze

With the aim of reducing the operating noise and vibration of the planetary gearsets used in automotive automatic transmissions, a meshing phase difference was applied to the planet gears that mesh with the sun and ring gears. Shaved and hardened helical gears with and without grinding were used as the component gears that were tested under varying rotational speeds and tooth loads. The experimental results clearly showed that planetary gearset noise and vibration were reduced when a meshing phase difference was applied.Copyright © 2003 by ASME

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Investigation of the Noise and Vibration of Planetary Gear Drives

Resistance to wear of CBN grinding wheels is much higher than that of conventional (Al2O3) wheels. However, CBN grinding wheels are seldom used in gear grinding, when production scale is small, due to the difficulty in truing. Moreover, wear of the grinding wheel greatly affects the accuracy of tooth trace, in most cases. Considering this problem, the authors proposed new processes in which the accuracy of the tooth trace and tooth profile was hardly affected by wear of the wheel. While grinding was performed using a conventional method, a concave tooth-trace error of about 2 μm occurred after grinding only 30 teeth. In one of the proposed methods, the concave tooth trace error never occurred even when 2000 teeth were ground by the same wheel. In the third method, the CBN layer is effectively used for gear grinding by giving an additional motion which is independent of the tooth profile generating motion.

Akira Ishibashi

Papers

Studies on Friction Welding of Carbon and Alloy Steels : 3rd Report : Adequate Welding Conditions for High Alloy Steels and Distributions of Alloy Elements near Weld Interface

Design and Manufacture of Gear Cutting Tools and Gears with an Arbitrary Profile : Vibration, Control Engineering, Engineering for Industry

Remarkable effects of running-in upon surface durability of steel and bronze

Investigation of the Noise and Vibration of Planetary Gear Drives

Minimization of effect of CBN wheel wear on ground gear errors