Tooth Contact Analysis for a Double-Crowned Involute Helical Gear With Twist-Free Tooth Flanks Generated by Dual-Lead Hob Cutters

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Van-The Tran ◽  
Ruei-Hung Hsu ◽  
Chung-Biau Tsay

To double-crown an involute helical gear, a hobbing method is proposed by setting the hob's diagonal feed motion as a second-order function of hob's traverse movement and modifying the tooth profile of hob cutter into a dual-lead form with pressure angle changed in its longitudinal direction. Merits of the proposed double-crowning method are also verified by using three computer simulation examples to illustrate and compare the topographies of tooth flanks, contact ellipses, and transmission errors under various assembly errors of the double-crowned gear pairs with those produced by using the conventional modified hob cutter and dual-lead hob cutter. Computer simulation results reveal the advantages of the proposed hobbing method for involute helical gear manufacturing.

Author(s):  
Van-The Tran ◽  
Ruei-Hung Hsu ◽  
Chung-Biau Tsay

In the gear finish hobbing process, to obtain a twist-free tooth flank of helical gears, a novel hobbing method for longitudinal crowning is proposed by applying a new hob’s diagonal feed motion with a dual-lead hob cutter. Wherein the hob’s diagonal feed motion is set as a second order function of hob’s traverse movement and tooth profile of hob cutter is modified in a dual-lead form with pressure angle changed in it’s longitudinal direction. The proposed method is verified by using two computer simulation examples to compare topographies of the crowned work gear surfaces hobbed by the standard and dual-lead rack cutters. The results reveal the superiority of the proposed novel finish hobbing method.


2017 ◽  
Vol 39 (2) ◽  
pp. 97-108
Author(s):  
Van-The Tran

In the conventional hobbing process, a double-crowned involute helical gear is generated by the hob cutter with parabolic-curve tooth profiles for the cross-profile crowning and varied the center distance between the hob and work gear for the longitudinal crowning. Therefore, to cut a double-crowned helical gear not only requires at least four synchronous axes and hob cutter regrinding (which increases production costs) but also induces twisted tooth flanks on the generated work gear. In this paper, I propose a hobbing method by applying a modified work gear rotation angle that enables double-crowning of involute helical gear's tooth flanks using a standard hob cutter and a computer numerical control (CNC) hobbing machine with only three synchronous axes. The proposed method has also verified by using two computer simulation examples to compare the meshing-conditions, contact ellipses, and transmission errors of the double-crowned gear pairs with that produced by applying the conventional hobbing method. Computer simulation results reveal the advantages of the proposed novel hobbing method.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Wei-Shiang Wang ◽  
Zhang-Hua Fong

This paper proposes a new type of double-crowned helical gear that can be continuously cut on a modern Cartesian-type hypoid generator with two face-hobbing head cutters and circular-arc cutter blades. The gear tooth flank is double crowned with a cycloidal curve in the longitudinal direction and a circular arc in the profile direction. To gauge the sensitivity of the transmission errors and contact patterns resulting from various assembly errors, this paper applies a tooth contact analysis technique and presents several numerical examples that show the benefit of the proposed double-crowned helical gear set. In contrast to a conventional helical involute gear, the tooth bearing and transmission error of the proposed gear set are both controllable and insensitive to gear-set assembly error.


2018 ◽  
Vol 12 (1) ◽  
pp. JAMDSM0026-JAMDSM0026 ◽  
Author(s):  
Shigenori HAMADA ◽  
Kazumasa KAWASAKI ◽  
Isamu TSUJI

2013 ◽  
Vol 372 ◽  
pp. 543-546
Author(s):  
Xiao Fang Yang ◽  
Zong De Fang ◽  
Yong Zhen Zhang ◽  
Yuan Fei Han

According to the principle of tri-branching, a mechanism structural model was developed to analyze the helical gear transmission system. On the base of loaded tooth contact analysis (LTCA), the load transmission error of each gear stage is simulated at the any engagement position, and the fitting curves of the torsion mesh stiffness are obtained, which can improve the numerical precision. The research results can be applied to analyze the actual application of tri-branching transmission system and provide a firm foundation for study the power-split and load-sharing characteristics.


2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Zhaoyao Shi ◽  
Xiaoyi Wang ◽  
Zanhui Shu

A theoretical method is proposed in this paper to calculate the unit curve of gear integrated error (GIE). The calculated GIE unit curve includes the quasi-static transmission error (TE) curves of the approach stage, the involute stage, and the recession stage of the ZI worm and helical gear transmission. The misalignments between the two axes of the worm and gear, as well as the modifications or errors of the tooth flanks of the gear, are considered in the procedure of calculation. Optimization algorithm is introduced to replace the solving of implicit differential equations of the conventional tooth contact analysis (TCA) method. It is proved that the proposed method is clearer and more convenient than the conventional TCA methods in calculating the GIE unit curve. The correctness and merits of the proposed method are verified by two experiments.


2002 ◽  
Vol 37 (7) ◽  
pp. 685-691 ◽  
Author(s):  
Shuren Wang ◽  
Dongan Zhan ◽  
Hua Liu ◽  
Shuyu Wang

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