Contact Characteristics of Circular-Arc Curvilinear Tooth Gear Drives

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
Yi-Cheng Wu ◽  
Kuan-Yu Chen ◽  
Chung-Biau Tsay ◽  
Yukinori Ariga

In this paper, the circular-arc curvilinear tooth gear drive is proposed. The gear and pinion tooth surfaces are generated by two complemented circular-arc rack cutters with curvilinear tooth-traces. According to the theory of gearing, the mathematical model of the proposed gear is developed. The tooth contact analysis technique is utilized to investigate the kinematical errors of circular-arc curvilinear tooth gear drives under different assembly errors. Contact patterns of the circular-arc curvilinear tooth gear drive are simulated by the developed computer-aided tooth contact analysis programs and surface topology method. Numerical examples are presented to show the kinematical errors of the circular-arc curvilinear tooth gear set under different assembly conditions. Relations among the circular-arc tooth profile, curvilinear tooth-trace, contact ratio, contact pattern, and kinematical error are also demonstrated by numerical examples.

2006 ◽  
Vol 129 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Faydor L. Litvin ◽  
Kenji Yukishima ◽  
Kenichi Hayasaka ◽  
Ignacio Gonzalez-Perez ◽  
Alfonso Fuentes

The computerized design, generation, and tooth contact analysis of a Klingelnberg-type cylindrical worm gear drive is considered wherein localization of contact is obtained by application of an oversized hob and mismatch geometries of hob and worm of the drive. A computerized approach for the determination of contacting surfaces and the investigation of their meshing and contact by tooth contact analysis is presented. The developed theory results in an improvement of bearing contact and reduction of sensitivity to misalignment. The theory is illustrated with numerical examples and may be applied for other types of cylindrical worm gear drives.


2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Wei-Liang Chen ◽  
Chung-Biau Tsay

Based on the previously developed mathematical model of a series of recess action (RA) worm gear drive (i.e., semi RA, full RA, and standard proportional tooth types) with double-depth teeth, the tooth contact analysis (TCA) technique is utilized to investigate the kinematic error (KE), contact ratio (CR), average contact ratio (ACR), instantaneous contact teeth (ICT) under different assembly conditions. Besides, the bearing contact and contact ellipse are studied by applying the surface topology method. Three numerical examples are presented to demonstrate the influence of the assembly errors and design parameters of the RA worm gear drive on the KE, CR, ACR, ICT, and contact patterns.


2011 ◽  
Vol 86 ◽  
pp. 327-332
Author(s):  
Jin Hua Wang ◽  
Yun Bo Shen ◽  
Ze Yong Yin ◽  
Jie Gao ◽  
Yan Ying Jiang

Load sharing is one of the main factors that determine gear strength. In this paper, Tooth Contact Analysis (TCA) and Loaded Tooth Contact Analysis (LTCA) have been performed to investigate the effect of tooth surface modification on the contact ratio, load sharing and strength of an orthogonal offset face gear drive with spur involute pinion. The results indicate that the contact ratio of 2.0 or higher could be achieved. The maximum load carried by single tooth and bending stress are significantly reduced when appropriate tooth surface modification is applied to the orthogonal offset face gear drive.


2010 ◽  
Vol 139-141 ◽  
pp. 1154-1157 ◽  
Author(s):  
Hui Guo ◽  
Ning Zhao ◽  
Hao Gao

This paper proposes a modification method for tooth surface of face gear drive with a grinding worm on a numerical grinding machine. The surface equation of grinding worm is derived, and the coordinate System of generating the worm is established. Tooth contact analysis (TCA) is performed to investigate the performance of face gear drive before and after modification, and the alignment error is considered. This method can obtain a more stable bearing contact in contrast to the method by increasing tooth number of shaper. The longitudinal bearing contact on the face-gear tooth surface has been obtained which will increase the contact ratio. By modification the edge contact at surface edges of the gears can be avoided and the modification magnitude can be controlled freely.


Author(s):  
Layue Zhao ◽  
Robert C Frazer ◽  
Brian Shaw

With increasing demand for high speed and high power density gear applications, the need to optimise gears for minimum stress, noise and vibration becomes increasingly important. ISO 6336 contact and bending stress analysis are used to determine the surface load capacity and tooth bending strength but dates back to 1956 and although it is constantly being updated, a review of its performance is sensible. Methods to optimise gear performance include the selection of helix angle and tooth depth to optimise overlap ratio and transverse contact ratio and thus the performance of ISO 6336 and tooth contact analysis methods requires confirmation. This paper reviews the contact and bending stress predicted with four involute gear geometries and proposes recommendations for stress calculations, including a modification to contact ratio factor Zɛ which is used to predict contact stress and revisions to form factor YF and helix angle factor Yβ which are cited to evaluate bending stress. The results suggest that there are some significant deviations in predicted bending and contact stress values between proposal methods and original ISO standard. However, before the ISO standard is changed, the paper recommends that allowable stress numbers published in ISO 6336-5 are reviewed because the mechanisms that initiate bending and contact fatigue have also changed and these require updating.


Author(s):  
Y-C Chen ◽  
M-L Gu

This article investigated the contact behaviours of a modified curvilinear gear set for parallel-axis transmission, which exhibits a pre-designed parabolic transmission error (TE) and localized bearing contact. The proposed gear set is composed of a modified pinion with curvilinear teeth and an involute gear with curvilinear teeth. Tooth contact analysis enabled the authors to explore the influences of assembly errors and design parameters on TEs and contact ellipses of this gear set. It is observed that TEs were continuous and the contact ellipses were localized in the middle of the tooth flanks, even under assembly errors. Finite-element contact analysis was performed to study stress distributions under different design parameters. In addition, numerical examples are presented to demonstrate the contact characteristics of the modified curvilinear gear set.


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.


Author(s):  
Zongde Fang ◽  
Hongbin Yang ◽  
Yanwei Zhou ◽  
Xiaozhong Deng

Abstract A new approach for optimizing the dynamic behavior of spiral bevel gear drives has been developed. The local synthesis, tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA) techniques were used to constitute the design process with feedback, by which a contact ratio being near 2.0 or 3.0 would be achieved. An improved dynamic behavior of the spiral bevel gear drives under certain operating load or a wide range of load could be obtained.


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