Compensation of errors of alignment and contact pattern repositioning in hypoid gears with low crossing shaft angle

Meccanica ◽  
2021 ◽  
Author(s):  
Siyuan Liu ◽  
Caichao Zhu ◽  
Chaosheng Song ◽  
Alfonso Fuentes-Aznar
Keyword(s):  
Contact Pattern ◽  
Hypoid Gears ◽  
Shaft Angle ◽  
Compensation Of Errors

Study of V/H/J of Pointing-Lapping for Hypoid Gears

2013 ◽  
Vol 300-301 ◽  
pp. 217-220 ◽  
Author(s):  
Hua Ru Yan ◽  
Miao Xin Xiao
Keyword(s):  
Nonlinear Equations ◽  
Surface Defects ◽  
Numerical Control ◽  
Tooth Surface ◽  
Contact Pattern ◽  
Hypoid Gears ◽  
Surface Contact

Pointing-lapping is a lapping way for modifying tooth surface defects of hypoid gears. For numerical control, V/H/J calculation principle of pointing-lapping of hypoid gears is introduced. According to mesh relations and coordinate relations, 8 nonlinear equations are formed on the basis of mesh theory of hypoid gears. V/H/J can be got by solving the nonlinear equations, which can be finished easily by computation program. The accuracy of the calculation principle has been proved by tooth surface contact pattern test in Y9550 roll checking machine.

Objektivierung der Tragbildprüfung/New Measurement Strategy for Quality Assurance of Lapped Hypoid Gear – Objectification of Contact Pattern Test

2021 ◽  
Vol 111 (06) ◽  
pp. 464-468
Author(s):  
Stefan Gerdhenrichs ◽  
Jimmy Chhor ◽  
Robert H. Schmitt
Keyword(s):  
Quality Assurance ◽  
Machine Vision ◽  
Expert Knowledge ◽  
Objective Evaluation ◽  
Operating Conditions ◽  
Contact Pattern ◽  
Hypoid Gear ◽  
Hypoid Gears ◽  
Measurement Strategy ◽  
Load Displacement

Die Fertigung und Prüfung geläppter Hypoidgetriebe basiert in der Praxis auf Erfahrungswissen und erschwert eine objektive Bewertung des Messverfahrens. Eine neu entwickelte Messstrategie nutzt simulierte Lastverschiebung und ein Bildverarbeitungssystem, um charakteristische Tragbildkennwerte aus erfassten Tragbildern in Mehrfachzahnkontakten zu extrahieren und erzielt unter Betriebsbedingungen erste vielversprechende Ergebnisse.   Current practices for manufacturing and testing of lapped hypoid gears exploit expert knowledge and impede an objective evaluation. A newly developed measurement strategy uses simulated load displacement and machine vision to extract characteristic contact pattern values in recordings of multiple tooth contacts. Early findings in operating conditions offer promising results and insights to this approach.

Optimization of the Loaded Contact Pattern in Hypoid Gears by Automatic Topography Modification

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Alessio Artoni ◽  
Andrea Bracci ◽  
Marco Gabiccini ◽  
Massimo Guiggiani
Keyword(s):  
Optimization Problems ◽  
Mathematical Framework ◽  
Contact Pattern ◽  
Tooth Contact ◽  
Hypoid Gears ◽  
Computational Speed ◽  
Tool Setting ◽  
Unconstrained Nonlinear Optimization ◽  
Time Required ◽  
Time Frames

Systematic optimization of the tooth contact pattern under load is an open problem in the design of spiral bevel and hypoid gears. In order to enhance its shape and position, gear engineers have been assisted by numerical tools based on trial-and-error approaches, and/or they have been relying on the expertise of skilled operators. The present paper proposes a fully automatic procedure to optimize the loaded tooth contact pattern, with the advantage of eventually reducing design time and cost. The main problem was split into two identification subproblems: first, to identify the ease-off topography capable of optimizing the contact pattern; second, to identify the machine-tool setting variations required to obtain such ease-off modifications. Both of them were formulated and solved as unconstrained nonlinear optimization problems. In addition, an original strategy to quickly approximate the tooth contact pattern under load was conceived. The results obtained were very satisfactory in terms of accuracy, robustness, and computational speed. They also suggest that the time required to optimize the contact pattern can be significantly reduced compared with typical time frames. A sound mathematical framework ensures results independent of the practitioner’s subjective decision-making process. By defining a proper objective function, the proposed method can also be applied to affect other contact properties, such as to improve the motion graph or to decrease the sensitivity of the transmission to assembly errors. Furthermore, it can be easily adapted to any gear drive by virtue of its systematic and versatile nature.

Loaded TCA of Measured Tooth Flanks for Lapped Hypoid Gears

2007 ◽  
Author(s):  
Kohei Saiki ◽  
Keiichiro Tobisawa ◽  
Masaki Kano ◽  
Yasuharu Ohnishi ◽  
Takashi Kusaka
Keyword(s):  
Coordinate Measuring Machine ◽  
Contact Pattern ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Hypoid Gears ◽  
Practical Applications ◽  
Wheel Drive ◽  
Measuring Machine ◽  
Loaded Tooth Contact Analysis ◽  
Shape Data

Usually, the Loaded Tooth Contact Analysis (i.e. LTCA) of hypoid gears uses the nominal tooth flanks described by the machine setting and the cutter specifications. Only a few studies are performed on the LTCA directly using the measured tooth flanks such as carbonize-hardened and lapped hypoid gears. This paper presents an innovative LTCA method directly using the measured tooth flanks at each manufacturing step including not only the milling or hobbing process but also the troublesome heat-treatment, lapping or grinding processes. The proposed new LTCA method is extremely concise. Firstly, the 3-D shape data of the manufactured tooth flanks, which are the original x-y-z coordinates but not the differences against their nominal tooth flanks as before, are obtained on a coordinate-measuring machine. Another important factors the load deflections are measured on the assembled transmission by applying the static transmitting torque. Secondly, the pinion and gear are localized at the nominal mounting position, and the no load TCA can be obtained by calculating the gap between the original tooth flanks at each roll angle. Lastly, since the load deflections can be considered as the movement of mounting position, the Loaded TCA can be obtained by calculating the gap between the moved tooth flanks at new mounting position. As practical applications, the new LTCA method is used to improve the strength of high-torque hypoid gears for an All-Wheel-Drive transmission. As a result, the tooth contact pattern and pitting position observed in endurance test agreed well to the LTCA predictions and the demanding life is achieved by modifying the loaded contact pattern of lapped hypoid gears.

Robust Optimization of the Loaded Contact Pattern in Hypoid Gears With Uncertain Misalignments

2009 ◽  
Author(s):  
M. Gabiccini ◽  
A. Bracci ◽  
M. Guiggiani
Keyword(s):  
Optimization Problems ◽  
Optimization Procedure ◽  
Target Area ◽  
Contact Pattern ◽  
Unified Framework ◽  
Hypoid Gears ◽  
Contact Patterns ◽  
Unconstrained Nonlinear Optimization ◽  
The One ◽  
Micro Topography

This paper presents an automatic procedure to optimize the loaded tooth contact pattern of face-milled hypoid gears with misalignments varying within prescribed ranges. A two-step approach is proposed to solve the problem: in the first step, the pinion tooth micro-topography is automatically modified to bring the perturbed contact patterns (as the assembly errors are varied within the tolerance limits) match a target area of the tooth, while keeping them off the edges; in the second step, a subset of the machine-tool settings is identified to obtain the required topography modifications. Both steps are formulated and solved as unconstrained nonlinear optimization problems. While the general methodology is similar to the one recently proposed by the same authors for the optimization at nominal conditions, here the robustness issues with respect to misalignment variations are considered and directly included in the optimization procedure: no a posteriori check for robustness is therefore required. Numerical tests show that nominally satisfactory and globally robust hypoid pairs can be designed by a direct process and within a unified framework, thus avoiding tiresome trial-and-error loops.

Computational Study on Machine Settings for Face-Milled Hypoid Gears With Low Shaft Angles

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Xingyu Yang ◽  
Chaosheng Song ◽  
Caichao Zhu ◽  
Siyuan Liu ◽  
Chengcheng Liang
Keyword(s):  
Manufacturing Process ◽  
Computational Study ◽  
Cone Angle ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Contact Pattern ◽  
Hypoid Gear ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Shaft Angle

Abstract Hypoid gear with small cone angle and large pitch cone distance can be directed at the transmission with low shaft angle (LSA). The manufacturing process has more freedoms of motion to control the tooth surface and ensure higher mesh performance. However, it is difficult to adjust the machine settings due to the extreme geometry. This paper focused on the manufacturing process and machine settings calculation of hypoid gear with low shaft angle (LSA hypoid gear). Based on the generating process, nongenerated gear, and generated pinion manufactured by circular cutter blade, the mathematic model of tooth surface of LSA hypoid gear was developed, and the expressions of principal directions and curvatures of LSA hypoid gear were derived. The relationship of curvatures between pinion and gear was also proposed. Then based on the basic relationships of two mating surfaces, an approach to determinate machine settings for LSA hypoid gear was proposed. Finally, the tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA) were directed at the validation of machine settings’ derivation. TCA contact pattern results highly coincide with the preset values. And the LTCA contact pattern also highly coincides with TCA results, it can be considered that the determination approach of machine settings is valid. The TCA transmission error result also shows that the ratio of contact is quite large, which is a little bigger than 2. Thus, the load bearing ability and stability of LSA hypoid gear may be superior.

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