scholarly journals Alternative methods of verifying the reconstructed outline of a non-standard spur gear

2021 ◽  
Vol 1199 (1) ◽  
pp. 012001
Author(s):  
K Konecki ◽  
R Pytliński ◽  
A Kołodziej ◽  
G Domek

Abstract Common methods of checking a gear that have been designed in reverse engineering are, for example, measurement with a modular caliper or disc micrometer. However, although these methods are among the most accurate, they allow only one or a few of the selected geometric parameters to be measured. The paper presents alternative methods of verification of the reconstructed outline of a very non-standard involute gear with the parameters m = 4.98, α = 26.325 °, x = 0.0695, y = 0.795, c* = 0.383. These methods are less accurate than the classic ones, but they allow for a comprehensive check of the entire outline of the reconstructed tooth. They are often used in industrial practice. However, here, in addition to the methodology, a short tolerance analysis was also carried out, which may to some extent compensate for the aforementioned measurement inaccuracy. The method consists in using the potential of a spreadsheet and CAD technique to generate an involute outline of a gear tooth whose geometry is recreated.

2021 ◽  
Vol 1199 (1) ◽  
pp. 012105
Author(s):  
K Konecki ◽  
D Wojtkowiak ◽  
K Talaśka ◽  
A Kołodziej ◽  
G Domek

Abstract Modern machine manufacturers are making the design and technology of their products more and more complicated. This is to protect against a frequently used practice at customers, i.e. making extra parts on your own. This is because entrepreneurs often cannot afford to order expensive original spare parts and - using reverse engineering - prepare working drawings and commission the components to be made in their own machine park or externally from local suppliers. However, the matter is more complex in the case of gears, which so far have been designed on the basis of the selection of standard geometric parameters. A small modification of one or more of these parameters is enough and it becomes very difficult to recreate the geometry of such a gear. This paper presents the issues related to the reverse engineering of a spur involute gear with very non-standard parameters m = 4.98, α = 26.325 °, x = 0.0695, y = 0.795, c* = 0.383. Further metrological steps were proposed that should be taken to correctly identify at least the fact that the test object is not a part produced by standard modular tools (Fellows cutter, Maag rack cutter, worm cutter, etc.). The work also includes short graphical analyzes of the recreated geometry.


Author(s):  
Ravi Datt Yadav ◽  
Anant Kumar Singh ◽  
Kunal Arora

Fine finishing of spur gears reduces the vibrations and noise and upsurges the service life of two mating gears. A new magnetorheological gear profile finishing (MRGPF) process is utilized for the fine finishing of spur gear teeth profile surfaces. In the present study, the development of a theoretical mathematical model for the prediction of change in surface roughness during the MRGPF process is done. The present MRGPF is a controllable process with the magnitude of the magnetic field, therefore, the effect of magnetic flux density (MFD) on the gear tooth profile has been analyzed using an analytical approach. Theoretically calculated MFD is validated experimentally and with the finite element analysis. To understand the finishing process mechanism, the different forces acting on the gear surface has been investigated. For the validation of the present roughness model, three sets of finishing cycle experimentations have been performed on the spur gear profile by the MRGPF process. The surface roughness of the spur gear tooth surface after experimentation was measured using Mitutoyo SJ-400 surftest and is equated with the values of theoretically calculated surface roughness. The results show the close agreement which ranges from −7.69% to 2.85% for the same number of finishing cycles. To study the surface characteristics of the finished spur gear tooth profile surface, scanning electron microscopy is used. The present developed theoretical model for surface roughness during the MRGPF process predicts the finishing performance with cycle time, improvement in the surface quality, and functional application of the gears.


Measurement ◽  
2016 ◽  
Vol 91 ◽  
pp. 479-487 ◽  
Author(s):  
José A. Brandão ◽  
Jorge H.O. Seabra ◽  
Manuel J.D. Castro

Author(s):  
Shih-Liang Wang

Abstract Motion simulation of mechanism of line contact like gears and cams has been difficult in the past. With Working Model, NURBS based complex geometry can be modeled fairly easily, and its simulation engine can animate this type of mechanism accurately. In this paper several Working Model files are developed for visualization and analysis. An algorithm to generate involute gear tooth profile is introduced in this paper for the involute and a portion of non-involute surface.


1981 ◽  
Vol 103 (2) ◽  
pp. 516-527 ◽  
Author(s):  
G. Castellani ◽  
V. P. Castelli

Synthetic formulas are written suitable to represent and compare the AGMA and ISO Standards for rating gear tooth strength. The corresponding tooth form and stress correction factors are compared for different kinds of involute gear teeth. A unified procedure is given to enable computing of the root parameters for teeth generated by any kind of tool which completes the ISO method, extending it to the case of shaped teeth. Both AGMA and ISO methods are also applied to the calculation of the aforesaid factors for internal gear teeth. In this case reliability is checked by finite element method. The comparison shows that research is necessary to review some items relating to calculation of stress correction factors.


1982 ◽  
Vol 104 (4) ◽  
pp. 759-764 ◽  
Author(s):  
J. J. Coy ◽  
C. Hu-Chih Chao

A method of selecting grid size for the finite element analysis of gear tooth deflection is presented. The method is based on a finite element study of two cylinders in line contact, where the criterion for establishing element size was that there be agreement with the classic Hertzian solution for deflection. Many previous finite element studies of gear tooth deflection have not included the full effect of the Hertzian deflection. The present results are applied to calculate deflection for the gear specimen used in the NASA spur gear test rig. Comparisons are made between the present results and the results of two other methods of calculation. The results have application in design of gear tooth profile modifications to reduce noise and dynamic loads.


2013 ◽  
Vol 302 ◽  
pp. 468-473 ◽  
Author(s):  
Per Lindholm ◽  
Jian Qin

One way to achieve lightweight and lubricant-free drive train is, among others, to convert conventional steel to polymer composite materials. This paper describes a part of this endeavor by taking a spur gear pair as a study object. One of the steel gear wheel is replaced with three different materials including Victrex PEEK 650G, Victrex PEEK 650CA30 and Luvocom PEEK 1105-8165 while keeping the gear geometry unchanged. Mechanical stresses and thermal properties are two major criteria for material selection at this stage. Therefore carbon fiber filled PEEK (Victrex PEEK 650CA30) and PEEK filled with thermal conductive minerals (Luvocom 1105-8165) are chosen to benchmark each of the criterion. The evaluation is done by modeling the gear mesh and analyzing the contact forces and heat generated in the gear tooth. The results show surface temperature on the tooth flanks, root tensional stress and contact pressure during the tooth mesh. The work suggests a guideline of materials selection. Depending on actual application a compromisation between mechanical and thermal properties often needs to be considered within the tolerance boundary in order to obtain optimized results. This work only deals with material selection. Gear design such as optimization of tooth geometry for polymer gears is out of the scope of this study and will not be discussed.


Author(s):  
Chia-Chang Liu ◽  
Chung-Biau Tsay

Abstract A beveloid gear can be viewed as an involute gear of which the profile-shifted coefficient linearly decreases from the heel to the toe. Therefore, tooth undercutting occurs and singular points appear on the tooth surfaces near the toe. When undercutting occurs, the gear tooth is comparatively weak. In this study, the conditions of tooth undercutting of beveloid gears were derived and specific phenomena were also investigated by numerical illustrated examples. In addition, according to the characteristics of tooth undercutting on the beveloid gear tooth surface, a novel type hob cutter with varying cutting depths was designed to avoid tooth undercutting of the beveloid gear.


Sign in / Sign up

Export Citation Format

Share Document