105 Studies on Friction Loss of Spur Gears : Influence of Center Distance and Gear Ratio

2000 ◽  
Vol 2000 (0) ◽  
pp. 17-18
Author(s):  
Yasuhiro SUGIYAMA ◽  
Shoji HAIZUKA
2003 ◽  
Vol 69 (684) ◽  
pp. 2186-2193
Author(s):  
Shoji HAIZUKA ◽  
Yasuhiro SUGIYAMA ◽  
Hiroshi MORIKAWA

Author(s):  
M. A. Sahir Arikan

Although it is possible to find some recommended conventional values both for the sum of the addendum modification coefficients and for the allocation of the sum of the addendum modification coefficients (e.g. ISO/TR 4467), a detailed analysis is necessary to determine the addendum modification coefficient values for the desired optimization criteria and the performance since the main objective of the above mentioned sources is to facilitate practical design of non-standard gear drives which will not have problems while operating. They give practical average values within a safe range. In this study, by considering the required gear ratio, center distance and the desired backlash, alternative gear pairs are determined and corresponding gear performance variables are calculated in order to allocate the addendum modification coefficients for the pinion and the gear by using criteria such as: not having undercut or pointed (or excessively-thinned-tip) tooth, having desired proportions for the lengths of the dedendum and addendum portions of the line of action, having maximum contact ratio, having sufficient bottom clearance, having minimum contact stresses, having balanced pinion and gear tooth root stresses, having equal pinion and gear lives, etc.


Author(s):  
Miguel Pleguezuelos ◽  
Jose´ I. Pedrero ◽  
Miryam B. Sa´nchez

An analytic model to compute the efficiency of spur gears has been developed. It is based on the application of a non-uniform model of load distribution obtained from the minimum elastic potential criterion and a simplified non-uniform model of the friction coefficient along the path of contact. Both conventional and high transverse contact ratio spur gears have been considered. Analytical expressions for the power losses due to friction, for the transmitted power and for the efficiency are presented. From this model, a complete study of the influence of some design parameters (as the number of teeth, the gear ratio, the pressure angle, the addendum modification coefficient, etc.) on the efficiency is presented.


Author(s):  
Seizo Uematsu ◽  
Masana Kato

Abstract Finish roll forming under the constant center distance by forced feed of tool can be conceived as a method of eliminating errors in conventional form rolling under constant loads. This method generates a high-precision tooth profile by low-speed form rolling when a high rigid screw or cam is used as loading parts. In this study, the high-speed rolling conditions of this method for necessary to be applied in practical situations are discussed. The following conclusions are obtained. When the following design data are given (module, number of teeth, addendum modification coefficient, prescribed design precision, and material characteristics), the accuracy of rolled gear can be predicted from the relationship between the required feed for the tool and the theoretically calculated plastic deformation on the tooth profile. These conclusions are verified experimentally. For example, the tooth accuracy of rolled gears with module 5 can improve from JIS class 3 to JIS class 0 or 1 when the load Fmax is 4 to 5kN and the pitch line velocity is 7 m/min.


1999 ◽  
Vol 42 (4) ◽  
pp. 1041-1049 ◽  
Author(s):  
Shoji HAIZUKA ◽  
Takaaki KIKUSAKI ◽  
Chotaro NARUSE

1982 ◽  
Vol 104 (4) ◽  
pp. 749-757 ◽  
Author(s):  
M. Savage ◽  
J. J. Coy ◽  
D. P. Townsend

The design of a standard gear mesh is treated with the objective of minimizing the gear size for a given ratio, pinion torque, and allowable tooth strength. Scoring, pitting fatigue, bending fatigue, and the kinematic limits of contact ratio and interference are considered. A design space is defined in terms of the number of teeth on the pinion and the diametral pitch. This space is then combined with the objective function of minimum center distance to obtain an optimal design region. This region defines the number of pinion teeth for the most compact design. The number is a function of the gear ratio only. A design example illustrating this procedure is also given.


2013 ◽  
Vol 2013 ◽  
pp. 1-14 ◽  
Author(s):  
Miguel Pleguezuelos ◽  
José I. Pedrero ◽  
Miryam B. Sánchez

Simple, traditional methods for computation of the efficiency of spur gears are based on the hypotheses of constant friction coefficient and uniform load sharing along the path of contact. However, none of them is accurate. The friction coefficient is variable along the path of contact, though average values can be often considered for preliminary calculations. Nevertheless, the nonuniform load sharing produced by the changing rigidity of the pair of teeth has significant influence on the friction losses, due to the different relative sliding at any contact point. In previous works, the authors obtained a nonuniform model of load distribution based on the minimum elastic potential criterion, which was applied to compute the efficiency of standard gears. In this work, this model of load sharing is applied to study the efficiency of both standard and high contact ratio involute spur gears (with contact ratio between 1 and 2 and greater than 2, resp.). Approximate expressions for the friction power losses and for the efficiency are presented assuming the friction coefficient to be constant along the path of contact. A study of the influence of some transmission parameters (as the gear ratio, pressure angle, etc.) on the efficiency is also presented.


2003 ◽  
Vol 2003 (0) ◽  
pp. 249-250
Author(s):  
Shingo KIZAWA ◽  
Shoji HAIZUKA ◽  
Hiroshi TADOKORO

2011 ◽  
Vol 79 ◽  
pp. 293-297
Author(s):  
Li Hong Liu ◽  
Zhan Ni Li ◽  
Han Bing Cao

Applying elastic-hydrodynamic lubrication theory, oil film thickness of tooth surface was studies in accordance with the quasi-steady state. This paper focused on the influence of gear parameters such as gear ratio, module and center distance on the thickness of oil film of tooth flank. The results show, as speed ratio increases, oil film thickness increases significantly. When the number of teeth is fixed, oil film thickness increases significantly with the increase of module. When center distance is fixed, oil film thickness declines greatly with the increase of module in both into meshing and out of meshing points. Therefore when center distance is fixed, less module and more teeth are selected,on the condition that gear intensity is met. By results analyzing, the minimal oil film thickness may occur in the single tooth meshing area and into meshing or out of meshing points.


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