Contact Pressure Estimates of Tooth Surfaces of Gear Couplings

2000 ◽  
Author(s):  
Hiroshi Mukoyama ◽  
Shigeyuki Shimachi ◽  
Yoshihide Hakozaki
Keyword(s):  
Contact Pressure ◽  
Spur Gear ◽  
Tooth Surface ◽  
Maximum Pressure ◽  
Successive Approximation Method ◽  
Infinite Plane ◽  
Tooth Contact ◽  
Total Load ◽  
Edge Contact ◽  
Face Width

Abstract Recent demands for gear couplings are to reduce the backlash and to increase the shaft angle limit. On coping with these demands, the tooth contact pressure is recognized as the trade-off problem. In the traditional estimation of tooth contact pressure, the deflection of tooth is calculated by using the formula for spur gear that has long contact bearing in the face width direction, although gear coupling has it in the tooth depth direction. And, the Hertz depression of the tooth surface is estimated as that of the infinite plane. Additionally, the traditional methods don’t consider about the edge contact on the tip or end of tooth. A successive approximation method is established to find the load distribution on the mating teeth surfaces. As for the effect of the edge contact on the tip or end of tooth, it is cleared that the contact pressure distribution deforms itself severely, but the maximum pressure is almost constant. The expressions estimating the maximum pressure and the displacement of tooth base are constructed for 6 parameters as follows; total load coefficient, relative curvature of teeth surfaces, tooth module, ratio of tooth height to face width, angle of tip contact and deviation of end contact.

Optimal Tooth Surface Modifications in Face-Hobbed Hypoid Gears

2013 ◽  
Vol 572 ◽  
pp. 351-354
Author(s):  
Simon Vilmos
Keyword(s):  
Contact Pressure ◽  
Angular Displacement ◽  
Optimization Procedure ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Hypoid Gears ◽  
Transmission Errors ◽  
Loaded Tooth Contact Analysis

In this study, an optimization methodology is proposed to systematically define head-cutter geometry and machine tool settings to introduce optimal tooth modifications in face-hobbed hypoid gears. The goal of the optimization is to simultaneously minimize tooth contact pressures and angular displacement error of the driven gear, while concurrently confining the loaded contact pattern within the tooth boundaries. The proposed optimization procedure relies heavily on a loaded tooth contact analysis for the prediction of tooth contact pressure distribution and transmission errors. The objective function and the constraints are not available analytically, but they are computable, i.e., they exist numerically through the loaded tooth contact analysis. The core algorithm of the proposed nonlinear programming procedure is based on a direct search method. Effectiveness of this optimization was demonstrated by using a face-hobbed hypoid gear example. Considerable reductions in the maximum tooth contact pressure and in the transmission errors were obtained.

Computer Simulation Analysis of Bending Stress for Face Gear with a New Type Fillet Tooth Surface

2011 ◽  
Vol 86 ◽  
pp. 411-414
Author(s):  
Yun Bo Shen ◽  
Jie Gao ◽  
Wen Qiang Ding
Keyword(s):  
Computer Simulation ◽  
Surface Structure ◽  
Spur Gear ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Bending Stress ◽  
Face Gear ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
The Face

Bending stress is a principal factor that defines the fatigue life of face gear. A new tooth surface structure with circular arc of fillet surface for the face gear has been developed. A method of processing or cutting of fillet surfaces of helical face gear by application of a shaper with tooth rounded top has also been represented. The bending stress of the tooth of face gear with new surface structure has been performed by computer simulation. Two versions of finite element model of tooth surfaces of face gear are generated by application of numerical technology. One version is based on the cutting shaper with tooth top shaper corner and another version is with addendum rounded top. Tooth contact analysis (TCA) and loaded tooth contact analysis (LTCA) for the two versions of face gear drives with helical spur gear are also considered. The results of simulation show that the bending stress of tooth surface of the face gear with fillet surface generated by the rounded top of the shaper is 12% lower than the first version’s.

Surface design and tooth contact analysis of an innovative modified spur gear with crowned teeth

2005 ◽  
Vol 219 (2) ◽  
pp. 193-207 ◽  
Author(s):  
J-L Li ◽  
S-T Chiou
Keyword(s):  
Gear Tooth ◽  
Point Contact ◽  
Spur Gear ◽  
Contact Analysis ◽  
Tooth Surface ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Surface Design ◽  
Tooth Surfaces ◽  
Meshing Characteristics

An innovative modified spur gear with crowned teeth and its generating mechanism are proposed in this study. The main purpose of tooth surface modification is to change line contact to point contact at the middle of gear tooth surfaces in order to avoid edge contact resulting from possible unavoidable axial misalignment. Moreover, the surface of one gear tooth can be generated with just one cutting process, thereby facilitating easy manufacturing. Based on gearing theory, the model for surface design is developed. A tooth contact analysis (TCA) model for the modified gear pair is also built to investigate meshing characteristics, so that transmission errors (TEs) under assembly errors can also be studied. Examples are included to verify the correctness of the models developed and to demonstrate gear characteristics.

Tooth Contact Analysis of Double Enveloping Hourglass Worm Gearing on the Condition That Errors Mixed With Deformation

2000 ◽  
Author(s):  
Datong Qin ◽  
Dongxing Qin ◽  
Yalian Yang ◽  
Jianjun Hu
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Element Model ◽  
Tooth Surface ◽  
Penalty Function Method ◽  
Contact Pattern ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Manufacturing Errors ◽  
Worm Gearing

Abstract An accurate geometry and contact finite element model of double enveloping hourglass worm gearing with manufacturing errors are constructed. The hybrid method of finite element method and penalty function method is employed to investigate the contact pattern and contact pressure on tooth surface as well as the load share among contacting tooth pairs with the coexistence of manufacturing error and load. The influences of different values of load and different types of errors on contact pattern and contact pressure as well as load share are studied. The mutual influences of the load and the error on tooth contact and load share are also analyzed. Some results useful for production and application of the worm gearing are presented.

Modeling of surface roughness in a novel magnetorheological gear profile finishing process

2020 ◽  
pp. 095440622097826
Author(s):  
Ravi Datt Yadav ◽  
Anant Kumar Singh ◽  
Kunal Arora
Keyword(s):  
Surface Roughness ◽  
Gear Tooth ◽  
Surface Characteristics ◽  
Spur Gear ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Finishing Process ◽  
Gear Profile

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.

Optimal Tooth Modifications in Hypoid Gears

2004 ◽  
Vol 127 (4) ◽  
pp. 646-655 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Load Distribution ◽  
Angular Position ◽  
Point Contact ◽  
Tooth Surface ◽  
Gear Pair ◽  
Hypoid Gear ◽  
Tooth Contact ◽  
Hypoid Gears ◽  
Transmission Errors ◽  
Tool Profile

A method for the determination of optimal tooth modifications in hypoid gears based on improved load distribution and reduced transmission errors is presented. The modifications are introduced into the pinion tooth surface by using a cutter with bicircular profile and optimal diameter. In the optimization of tool parameters the influence of shaft misalignments of the mating members is included. As the result of these modifications a point contact of the meshed teeth surfaces appears instead of line contact; the hypoid gear pair becomes mismatched. By using the method presented in (Simon, V., 2000, “Load Distribution in Hypoid Gears,” ASME J. Mech. Des., 122, pp. 529–535) the influence of tooth modifications introduced on tooth contact and transmission errors is investigated. Based on the results that was obtained the radii and position of circular tool profile arcs and the diameter of the cutter for pinion teeth generation were optimized. By applying the optimal tool parameters, the maximum tooth contact pressure is reduced by 16.22% and the angular position error of the driven gear by 178.72%, in regard to the hypoid gear pair with a pinion manufactured by a cutter of straight-sided profile and of diameter determined by the commonly used methods.

Optimal Machine-Tool Settings for the Manufacture of Face-Hobbed Spiral Bevel Gears

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Contact Pressure ◽  
Optimization Problem ◽  
Transmission Error ◽  
Search Method ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Transmission Errors ◽  
Bevel Gears ◽  
Spiral Bevel ◽  
Loaded Tooth Contact Analysis

In this study, an optimization methodology is proposed to systematically define the optimal head-cutter geometry and machine-tool settings to simultaneously minimize the tooth contact pressure and angular displacement error of the driven gear (the transmission error), and to reduce the sensitivity of face-hobbed spiral bevel gears to the misalignments. The proposed optimization procedure relies heavily on the loaded tooth contact analysis for the prediction of tooth contact pressure distribution and transmission errors influenced by the misalignments inherent in the gear pair. The load distribution and transmission error calculation method employed in this study were developed by the author of this paper. The targeted optimization problem is a nonlinear constrained optimization problem, belonging to the framework of nonlinear programming. In addition, the objective function and the constraints are not available analytically, but they are computable, i.e., they exist numerically through the loaded tooth contact analysis. For these reasons, a nonderivative method is selected to solve this particular optimization problem. That is the reason that the core algorithm of the proposed nonlinear programming procedure is based on a direct search method. The Hooke and Jeeves pattern search method is applied. The effectiveness of this optimization was demonstrated on a face-hobbed spiral bevel gear example. Drastic reductions in the maximum tooth contact pressure (62%) and in the transmission errors (70%) were obtained.

scholarly journals A Method for Thermal Analysis of Spiral Bevel Gears

1996 ◽  
Vol 118 (4) ◽  
pp. 580-585 ◽  
Author(s):  
R. F. Handschuh ◽  
T. P. Kicher
Keyword(s):  
Three Dimensional ◽  
Contact Analysis ◽  
Heat Transfer Analysis ◽  
Maximum Pressure ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Finite Element Program ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Spiral Bevel

A modelling method for analyzing the three-dimensional thermal behavior of spiral bevel gears has been developed. The model surfaces are generated through application of differential geometry to the manufacturing process for face-milled spiral bevel gears. Contact on the gear surface is found by combining tooth contact analysis with three-dimensional Hertzian theory. The tooth contact analysis provides the principle curvatures and orientations of the two surfaces. This information is then used directly in the Hertzian analysis to find the contact size and maximum pressure. Heat generation during meshing is determined as a function of the applied load, sliding velocity, and coefficient of friction. Each of these factors change as the point of contact changes during meshing. A nonlinear finite element program was used to conduct the heat transfer analysis. This program permitted the time- and position-varying boundary conditions, found in operation, to be applied to a one-tooth model. An example model and analytical results are presented.

A Theoretical Tribological Comparison Between Soft and Hard Coatings of Spur Gear Pairs

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Huaiju Liu ◽  
Caichao Zhu ◽  
Zhanjiang Wang ◽  
Ye Zhou ◽  
Yuanyuan Zhang
Keyword(s):  
Surface Deformation ◽  
Tribological Behavior ◽  
Elastohydrodynamic Lubrication ◽  
Spur Gear ◽  
Hard Coatings ◽  
Radius Of Curvature ◽  
Maximum Pressure ◽  
Gear Pair ◽  
The Coefficient Of Friction ◽  
Squeeze Effect

A thermal elastohydrodynamic lubrication (TEHL) model is developed for a coated spur gear pair to investigate the effect of soft coatings and hard coatings on the tribological behavior of such a gear pair during meshing. The coating properties, i.e., the ratio of the Young's modulus between the coating and the substrate, and the coating thickness, are represented in the calculation of the elastic deformation. Discrete convolution, fast Fourier transform (DC-FFT) is utilized for the fast calculation of the surface deformation. The variation of the radius of curvature, the rolling speed, the slide-to-roll ratio, and the tooth load along the line of action (LOA) during meshing is taken into account and the transient squeeze effect is considered in the Reynolds equation. Energy equations of the solids and the oil film are derived. The temperature field and the pressure field are solved iteratively. The tribological behavior is evaluated in terms of the minimum film thickness, the maximum pressure, the temperature rise, the coefficient of friction, and the frictional power loss of the tooth contact during meshing. The results show discrepancies between the soft coating results and hard coating results.

Visualization of Contact-Pressure Distribution between Material and Backing Plate in Friction Stir Processing

2018 ◽  
Vol 765 ◽  
pp. 199-203
Author(s):  
Takahiro Ohashi ◽  
Xin Tong ◽  
Zi Jie Zhao ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Pressure Distribution ◽  
Contact Pressure ◽  
Friction Stir Processing ◽  
Maximum Pressure ◽  
Height Distribution ◽  
Contact Pressure Distribution ◽  
Friction Stir ◽  
Backing Plate ◽  
Load Sensor ◽  
Tool Position

In this study, the authors evaluated pressure distribution on a backing plate in friction-stir processing (FSP) utilizing an embedded pressure pin connected to a load sensor. They conducted FSP on aluminum alloy plates repeatedly offsetting the path-lines from the center of the pin and recorded change of forming pressure with tool position, which was compiled from the bearing load of the pin. The authors mapped the results to visualize the two-dimensional contact pressure distribution on a backing plate during FSP. They then compared the height distribution of the wall fabricated by friction-stir forming (FSF) utilizing a die having a groove with the observed distribution of pressure. Consequently, maximum pressure was observed beneath the rim of the tool probe at the retreating side (RS), and the highest points of the wall were observed at the RS.

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