Methods of Describing Plastic Gear Geometry After a Temperature Change With Application to the Prediction of Gear Load Distribution

2011 ◽  
Author(s):  
Sumanth Kashyap ◽  
Donald R. Houser ◽  
Zan Smith ◽  
Senthilvelan Selvaraj ◽  
James M. Casella ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Load Distribution ◽  
Gear Tooth ◽  
Linear Thermal Expansion ◽  
Transmission Error ◽  
Distribution Analysis ◽  
Element Analysis ◽  
Slope Change ◽  
Measuring Machine ◽  
Plastic Gears

In Polymer gears, the rise in temperature not only influences gear rigidity but also tooth geometry. This paper presents methods to represent the influence of temperature by change in micro-geometry and macro-geometry parameters of the gear tooth. These macro and micro-geometry parameters of gear are entered into advanced gear analysis programs such as those for performing load distribution analysis and transmission error prediction. This theoretical model assumes linear thermal expansion of the material of the gear. This model is verified using a Finite Element Analysis (FEA) of the gear tooth. Two approaches were successfully used to model the thermal expansion of the material, one being to change the module of the gear and the other being to apply a pressure angle slope change to the tooth form. The profile change was verified by elevating the temperature of plastic gears of several materials and then measuring them on a Gear–Co-ordinate Measuring Machine. The two approaches were used in compatible load analysis programs that produced essentially identical transmission error predictions.

scholarly journals Thermal analysis of metal-ceramic bonding using finite element method

2014 ◽  
Vol 3 (2) ◽  
pp. 216 ◽  
Author(s):  
S. Gopinath ◽  
R Sabarish ◽  
R. Sasidharan
Keyword(s):  
Finite Element ◽  
Thermal Expansion ◽  
Thermal Stress ◽  
Bonding Strength ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Processing Temperature ◽  
Element Analysis ◽  
Metal Ceramic ◽  
The Difference

This paper reports a finite element study of effect of bonding strength between metal and ceramic. The bonding strength is evaluated with different processing temperature and holding time. The difference between the coefficients of linear thermal expansion (CTEs) of the metal and ceramic induces thermal stress at the interface. The mismatch thermal stress at the interface region plays an important role in improving bonding strength. Hence, it is essential to evaluate the interface bonding in metal-ceramics joints. The Al/SiC bonding was modeled and analyzed using finite element analysis in ANSYS (v.10). Keywords: Bonding Strength, Coefficient of Thermal Expansion, Thermal Stress, Interface, Al/Sic, FEA.

Recent Progress and Prospect on Tooth Modification of Involute Cylindrical Gear

2021 ◽  
Vol 14 ◽  
Author(s):  
Lin Han ◽  
Yang Qi
Keyword(s):  
Load Distribution ◽  
Power Transmission ◽  
Gear Tooth ◽  
Transmission Error ◽  
Gear Pair ◽  
Cylindrical Gear ◽  
Tooth Width ◽  
Modification Method ◽  
Power Transmission Systems ◽  
Tooth Modification

Background: Recent reviews on tooth modification of involute cylindrical gear are presented. Gear pairs are widely employed in motion and power transmission systems. Manufacturing and assembling errors of gear parts, time-varying mesh stiffness and transmission error of gear pair, usually induce vibration, noise, non-uniformly load distribution and stress concentration, resulting in earlier failure of gear. Tooth modification is regarded as one of the most popular ways to suppress vibration, reduce noise level, and improve load distribution of gear pairs. Objective: To provide an overview of recent research and patents on tooth modification method and technology. Methods: This article reviews related research and patents on tooth modification. The modification method, evaluation, optimization and machining technology are introduced. Results: Three types of modifications are compared and analyzed, and influences of each on both static and dynamic performances of gear pair are concluded. By summarizing a number of patents and research about tooth modification of cylindrical gears, the current and future development of research and patent are also discussed. Conclusion: Tooth modification is classified into tip or root relief along tooth profile, lead crown modification along tooth width and compound modification. Each could be applied in different ways. In view of design, optimization under given working condition to get optimal modification parameters is more practical. Machining technology and device for modified gear is a key to get high quality performance of geared transmission. More patents on tooth modification should be invented in future.

Analysis of a Cycloid Speed Reducer Considering Tooth Profile Modification and Clearance-Fit Output Mechanism

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Xuan Li ◽  
Chaoyang Li ◽  
Yawen Wang ◽  
Bingkui Chen ◽  
Teik C. Lim
Keyword(s):  
Performance Evaluation ◽  
Load Distribution ◽  
Transmission Error ◽  
Gear Ratio ◽  
Analytical Models ◽  
Distribution Analysis ◽  
Profile Modification ◽  
Proposed Model ◽  
Speed Reducer ◽  
Stress Transmission

The load distribution analysis plays a significant role in the performance evaluation of cycloid speed reducer. However, current analytical models usually ignore elastic deformation, clearances, or assembly errors. These factors must be considered for realistic performance evaluation of cycloid speed reducer. This paper proposes an analytical model for cycloid speed reducer based on unloaded tooth contact and load distribution analyses. The proposed model can predict the loads on various components of the speed reducer in the presence of clearances and eccentricity errors. The results are compared with those predicted by the cycloid speed reducer model based on theoretical geometry. The effect of radial and pin-hole clearances as well as eccentricity errors, on some key design factors, such as contact stress, transmission error, gear ratio, and load on bearing, is investigated. This study can be used to assist the optimal design of cycloid speed reducers.

Minimization of transmission errors in highly loaded plastic gear trains

2007 ◽  
Vol 221 (9) ◽  
pp. 1117-1129 ◽  
Author(s):  
P Klein Meuleman ◽  
D Walton ◽  
K D Dearn ◽  
D J Weale ◽  
I Driessen
Keyword(s):  
Gear Tooth ◽  
Dissimilar Materials ◽  
Design Guidelines ◽  
Beam Model ◽  
Element Analysis ◽  
Transmission Errors ◽  
Theoretical Predictions ◽  
Tooth Stiffness ◽  
Gear Trains ◽  
Plastic Gears

Transmission errors (TEs) are an important source of unwanted noise and vibration in gear drives. Errors can result from geometrical inaccuracies and from elastic deformations. Plastic drives are often loaded in a way that produces high deflections relative to steel gears, and the elastic component of TE is relatively more important. Furthermore, plastic gears are often run in mesh with gears made from steel or other metals. In this case there is a large difference in tooth stiffness, which leads to unusual TE problems. The current paper discusses the origins of elastic TEs and means of their calculation. A simple beam model is used to demonstrate the stiffness of a pair of meshing gear teeth. A finite-element analysis is used to refine this model and to run iterative tooth meshing enabling TEs to be accurately characterized. A number of TE traces from gear pairs running under high loads are included and compared with the theoretical predictions. Several different scenarios are proposed including balancing gear tooth stiffness for dissimilar materials and the adjustment of pressure angle to account for tooth deflection. A set of design guidelines are presented in the conclusions. A case study of a precision printer drive is used to illustrate some of the techniques for the minimization of TEs.

Load Distribution in Cylindrical Worm Gears

2000 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

Abstract A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases — that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

scholarly journals Experimental Study of Drilling Temperature, Geometrical Errors and Thermal Expansion of Drill on Hole Accuracy When Drilling CFRP/Ti Alloy Stacks

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3232 ◽  
Author(s):  
Vitalii Kolesnyk ◽  
Jozef Peterka ◽  
Marcel Kuruc ◽  
Vladimír Šimna ◽  
Jana Moravčíková ◽  
...  
Keyword(s):  
Experimental Study ◽  
Thermal Expansion ◽  
Time Delay ◽  
Ti Alloy ◽  
Element Analysis ◽  
Machine Method ◽  
Drilling Temperature ◽  
Measuring Machine ◽  
The Impact ◽  
Delay Factor

The drilling of holes in CFRP/Ti (Carbon Fiber-Reinforced Plastic/Titanium alloy) alloy stacks is one of the frequently used mechanical operations during the manufacturing of fastening assemblies in temporary civil aircraft. A combination of inhomogeneous behavior and poor machinability of CFRP/Ti alloy stacks in one short drilling brought challenges to the manufacturing community. The impact of the drilling temperature and time delay factor under various cutting conditions on hole accuracy when machining CFRP/Ti alloy stacks is poorly studied. In this paper, the drilling temperature, the phenomenon of thermal expansion of the drill tool, and hole accuracy are investigated. An experimental study was carried out using thermocouples, the coordinate measuring machine method, and finite element analysis. The results showed that the time delay factor varied from 5 (s) to 120 (s), influences the thermal-dependent properties of CFRP, and leads to an increase in hole roundness. Additionally, the thermal expansion of the drill significantly contributes to the deviation of the hole diameter in Ti alloy.

Load Distribution in Cylindrical Worm Gears

2003 ◽  
Vol 125 (2) ◽  
pp. 356-364 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases—that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

scholarly journals Statistical Analysis for Transmission Error of Gear System with Mechanical and Thermal Deformation Uncertainties

2021 ◽  
Vol 11 (14) ◽  
pp. 6582
Author(s):  
Joon-Ho Lee ◽  
Hee-Sun Choi ◽  
Jong-Hyeon Sohn ◽  
Geun-Ho Lee ◽  
Dong-Il Park ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Thermal Deformation ◽  
Gear Tooth ◽  
Transmission Error ◽  
Spur Gear ◽  
Geometric Error ◽  
Tooth Contact Analysis ◽  
System Uncertainties ◽  
Plastic Gears ◽  
The Impact

We establish a robust algorithm to analyze the influence of system uncertainties on the transmission error of a spur gear pair under 2D simplification. The algorithm provides a way of generating smooth cutter profiles with machining uncertainties and measuring the thermal deformation through the uncertainties in material properties. Then, it produces realizations of gear tooth profiles based on the analytical method for accuracy and computational efficiency. Numerical investigations show the statistical analysis on the tooth contact analysis by comparing steel and plastic gears. It is worthwhile remarking that the plastic gear is susceptible to the geometric error caused by thermal deformation. Moreover, although the impact of thermal deformation on steel gear may seem slim, it can have a noticeable influence when it exists with mechanical uncertainties together.

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