scholarly journals Dynamic Stiffness Effect of Mechanical Components on Gear Mesh Misalignment

2018 ◽  
Vol 8 (6) ◽  
pp. 844 ◽  
Author(s):  
Jin-Gyun Kim ◽  
Ga Gang ◽  
Seung-Je Cho ◽  
Geun Lee ◽  
Young-Jun Park
Keyword(s):  
Dynamic Stiffness ◽  
Gear Mesh ◽  
Mechanical Components ◽  
Gear Mesh Misalignment

Hobbing of Cylindrical Wheels without Coolants

2019 ◽  
Vol 973 ◽  
pp. 139-144
Author(s):  
Aleksandr S. Kalashnikov ◽  
Yuriy A. Morgunov ◽  
Pavel A. Kalashnikov
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Dynamic Stiffness ◽  
High Speed Steel ◽  
Cutting Conditions ◽  
Automation System ◽  
Cutting Fluids ◽  
Experimental Conditions ◽  
Gear Mesh ◽  
Worm Wheel

This article studies dry hobbing of external cylindrical wheels by worm wheel hobs and reasons why some gear manufactures use hobbing without cutting fluids. Cutting fluids reduce frictional wear, provides temperature cooling of the tool or workpiece and helps flush away the chips from the cutting zone. But uneven cooling and different cutting conditions on the engaging and disengaging sides of a gear mesh provoke intensive wear of the teeth of the worm wheel hob, thus decreasing the life of worm hobs and increasing both the consumption of cutting tools and expenses for them. In this context, it becomes rather difficult to achieve efficiency and stability for the hobbing process. In the recent times, the cost of coolant disposal has been raised; in some cases, it accounts for 15-20% in terms of shop costs. Research was carried out under the following experimental conditions: a hobbing machine equipped with an automation system of high efficiency and with basic units of high static and dynamic stiffness; a high-accuracy worm hob from powdered metal wear-resistant high-speed steel of grade Р6М5К5; a workholding device with an elastic bush, and various cutting modes. Recommendations are given on using the multi-cycle hob-shifting strategy rather than the strategy of single-cycle shifting; and advantages gained by this technique are observed. Best cutting conditions and precision attained by dry gear-hobbing are described.

scholarly journals Experimental study of the effect of assembly error on the lightly loaded transmission error of spur gear with crown modification

2019 ◽  
Vol 39 (4) ◽  
pp. 1039-1051 ◽  
Author(s):  
Xiong Chun ◽  
Chen Siyu
Keyword(s):  
Transmission Error ◽  
Spur Gear ◽  
Optical Encoder ◽  
Input Shaft ◽  
Gear Mesh ◽  
Impact Deformation ◽  
Dynamic Transmission Error ◽  
Gear Mesh Misalignment ◽  
Assembly Error ◽  
Gear Rattle

Experimental measurement of transmission error and vibration of a gear pair with crown modification are developed. With the help of high-precision optical encoder, effects of gear misalignment on unloaded and lightly loaded dynamic transmission error, which are relative to gear rattle, are investigated. The gear mesh misalignment is introduced by eccentric sleeve assembled on the output shaft. Effects of modification and misalignment on the dynamic transmission error, are studied at different load and driving velocity conditions. The experimental results show that, with the increase of the crown amplitude, the peak-to-peak values of dynamic transmission error are decreasing dramatically. Impact deformation or elastic deformation is a very important part of the dynamic transmission error although they are unloaded or lightly loaded. The components in harmonics of meshing frequency will change distinctly comparing cases at low input shaft velocity without and with misalignment, but different phenomena are detected while increasing the input shaft velocity. Finally, the relation between transmission error and gear box vibration is illustrated, and spectrum kurtosis is introduced to reveal gear rattle.

Research on Gear Mesh Misalignments under the System Deformation

2014 ◽  
Vol 721 ◽  
pp. 140-143 ◽  
Author(s):  
Xiao He Deng
Keyword(s):  
Working Conditions ◽  
Elastic System ◽  
Commercial Vehicle ◽  
Integrated System ◽  
Gear Transmission ◽  
Elastic Model ◽  
Gear Mesh ◽  
Ideal Position ◽  
Gear Mesh Misalignment ◽  
The Ideal

The gear transmission is a complex elastic system. The system deformation under the load will make the position of mating gear deviating from the ideal position. The deformation varies with different gear shifts and load that will cause the different type of gear mesh misalignments. Therefore, the researches on the gear mesh misalignment should consider the effect of deformation of gear system under different working conditions. The paper established an elastic model of commercial vehicle transmission system. The gear mesh misalignments under different shifts and different load are obtained considering the integrated system deformation. The variation values of gear mesh misalignments are analyzed correspondingly.

Analysis of Wind Turbine Gearbox Based on RomaxWIND Flexible FE Structures

2012 ◽  
Vol 512-515 ◽  
pp. 669-674
Author(s):  
You Liang Su ◽  
Chun Xiu Wang ◽  
Wei Jiang ◽  
Li Sun
Keyword(s):  
Simulation Model ◽  
Wind Turbine ◽  
High Reliability ◽  
Ring Gear ◽  
Wind Turbine Gearbox ◽  
Transmit Power ◽  
Gear Mesh ◽  
Gear Mesh Misalignment

Wind turbine gearbox is a key component to transmit power in wind turbine driveline. It is necessary for gearbox to have high reliability and durable quality, and so, it is obviously important to analyze the reliability of key components and the root of common failure. By means of RomaxWIND software, gearbox simulation model was built which is based on the flexible FE structures. Considering the effects of flexible FE structures, such as housing and ring gear, and capturing system effects, analysis is performed to estimate the performance of components under 20 years’ LDD, and the bearing and gear report were generated. Gear mesh misalignment is one of the major gearbox failure causes. In view of it, three different models were built for the analysis of mesh misalignment, the result reveal that the effect of flexible FE structures should not be ignored.

EVALUATION OF MECHANICAL SYSTEMS USED IN PERFUSION

1972 ◽  
Vol 68 (2_Supplb) ◽  
pp. S44-S73 ◽  
Author(s):  
Eugene F. Bernstein
Keyword(s):  
Mechanical Systems ◽  
Organ Perfusion ◽  
Critical Factors ◽  
System 2 ◽  
Common Problems ◽  
Mechanical Components ◽  
Perfusion Experiment ◽  
Selection Of

ABSTRACT Among the critical factors in organ perfusion are (1) the mechanical components of the system, (2) the composition of the perfusate, and (3) the perfusing conditions. In this review, particular consideration is given to the pump, the oxygenator, and cannulas in such systems. Emphasis is placed upon the selection of pertinent equipment for the goals of a particular perfusion experiment, based upon the criteria of adequacy of the perfusion. Common problems in organ perfusion are summarized, and potential solutions to the perfusion problem, involving either biologic or mechanical extracorporeal systems, are suggested.

Repeatability vs. multiple-trait models to evaluate shell dynamic stiffness for layer chickens

2017 ◽  
Vol 95 (1) ◽  
pp. 9 ◽  
Author(s):  
A. Wolc ◽  
J. Arango ◽  
P. Settar ◽  
N. P. O’Sullivan ◽  
J. C. M. Dekkers
Keyword(s):  
Dynamic Stiffness ◽  
Multiple Trait ◽  
Layer Chickens

Dynamic analysis of a helical gear reduction by experimental and numerical methods

2020 ◽  
Vol 68 (1) ◽  
pp. 48-58
Author(s):  
Chao Liu ◽  
Zongde Fang ◽  
Fang Guo ◽  
Long Xiang ◽  
Yabin Guan ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Fourth Order ◽  
Numerical Models ◽  
Helical Gear ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Lumped Mass ◽  
Gear Mesh

Presented in this study is investigation of dynamic behavior of a helical gear reduction by experimental and numerical methods. A closed-loop test rig is designed to measure vibrations of the example system, and the basic principle as well as relevant signal processing method is introduced. A hybrid user-defined element model is established to predict relative vibration acceleration at the gear mesh in a direction normal to contact surfaces. The other two numerical models are also constructed by lumped mass method and contact FEM to compare with the previous model in terms of dynamic responses of the system. First, the experiment data demonstrate that the loaded transmission error calculated by LTCA method is generally acceptable and that the assumption ignoring the tooth backlash is valid under the conditions of large loads. Second, under the common operating conditions, the system vibrations obtained by the experimental and numerical methods primarily occur at the first fourth-order meshing frequencies and that the maximum vibration amplitude, for each method, appears on the fourth-order meshing frequency. Moreover, root-mean-square (RMS) value of the acceleration increases with the increasing loads. Finally, according to the comparison of the simulation results, the variation tendencies of the RMS value along with input rotational speed agree well and that the frequencies where the resonances occur keep coincident generally. With summaries of merit and demerit, application of each numerical method is suggested for dynamic analysis of cylindrical gear system, which aids designers for desirable dynamic behavior of the system and better solutions to engineering problems.

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