Effects of Moving Speeds of Dynamic Loads on the Deflections of Gear Teeth

1981 ◽  
Vol 103 (2) ◽  
pp. 357-363 ◽  
Author(s):  
K. Nagaya ◽  
S. Uematsu

For the dynamic response problems of gear teeth, the dynamic loads which act upon the gear teeth should be considered as a function of both the position and the moving speed. In previous studies, the effects of the moving speed have not been considered. In this paper the effects of the moving speed of dynamic loads on the deflection and the bending moment of the gear tooth are investigated. The results are obtained from the elastodynamic analysis of the tapered Timoshenko beam.

2014 ◽  
Vol 889-890 ◽  
pp. 527-531
Author(s):  
V. Balambica ◽  
T. Jayachandra Prabhu ◽  
R. Venkatesh Babu

Gears play an important role in every aspect of power and motion of transmission from historical period to modern day period . Due to this , gear design has become a complicated art.A considerable amount of research has been carried out to determine the amount of dynamic gear tooth loads acting.The findings of the dynamic load between the gear teeth results in difficulty for the designer.In this paper, an effort has been made to formulate a simple design procedure for calculating the dynamic load .Earlier the stiffness characteristics and deformation of the gear tooth were studied to predict the dynamic load acting. This was developed with the tooth assumed as a short cantilever.Whereas in reality, an involute profile exists in a spur gear tooth.Based on this reality, work has been done to model the exact profile of the tooth.Later ,the stiffness characteristics were carefully analysed and an improvement was thus made. It was proved that FEA is one such technique that can be used for predicting dynamic loads acting on a gear tooth.


1985 ◽  
Vol 52 (2) ◽  
pp. 439-445 ◽  
Author(s):  
T. J. Ross

The problem of a viscoelastic Timoshenko beam subjected to a transversely applied step-loading is solved using the Laplace transform method. It is established that the support shear force is amplified more than the support bending moment for a fixed-end beam when strain rate influences are accounted for implicitly in the viscoelastic constitutive formulation.


2003 ◽  
Vol 267 (5) ◽  
pp. 1065-1084 ◽  
Author(s):  
L. Vedmar ◽  
A. Andersson
Keyword(s):  

Author(s):  
Timothy L. Krantz

Abstract Two versions of the planetary reduction stages from U.S. Army OH-58 helicopter main rotor transmissions were tested at the NASA Lewis Research Center. One sequential and one nonsequential planetary were tested. Sun gear and ring gear teeth strains were measured, and stresses were calculated from the strains. The alternating stress at the fillet of both the loaded and unloaded sides of the teeth and at the root of the sun gear teeth are reported. Typical stress variations as the gear tooth moves through the mesh are illustrated. At the tooth root location of the thin-rimmed sun gear, a significant stress was produced by a phenomenon other than the passing of a planet gear. The load variation among the planets was studied. Each planet produced its own distinctive load distribution on the ring and sun gears. The load variation was less for a three-planet, nonsequential design as compared to that of a four-planet, sequential design. The results reported enhance the data base for gear stress levels and provide data for the validation of analytical methods.


2019 ◽  
Vol 5 (8) ◽  
pp. 1738-1752 ◽  
Author(s):  
Saif Khalil Ibrahim ◽  
Waad A. Zakaria

This paper presents an experimental study on the dynamic response of square footings under effect of dynamic load comes from adjacent footing called the (source of vibration (which is excited by a known vibration source placed on the top of it, the objective is to study the effect of dynamic motion of the source of vibration on a nearby footing, called second footing, both footings rest on collapsible soil (gypseouse soil) with gypseouse content (60%). The study is performed through wide experimental program in dry and soaked condition. The first footing (source vibration) and the second footing have dimensions (80 80 40), (100 100 40) mm respectively and are manufactured from steel, then the two footings placed centrally over soil after prepared it in layers’ form in steel container with (1000 500 500) mm. The first footing exposed to vertical harmonic loading by using a rotating mass type mechanical oscillator to gives a similar effect of the dynamic loads, the second footing loaded with static weight only, under the dynamic excitation. The tests are conducted under dynamic response for three frequencies (10, 20, 30) Hz, the movement (displacement amplitude, velocity, and acceleration) of the second footing studied by varying spacing between the footings. The results showed that the amplitude of displacement, velocity, and acceleration for the second footing decreases when the spacing between footing increase. In addition, the value of these parameters at dry state is greater than its value at soaked state.


Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 609
Author(s):  
Lingli Cui ◽  
Tongtong Liu ◽  
Jinfeng Huang ◽  
Huaqing Wang

This paper investigates the effect of a gear tooth peeling on meshing stiffness of involute gears. The tooth of the gear wheel is symmetric about the axis, and its symmetry will change after the gear spalling, and its meshing stiffness will also change during the meshing process. On this basis, an analytical model was developed, and based on the energy method a meshing stiffness algorithm for the complete meshing process of single gear teeth with peeling gears was proposed. According to the influence of the change of meshing point relative to the peeling position on the meshing stiffness, this algorithm calculates its stiffness separately. The influence of the peeling sizes on mesh stiffness is studied by simulation analysis. As a very important parameter, the study of gear mesh stiffness is of great significance to the monitoring of working conditions and the prevention of sudden failure of the gear box system.


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.


1976 ◽  
Vol 19 (133) ◽  
pp. 808-813 ◽  
Author(s):  
Toshimi TOBE ◽  
Keijin SATO ◽  
Nobuo TAKATSU

2013 ◽  
Vol 706-708 ◽  
pp. 1290-1293 ◽  
Author(s):  
Lei Zhao ◽  
Qing Qing Lv ◽  
Li Quan Yang

Based on the FEA software ANSYS Workbench, the soft body dynamics performance of the gear pump gear mesh of a hydraulic pump company was analyzed. In the practical engineering applications, gear pump gear teeth are effected by alternating pressure in the two working cavity. It can cause pitting corrosion damage for gear tooth, and even cause tooth crack and fracture. At first, a three dimension finite element models of the gear pump gear teeth was established. In the start-up process, the gear pump tooth mesh deputy of tooth contact stress strain and dynamic characteristics of gear teeth was analyzed. Obtain the velocity curves, acceleration curve and tooth contact stress and strain dynamic curves of the tooth of gear pump. Providing a new analysis method for gear pump of gear Structure design and having a practical application value.


Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1224
Author(s):  
Layue Zhao ◽  
Yimin Shao ◽  
Minggang Du ◽  
Yang Yang ◽  
Jixuan Bian

Micropitting is a surface fatigue phenomenon that occurs in Hertzian type of rolling and sliding contact that operates in elastohydrodynamic or boundary lubrication regimes and can progress both in terms of depth and extent. If micropitting continues to propagate, it may result in reducing gear tooth accuracy, increasing dynamic loads and noise. Eventually, it can develop into macropitting and other modes of gear failure such as flank initiated bending fatigue. Micropitting has become a particular problem in the gear surface fatigue. Usually micropitting initiates in the dedendum of the driver and driven at the asperities on the surface. However, the authors found for some gears with interference fit connections of their conical surface, micropitting on the pinion occurs in the addendum. This study attempted to find the reason using a 3D–TCA method based on ISO/TR 15144-1 to predict the micropitting and try to understand the key influence likely to affect micropitting location.


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