The Impact of Helical Gear Parameters Based on Axial Meshing Transmission on Swash Plate Pulse CVT Characteristics

2011 ◽  
Vol 101-102 ◽  
pp. 224-227 ◽  
Author(s):  
Jian Dong Sun ◽  
E. Tian ◽  
Hong Lei ◽  
Zi Ping Liu ◽  
Wen Yu Fu
Keyword(s):  
Cross Section ◽  
Gear Tooth ◽  
Helix Angle ◽  
Helical Gear ◽  
Plate Surface ◽  
Input Shaft ◽  
Output Torque ◽  
Swash Plate ◽  
Mechanical Pulse ◽  
The Impact

A new structure of mechanical pulse CVT –rotational swash plate pulse CVT was put forward. This paper analyzed the impact of helical gear parameters on swash plate pulse CVT characteristics, it can be seen that the angular velocity of output shaft is proportional to the angle between Swash plate surface and vertical cross section of the input shaft and the swash plate surface, the gear modulus has no effect on the transmission ratio, the guide rod pitch diameter is the major factor contacting gear tooth Strength, when the other parameters unchanged, ( is the pitch helix angle)is proportional to the output torque, and is inversely proportional to the output torque.

Investigating the effect of helix angle and pressure angle on bending stress in helical gear under dynamic state

2018 ◽  
Vol 15 (4) ◽  
pp. 478-488
Author(s):  
Prashant Jaysing Patil ◽  
Maharudra Patil ◽  
Krishnakumar Joshi
Keyword(s):  
Gear Tooth ◽  
Helix Angle ◽  
Helical Gear ◽  
Dynamic State ◽  
Load Carrying Capacity ◽  
Bending Stress ◽  
Content Type ◽  
Gear Design ◽  
Pressure Angle ◽  
Load Carrying

Purpose The aim of this paper is to study the effect of pressure angle and helix angle on bending stress at the root of helical gear tooth under dynamic state. Gear design is a highly complex process. The consistent demand to build low-cost, quieter and efficient machinery has resulted in a gradual change in gear design. Gear parameters such as pressure angle, helix angle, etc. affect the load-carrying capacity of gear teeth. Adequate load-carrying capacity of a gear is a prime requirement. The failure at the critical section because of bending stress is an unavoidable phenomenon. Besides this fact, the extent of these failures can be reduced by a proper gear design. The stresses produced under dynamic loading conditions in machine member differ considerably from those produced under static loading. Design/methodology/approach The present work is intended to study the effect of pressure angle and helix angle on the bending stress at the root of helical gear tooth under dynamic state. The photostress method has been used as experimental methods. Theoretical analysis was carried out by velocity factor method and Spott’s equation. LS DYNA has been used for finite element (FE) analysis. Findings The results show that experimental method gives a bending stress value that is closer to the true value, and bending stress varies with pressure angle and helix angle. The photostress technique gives clear knowledge of stress pattern at root of tooth. Originality/value The outcomes of this work help the designer use optimum weight-to-torque ratio of gear; this is ultimately going to reduce the total bulk of the gear box.

Laser Holographic Measurement of Tooth Flank Form of Cylindrical Involute Gear: Part 2 — For Helical Gear Tooth

1992 ◽  
Author(s):  
H. Fujio ◽  
A. Kubo ◽  
S. Tochimoto ◽  
H. Hanaki ◽  
S. Saitoh ◽  
...  
Keyword(s):  
Gear Tooth ◽  
Measuring Method ◽  
Helix Angle ◽  
Helical Gear ◽  
Helical Gears ◽  
Error Surface ◽  
Tooth Flank ◽  
Form Deviation ◽  
Laser Holography ◽  
Holographic Measurement

Abstract The interferometry using laser holography is applied to measure the form deviation of tooth flank of involute helical gears. One problem of this method is that the increase of helix angle reduces the region of the flank to which the laser beam can irradiate at a same time. To solve this problem, following method is developed: The objective tooth flank is divided into some regions, and the interferometry measurement is worked out for each region. The measured values for the form deviation of each region of the tooth flank are transformed to the values on the plane of action of this gear. These values for each region of the tooth flank are then concatenated successively until they result the curved surface for the form deviation of the whole tooth flank of the helical gear. The error surface of the tooth flank of helical gear obtained by this procedure is compared with that of conventional measuring method using contacting stylus.

Simulation Research on Tooth Root Dynamic Stress of Marine Helical Gear Meshing Impact

2013 ◽  
Vol 331 ◽  
pp. 7-10
Author(s):  
Yu Bai Zhang ◽  
Hui Qun Yuan ◽  
Ming Xuan Liang
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Performance Optimization ◽  
Dynamic Stress ◽  
Gear Tooth ◽  
Dynamic Performance ◽  
Element Model ◽  
Helical Gear ◽  
Tooth Root ◽  
The Impact

Finite element model of helical gear meshing of large burden marine is built based on explicit dynamics finite element method, dynamics stress variation of helical gear tooth is simulated under multiple working conditions, research is focused on the impact of changes in working conditions on the dynamic stress of the tooth root. The results show that helical gear pair speed and center distance error have great impact on dynamic stress of tooth root. The results provide reference for dynamic performance optimization of marine gears.

Contact Stress Analysis of a Helical Gear

2015 ◽  
Vol 766-767 ◽  
pp. 1070-1075 ◽  
Author(s):  
R. Devaraj
Keyword(s):  
Stress Analysis ◽  
Contact Stress ◽  
Gear Tooth ◽  
Element Model ◽  
Helix Angle ◽  
Helical Gear ◽  
Bending Stress ◽  
Helical Gears ◽  
Modeling Software ◽  
Main Factors

The main factors that cause the failure of gears are the bending stress and contact stress of the gear tooth. Out of these, failure of gears due to contact stress is high compared to bending stress. Stress analysis has been a key area of research to minimize failure and optimize design. This paper gives a finite element model for introspection of the stresses in the tooth during the meshing of gears. Specifically, helix angle is important for helical gears. Using modeling software, 3-D models for different helix angles in helical gears were generated, and the simulation was performed using ANSYS 12.0 to estimate the contact stress. The Hertz equation and AGMA standard was used to calculate the contact stress. The results of the theoretical contact stress values, using Hertz and AGMA are compared with the stress values from the FEA for different helix angles and the results are tabulated and discussed.

Simulated Helical Gear Pump Analysis Using a New CFD Approach

2009 ◽  
Author(s):  
Aaron S. Heisler ◽  
John J. Moskwa ◽  
Frank J. Fronczak
Keyword(s):  
High Speed ◽  
System Development ◽  
Gear Tooth ◽  
Fluid Motion ◽  
Computation Time ◽  
Helix Angle ◽  
Helical Gear ◽  
Gear Pump ◽  
Helical Gears ◽  
Gear Pumps

The purpose of this paper is to focus on cavitation prediction at high-speeds in helical gear pumps for the purpose of hydrostatic dynamometer system development. Details of the fluid motion will be described through various stages of fluid transfer from the pump inlet to the outlet using various mesh densities. Using the results of these simulations, a discussion of design improvements for high-speed hydrostatic dynamometer operation is included. Conducting CFD simulations on external gear pumps is a difficult problem depending upon the complexity of the individual components. Simulating helical gears is especially taxing due to the complexity of the gear tooth profile. The additional detail in a helical gear pump model leads to an increase of the required mesh density and therefore increased computation time. A less computationally complex approach to simulating helical gears is to consider a helical gear as a series of thin spur gears rotated according to a predetermined helix angle. Details of this approach and results are discussed in this paper.

scholarly journals Charged current Drell-Yan production at N3LO

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Claude Duhr ◽  
Falko Dulat ◽  
Bernhard Mistlberger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Production Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
Charge Asymmetry ◽  
Charged Current ◽  
Leading Order ◽  
Neutrino Pair ◽  
The Impact

Abstract We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to-leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual W± boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of W± bosons, as well as on the ratios of the production cross sections for W+, W− and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC.

Influence of gear tooth addendum and dedendum on the helical gear optimization considering mass, efficiency, and transmission error

2021 ◽  
Vol 166 ◽  
pp. 104476
Author(s):  
Chanho Choi ◽  
Hyoungjong Ahn ◽  
Young-jun Park ◽  
Geun-ho Lee ◽  
Su-chul Kim
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Helical Gear

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

Geometry Design and Contact Ratio Analysis for Circular Arc Parallel-Axis Helical Gears

2016 ◽  
Author(s):  
Z. Chen ◽  
B. Lei ◽  
Q. Zhao
Keyword(s):  
Rolling Process ◽  
Helical Gear ◽  
Space Curve ◽  
Impact Factors ◽  
Contact Ratio ◽  
Circular Arc ◽  
Practical Applications ◽  
Geometry Design ◽  
Gear Mechanism ◽  
The Impact

Based on space curve meshing theory, in this paper, we present a novel geometric design of a circular arc helical gear mechanism for parallel transmission with convex-concave circular arc profiles. The parameter equations describing the contact curves for both the driving gear and the driven gear were deduced from the space curve meshing equations, and parameter equations for calculating the convex-concave circular arc profiles were established both for internal meshing and external meshing. Furthermore, a formula for the contact ratio was deduced, and the impact factors influencing the contact ratio are discussed. Using the deduced equations, several numerical examples were considered to validate the contact ratio equation. The circular arc helical gear mechanism investigated in this study showed a high gear transmission performance when considering practical applications, such as a pure rolling process, a high contact ratio, and a large comprehensive strength.

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