scholarly journals Design Method of Vibrationally Optimum Tooth Flank Form for Involute Helical Gears with Scattering in Pressure Angle and Helix Angle Deviation.

2000 ◽  
Vol 66 (646) ◽  
pp. 1959-1966 ◽  
Author(s):  
Masaharu KOMORI ◽  
Aizoh KUBO ◽  
Yoshiki KAWASAKI
Keyword(s):  
Design Method ◽  
Helix Angle ◽  
Helical Gears ◽  
Pressure Angle ◽  
Angle Deviation ◽  
Tooth Flank

Design Method of Vibrationally Optimum Tooth Flank Form for Involute Helical Gears With Scattering in Pressure Angle and Helix Angle Deviation

2000 ◽  
Author(s):  
Masaharu Komori ◽  
Aizoh Kubo ◽  
Yoshiki Kawasaki
Keyword(s):  
Vibrational Excitation ◽  
Helix Angle ◽  
Design Stage ◽  
Geometrical Shape ◽  
Contact Ratio ◽  
Design Algorithm ◽  
Actual Contact ◽  
Pressure Angle ◽  
Angle Deviation ◽  
Tooth Flank

Abstract The detail in geometrical shape of each tooth flank of a mass-production gear is usually not the same. Even a slight deviation of tooth flank form of several micrometers has a big influence on the running vibration/noise of transmission gear box. The influence of scattering in tooth flank form on the vibrational characteristics of gears must therefore be taken into consideration at the design stage to achieve low vibration gears. In this report, the influence of typical types of scattering, i.e. in pressure angle deviation and helix angle deviation, on the vibrational excitation is clarified in terms of the relationship between vibrational excitation and actual contact ratio. Those types of scattering decrease the actual contact ratio of a gear pair from that value of the tooth flank form designed on a draft. Gears with scattering in tooth flank form can run silenter, when some less amount of tooth flank form modification than the optimum one for gears without scattering is given. The design algorithm for optimum modification of tooth flank form with scattering is proposed.

A Novel Finish Hobbing Methodology for Longitudinal Crowning of a Helical Gear With Twist-Free Tooth Flanks by Using Dual-Lead Hob Cutters

2014 ◽  
Author(s):  
Van-The Tran ◽  
Ruei-Hung Hsu ◽  
Chung-Biau Tsay
Keyword(s):  
Computer Simulation ◽  
Longitudinal Direction ◽  
Helical Gear ◽  
Tooth Profile ◽  
Second Order ◽  
Order Function ◽  
Helical Gears ◽  
Pressure Angle ◽  
Dual Lead ◽  
Tooth Flank

In the gear finish hobbing process, to obtain a twist-free tooth flank of helical gears, a novel hobbing method for longitudinal crowning is proposed by applying a new hob’s diagonal feed motion with a dual-lead hob cutter. Wherein the hob’s diagonal feed motion is set as a second order function of hob’s traverse movement and tooth profile of hob cutter is modified in a dual-lead form with pressure angle changed in it’s longitudinal direction. The proposed method is verified by using two computer simulation examples to compare topographies of the crowned work gear surfaces hobbed by the standard and dual-lead rack cutters. The results reveal the superiority of the proposed novel finish hobbing method.

Modal Analysis and Parameters Research of Internal Helical Gears Based on AWE

2011 ◽  
Vol 86 ◽  
pp. 904-907 ◽  
Author(s):  
Yan Jun Gong ◽  
Xue Yao Wang ◽  
Han Zhao ◽  
Kang Huang
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
Helix Angle ◽  
Helical Gear ◽  
Vibration Characteristics ◽  
Helical Gears ◽  
Pressure Angle ◽  
Number Of Teeth ◽  
Gear Change

The paper conducted a modal analysis of an internal helical gear based on AWE, and obtained its first 6 order natural frequency. Then the paper analyzed the influence of its parameters on the vibration characteristics of the internal helical gear, found that if the helix angle, the normal module, the number of teeth of the internal helical gear change, its vibration characteristics will change, but the change of the pressure angle doesn’t influence its vibration characteristics.

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.

Artifact Design and Measurement Error Analysis in the Evaluation of Lead Measurement Accuracy of Helical Gear Using Wedge Artifact

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
Masaharu Komori ◽  
Fumi Takeoka ◽  
Aizoh Kubo ◽  
Kazuhiko Okamoto ◽  
Sonko Osawa ◽  
...  
Keyword(s):  
Evaluation Method ◽  
Plane Surface ◽  
Design Method ◽  
Measuring Instrument ◽  
Setting Error ◽  
Geometrical Form ◽  
Measurement Experiment ◽  
Mechanical Devices ◽  
Tooth Flank ◽  
Artifact Design

The reduction in the vibration and noise of gears is an important issue in mechanical devices such as vehicles and wind turbines. The characteristics of the vibration and noise of gears are markedly affected by deviations of the tooth flank form of micrometer order; therefore, strict quality control of the tooth flank form is required. The accuracy of the lead measurement for a gear-measuring instrument is usually evaluated using a helicoid artifact. However, it is difficult to manufacture it with high accuracy because the helix is a complicated geometrical form. To solve this problem, a method of evaluating a gear-measuring instrument using a wedge artifact, which includes a highly precise plane surface, has been proposed. In this research, to put the wedge artifact into practice, a design method of the wedge artifact is developed. In addition, the effects of the measuring condition and the setting error of the wedge artifact on the measurement result are investigated. The uncertainty for the evaluation method using a wedge artifact is assessed by a measurement experiment and simulation.

Improving the Characteristics of Gear Pumps: Part A — Discharge

2003 ◽  
Author(s):  
Ahmed M. M. El-Bahloul ◽  
Yasser Z. R. Ali
Keyword(s):  
Correction Factor ◽  
Helix Angle ◽  
Tooth Profile ◽  
Radius Of Curvature ◽  
Circular Arc ◽  
Pressure Angle ◽  
Face Width ◽  
Angle Change ◽  
Number Of Teeth ◽  
Gear Pumps

The main objective of this paper is to study the effect of gear geometry on the discharge of gear pumps. We have used gears of circular-arc tooth profile as gear pumps and have compared between these types of gearing and spur, helical gear pumps according to discharge. The chosen module change from 2 to 16 mm, number of teeth change from 8 to 20 teeth, pressure angle change from 10 to 30 deg, face width change from 20 to 120 mm, correction factor change from −1 to 1, helix angle change from 5 to 30 deg, and radii of curvature equal 1.4, 1.5, 2, 2.5, 2.75, and 3m are considered. The authors deduced that the tooth rack profile with radius of curvature equal 2.5, 2.75, 3m for all addendum circular arc tooth and convex-concave tooth profile, and derived equations representing the tooth profile, and calculated the points of intersections between curves of tooth profile. We drive the formulas for the volume of oil between adjacent teeth. Computer program has been prepared to calculate the discharge from the derived formulae with all variables for different types of gear pumps. Curves showing the change of discharge with module, number of teeth, pressure angle, face width, correction factor, helix angle, and radius of curvature are presented. The results show that: 1) The discharge increases with increasing module, number of teeth, positive correction factor, face width and radius of curvature of the tooth. 2) The discharge increases with increasing pressure angle to a certain value and then decreases with increasing pressure angle. 3) The discharge decreases with increasing helix angle. 4) The convex-concave circular-arc gears gives discharge higher than that of alla ddendum circular arc, spur, and helical gear pumps respectively. 5) A curve fitting of the results are done and the following formulae derived for the discharge of involute and circular arc gear pumps respectively: Q=A1bm2z0.895e0.065xe0.0033αe−0.0079βQ=A2bm2z0.91ρ10.669e−0.0047β

scholarly journals Enhanced application limits for crossed helical gearboxes using new geometries for smaller sliding paths or smaller contact pressures

2019 ◽  
Vol 287 ◽  
pp. 01010
Author(s):  
Christoph Boehme ◽  
Dietmar Vill ◽  
Peter Tenberge
Keyword(s):  
Calculation Method ◽  
Helix Angle ◽  
Helical Gear ◽  
Design Parameters ◽  
Helical Gears ◽  
Positive Effects ◽  
Tooth Stiffness ◽  
Lubrication Condition ◽  
Overlap Ratio ◽  
Helical Gear Pair

Crossed-axis helical gear units are used as actuators and auxiliary drives in large quantities in automotive applications such as window regulators, windscreen wipers and seat adjusters. Commonly gear geometry of crossed helical gears is described with one pitch point. This article deals with an extended calculation method for worm gear units. The extended calculation method increases the range of solutions available for helical gears. In general, for a valid crossed helical gear pair, the rolling cylinders do not have to touch each other. In mass production of many similar gears, individual gears can be reused because they can be paired with other centre distances and ratios. This also allows the use of spur gears in combination with a worm, making manufacturing easier and more efficient. By selecting design parameters, for example the axis crossing angle or the helix angle of a gear, positive effects can be achieved on the tooth contact pressure, the overlap ratio, the sliding paths, the lubrication condition, the tooth stiffness and, to a limited extent, on the efficiency of the gearing. It can be shown that for involute helical gears, in addition to the known insensitivity of the transmission behaviour to centre distance deviations, there is also insensitivity to deviations of the axis crossing angle. This means that installation tolerances for crossed helical gearboxes can be determined more cost-effectively.

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.

On the influence of helix angle and face width on gear windage losses

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1101-1112 ◽  
Author(s):  
Nicolas Voeltzel ◽  
Yann Marchesse ◽  
Christophe Changenet ◽  
Fabrice Ville ◽  
Philippe Velex
Keyword(s):  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Helix Angle ◽  
Spur Gears ◽  
Power Losses ◽  
Flow Rates ◽  
Helical Gears ◽  
Face Width ◽  
Loss Prediction ◽  
Simulated Flow

This paper investigates the windage power losses generated by helical gears rotating in pure air based on experimental results and a computational fluid dynamic code. It is found that the simulated flow patterns are totally different from those calculated for spur gears and that both tooth face width and helix angle are influential. The windage losses derived from Dawson’s and Townsend’s formulae are critically assessed using computational fluid dynamic results thus highlighting the limits of a unique formulation for accurate windage loss prediction. Finally, an analytical approach is suggested which gives good results providing that the flow rates at the boundaries of the inter-tooth domains can be estimated.

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