Gear Generation Research Articles

Generation and Experimental Stress Analysis of Elliptical Gears with Combined Teeth

In this study, generation of elliptical gears with different teeth profiles of crowned involute, double circular arc (DCA), and combined (crowned involute with DCA) has been developed. The resulting mathematical equations have been computerized and feed to CNC end mill machine to manufacture elliptical gear models with different profiles. These models are investigated in plane polariscope to show the resulting stresses under certain load. Comparison of photo-elastic stress results shows that combined elliptical gears with DCA side as a loaded side have a minimum resulting contact stress with a reduction percentage of 40% compare with contact stresses in counterpart elliptical gear of involute profile (which is commonly used in several applications). In this case, bending tooth stress reduction is 47.05% compare with involute elliptical gear. While the reduction in bending stresses of combined elliptical gear becomes higher (52.94% lower than involute gear) when crowned involute side is the loaded side, but the contact stress reduction in this case becomes lower (20% relative to involute gear). Maximum reduction in bending stress can be obtained when single profile of DCA type is used with a reduction of 64.7% relative to involute gear. Therefore; when the application requires a high contact stress resistance, combined profile can be used with DCA side as a loaded side. While in the applications that require high bending stress resistance, DCA profile can be used.

Online estimate and compensation of the gear machining error based on electronic gearbox cross-coupling controller

A novel method for online estimate and compensation of the gear machining error based on the flexible electronic gearbox (EGB) is introduced. EGB is a multi-axis controller, which is used to realize the gear generation process. Gear processing quality is directly dependent on the control precision of EGB. The present work focuses on the estimation, analysis, and compensation of the gear machining error during the gear hobbing process. First, an efficient method for the online evaluation of the helical gear tooth profile deviation, pitch error, and helix deviation is presented, from the perspective of the combination of the multi-axis linkage control structure model and the gear processing technology. Second, the online compensation architecture for the five-axis gear hobbing linkage is proposed, which is composed of an asymmetric cross-coupling controller and a master-slave EGB controller. Simulation results show that the proposed online compensation architecture has better control precision, in comparison to the conventional EGB. Finally, experiments are performed on a six-axis gear hobbing machine, where higher accuracies are obtained for the helical gear, processed by the proposed method.

Intelligent Maximum Power Tracking Control For a Wind Energy System Based on Magnetic Gear Generator

This paper studies maximum wind power extraction from magnetic gear generator using an artificial neural network for the wind energy system. High speed can be reached with this representation either with magnetic gear generator, under low wind conditions often found inland, or without mechanical gear. In order to track maximum power, the artificial neural network controller adjusts the outer rotor speed, and thus, inner rotor speed. The proposed system is supported by simulation results.

A grinding method of face gear mating with a conical spur involute pinion

A grinding method of face gear manufactured by a disk wheel is proposed in this paper. The computerized generation of the face gear by application of a conical spur involute shaper is presented. The tooth surfaces of the face gear are ground point by point with the disk wheel. In addition, a numerical model for determination of envelope residuals of the ground face gear surfaces is established. This model is used to determine the grinding tracks of the disk wheel according to the prescribed processing precision. The manufacture of four different cases of face gears is simulated by applying a simulation platform to illustrate the effectiveness of the proposed grinding method. The results show that deviations of excess greater than the prescribed processing precision only exist on the fillet surfaces and the root of the ground tooth, and increase from the fillet surfaces to the mean section of the root of the face gear. However, this has no influence on the meshing of the face gear drive. The processing efficiency of the face gear grinding is sufficiently affected by the prescribed processing precision.

Issues of Electronic Waste on Life - A Reality

<p>Electronic waste or e-squander is one of the quickest developing issues of the world. E-squander involves a large number of parts, some containing poisonous substances that can adversely affect human wellbeing and the earth if not dealt with legitimately. In India, e-squander the board expect more noteworthy essentialness not just because of the age of its own e-squander, yet additionally as a result of the dumping of e-squander from created nations. This is combined with India's absence of proper foundation and methods for its transfer and reusing. The generation of electrical and electronic gear (EEE) is one of the quickest developing worldwide assembling exercises. Quick monetary development, combined with urbanization and developing an interest for customer merchandise, has expanded both the utilization and the creation of EEE. The Indian data innovation (IT) industry has been one of the real drivers of progress in the economy in the most recent decade and has contributed essentially to the advanced unrest being experienced by the world. New electronic contraptions and machines have invaded each part of our everyday lives, furnishing our general public with more solace, wellbeing, and security and with simple data procurement and trade. The information society anyway is making its own poisonous impressions.</p>

A new closed-form calculation of envelope surface for modeling face gears

Envelope approaches have been widely applied in mechanical engineering to build mathematical and 3D models, which are fundamental elements for the design and manufacturing. It is difficult to obtain both models of face gears since their tooth surfaces are derived from a complex double envelope generation process: the face gear generation with a shaper, and the shaper generation with a rack cutter. According to this process, the conventional approaches calculate the face gear tooth surface from the well-known nonlinear equation of meshing. To avoid this problem, a completely new calculation method of envelope surface is established according to the geometry characteristic of the shaper tooth surface, so the mathematical model of the face gear tooth surface can be directly represented as a closed-form (explicit) rather than implicit one. This method is available to the face gear drives with general spur pinions or the involute helical pinion. Furthermore, an efficient approach is developed to automatically generate the 3D models of face gears. The presented work has two main contributions: (1) the closed-form envelope approach is beneficial to general envelope calculations; (2) The efficient modeling method can also be applied to other types of gear.

ВИКОРИСТАННЯ AUTODESK INVENTOR API ТА МОВИ ПРОГРАМУВАННЯ VISUAL BASIC ДЛЯ ОПРАЦЮВАННЯ ПАРАМЕТРІВ МОДЕЛІ (НА ПРИКЛАДІ ЗУБЧАСТИХ КОЛІС)

The consideration of the adaptation of the Autodesk Inventor package for the execution of drawings, in accordance with current standards was continued. The proposed changes relate to the development of gear models using the appropriate design wizard and the design of their drawings, in particular, the parameter table, according to standards. The created software application for the Autodesk Inventor package is described. It is implemented in the Visual Basic programming language, which provides access to the model database through the application programming interface (API). The choice of the specified programming environment is due to the fact that it is built-in to the Inventor package and has a powerful code debugger. The proposed module creates a number of additional user parameters for the gear model, which are transferred to the drawings made on the basis of the previously developed gear drawings template. This template contains the necessary tables for all variants of cylindrical and conical gears and was described in a previous article [6]. The problem of finding and selecting the necessary parameters from the database of the part has been solved, regardless of the mode of operation of the design wizard used (“component” or “element” modes). Also supported are the models obtained after creating gears with a valid involute tooth profile, obtained in the special mode of the gear generator. The launch of the proposed program is organized with the help of the created command button located on the tool ribbon of the “3D Model” tab. This application is introduced into the educational process and is recommended for industry, which will significantly speed up and simplify the work with the package. Keywords: computer modeling, parameterization, gears, software application, Inventor API, VBA.

Construction of cylindrical toothed gear with a corrected teeth in Inventor. Generator of a cylindrical toothed gear

The article presented the process of construction of a corrected cylindrical gear with straight teeth. The operation of the gear generator is discussed. The procedure of gear engagement correction based on P0 type correction was indicated. Preliminary calculations were made using analytical methods. The work of the generator of gear components was analyzed. Calculation module errors are indicated.

Computerized generation and meshing simulation of face gear drives manufactured by circular cutters

The procedure of computerized generation and the results of simulation of meshing and stress analysis of face gear drives manufactured by circular cutters without considering the feed motion of the circular cutters is presented. A cutter profile tilt angle is introduced and investigated to approximate the generating surfaces of the circular cutter as much as possible to those of the theoretical reference shaper. Six different cases of design are considered to investigate the influence of design parameters on the contact patterns of the gear tooth surfaces. The results include the distribution of deviations of the face gear tooth surfaces with respect to the reference surface geometry generated by a shaper, the contact patterns, function of transmission errors, and the evaluation of stresses all over two cycles of meshing. The analysis of the results shows that the surface deviations due to the generation of the face gear by circular cutters can result in edge contacts, interference, and high stress concentration. However, if the appropriate design parameters for the circular cutters are properly evaluated as a result of simulation and applied as proposed here, the mechanical behavior of the face gear, by means of contact patterns and evolution of stresses can be as good as for the standard geometry of the face gears.

Generation of the teeth precessional gears by plastic deformation

The paper presents a method for obtaining the teeth of the precessional gear by plastic deformation. There are analyzed the basic problems that must be resolved to apply this process: determination of dimensions of initial workpiece; choosing the correct machining regime; determination of necessary forces for material deformation for dimensioning of mechanisms used in machine-tool. The aim is obtaining of precessional gear wheel teeth, still from workpiece to ensure a minimum cost of machining and to improve operating conditions by providing a continuous material fibrillation.

Design and manufacture of new type of non-circular cylindrical gear generated by face-milling method

Face-milling cutting method, widely used in the generation of spiral bevel gear, can also be applied to cylindrical gear fabrication. This paper, generalizing the method to non-circular gear fabrication, proposes a new curvilinear non-circular cylindrical gear type.Compared to spur non-circular gear, this new gear type has a higher contact ratio and compared to helix non-circular gear, it has a smaller axial thrust force. Besides, demonstrating a localized contact pattern, the gear is insensitive to processing and alignment errors. Furthermore, during the driving process, the gear can retain oil within the concave tooth surface, bringing better lubrication.Based on the face-milling cutting method and non-circular gear meshing theory, this paper investigates into curvilinear non-circular gear generation, including the mathematical model for design and the linkage model for manufacture.

Computerized generation and gear mesh simulation of straight bevel gears manufactured by dual interlocking circular cutters

The computerized generation of straight bevel gears manufactured by dual interlocking circular cutters is developed, and the results of the simulation of meshing and contact as well as finite element analysis are shown. The geometry of the crown-rack that theoretically generates the reference octoidal gear is described and, based on it, the positioning of the generating interlocking circular cutters is determined. The influence of the radius of the cutting disks on the maximum bending stresses is investigated and the results exposed. The application of a blade angle to the cutting disks to provide straight bevel gears with longitudinal crowning has also been studied. The influence of the blade angle and disk radius on the amount of crowning applied to the gears is presented. It has been found that when no blade angle is applied and therefore line contact occurs, straight bevel gears generated by cuttings disks with a mean radius larger that a certain value yield lower bending stresses than similar octoidal gears without curved root geometry. For smaller radius, the maximum bending stresses increase exponentially. When the contact is localized by using a blade angle higher than zero, the effect of the curved root geometry of straight bevel gears generated by dual interlocking circular cutters is increased, yielding higher bending stresses with respect to equivalent theoretical octoidal gears with the same amount of longitudinal crowning but without curved root geometry.

Effect of hydrophobic finishing on drag force of swimwear

PurposeDuring 2008 Olympics, Michael Phelps had a record-breaking performance. One contributing factor to his success was the full-body swimsuit he was wearing. Cases like these were the reason for the initiation of study and research for improvement in the new generation of sport gears. The purpose of this paper is to show that drag force plays a significant role in swimmers’ speed through the water; thus, using swimsuit with minimized drag force becomes imperative for Olympians like Michael Phelps.Design/methodology/approachThis paper shows a comparative evaluation of hydrodynamics of three PET fabrics with different finishings that have hydrophobic behavior over a range of Reynolds number 1.0218×103 and 1.365×103 in the air medium at 20°C ambient temperature, and Reynolds number ranging from 15.68856×103 to 20.958×103 in the water medium at 20°C ambient temperature under stable stretch conditions.FindingsThe results show that hydrophobic finishing reduces the drag force by 1.5 percent at the angles of attack of 0 and 90 degrees.Originality/valueIf all the factors are considered to be stable for the swimmer, the drag force reduces by 1.5 percent, thereby increasing the speed of swimmer by 1.22 percent, which means that the record of the swimmer improves by 0.819 seconds.

Revisiting Generation and Meshing Properties of Beveloid Gears

The teeth of ordinary spur and helical gears are generated by a (virtual) rack provided with planar generating surfaces. The resulting tooth surface shapes are a circle-involute cylinder in the case of spur gears, and a circle-involute helicoid for helical gears. Advantages associated with involute geometry are well known. Beveloid gears are often regarded as a generalization of involute cylindrical gears involving one additional degree-of-freedom, in that the midplane of their (virtual) generating rack is inclined with respect to the axis of the gear being generated. A peculiarity of their generation process is that the motion of the generating planar surface, seen from the fixed space, is a rectilinear translation (while the gear blank is rotated about a fixed axis); the component of such translation that is orthogonal to the generating plane is the one that ultimately dictates the shape of the generated, envelope surface. Starting from this basic fact, we set out to revisit this type of generation-by-envelope process and to profitably use it to explore peculiar design layouts, in particular for the case of motion transmission between skew axes (and intersecting axes as a special case). Analytical derivations demonstrate the possibility of involute helicoid profiles (beveloids) transmitting motion between skew axes through line contact and, perhaps more importantly, they lead to the derivation of designs featuring insensitivity of the transmission ratio to all misalignments within relatively large limits. The theoretical developments are confirmed by various numerical examples.

Generation of a double-crowned involute helical gear with twist-free tooth flanks by a CNC hobbing machine with three synchronous axes

In the conventional hobbing process, a double-crowned involute helical gear is generated by the hob cutter with parabolic-curve tooth profiles for the cross-profile crowning and varied the center distance between the hob and work gear for the longitudinal crowning. Therefore, to cut a double-crowned helical gear not only requires at least four synchronous axes and hob cutter regrinding (which increases production costs) but also induces twisted tooth flanks on the generated work gear. In this paper, I propose a hobbing method by applying a modified work gear rotation angle that enables double-crowning of involute helical gear's tooth flanks using a standard hob cutter and a computer numerical control (CNC) hobbing machine with only three synchronous axes. The proposed method has also verified by using two computer simulation examples to compare the meshing-conditions, contact ellipses, and transmission errors of the double-crowned gear pairs with that produced by applying the conventional hobbing method. Computer simulation results reveal the advantages of the proposed novel hobbing method.

Investigation into the meshing friction heat generation and transient thermal characteristics of spiral bevel gears

Friction loss and scuffing failure are two primary research subjects in improving the performance of spiral bevel gears. Aimed at improving the thermal characteristics with machine-setting parameter adjustment, a coupled thermo-elastic 3D finite element model has been developed to analyse the frictional heat generation and transient thermal behaviour of spiral bevel gears. The heat fluxes due to friction effects are applied to the gear tooth to investigate thermal characteristics and prediction of transient temperature fields. The resulting thermal characteristics agree with earlier work, thus verifying the model and numerical approach. This study permits an in-depth understanding of the temperature fields, together with the frictional heat generation process. Furthermore, by investigating the transient thermal behaviour among different pinion machine-setting parameters, the tilted and extended tooth contact pattern achieved by adjusting the machine-setting parameters can result in an optimal tooth contact pattern that produces a uniform temperature field of much lower value, thereby achieving higher efficiency of transmission along with stronger anti-scuffing performance.

Synthesis of Shaped Noncircular Gear Using a Three-Linkage Computer Numerical Control Shaping Machine

Gear shaping, commonly regarded as the most widely used machining method for cylindrical gear, is in fact an ideal manufacturing method for noncircular gear due to its merit of not being restricted by gear type or pitch curve in contrast to gear hobbing. However, concerning researches are mainly focused on the generation of noncircular straight external gear, paying rare attention to noncircular internal gear and noncircular helix gear. Considering that this paper, through using a three-linkage computer numerical control (CNC) shaping machine, aims to synthesize shaped noncircular gear, covering external, internal, straight, and helix gear. The mathematical model, a three-linkage model, is first established. The corresponding manufacturing process in practice is subsequently discussed. Finally, with practical shaping experiments, the correctness of the proposed model and the appropriateness of the manufacturing process are verified.

RESEARCH ON THE MANUFACTURING AND EVALUATION METHOD FOR A CURVE-FACE GEAR

Curve-face gear is a new type transmission device combining the common transmission characteristics of non-circular gears and face gears, which can transfer the motion and power between the intersecting shaft and staggered shaft. Given the complexity of the tooth generation of curve-face gear, 1) some machining methods, including three axis NC machining method , five-axis CNC machining method and the combined processing method of additive manufacturing and five-axis CNC machining, were introduced. 2) Based on space gear meshing theory and the machining principle, the machining models of curve-face gear were established.In order to verify the accuracy of the obtained gear, tooth surface measurement was applied, a new accuracy evaluation method for pitch deviations and tooth profile deviation of curve-face gear was processed. The results show that the tooth surface accuracy of the curve-face gear is high. The design of the curve-face gear, and its processing methods have been verified.

Determination of effective involute parameter limit in generation simulation of gears manufactured by rack-type cutters

This paper studies the computerized tooth profile generation of involute gears cut with rack-type cutters. Based on the theory of gearing the mathematical models of generating cutter with asymmetric involute teeth and generated involute gears are given. Beveloid (conical involute) gears are considered for a generalized type of involute gearing for connecting parallel shafts. Effective limits of involute design parameters that determine the actual tip circle radii of the generated gears are investigated. An approach based on contact path of mating gears is proposed to eliminate further operations for standard value of tip circle radius. Computer simulation programs are developed to obtain graphs of generating tools and generated teeth surfaces.

RETRACTED: Generation and analysis of gear drive with tubular tooth surfaces having double contact points

The gear drive with tubular tooth surfaces having double contact points is proposed. The generation of gear pair is investigated based on two mismatched rack cutters. The basic tooth profiles of rack cutters for generating the pinion and the gear are designed, respectively. Mathematical models of tooth surfaces are derived according to the geometric relationships. Solid models of gear pair are also established. Stress analysis of tubular tooth surfaces having double contact points is carried out using the finite element method. The results show that the proposed gear drive has the better transmission characteristics. Gear prototype is finished with CNC machining technology. The further studies on the dynamic characteristics and experimental test of this gear drive will be carried out.