The tooth numbers are n 2 24, n 3 18, n 5 22, and n 6 64. Dedendum of a tooth is its radial depth below the pitch circle. Design and optimization of planetary gears considering all. Procedure for optimum design of a twostage spur gear system. So the counter shaft is always in running condition. Understanding the contact ratio for spur gears with some. They are simple in construction, easy to manufacture and cost less. Relationship between the involute elements determination of base tooth thickness from a known thickness and viceversa. Dec 23, 2017 gearbox design for machine tools, easy explanation of gearbox design with example of 8 speed gearbox. Let the values of the diametral pitch correspond to those shown in figure 5. Planetary gears gsa the easytomount highend economy gearbox for high power transmissions. Why spend time choosing the right motor and gearbox. Most gears are in the hardness range of approximately rc 30 to rc 38 or rc 55 to rc it is interesting to note that oil sample collected after 3 hours of operating gear at rpm no load conition show wear fig. Another class of gear train has wide application, the epicyclic or planetary train.
Provide means of connection and disconnection of engine with rest of power train without shock and smoothly. Epicyclic gear train nptel pdf automatic transmission has not better fuel economy. The preferred step ratio is mentioned as basic series named as r5, r10,r20,r40 and r80. Assembled gearboxes for particular ratios are also stock items. The frame in the middle, where the coordinate system is shown, is the design space of your gearbox.
A typical case would involve the design of the gearing for a hoist to raise a certain weight w ata uniform speed, when making use of a motor with a given horsepower hp running at a given speed rpm and driving through a pinion with number of teeth np, fig. Following this, the design procedures for the internal gear pack are discussed, along with the arrangements of the various shafts. The intent of this project was to design a gearbox containing two shafts, one coupling, four bearings and two helical gears. Each of the chapters will deal with aspecific problem which is encountered during the design phases and during operation. Spur gear creation american society for engineering. Procedure for optimum design of a twostage spur gear system article pdf available in jsme international journal series c 464. In involute gear design, all contact between two gears occurs in the same fixed, flat plane. Gear size, pressure angle, number of teethwe introduce the basic terminology, measurement, and relational expressions necessary to understand basic gear technology. This being the reason a gearbox is widely used and a common piece of equipment through heavy industry driving conveyors, mills, crushers and pumps. Please start with the tutorial for shaft calculation to see how to introduce geometry and supports for single shafts. Choosing the correct combination of a motor and a gearbox for a given application is very important, both in the first robotics competition frc. The involute of a circle is the spiraling curve traced by the end of an imaginary taut string unwinding itself from that stationary circle. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices. Surface contact fatigue of gear teeth is one of the most common causes of gear operational failure due to excessive local.
The lowbacklash planetary gearheads of the gsa series are designed for high positioning accuracy and highly dynamic cycle operation. Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. Rslqdwk 3uri 0 0 0dxudp,qgldq,qvwlwxwhri7hfkqrorjdgudv module 2 gears. The gears throughout a gearbox are precision manufactured with high accuracy. A complete gear train design will necessarily involve considerations of strength of materials and the complicated stress states to which gear teeth are subjected. Spur gear helical gear double helical or herringbone gear internal gear rack and pinion bevel gear a straight b spiral c hypoid 1. This is a twodimensional case which allows for observation in a plane. Locate and secure components in an appropriate manner and in their proper position. In gearbox design a set of preferred step ratio or preferred numbers is used to obtain the series of output speed of gearbox. A twostage planetary gear stage is defined using the program. There are no great advances in gear technology described. The dedendum for a pinion and mating gear are equal except in the long addendum design where the pinion dedendum is decreased while.
Formulas for gear calculation external gears contents. This chapter begins with a comparison of the merits of spiral bevel gears and hypoid gears when employed as the final drive in the automotive gearbox, ix. Complete the gear design part and draw the layout of gears on 27 march, 2017 z 1 z 2 z 3 z 4 important. Calculation of a planetary gear train this tutorial shows the usage of mesys shaft calculation with shaft systems. Gearbox design for machine tools, easy explanation of gearbox design with example of 8 speed gearbox. Design and optimization of 2stage reduction gearbox. Design and fabrication of gear box full report download gearbox a gearbox, also known as a gear case or gear head, is a gear or a hydraulic system responsible for transmitting mechanical power from a prime mover an engine or electric motor into some form of useful output.
Spaceoptimized 2 stage design the highend gearbox lines are constructed in a spaceoptimized, twostage design. Large reduction gearboxes are designed to transmit high torque by reducing the high input speed to the desired output speed. Of that reason, follows a demand of developing a computer based tool for analyzing contact mechanics in gears. Working of a principle gear box in a gear box, the counter shaft is mashed to the clutch with a use of a couple of gear. Design and optimization of 2stage reduction gearbox 1neeraj patel 2tarun gupta 3aniket wankhede 4vilas warudkar 1 23b. The dedendum of a standard proportion tooth equals 1. Gearbox design gear transmission mechanics free 30. The menu on the right is the element explorer, where you can select the required machine elements. Modeling the shafts in the graphical input are shafts modeled by single parts. Gear design in mdesign gearbox march 2012 driveconcepts gmbh, dresden 3.
Helical gearing, in which the teeth are cut at an angle with the axis of rotation, was developed after spur gearing and has the advantages that has the smoother action and tends to be trainw fig. Housing the housings of the high end range are designed from a onepiece, robust housing. With mechdesigner, it is easy to design any number of mechanisms and cams in one model, then analyze, scrutinize and optimize all of them together, so that. Gear wreck will happen because of its tooth fatigue and tooth surface wear, so strength design from both side is necessary. Design of crane hook in this phase basic dimensions for crane hook are calculated like bed diameter, throat diameter, depth of crane hook. The fourspeed sequential synchromesh gearbox, although elegant in design, proved to be a bit too heavy for a practical racing application.
This book is an attempt to apply that principle to gear design by presenting information from a manufacturing pointofview rather than a theoretical one. The opening pages deal with the aims of the gearbox and the reasons for each of the aims. Spur gear design and selection objectives apply principles learned in chapter 11 to actual design and selection of spur gear systems. Spur gear design as an exercise in gear selection, a stepbystep procedure will be demonstrated on how to design a gearset pinion and gear for a gearbox that is to be mass produced for a general industrial application. Enable power transmission at varied angles and varied lengths. The importance of bearing selection on gearbox performance. August 15, 2007 28 combined stresses in shafts as seen in chap 4.
Gear design and strength iupital has good strength, durability, wear resistance, and chemical resistance, so can be used to each gear. Therefore you have to click in the element explorer shaft shaft section and drag it with pressed mouse button in the 3dview. Design procedure list of components used in hoisting mechanism of eot crane design 1. Calculation of a two stage gearbox this tutorial shows the usage of mesys shaft calculation with systems of parallel shafts. When pinion is the driver, it results in step down drive in which nptl output speed. After the designer picks a size, the gearbox manufacturers catalog or website lists values for the maximum overhung load that is permissible for that sized unit. It is their very simplicity that led to their being so widely used at the beginning of the industrial revolution. Whole depth or total depth of a gear tooth equals the addendum plus the dedendum.
Even today they are the actuator of choice for many low cost machine tools. Design and analysis of differential gearbox full report download abstract abstract my project design and analysis of differential gearbox mainly focuses on the mechanical design and analysis of gearbox as transmit the power. Design of gearbox free download as powerpoint presentation. These gearboxes are simple in design and are similar to those used for speed changing 2. Mayuram module 2 gears lhfwxuh bevel gears crqwhqwv.
Working depth of a tooth equals the whole depth minus the height of the. Shaft design objectives compute forces acting on shafts from gears, pulleys, and sprockets. The wind power industry is however still young when machines over 2 mw. Nptel provides elearning through online web and video courses various streams. When the counter shaft is bring in contact with the main shaft by use of meshing gears, the main shaft start to rotate according to the gear ratio. There will be no torque being transferred from the engine to the transmission and wheels. Lecture 7 helical tooth spur gear and loads on gear shaft. T, bharuch shri sad vidya mandal institute of technology bharuch 2. Design of an sae baja racing offroad vehicle powertrain. In this type of transmission system, the driver has to manually select and engage the gear ratios.
Oct 21, 2017 for the love of physics walter lewin may 16, 2011 duration. Spur gear design nptel indian institute of technology. The gearbox is being powered by a 5 hp, 60hz ac, electric motor with a speed of 1725 revmin. His teaching and research interests are machine design, gear. Clutch fully depressed the clutch is fully disengaged when the pedal is fully depressed. Functions of a gear power transmission change rotational speedtorque maintain constant speed ratio me 338.
Gear metrology welcome to iit mechanical iit mechanical. Cylindrical spur gears with standard profile cylindrical spur gears with corrected profile without centre distance variation with centre distance variation. Calculate forces on teeth of spur gears, including impact forces associated with velocity and clearances. Ground, helical toothed precision components inside the gear ensure low running noise and high running smoothness. Pdf procedure for optimum design of a twostage spur gear. Design of machinery an introduction to the synthesis and. Design and fabrication of gear box full report download. These gearboxes are widely used in generalpurpose machine tools, transmit high torques, and operate at high speeds. This configuration and its design iteration have existed for many years. Regardless of the maturity of the gearbox design and design process, however, most wind turbine downtime is attributed to gearbox related issues. If the transmission of rotation should occur with a constant ratio, which means that in case of a con. Al s b it f h d k t h f assembled plan view also submit a freehand sketch of plan view one copy per group. Gear design in mdesign gearbox march 2012 driveconcepts gmbh, dresden in the graphical input you will find different categories. Stadtfeld introduction the most basic case of a gear train is the transmission of rotation and power between two parallel shafts.
Tutorial for gear design and calculation with mdesign gearbox. Gearbox modeling and load simulation of a baseline 750kw. Basic gear terminology and calculation lets learn the basics of basic gear technology. Mayuram spur gears have their teeth parallel to the axis fig. I had developed this work as my semester project with a view to get familiar with the technologies as well as application. Provide a varied leverage between the engine and the drive wheels provide means to transfer power in opposite direction. Rathindranath maiti is at present professor in mechanical engineering department. Introduction to gear design introduction albert einstein once said. Planetary gear trains example for the speed reducer shown, the input shaft a is in line with output shaft b. Lecture gear unit design failure of gear tooth probable dynamic load and wear load capacity download. The results of the design shows that weight of new rack and pinion gearbox is 20% less than the oem rpg with nearly 40% reduction in the cost achieving the desired steering ratio. Mahida abhiraj 450119043 mehta divyang 450119047 guided by.
Find the ratio of the output speed to the input speed. The kinematic design of gear trains is principally involved with the selection of appropriate ratios and gear diameters. Things should be made as simple as possible, but no simpler. Figure shows a typical gearbox that provides four different ratios. Sppu s17 3 a six speed gear box is required to be designed for a machine tool drive. Determine allowable force on gear teeth, including the factors necessary due to. This final chapter covers the design of a racingtype rear engine mounted gearbox. Contact mechanics in gears chalmers publication library.
The gearbox is part of a system to test the idling characteristics of an automotive timing drive system. Now it is an epicyclic or planetary gear drive with external toothed gears. For each gear ratio, plot the contact ratio, cras a function of the diametral pitch, p. Vicura ab is an engineering company that delivers products which are used in. Compare combined stresses to suitable allowable stresses. At the same time, expectations for gear reliability are high. Due to the lower torque values, the input stage is dimensionally smaller than the output stage. The main aim of this paper is to focus on the mechanical design and analysis on assembly of gears in gear box when they transmit power at different speeds i. Epicyclic gear train nptel pdf but in case of epicyclic gear trains, the axes of the shafts on which the gears are mounted may move relative to a fixed axis.