Boston gear s spur gears, which are designed to transmit motion and power between parallel shafts, are the most economical gears in the power transmission industry. Insidepenton com electronic design adobe pdf logo tiny. They are, a surface fatigue limit index, a surface fatigue lifetime index, a bending fatigue limit index, a bending fatigue lifetime index, an abrasive wear index, and a machinability index. Apr 25, 2017 for car transmission gears, steel is the preferred material. However, this is not enough, as gears will fail due to wear and fatigue in critical tension spots. Tutorial for gear design and calculation with mdesign gearbox.
This course, developed jointly by agma and asm international, will provide an overview of materials selection and heat treatment of gears. A road map is presented listing critical considerations and optimal use of materials and methods in the construction of large gears. Chapter 1, basic understanding of gears, discusses the various types of gears used, important gear nomenclature, and applied stresses and strength requirements associated with gears. The selection of gear material is complex, and must be related to the specific duty and life required by the application. Me349 engineering design projects introduction to materials selection the material selection problem design of an engineering component involves three interrelated problems.
Tutorial for gear design and calculation with mdesign gearbox dipl. Electrical properties voltage requirementsrequirements dielectric strength tracking requirements insulation requirements surface and volume resistivity conductivedissipative plastic materials selection. Material index combination of material properties which characterize performance in a given application. This study aims to select optimum materials for particular spur gear designs. High temperature alloys in order of increasing performance alloy comments carbon steel, such as astm a 387 grade this may be used to 1,200f 649c. Sometimes, expensive materials are more economical than low cost material, which difficult to machine. Pdf advanced material selection technique for high strength. Gear material selection and construction for large gears frank c. Getting this selection right the first time by selecting the optimal. This project dealt with the selection of materials for a harmonic planetary gear system. Jeremy gregory and randolph kirchain, 2005 materials selection i slide 27 material index examples an objective defines a performance metric. An advanced material selection technique called ashbys. Department of mechanical engineering, mckv institute of engineering, liluah, howrah7111204, india.
New developments in gear technology, particularly from the materials and heat treatment perspectives, have improved gear performance. Materials for automobiles indian institute of technology. Their unique characteristics are also being enhanced with new developments, both in materials. See the internal gear interference portion of the technical section to avoid problems in assembling these items. For every application, there is limiting cost beyond which the designer cannot go. Contact stress analysis of spur gear for different materials using ansys and hertz equation putti srinivasa rao1, nadipalli sriraj2, mohammad farookh2 1professor, dept. Design and materials selection for power transmitting gears abstract the great majority of all power gears are manufactured in hardened or casecarburized steel with a smaller number manufactured from cast iron and from nonmetallic materials such as thermoplastics and laminated bonded wood, fabric and paper materials. Selection of gear materials reprinted from handbook of gears, stock drive products component design material database gear design home page please send your comments to. Michael is principal engineer and trainer at industrial metallurgists, llc. In this paper, a mechanical gear actuated solar tracking system has been proposed that uses a pair of involute spur gears, and for which the material selection is to. Titanium 64 ti 6al 4v is the workhorse of the industry and still accounts for nearly 60% of the production volume. Although the information and statements herein are believed to be accurate, no guarantee of their accuracy is made.
Lets take a closer look at the factors that should be considered when choosing gear material, and some of the materials that are most commonly used in. When the limit exceeded the designer has to consider an alternative material. The best selection would depend on the intended use of the gear box. Of primary importance is a basic understanding of polymer morphology and the properties different morphologies bring to the picture. If you havent drawn it up yet id try to incorporate those gears. The landing gear is a highly stressed structural part, and. Spur gear gear formulas drive selection horsepower and torque tables. Material selection for gears is an important process because these are the components that are under stresses while working. First, a set of major gear design criteria are used to develop six material performance indices for material selection purposes. It is the gears that decides the torque, speed and direction of rotation of all the driven machine elements. A complete list of all the prospective materials from the best to the worst is obtained, taking into account multiconflicting material selection attributes. The introduction of aermet100 and af1410 has made inroads in the steel section and replaced some of. What are important properties of material for gear.
Types of gears material used for gears application. Rack and pinion drive calculation and selection module 1. Contact stress analysis of spur gear for different materials. The selection of a proper material, for engineering purposes, is one of the most difficult problems.
Recent advancements in material engineering have provided alternatives for gear materials. Gear materials selection metallurgy, heat treatment, and. And, how many times have you had to work in wet, clammy turnout gear. All books are in clear copy here, and all files are secure so dont worry about it. The simplicity of spur gears means that they are commonly used in number of machines, from. Linear static analysis, tet collapse, nose landing gear, rbe3, ferrium s53, al 2040, ti 1023. Project select the material to use for a 12inch diameter, six foot long drive shaft used to run a power tool attached to one end of a pole assembly. The simplicity of spur gears means that they are commonly used in number of machines, from cars to household appliances. A spur gear is the most basic type of gear available. The selected materials had to meet strength requirements while being cost effective. Materials selection are a key issue in the optimal design of the industrial product. The selection should be based on polymers meeting both the environmental and mechanicalphysical requirements.
Worm gear this figure shows the two members of a worm gear set which. The strength of gears differs depending on the type of material, heat treatment or quenching applied. Design and materials selection for powertransmitting gears. Material selection in engineering design process is very important to ensure that the final product is capable of withstanding the ultimate test which is user satisfaction in the long run. In all gears the choice more detailed information on the factors that of material must be made only after careful con in. Gear material selection using complex proportional. Nfpacertified turnout gear consists of a threelayer ensemble made up of an outer shell, moisture barrier, and thermal liner with each layer performing a critical function. For example, one gear may have to transfer over 100 horsepower to the next gear. Which materials to select to design gear box shaft, gear. Pdf this study aims to select optimum materials for particular spur gear designs. Spur gear design and selection objectives apply principles learned in chapter 11 to actual design and selection of spur gear systems. Discover the factors that should be considered when choosing gear material, as well as commonly used materials in gear manufacturing. Fairfax street, fifth floor, alexandria, va 223141587. Material selection is a difficult and subtle task because of an immense number of different available materials.
Make splined shafts to accept the quickchange spur gears used in stock cars and sprint cars. All of these important technical aspects of gear technology are brought together in the present offering, gear materials, properties, and manufacture. Bearing failures are responsible for a lot of gearbox failures, you shouldn. Analysis of design and material selection of a spur gear pair for.
Gear box propeller shaft rear axle gears and axle shaft. Broadly speaking, gear types may be grouped into five major categories. Pdf advanced material selection technique for high. As with any material, evaluation of the material under enduse. Gear material selection guidelines many factors influence the selection of materials for gears, and the relative importance of each can vary. An advanced material selection technique called ashbys method was used to determine suitable materials according to.
The material choice is bronze for the worm drive and. Selection of material depends on any considerations, which is in general be categorized as cost and structural performance. Select the material to use for a 12inch diameter, six foot long drive shaft used to run a power tool attached to one end of a pole assembly. Gear material selection and construction for large gears. Worms and worm gears selection guide engineering360. And dont forget to spend as much time on the lubrication scheme as you do on the gear teeth.
Widely applicable due to low cost and large selection of. Mechanical properties, grade and heat treatment, cleanliness, dimensional stablility, availability and cost, hardenability and size effects machinability and other manufacturing characteristics. When youre wearing scba and dragging a fully charged 1 34 hose line, the last thing you need is your gear sucking up water and adding more weight to what youre already lugging around. Carbon steel for structural machine usage jis material no. Ksurcpf ksurcpfd 5, 0 500, 000 sus304 solution treated cut 5 suitable for food machinery due to sus304 material s rustresistant quality.
In cost analysis, there are two factors namely cost of material and the cost of processing the material into finished goods. The material selection process requires a preliminary understanding of polymers, additives and their properties. Gear material selection using complex proportional assessment. Hardened material c45 c45 pinion heat treatment soft ind. A worm drive is a cylindrical gear with a shallow spiral thread that engages the worm gear in a nonintersecting, perpendicular axes configuration. The gear strength values shown in the product pages were computed by assuming a certain application environment. The annular gear has parallel teeth similar to the spur gear but cut on the inside rim of the ring. Materials selection considerations for thermal process equipment. Material selection can be the difference between whether a gear. They usually dont garner much attention until there is a problem with an application or if there are high maintenance cost to service the gasket. G80 gear selection stock spur gear drive selection when designing a stock gear drive using the horsepower tables in catalog 2001, the following steps must be taken.
It consists of nothing more than a cylinder or disk with radially projecting teeth aligned parallel to the rotational axis. Pdf investigation of materials for shaft and sun gear of. Gear materials, selection, metallurgy march 1921, 2019 hilton garden inn las vegas, las vegas, nv register now course outline pdf registration form pdf. If the gears were made of a soft material such as aluminum, the teeth. Take note of the following while selecting material with manufacturing expense and. Case hardening steels provide the ideal features required for gear material. Material selection is also important as it define the weight and cost of the product. An overview of the plastic material selection process for.
This volume complements other gear texts that emphasize the design, geometry. Description the main requirements for the shaft material were. Worms and worm gears are gear sets that offer high gear reduction and torque multiplication with a small footprint. This lecture introduces to the aspects of iterative design process, concept of doubling time, mcelvey diagram, ecoefficiency including its 7dimensions and the ashby charts. Material is generally 8620 9310 for the expensive ones.
Thoroughly defined application requirements are needed to select appropriate candidate. Selection of gear materials reprinted from handbook of gears, stock drive products component design material database gear design home page. This publication is being made available in pdf format as a benefit to members and. The materials must be strong enough to support heavy takeoff weight when an aircraft has a full load of fuel and the high impact loads on landing. Aimed to provide coherent overview of material selection materials and structural configurations and processes should be selected for applications based on measurable criteria often combinations of material properties material properties group according to class of material metal, ceramic, polymers. The material choice is bronze for the worm drive and aluminium for the worm gear. However, new materials have reached the market in recent years. Such selection emphasizes on core hardness instead of surface strength. Cast iron is a common gear material due to its good wearing properties, machinability, and the. This book is very useful for learning about gears and gearing. The designer has to make sure that he is knowledgeable of all the possible conditions the product may come across.
It is important consideration in selection of materials. Then only he can conclude the best materials for the design. Christianhartmanngerlach, driveconcepts gmbh dresden dr. Khk offers for free the gear technical data book in pdf format. Gear material selection using complex proportional assessment and additive ratio assessmentbased approaches. Designing with plastic gears and general considerations of. In accordance to their usage, gears are made of various types of materials, such as ironbased materials, nonferrous metals, or plastic materials. The main driving element on certain types of tractors is a typical example of the use of gears of this type. Gear data gear formulas drive selection horsepower and. Landing gear materials must therefore have high static strength, good fracture toughness and fatigue strength, and the most commonly used materials are highstrength steel and titanium alloy.
Efficiency of a worm drive is determined by the lead angle and the number of. The input shaft was modelled as a cantilever beam carrying the weight of the. Jeremy gregory and randolph kirchain, 2005 materials selection slide 1 materials selection for mechanical design i a brief overview of a systematic methodology jeremy gregory research associate laboratory for energy and environment. It is likely that the cost of material might be low. Steel is strong and holds its shape well, which is critical since all the engines output horsepower flows through the transmission. Initial gear material selection what are the advantages and disadvantages of the various gear material choices, including steel, cast iron, ductile iron, plastics, bronze and more exotic choices. Rack and pinion drive calculation and selection module 1 straight tooth system rack br quality 9 10 material c45 c45 rack heat treatment soft ind. When it comes to large scale production, gear engineering and design is crucial.
While there are many aspects to consider, one that shouldnt be overlooked is the selection of gear material. Apr 22, 2016 as with most mechanical parts, you make your first iterations based on young modulus and yield limit. Cast iron is extremely durable, and cheap, but its heavy. Even at 98% efficiency for one mesh, at 200 hp youll have to dissipate 4 hp 3kw in heat. From the beginning of the century, the demand for better productivity of gear manufacturing. Gears look to the future for material machine design. They are fixedcenter sets and there is a very large selection. Materials for automobiles lecture no 2 6 august 2011. Types of gears, material used for gears,design specification and application gears are power transmission elements. Gear materials, properties, and manufacture asm international. This is not a problem if you are building the gearbox for use in a farm tractor, but its no good in a sports car. Download gear material selection and construction for large gears book pdf free download link or read online here in pdf.
Basis for selection of either of the two depends on application. Browse our material offering below, or download the selection guide as a pdf. Gear materials, properties, and manufacture is intended for gear metallurgists and materials specialists, manufacturing engineers, lubrication technologists, and analysts concerned with gear failures who seek a better understanding of gear performance and gear life. The companion pinion, how ever, is a standard gear. Material selection for gearbox practical machinist. Basic facts to consider for material selection in engineering. The ranking performance of these two methods is also compared with that of the past researchers. Material based structural analysis of a typical landing gear. Materials selection considerations for thermal process equipment table 1. Designing with plastic gears and general considerations of plastic gearing general considerations of plastic gearing plastic gears are continuing to displace metal gears in a widening arena of applications. Tobias schulze, driveconcepts gmbh dresden conclusion this is a guide for generating a gear model and subsequent recalculation of the kinematics and the single parts with the software mdesign gearbox.
Heat treatment processes and their relation to gear performance, cost, reliability and load. As with most mechanical parts, you make your first iterations based on young modulus and yield limit. Most commonly used engineering material cast iron alloy steel plastic aluminum alloy 11. Determine allowable force on gear teeth, including the factors necessary due to angle of involute of tooth shape and materials selected for gears. Read online gear material selection and construction for large gears book pdf free download link book now.