Tractor Design And Testing - AgriMoon

Tractor Design and TestingIV. Hydraulic System:Irish mechanic Harry Ferguson developed a tractor that incorporated an innovativehydraulic draft control system, which raised and lowered attached implements—such astillers, mowers, post-hole diggers, and plows are automatically adjust their needed depth.In1917, Henry Ford had formed a company (Ford and Son) separate from his automobilebusiness to manufacture farm tractors (Wendell, 1979). Their Fordson tractor wasmanufactured and sold until 1928, at which point Ford & Son was merged back into the FordMotor Company. The David Brown Company in England was the first to build the tractor,but Ferguson also claim it to Henry Ford in the United States. With a handshake agreement,Ford manufactures Ferguson‘s tractor and implements from 1939 to 1948. The three pointhitch was developed by Harry Ferguson by 1935, after 17 years of experimentation. In 1936;he began selling a light tractor equipped with the hitch in the British Isles and Norway. TheFerguson system included an automatic draft control system that was very effective. In 1938,Ferguson demonstrated his tractor to Henry Ford in the U.S. (Gray 1954b). A few years laterFerguson‘s company merged with Canadian company Massey-Harris to form MasseyFerguson.Tractor sales continued to climb, peaking in 1951, when about 0.8 million tractors were soldin the United States.Pulled and powered by tractors, an increasingly wide variety of farmimplements were mechanizing just about every step in the crop-growing process, from seedpreparation, planting of seed to the harvesting of the final seed/fruit.Equally important developments were occurring on the other side of the hitch system. Untilthe three-point hitch standard was developed by ASAE in 1959, each tractor producer had adifferent method of attaching implements to their tractors. Typically, it was difficult orimpossible to mount one manufacturer's implements on another manufacturer's tractor. Adecade later, Henry Ford was ready to re-enter the farm tractor business. He liked Ferguson'sthree-point hitch and entered into a verbal agreement to manufacture tractors equipped withit. These Model 9N tractors entered the market in 1939 when a dispute ended the verbalagreement in 1946, Ford formed the Dearborn Motors Company to produce Ford tractors.Harry Ferguson began producing his Ferguson tractor at a new Ferguson Park plant inDetroit. In 1953, Ferguson‘s company merged with Massey Harris and production of theMassey Ferguson tractor began (Wendell, 1979). In the early 1950, Oliver introduced a threepoint hitch without draft control.After ASAE developed their three point hitch standard in 1959, most other tractormanufacturers adopted it, as a result, it became possible to use the implements produced byany manufacturers on nearly any tractor. Development of the three point hitch also spurredthe trend to larger average farm sizes. Implements fully mounted over roadways at higherspeeds on road than would have been possible with pull type implements.Open-center hydraulic systems include a fixed-displacement pump supplying an actuatorthrough a tandem-center directional-control valve. Such systems are inexpensive andfunction well with a single actuator. When more than one actuator is used, the systempressure rises to that of actuator with the lowest pressure demand, which could createproblems. International Harvester Company (IHC) in 1960, developed a sickle bar mowerpowered by a hydraulic motor. In a field test, the mower worked well in cutting heavy grass7www.AgriMoon.Com

Tractor Design and Testinguntil the operator raised the hitch, at which point the mower stalled. The hitch lift cylinderhad a lower pressure demand than the hydraulic motor powering the mower. Thus, thehydraulic fluid took the path of least resistance and stopped flowing to the hydraulic motor.The phenomenon is called sequencing, i.e., when two actuators have different pressuredemands, the one with the heavier demand has to wait until the one with the lighter demandstops receiving hydraulic fluid. Over the years, improved hydraulic systems were developed.When John Deere introduced their "New Generation of Power‖ in 1960, they introduced aconstant-pressure system featuring a 'variable-displacement pump that adjusted its stroke tomaintain constant system pressure at a level designed to handle the heaviest load. Theconstant pressure systems were later succeeded by load-sensing systems. These systemsinclude a variable-displacement pump in which a stroke control valve senses the highestpressure demand in the system and increases the pump stroke enough to meet that demand.Constant pressure and load-sensing system work, if the total fluid demand can be suppliedby the pump operating at part stroke. With the touch of a lever, the operator can now controlthe movement of very heavy loads. When coupled with electronic system, hydraulic systemsalso enable automatic control of steering and other functions, control that would have beenvery difficult to provide without hydraulics.V. Fuels:One advantage of using draft animals was that farmers could grow their own "fuel," i.e., feedfor the animals. With tractors, it was necessary to buy the fuel. Between 1900 and 1960,gasoline was the predominant fuel, with kerosene (the Rumely Oil Pull was the most notableof this kind) and ethanol being common alternatives. Generally, one engine could burn anyof those, although cold starting was easiest on gasoline. Often, a small auxiliary fuel tank wasavailable to hold gasoline for cold starting and warm-up, while the main fuel tank heldwhatever fuel was most convenient or least expensive for the particular farmer. Dieselisationgained momentum starting in the 1960s, and modern farm tractors usually employ dieselengines, which range in power output from 18 to 575 horsepower (15 to 480 kW). Size andoutput are dependent on application, with smaller tractors used for lawn mowing,landscaping, orchard work, and truck farming, and larger tractors for vast fields of rice,wheat, maize, soybean and other crops.Diesel engines made an early appearance about 1930, but the required precision-made fuelmetering parts made them too expensive for most farm tractors and starting was also aproblem. Diesel powered tractors usually included a small, gasoline-powered "pony" motorto crank the diesel engine. Minneapolis-Moline introduced their Model U diesel tractor in1952. The International Harvester Company (IHC) Model MD tractor used a unique startingsystem. A spark plug for each cylinder was in a small auxiliary chamber linked through athird valve to the main chamber.Opening this cam-operated valve reduced the compression ratio and allowed the engine tnbe started on gasoline supplied via a carburettor: the valve was closed and the carburettorbypassed to switch to diesel operation. Diesels steadily gained market share in the 1950s, andvirtually all new tractors since 1976 have had diesel engines. Electrical systems haddeveloped enough by that time to allow electric starters to replace pony motors. Dieselengines provide much higher fuel efficiency than gasoline engines. The switch to diesels hada letter effect on biofuels development, when farmers again began to grow fuel. Ethanol is8www.AgriMoon.Com

Tractor Design and Testingnot a suitable fuel for typical, unmodified compression-ignition (Cl) engines. The biofueldeveloped for Cl engines are calledbiodiesel, the subject of a recent ASABE lecture (VanGerpcn et al., 2007).VI. Safety Features:Around 1985, it became mandatory to fit tractors with 'roll over protection structures' tolessen the high risk of fatal injury if the tractor rolled over.This basic design has remainedunchanged for a number of years, but enclosed cabs are being fitted now on modern models,for reasons of operator safety and comfort.VII. Recent Advances:After 1994, space technology has been incorporated into agriculture in the form of GPSdevices, and robust on-board computers installed as optional features on farm tractors. Thesetechnologies are used in modern, precision farming techniques. The spin-offs from the spacerace have actually facilitated automation in plowing and the use of light bar or autosteersystems on tractors, the idea being to neither overlap and use more fuel nor any missingwhen performing jobs such as cultivating. Global Positioning System (GPS) receivers ontractors to record precise locations on their farms to determine which areas need particularquantities of water, fertilizer, and pesticides.9www.AgriMoon.Com

Tractor Design and TestingLesson 2. Different Type of Tractors Available in India/abroad & it’sImportance inAgriculture1. IntroductionThere are evidences of the revolution in agriculture brought by mechanization. Beginningwith the internal combustion (IC) engines and moving on to rubber tires. Mechanization alsoimproved the farm implements designed for planting, harvesting, and threshing. At the endof 20thcentury, precision agriculture became the practice, combining the farmer's down-toearth know-how with space-based technology. Now a days tractor is the major farm powersource used Worldover for different farm operations.The name tractor came from Latin word ―trahere‖ means to pull and latter became one wordfrom combination of traction motor. Tractor is a wheeled or tracked selfpropelledengineering vehicle specifically designed to deliver a high tractive effort (or torque)at slow speeds as well as for the purposes of hauling a trailer or machinery used inagriculture or construction. Most commonly, the term is used to describe a farm vehicle thatprovides the power and traction to mechanize agricultural operations. Agriculturalimplements may be towed behind or mounted with the tractor and the tractor may alsoprovide a source of power through power takeoff (PTO) or belt pulley,if the agriculturalmachinery is stationary.This basic design has remained unchanged for a number of years, but enclosed cabs are beingfitted now on modern models, for reasons of operator safety and comfort.2. DevelopmentThe tractor evolved in the second half of the 19th century and first half of the 20th into itspresent, conventional, two wheel drive form and four wheel drive variation. This form owesmuch to history but also the fact that it is an inherently logical arrangement. Designersfollowed early tractor designs that were simply replacements for horses or other draughtanimals. The layout takes advantage of the transfer of weight to the main driving wheels atthe rear, as the drawbar pull on the tractor increases. The layout is inherently stable in thehorizontal plane because the implement commonly being pulled behind the tractor tends tofollow the latter and to pull it into straight line operation. Rear mounted implements offer aminimum offset loading and moment in the horizontal plane; this contrasts with sidemounted implements.I. Type of Tractors Available in India/AbroadFarm Tractors are classified as Follows;10www.AgriMoon.Com

Tractor Design and Testing(A). According to use, modern farm tractors are classified in three groups:1. General purpose (land utility) tractorsGeneral purpose or land utility tractors are used for major farm operations, which arecommon to the cultivation of most crops, such as tillage, harrowing, sowing and harvesting.These tractors are characterized by a l

Lesson 17. Hydraulic system design considerations 140-143 Lesson 18. Design of main components of a hydraulic System 144-150 Module 8. Study of electrical, electronics and guidance system of a tractor Lesson 19. Electrical System of tractor Lesson 20. Electronics and guidance system of tractor