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CHAPTER 01 1. INTRODUCTION 1.1 Background The undergraduate project which is to be done within the period of the final year as the part of Bachelor of Science of Engineering Program in Mechanical and Manufacturing field, which gives an excellent opportunity to ourselves to apply theoretical knowledge, practical experience etc to understand a real world problem and analyze it to find a better solution. Also undergraduate project helps us to improve our analytical and design skills, written and oral communication skills and presentation skills that are very helpful for our future engineering career. Relative to the final year undergraduate project in Department of Mechanical and Manufacturing, Faculty of Engineering, University of Ruhuna, we decided to “Design and fabrication of a Jatropha oil extractor” as our undergraduate project in year 2006/2007. The fast pace of economic development consequent with ever increasing consumption of fossil fuel and petroleum products has been a matter of concern for the country as it is related to huge outgo of foreign exchange on one hand and increasing emission causing environmental hazards on the other. Public at large are raising their concerns over the declining state of environment and health. With domestic crude oil output stagnating, the momentum of growth experienced a quantum jump since 1990s when the economic reforms were introduced paving the way for a much higher rate of development leading the demand for oil to continue to rise at an ever increasing pace. The situation offers us a challenge as well as an opportunity to look for substitutes of fossil fuels for both economic and environmental benefits to the country. Petroleum resources are finite and therefore search for alternative is continuing all over the world. Development of bio-fuels as an alternative and renewable source of energy for transportation has become critical in the national effort towards maximum self-reliance. Biofuels like bio-diesel being environment friendly, will also help us to conform to the stricter emission norms.

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Jatropha is a quick maturing plant species that starts bearing fruits within a year of its planting and following the extraction of the oil can be blended with petroleum diesel for use. It is a very hardy plant and grows in a wide variety of agro-climatic conditions from arid to high rainfall areas and on lands with thin soil cover to good lands. It is also not browsed by cattle and so its plantation can be easily under taken in the farmers’ fields and their boundaries, under-stocked forests, public lands and denuded lands facing increasing degradation. Its plantation, seed collection, oil extraction etc. will create employment opportunities for a large number of people, particularly the poor, and will help rehabilitate unproductive and wastelands and save precious foreign exchange by substituting imported crude. The capacity of Jatropha and similar other oil seeds bearing plants to rehabilitate degraded or dry lands, from which the poor mostly derive their sustenance, by improving their water retention capacity, makes it an instrument for up-gradation of land resources and especially for helping the poor. Thus, grown on a significant scale, they can clean the air and green the country, add to the capital stock of the farmers and the community and promote crop diversification which is imperative in agriculture. The chain of activities from raising nurseries, planting, maintaining, primary processing and oil extraction is labor intensive and will generate employment opportunities on a large scale, particularly for the rural landless and help them to escape poverty.

1.2 Objectives The Jatropha already grows widely in many rural villages in Sri Lanka where it is used as a ‘live fence’ to protect crops from livestock (the leaves are inedible). Its nuts are not currently used for anything and have no commercial value.

 To design Jatropha oil extractor with easy operation than the existing oil extractor.  To meet the higher oil yield than the existing oil extractor.  Provide higher production rate and lower cost than the existing oil extractor.  To avoid the difficulty of removing the husk of the Jatropha seed by crushing the seeds with the husk.  To minimize the size of oil extractor and provide easy moving in domestic areas.

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 To provide Jatropha oil in meeting domestic needs of energy services including cooking and lighting;  To provide rural communities with a new, cheaper, 100% renewable and 100% locally produced fuel to substitute for diesel fuel.  Potential of Jatropha as an additional source of household income and employment through markets for fuel, fertilizer, animal feed medicine, and industrial raw material for soap, cosmetics, etc.

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CHAPTER 02 2. LITERATURE REVIEW 2.1 Introduction Jatropha is a tall bush or small tree (up to 6 m hight) and belongs to the euphorbia family. The genus Jatropha contains approximately 170 known species1. The genus name Jatropha derives from the Greek jatrós (doctor), trophé (food), which implies medicinal uses. The seeds are toxic and they contain about 35 % 11of nonedible oil. The plant is planted as a hedge (living fence) by farmers all over the world around homesteads, gardens and fieldes, because it is not browsed by animals Jatropha originates from Central America. From the Caribbean, Jatropha was probably distributed by Portuguese seafarers via the Cape Verde Islands and former Portuguese Guinea (now Guinea Bissau) to other countries in Africa and Asia. The wood and fruit of Jatropha can be used for numerous purposes including fuel. The seeds of Jatropha contains (. 50% by weight) viscous oil11, which can be used for manufacture of candles and soap, in the cosmetics industry, for cooking and lighting by itself or as a diesel/paraffin substitute or extender. This latter use has important implications for meeting the demand for rural energy services and also exploring practical substitutes for fossil fuels to counter greenhouse gas accumulation in the atmosphere. Jatropha is not browsed, for its leaves and stems are toxic to animals, but after treatment, the seeds or seed cake could be used as an animal feed. Being rich in nitrogen, the seed cake is an excellent source of plant nutrients. Various parts of the plant are of medicinal value, its bark contains tannin, the flowers attract bees and thus the plant has honey production potential. Like all trees, Jatropha removes carbon from the atmosphere, stores it in the woody tissues and assists in the build up of soil carbon.

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2.2 Possible Uses of the Jatropha

Fig. 2.1. Jatropha press cake & Jatropha oil  Traditionally the Jatropha plant is used as a medicinal plant.  Jatropha is planted in the form of hedges around gardens and fields to protect the crops against roaming animals like cattle or goats.  Jatropha hedges are planted to reduce erosion caused by water and/or wind.  Jatropha is planted to demarcate the boundaries of fields and homesteads.  Jatropha plants are used as a source of shade for coffee plants (on Cuba).  In Comore islands, in Papua New Guinea and in Uganda, Jatropha plants are used as a support plant for vanilla.  The seeds can be processed (oil, press cake) or sold directly as seed or for industrial use.  Because of its mineral content, which is similar to that of chicken manure, it is valuable as organic manure. In practical terms an application of 1 ton of Jatropha press cake is equivalent to 200 kg of mineral fertilizer. 2.2.1 Jatropha as an Energy Source

Fig. 2.2. Jatropha oil lamp & Cooking using jatropha oil

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Jatropha oil is an important product from the plant for meeting the cooking and lighting needs of the rural population, boiler fuel for industrial purposes or as a viable substitute for diesel. Substitution of firewood by plant oil for household cooking in rural areas will not only alleviate the problems of deforestation but also improve the health of rural women who are subjected to the indoor smoke pollution from cooking by inefficient fuel and stoves in poorly ventilated space. Jatropha oil performs very satisfactorily when burnt using a conventional (paraffin) wick after some simple design changes in the physical configuration of the lamp. About one-third of the energy in the fruit of Jatropha can be extracted as oil that has a similar energy value to diesel fuel. Jatropha oil can be used directly in diesel engines added to diesel fuel as an extender or trans-esterised to a bio-diesel fuel. In theory, a diesel substitute can be produced from locally grown Jatropha plants, thus providing these areas with the possibility of becoming self sufficient in fuel for motive power. There are technical problems to using straight Jatropha oil in diesel engines that have yet to be completely overcome. Moreover, the cost of producing Jatropha oil as a diesel substitute is currently higher than the cost of diesel itself that is either subsidized or not priced at "full cost" because of misconceived and distorted national energy policies. Nevertheless the environmental benefits of substituting plant oils for diesel provides for make highly desirable goals.

Table 2.1. The chemical analysis of Jatropha oil ITEM VALUE Acid value 38.2 Iodine value 101.7 Viscosity (31oC) cp 40.4 Fatty acids composition Table 2.2. The comparison of properties oil and standard specifications of diesel oil Palmitic acid % of Jatropha 4.2 Stearic acid % 6.9 Oleic acidspecification % 43.1 Specification Standard of Standard specification of Linoleic acid % 34.3 Diesel OtherJatropha acids % oil 1.4 Specific gravity 0.9186 0.82/0.84 Flash point 240/110°C 50°C Carbon residue 0.64 0.15 or less Cetane value 51.0 > 50.0 Distillation point 295°C 350°C Kinematics Viscosity 50.73 cp > 2.7 cp (Source: www.svlele.com) Sulpher % 0.13 % 1.2 % or less

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Calorific value Pour point Colour

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9,470 kcal/kg 8°C 4.0 (Source: www.svlele.com)

10,170 kcal/kg 10°C 4 or less

Table 2.3. Physical and chemical properties of diesel fuel and Jatropha oil Property Viscosity (cp) (30°C) Speciflc gravity (15°C/4°C) Solidfying Point (°C) Cetane Value Flash Point (°C) Carbon Residue (%) Distillation (°C) Sulfur (%) Acid Value Iodine Value Refractive Index (30°C)

Jatropha Oil 5.51 0.917/ 0.923(0.881) 2.0 51.0 110 / 340 0.64 284 to 295 0.13 to 0.16 1.0 to 38.2 90.8 to 112.5 1.47

Diesel Oil 3.60 0.841 / 0.85 0.14 47.8 to 59 80 < 0.05 to < 0.15 < 350 to < 370 < 1.0 to 1.2

(Source: www.svlele.com)

2.3 Features of Jatropha 2.3.1 Botanical Features It is a small tree or shrub with smooth gray bark, which exudes whitish colored, watery, latex when cut. Normally, it grows between three and five meters in height, but can attain a height of up to eight or ten meters under favorable conditions. 2.3.2 Leaves It has large green to pale-green leaves, alternate to sub-opposite, three-to five-lobed with a spiral phyllotaxis.

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Fig. 2.3. Leaves

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2.3.3 Flowers The petiole length ranges between 6-23 mm. The inflorescence is formed in the leaf axil. Flowers are formed terminally, individually, with female flowers usually slightly larger and occur in the hot seasons. In conditions where continuous growth occurs, an unbalance of pistillate or staminate flower production results in a higher number of female flowers. More number of female flowers are grown by the plant if bee keeping is done along with. More female flowers give more number of seeds.

2.3.4 Fruits

Fig. 2.4. Flowers

Fruits are produced when the shrub is leafless, or it may produce several crops during the year if soil moisture is good and temperatures are sufficiently high. Each inflorescence yields a bunch of approximately 10 or more ovoid fruits.

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Fig. 2.5.Fruits

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2.3.5 Seeds The seeds become mature when the capsule changes from green to yellow, after two to four months from fertilization. The blackish, thin shelled seeds are oblong and resemble small castor seeds.

Fig.2.6. Seeds

2.3.6 Ecological Requirements for Production of Jatropha Jatropha is a fast growing plant and can achieve a height of three meters within three years under a variety of growing conditions. Seed production from plants propagated from seeds

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can be expected within 3-4 years2. Use of branch cutting for propagation is easy and results in rapid growth; the bush can be expected to start bearing fruit within one year of planting. Whilst Jatropha grows well in low rainfall conditions (requiring only about 200 mm of rain to survive) it can also respond to higher rainfall (up to 1200 mm) particularly in hot climatic conditions. Jatropha does not thrive in wetland conditions. The plant is undemanding in soil type and does not require tillage. The recommended spacing for hedgerows or soil conservation is 15cm - 25cm x 15cm-25cm in one or two rows respectively and 2m x 1.5m to 3m x 3mm for plantations. Thus there will be between 4,000 to 6,700 plants per km 2. for a single hedgerow and double that when two rows are planted. The number of trees per hectare at planting will range from 1,600 to 2,200. 2 In equatorial regions where moisture is not a limiting factor (i.e. continuously wet tropics or under irrigation), Jatropha can bloom and produce fruit all year. A drier climate has been found to improve the oil yields of the seeds, though to withstand times of extreme drought, Jatropha plant will shed leaves in an attempt to conserve moisture which results in somewhat decreased growth. Seed production ranges from about 0.4 tons per hectare per year to over 12 t. /ha. /y after five years of growth2. Although not clearly specified, this range in production may be attributable to low and high rainfall areas... The practices being undertaken by the Jatropha growers currently need to be scientifically documented along with growth and production figures. The growth and yield of wood may be in proportion to nut yield and Jatropha grows almost anywhere – even on gravelly, sandy and saline soils. It can thrive on the poorest stony soil. It can grow even in the crevices of rocks. The leaves shed during the winter months form mulch around the base of the plant. The organic matter from shed leaves enhance earth-worm activity in the soil around the root-zone of the plants, which improves the fertility of the soil. Climatically, Jatropha is found in the tropics and subtropics and likes heat, although it does well even in lower temperatures and can withstand a light frost. Its water requirement is extremely low and it can stand long periods of drought by shedding most of its leaves to reduce transpiration loss. Jatropha is also suitable for preventing soil erosion and shifting of sand dunes. Analysis of the Jatropha seed shows the following chemical composition7:

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

Moisture 6.20 %



Protein 18.00 %



Fat 38.00 %



Carbohydrates 17.00 %



Fiber 15.50 %



Ash 5.30 %

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The oil content is 25 – 30%7 in the seeds and 50 – 60%7 in the kernel. The oil contains 21%7 saturated fatty acids and 79%7 unsaturated fatty acids. There are some chemical elements in the seed, which are poisonous and render the oil not appropriate for human consumption.

2.4 Analysis of national energy availability and consumption (Source:www.energy.g ov.lk) Table 2.4. Primary Energy Supply (kTOE) INDICATOR Primary Energy Supply (thousand TOE) Biomass Petroleum Hydro Non-conventional TOTAL PRIMARY ENERGY SUPPLY Share of Biomass in Primary Energy Share of Renewable Energy in Primary Energy

2000

2001

2002

2003

2004

4,469.8 1 3,577.1 3 767.28 1.92 8,816.1 50.7% 59.4%

4,291.8 4 3,498.2 1 746.30 1.87 8,538.2 50.3% 59.0%

4,310.5 7 3,652.5 3 646.10 2.34 8,611.5 50.1% 57.6%

4,371.8 3 3,955.7 6 791.33 3.15 9,122.1 47.9% 56.6%

4,513.2 5 4,131.9 0 710.71 3.60 9,359.5 48.2% 55.9%

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Fig. 2.7. Pie chart of primary energy supply in 2003

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Table 2.5. Energy Consumption by Sector (kTOE)

Industry Transport Household, Commercial & Others Total

2002 1,681.38 1,737.91 3,767.03 7,186.32

% 23.39 24.18 52.48 100.0

2003 1,799.61 1,848.66 3,806.50 7454.77

% 24.41 24.80 51.10 100.00

0

Table 2.6. Electricity Generation by Resource (GWh)

Hydro Diesel Fuel Oil Residuel Oil Naptha Non-conventional, CEB Self-generation by Customers Off-grid, Conventional Off-grid, Non-conventional Gross Generation Sri Lanka

2002 1,137.45 4,135.60 711.90 1,365.40 219 3.60 140.80 105.10 9.70 7,087.00

2003 1,207.45 4,320.00 588.32 1,354.70 539.60 3.40 16.70 10.90 7,661.40

Table 2.7. Petroleum Product Imports (Thousand Metric Tonnes)

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2002 2,281.01 137.00 56.21 174.56 19.68 1,081.46 96.82 1,565.73

Crude Oil LPG Super Petrol Jet A-1 Kerosene Auto Diesel Fuel Oil Total Refine Products

2003 1,995.71 141.61 117.41 144.40 3.14 1,055.43 37.28 1,499.28

Table 2.8. Sectorial Consumption of Petroleum Products (Thousand Metric Tonnes) 2002 Domestic (LPG, Kerosene) 377.28 Transport (Gasoline, Auto Diesel, 1,530.53

% 11.60 47.12

2003 337.45 1,608.18

% 11.85 50.50

Super Diesel, Furnance Oil) Commercial (Auto Diesel,

1.44

44.76

1.41

Diesel, Furnance Oil) Power Generation (Naphtha, Auto 986.99

30.83

918.73

28.85

Diesel, Super Diesel, Furnance Oil) Industry (Kerosene, Auto Diesel, 306.31

9.43

275.33

8.64

Super 46.71

Super Diesel, FurnanceTOTAL Oil) GRID ELECTRICITY SALES BY SECTOR Total 3,247.82 100.0 3,184.45 100%

100.00

0

80%

(%)

60%

40%

20%

STREET LIGHTING COMMERCIAL INDUSTRIAL RELIGIOUS DOMESTIC 2002

1999

1996

1993

1990

0%

Year

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Fig. 2.8. Total grid electricity sales by sector

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2.5 Current Status in the world Oil extraction is isolation of oil from animal by-products, fleshy fruits such as the olive and palm, and oilseeds such as cottonseed, sesame seed, soybeans, and peanuts. Oil is extracted by three general methods: rendering, used with animal products and oleaginous fruits; mechanical pressing, for oil-bearing seeds and nuts; and extracting with volatile solvents, employed in large-scale… Presently the edible oil is extracted through traditional oil extractors. The recovery of oil in traditional oil extractors is lesser and of inferior quality. The capacity is also much less as compared to the improved expellers. Oil extraction can be more effectively carried out by the Pre-pressing of seeds lightly which can precede oil milling resulting higher capacity; lower power consumption, lower wear & tear and maintenance and two-stage pressing. Different oil expellers for Jatropha seed are build in many countries. 2.5.1 The Sayari Oil Expeller The Sayari oil expeller has been developed by FAKT consulting engineers Dietz, Metzler, Zarrate for the use in Nepal. Therefore it was designed out of iron sheets instead of cast iron

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Fig.2.9. Front View of Sayari oil expeller

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to limit the weight of the heaviest parts to 40 kg12 .It is now built in Tanzania by VYAHUMU Trust, Morogoro, and in Zimbabwe by POPA, Harare

2.5.2 The Yenga press The piston creates the pressure to force the oil out of the press cake. Sometimes the piston gets stuck and is difficult to move. Then the press has to be taken apart and the piston and its cylinder have to be cleaned thoroughly. The cage is welded from iron bars with a fine gap between them. Before starting the pressing, make sure that the gaps are free. The outlet is the regulation part of the ram press. The more it is closed, the more difficult it is to press the cake through the gap, the more oil is extracted (higher extraction rate). The outlet should be regulated in such a way that one person can push down the lever without too much force (not "hanging" on the lever).

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Fig.2.10.Yenga Press

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2.5.3 Komet Oil Expellers Komet Vegetable Oil Expellers are manufactured in Germany, whose range of products covers small hand operated as well as industrial machines. According to the product literature, Komet oil expellers feature a special cold pressing system with a single conveying screw to squeeze the oils from various oil-bearing seeds. The machines operate on a gentle mechanical press principle that does not involve mixing and tearing of the seeds. Virtually all oil-bearing seeds, nuts, and kernels can be pressed with the standard equipment without adjusting the screws or oil outlet holes.

Fig. 2.11. Sectional view of KOMET oil expeller

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CHAPTER 03 3. CURRENT OIL EXTRACTION PROCESS IN SRI LANKA As our main target is designing and fabrication of jatropha oil extractor, first we have studied about the purpose and steps involving in oil extraction process. This was more beneficial at the stage of the designing the maximum torque of the machine and determining the yield of the oil. The brief description of oil extraction process is described as in the following section.

Fig.3.1: Current jatropha oil extractor Oil can be extracted mechanically with an oil press, an expeller. Presses range from small, hand-driven models that an individual can build to power-driven commercial presses. Expeller pressing is the most popular method of jatropha oil extraction. Expellers have a rotating screw inside a horizontal cylinder that is capped at one end. Jatropha seeds are fed into a cylinder, and pressure is added as the screw turns and gradually increasing the pressure. This forces the separate the liquid oil and vegetation water from the solid seed. Then oil escapes from the cylinder through small holes or slots, the oil can be collected. Percentage oil extraction form the current machine is approximately 18%. The major disadvantages of

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available machine are hard operation and less oil extraction. Also the husk of the seed wanted to remove before fed into the machine that is more time consuming and hard work for labours. By doing this project we hope to minimize the current difficulties and develop the machine into a high yield oil extractor. Preparation of the raw material often includes removing husks or seed coats from the seeds and separating the seeds from the chaff. For successful pressing, the seed must be:  Dry. Moist seed will lead to low yields and clog the cage (a part of the press). Moist seed may also get moldy.  Clean. Fine dust in the seed may clog the cage. The seed will absorb some of the oil and keep it from getting squeezed out of the cage. Sand in the seed will wear the press out. Stones badly damage the piston.  Warm. Warm seed will yield the most oil for the least effort.

Fig.3.2: Removing the jatropha husk Seed that is slightly too damp may feel dry but will not press well. If it is too damp, but not yet moldy, it can be dried in the sun. (Never press moldy seed. It is not safe for human consumption.) Spread the seed out thinly on the ground, on plastic, or on roofing tin. At the end of the day, pile the seed up to keep it from absorbing moisture in the cool night air, and

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spread it out again in the morning. If there is any chance of rain, or if the morning dew is heavy, need to bag all the seed in the evening and put it back out the following morning. After two or more sunny days, the husks will be dry. Then bag the seed and store it for a week. In that time, the moisture in the seed will be drawn into the dry husk, and the entire seed will become evenly dry.

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CHAPTER 04 4. EXPERIMENTS 4.1 Experiment 01 DATE

: 14 / 12 / 2006

TITLE

: Performance of existing oil extractor.

INTRODUCTION

: Percentage of weight of the oil extracted from Jatropa seeds is the most critical factor in our project. Because our main objective is to increase the yield, there fore at the beginning we do a small practical using existing oil extractor to identify its performance.

RESULT

:

Table 4.1. Performance of existing machine Parameter Test 01

Test 02

Weight(g) Test 03

450

450

450

450.00

-

180 270 218 47

195 255 205 44

186 264 210 48

187.00 263.00 211.00 046.33

41.55 58.44 80.23 17.61

Seeds total weight Husk Core(Useful) Disposal Oil

Average

%

4.2 Experiment 02 DATE

: 18/12/2006

TITLE

: Moisture Test for Jatropha

INTRODUCTION

: The moisture content of jatropha seed is very much important for oil extraction process. High moisture level will lead to low yields and clog the cage. First take the weights of the samples Then jatropha seeds kept inside an oven under 100°C for 24 hours. Finally measure the weight again. The difference gives the weight of the water content in jatropha seed.

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RESULT

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:

Table 4.2. Moisture test details Parameter Weight of the container/(g) Weight (Before) /(g) Weight (After) /(g) Weight of Moisture/(g) Percentage of moisture content/(%)

Sample 01 9.592

Sample 02 9.690

Sample 03 26.550

Sample 04 9.451

Sample 05 26.554

50.262

50.124

50.120

50.290

50.760

44.916

44.659

44.885

44.976

45.33

5.346

5.465

5.235

5.314

5.43

10.64

10.90

10.44

10.57

10.70

Average percentage of moisture = 10.65%

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CHAPTER 05 5. PROPOSED MODEL Fig.5.1. shows the proposed model for the Jatropha oil extractor. It is a simple manual operated machine for domestic uses. Here we mainly consider the increase of the yield from jatropha seed and the easy operation.

5.1 Operation When the shaft is rotated by means of the handle, the helical gear wheel that’s connected to the shaft is rotated. Due to that, the other gear wheel which meshed with the drive gear also begins to rotate in the opposite direction. The gear ratio between two gears is one. When prepared Jatropha seeds put into the hopper as they slide through the hopper and fallen between two meshing gears, which are in motion. When gears are rotating they catch Jatropha seeds and then these seeds will move toward the exit side. Meanwhile due to the shear and compression actions generated by the meshing gears Jatropha seeds are crushed and squeezed. Because of these crushing and squeezing actions oil will expelled from the Jatropha seeds. Mixture of this extracted oil and crushed Jatropha particles are then collected to a strainer which has been placed outside of the main extractor. The collection will keep on the strainer for some time to extract the oil and then put in to the secondary extractor. Then the remaining is put in to the secondary extractor. After that crushed Jatropha particles compressed by means of a screw attachment. When the screw is rotated the plate attached to the end of this shaft will move downward and create squeezing action on the Jatropha particles. Due to this squeezing action oil will extracted and strained through the strainer to the collector

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5.2 Part list of proposed model Table 5.1. Part list Part

Function Main Extractor.

Hopper

To put Jatropha seeds into the extractor.

Helical gears

To crush & squeeze seeds.

Bearings

To create friction less rotation of shafts.

Strainer

To separate oil from crushed Jatropha particles

Handle

To rotate the driving gear.(To input power)

Bearing capes

To mount bearings

Shaft

For power transmission

End covers

To cover two ends of the machine

Housing

Exist two gears and generate shearing action on Jatropha seeds

Clamping plates

To clamp the extractor Secondary extractor (Screw press)

Cylinder

Provide space for squeezing operation

Screw

To generate squeezing action

Plate

To prevent escaping of particles

Stand

To retain the extractor

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Fig.5.2. Front view of the proposed model

Fig.5.3. Plan view of the proposed model

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Fig.5.4. Inside view of the proposed model

Fig.5.5. Helical gear wheel

Fig.5.6. Hopper

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Fig.5.7. Gear housing

Fig.5.8. Clamping plate

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Fig.5.9. Screw press

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CHAPTER 06 6. MATERIAL SELECTION An important aspect of design for mechanical, electrical, thermal, chemical or other application is selection of the best material or materials. Systematic selection of the best material for a given application begins with properties and costs of candidate materials. For example, a thermal blanket must have poor thermal conductivity in order to minimize heat transfer for a given temperature difference. Systematic selection for applications requiring multiple criteria is more complex. For example, a rod which should be stiff and light requires a material with high Young's modulus and low density. If the rod will be pulled in tension, the specific modulus, or modulus divided by density E / ρ, will determine the best material. But because a plate's bending stiffness scales as its thickness cubed, the best material for a stiff and light plate is determined by the cube root of stiffness divided density

.

6.1 Cost issues Cost of materials plays a very significant role in their selection. The most straightforward way to weight cost against properties is to develop a monetary metric for properties of parts. However, the geography- and time-dependence of energy, maintenance and other operating costs, and variation in discount rates and usage patterns between individuals, means that there is no single correct number for this. Thus as energy prices have increased and technology has improved, automobiles have substituted increasing amounts of light weight magnesium and aluminium alloys for steel, aircraft are substituting carbon fiber reinforced plastic and titanium alloys for aluminium, and satellites have long been made out of exotic composite materials.

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6.2 Materials for Gear Wheels The material used for the manufacture of gears depends on the strength and service conditions like wear, noise etc. the gears may be manufactured from metallic or non-metallic materials. The metallic gears with cut teeth are obtainable in cast iron, steel and bronze. The nonmetallic materials like wood, rawhide, compressed paper and synthetic resins like nylon are used for gears, especially for reducing noise. The cast iron is widely used for the manufacture of gears due to its good wearing properties, excellent machinability and ease of producing complicated shapes by casting method. The cast iron gears with cut teeth may be employed, where smooth action is not important.

6.3 Some Benefits and Advantages of Cast Irons

•

A family of materials capable of meeting a wide variety of engineering and manufacturing requirements (the "family" includes Gray Iron, Ductile Iron, Compacted Graphite Iron, Malleable Iron, and White Iron)

•

Available in a wide range of mechanical/physical properties, i.e. tensile strength from 20 KSI to over 200 KSI, hardness from 120 to about 300 Brinell in standard grades and up to about 600 Brinell in special abrasion resistant grades

•

Good strength to weight ratio

•

Typically lower cost than competing materials and relatively low cost per unit of strength than other materials

•

Lower density and higher thermal conductivity than steels at comparable tensile strength levels

•

Excellent machinability, allowing for high speeds and feeds and reduced (minimal) energy due to the presence of free graphite

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•

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Many iron castings can be used without heat treatment (as-cast) but, when needed, can be heat treated to enhance overall properties or localized properties such as

•

Surface hardness

•

Excellent damping capacity, especially in Gray Irons

•

Chemical analysis can be modified to provide improved special properties such as corrosion resistance, oxidation resistance, wear or abrasion resistance, etc.

•

Rapid transition from design to finished product

•

Capability of producing highly complex geometries and section sizes in a wide range of sizes, from ounces to over 100 tons

•

Flexibility in design and ability to optimize appearance for sales appeal

•

Possibility of casting intricate shapes as well as very thin to very thick section sizes

•

Capability of redesigning and combining two or more components from other materials into a single casting, thus reducing assembly cost and time

•

Capability of casting with inserts of other materials

•

Variety of casting processes for low, medium or high production

•

Reduced tendency toward residual stresses and warpage than some competitive materials

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CHAPTER 07 7. DESIGN Concerning our proposed machine, two helical gears are the most important component. So that in our designing process we give special attention on designing a helical gear, Apart from that there are few another parts to be design. They are; a) Shaft b) Bearings c) Keys

7.1 Design of the helical gear A helical gear has teeth in form of helix around the gear. Two such gears can be used to connect two parallel shafts in place of spur gears. The helixes may be right handed on one gear and left handed on other gear. The pitch surfaces are cylindrical as in spur gear, but teeth instead of being parallel to the axis, wind around the cylinders helically like screw threads. The teeth of helical gears with parallel axis have line contact, as in spur gearing. This provides gradual engagement and continuous contact of the engaging teeth. In our design to extract maximum amount of oil from ‘Jatropha’ seeds it required to generate better crushing and continuous squeezing action by using two gear wheels. Due to that reason we select two helical gears to obtain these actions because it can generate gradual engagement and continuous contact of the engaging teeth. 7.1.1 Gear Terms Used in Gears

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Pitch circle

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: The intersection of the pitch surface with a plane perpendicular the axis of rotation

Addendum circle

: It is the circle which bounds the outer ends of the teeth.

Addendum

: The radial distance between the pitch circle and the addendum circle.

Dedendum circle

: The circle which bounds the bottom of the teeth.

Dedendum circle.

: The radial distance between the pitch circle diameter and the addendum

Total depth of tooth

: The sum of addendum and addendum.

Clearance

: The difference between the dedendum and the addendum of mating gear teeth.

Base circle

: A circle from which the tooth profile curve is generated.

Tooth thickness

: The chord length measured along the pitch circle between the opposite faces of the same tooth.

Module

: The ratio of the pitch circle diameter to the number of the teeth, i.e. the reciprocal of the diametral pitch (DP).

Diametral pitch

: The ratio of the number of teeth to the pitch circle diameter.

Backlash

: The space between two consecutive teeth, measured along the pitch circle.

Circular pitch

: The distance measured along the pitch circle from a point on one tooth to the corresponding point on the adjacent tooth. P

= πd1/Z1

d1

: the pitch circle diameter of the pinion.

Z1

: is the number of the teeth of the pinion.

Where;

Helical angle

: It is a constant angle made b the helices with the axis of rotation.

Axial Pitch

: It is the distance, parallel to the axis, between similar faces of adjacent teeth.

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Normal Pitch

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: It is the distance between similar faces of adjacent teeth along a helix on the pitch cylinder normal to the teeth.

7.1.2 Strength of Helical Gears In helical gears contact between mating teeth is gradual, starting at one end and moving along the teeth so that at any instant the line of contact runs diagonally across the teeth. therefore in order to find the strength of helical gears, a modified Lewis equation is used. It is given by; WT = (σ 0 × CV ).b.π .m.Y / Where; WT

= Tangential tooth load

σ0

= Allowable static stress

CV

= Velocity factor

b

= Face width.

m

= Module

Y/

= Tooth form factor or Lewis factor

The values of the velocity factor ( CV ) are given as follow:

CV =

3 , for ordinary cut gears operating at velocities up to 12.5 m/s. (3 + V )

CV =

4.5 , for carefully cut gears operating at velocities up to 12.5 m/s. (4.5 + V )

CV =

6 , for very accurately cut and ground metallic gears operating at (6 + V ) velocities up to 20 m/s.

CV =

0.75 , for non-metallic gears (0.75 + V )

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7.1.3 Assume Data for the Design By doing some experiments we have identify that the maximum force required to crush and squish the ‘Jatropha’ seeds in order to extract maximum amount of oil is about 2600N. Considering a helical gear this force represents the Tangential Tooth Load ( WT ). There fore take; WT = 2600 N But considering the safety of the gear teeth take safety factor as 3 Then take; S .F . = 3

φ = 20 0 α = 30 0 Since our machine is designed for domestic use, it is prefer to operate it manually. Therefore maximum speed of the gear wheel cannot be a large value. So that we take that as 30 rpm. Then; N = 30rpm Also we select our material as ‘Cast Iron’. Ten from Table 11.1

σ 0 = 105 N / mm 2 Take the optimal length of the axel which used to introduce the torque as 400mm (0.4m) 7.1.4 Gear Design Calculations From data we know WT (Re quired ) = S .F . × WT = 3 × 2600 = 7800 N Then the peripheral velocity (v);

ν =

πDN π × 0.06 × 30 = = 0.0942m / s 60 60

Since we use ordinary cut gear and having ν < 12.5 m/s

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Cν =

3 = 0.9695 3 +ν

(1)

Also; T=

D 60 = m m

But equivalent number of teeth in spur gear ( TE ); TE =

T 60 92.38 = = 3 3 0 m cos α m × cos 30

For 200 Stub teeth; Y / = 0.175 −

0.841 TE

Y / = 0.175 − 0.00496m

(2)

Take; b = 20m Then from Lewis equation WT = (σ 0 × Cν )(bπ m)Y / 7800 = 105 × 0.9695 × (20m)(π m)(0.175 − 0.00496m) 1.219 = 0.175m 2 − 0.00496m 3 0.00496m 3 − 0.175m 2 + 1.219 = 0 m=3 There fore; b = 20 × 3 = 60mm

But considering over extracting process it should have lengthy process to extract oil Take; b = 30 × m = 90mm Because maximum face width bm 20 m < bm < 30 m Then face width = 90 mm Number of teeth = WT =

D 60 = = 20 m 3

T T = D 0.03 2

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Since WT required =2600 N Torque = 2600 × 0.03 = 78 Nm

Force required to rotate =

T 78 = = 195 N l 0.4

Force required to rotate axel in order to extract maximum amount of oil from ‘Jatropha’ seeds is = 195 N ≈ 200 N = Wt Tanα

Axial thrust ( W A )

= 7800 × Tan30 0 = 4503.33 N = 4500 N

Normal Force ( W N ) = Wt

Wt Tanα = Sinα Cosα

= 9006.66 N = 9000 N Dynamic Tooth Load (Wd)

WD = WT +

21.ν (b.c.Cos 2α + WT ) cos α

WD = 7800 + WD = 7800 +

21.ν + b.c.Cos 2α + WT

{(21× 0.0942)(75 × 714(Cos30

) + 7800)Cos30 0

0 2

}

(21 × 0.0942) + (75 × 714(Cos30 0 ) 2 + 7800) 1.9782 × (47962.S × Cos30 0 ) 1.9782 + 47962.S

WD = 8171.83N Wear load Ww = Q=

DP × b × Q × K Cos 2α

2T0 T0 + TP

But; T0 = TP , Q = 1

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Therefore; K=

σ 2 es × Sinφ 1.4

1   E × 2

But Tanφ n = Tanφ × Cosα = Tan 20 0 × Cos 20

φ n = 17.5 0

630 2 × Sin 20 0  2  K= 3  1.4  200 X 10  K = 0.85

Then; Ww =

60 × 90 × 1 × 0.85 Cos 2 30 0

Ww = 6120 N Gear Parameters. m=3

φ = 20 0 α = 30 0 T = 20 b = 90mm Troque = 78 Nm WT = 7800 N W A = 4500 N W N = 9000 N Axel = 400mm Axel Force( Max ) = 20 N S .F . = 3 Addendum

=0.8m = 2.4 mm

Dedendum

= 3mm

Working depth

=1.6m = 4.8 mm

Tooth thickness

= 1.5708m = 4.7124 mm

Minimum Clearance

= 0.2m = 0.6 mm

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Fillet radius at root

= 0.4m =1.2 mm

7.2 Designing the Shaft Shaft design is another important task in our project. Though shaft is a rotating machine element which is used to transmit power from one place to another, it required various members such as pulley, gears etc... in order to transmit power from one shaft to another. In other words, we can say that a shaft is used for the transmission of torque and bending moment. Here there are two shafts to support two gear wheels. Shaft can be divided in to two major parts. Transmission Shaft

: These shafts transmit power between the source and the machines absorbing power.

Machine shaft

: These shaft form an integral part of the machine it self. (crank shaft)

7.2.1 Standard sizes of Transmission shaft. The standard sizes of the transmission shaft are; 25mm to 60mm with 5mm steps 60 mm to 110 mm with 10 mm steps 10 mm to 140 mm with 15 mm steps 40 mm to 500 mm with 20 mm steps 7.2.2 Design methods Shafts can be designed on the basis of a) Strength b) Rigidity and stiffness In designing shaft on the basis of strength, the following cases may be considered; Shaft subjected to twisting moment or torque only.

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•

Shaft subjected to bending moment only.

•

Shaft subjected to combined twisting and bending moments.

•

Shaft subjected to axial loads in addition to combine torsional and bending load.

Shaft subjected to axial loads in addition to combine torsional and bending load In our case the main shaft is subjected to an axial force (due to helical gear) in addition to torsional and bending loads. There fore we used following method to calculate shaft diameter. From Maximum shear stress theory 2

τ max =

1  32 M  16T  + 4 3  πd 3  2  πd 

τ max =

16 πd 3

2

M 2 +T 2

Where; M

= Bending moment

T

= Torsion

d

= Diameter of the shaft

τ max

= Maximum shear stress M 2 + T 2 = Te = Equivalent twisting moment

For failure,

τ max = τ allowable = τ τ×

πd 3 = T2 +M2 16

According to the maximum normal stress theory, 1 1 σ b 2 + 4τ 2 Maximum normal stress in the shaft σ b (max) = σ b + 2 2 =

32 πd 3

[

1 2 2   2 ( M + M + T )

π 1 × σ b (max) × d 3 = M + M 2 + T 2 32 2        

]

EquivalantB . M .

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Finally if σ a is maximum allowable bending stress σ b

[

π 1 ×σ b × d 3 = M + M 2 + T 2 32 2

]

When shaft is subjected to an axial load( F ) in addition to torsion and bending loads, then the stress due to axial load must be added to the bending stress ( σ b ) The stress due to axial load =

4F π d2

Then resultant stress σ b res

σ b res =

32  1  4F ( M + M 2 + T 2 ) + 3  2 π d 2  πd R

R/2

R/2

65

65

Fig 7.2. Bearing arrangement Take; Considering the gear width and operational feasibility, in our design we decided to fix two bearings, 130mm apart. As shown in Fig.7.2. Then; L = 130mm Wt = 7800 N W = Wt .Secα = 7800 × Sec30 0 = 9000 N Wr = W .Tanφ = 900 × Tan 20 0 = 3275.73 N Wa = F = 4500 N

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Assumption: Since compare to the load applied due to squishing action self weight of the gear wheels is very much small, self weight of the gear is neglected. Then; 2

2

R = Wt + Wr = 8459.9 ≅ 8460 N R = 4230 N 2 M max =

R L 65 × = 4230 × = 274.95mm 2 2 1000

Maximum torque transmit

= 78 Nm

Maximum Bending Moment

= 274.95 Nm

Equivalent Bending Moment

=

1 2

=

1 274.95 + 274.95 2 + 78 2 2

{

M 2 +T 2 + M

}

{

}

= 280.37 Nm 2 For Mild Steel ( σ b = 56 Mpa = 56 N / mm )

π × 56 × 10 6 × d 3 32

=280.37+562.5.d

d

=.0380 m

d

= 38.00 mm

Select Mild steel shaft with diameter = 40 mm

7.3 Bearing Selection Since in our design it has to handle radial force and little amount of axial thrust we select single raw deep grove ball bearing to mount two helical gears. Data Axial thrust

= W A =4500N

Radial Load

= R 2 = 4230 N

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W R = 4230 N W A = 4500 N N = 30rpm Since we are designing this machine for domestic use, we assume that people will prefer to extract oil per day by operating this machine maximum two hours. Also we predict that the machine will last for minimum five years which are having maximum 300 operating days. Then bearing life in hours ( LH ) given as; LH = 2 × 300 × 5 = 3500hours Life of the bearing in revolution (L) = 60 × N × LH

L

= 60 × 30 × 3500 = 6.3 × 10 6 rev Basic dynamic equivalent radial load (W), W = X .V .WR + Y .W A Where; V

= A rotational factor = 1, for all type of bearings when the inner race is rotating = 1.2 for all types of bearings except self aligning, when inner race is stationary.

X

= Radial load factor

Y

= Axial load factor

Then; WA

Take

WA = 0.5 ;( C0

WR

=

4500 = 1.0638 4230

we don’t know C 0 )

Then from data sheets (Table 10.4) X = 0.56 & Y = 1.0 Also V= 1; because for all type of bearings when the inner race is rotating V=1

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= X .V .WR + Y .W A

W

= (0.56 × 1 × 4230) + (1 × 4500) = 6868.8 = 6.869 KN For uniform & steady load, service factor K s = 1 (From Table 11.3) Basic dynamic load rating,

 L  C =W 6  10 

1

3

 6.3 × 10 6  = 6868.8  6  10 

1

3

= 12686.08 N = 12.7 KN In this point we have to consider about both bearing loads as well as shaft diameter. Because if the shaft diameter is much lesser value than bearing bore then it gives designing failure. there fore in our case we have to select bearing which is having its bore closer to 30mm or less than that. By considering these two factors with Table 11.5 and Table 11.6. Select bearing number as 205 which gives following values C 0 = 7.1 , C = 11 Then WA

C0

=

4500 = 0.63 7.1 × 10 3

But using Table.11.1 we have to select WA = 0.5 C0 This gives same X & Y values as in our first case There fore we select deep groove ball bearing which is having bearing number 205

7.4 Designing of Key -Way

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7.4.1 Force acting on a Sunk Key When a key is used in transmitting torque from a shaft to a rotor or hub, the following two type of force act on the key: 1. Force (F1) due to fit of the key in its keyway, as in a tight fitting straight key or in a

tapered key driven in place. These forces produce compressive stresses in the key which are difficult to compute in magnitude. 2. Forces (F) due to the torque transmitted by the shaft. These forces produce shearing and compressive (or crushing) stresses in the key.

The distribution of the forces along the length of the key is not uniform because the forces are concentrated near the torque-input end. The non-uniformity of distribution is caused by the twisting of the shaft within the hub.

The forces acting on a key for a clockwise torque being transmitted from a shaft to hub are shown in Fig.7.3

Fig.7.3. Forces acting on a sunk key

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In designing a key, forces due to fit of the key are neglected and it is assumed that the distribution of forces along the length of key is uniform. 7.4.2 Strength of a Sunk Key T = Torque Transmitted by the shaft

Let

F = Tangential force acting at the circumference of the shaft d = Diameter of shaft l = Length of key w = Width of key t = Thickness of key

τ and σ c = Shear and crushing stresses for the material of key Little consideration will show that due to power transmitted by the shaft, the key may fail due to shearing or crushing. Considering shearing of key, the tangential shearing force acting at the circumference of the shaft, F = Area resisting shearing × Shear stress = l × w × τ ∴ Torquetransmitted by shaft , T =F×

d d = l × w ×τ × ................................................( i ) 2 2

Considering crushing of the key, the tangential crushing force acting at the circumference of the shaft, t F = Area resisting crushing × Crushing stress = l × × σ c 2 ∴ Torquetransmittedbyshaft , T =F×

d t d = l × × σ c × .................................................( ii ) 2 2 2

The key is equally strong in shearing and crushing, if

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l × w ×τ ×

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d t d = l × ×σ c × 2 2 2

w σc = ................................................................................( iii ) t 2π The permissible crushing stress for the usual key material is at least twice the permissible shearing stress. Therefore from equation (iii), we have w = t. In other word, a square key is equally strong in shearing and crushing. In order to find the length of the key to transmit full power of the shaft, the shearing strength of the key is equal to the tensional shear strength of the shaft. We know that shearing strength of the shaft, T = l × w ×τ ×

d .................................................( iv ) 2

and tensional shear strength of the shaft, T=

π × τ 1 × d 3 ..................................................( v ) 16

In our design the shaft diameter is 60mm then from the table 11.7 we select width and thickness as 20 mm and 12 mm. In our case we select material as mild steal then permissible shear ( )and crushing stresses( c) are 56N/mm and 112 N/mm Then considering shearing of the key. From equation iv T = l × 20 × 56 ×

60 = 33600l ............................................................( a) 2

And torsion shearing strength of the shaft. From equation v π T = × 42 × 60 3 = 1.78 × 10 6 ..........................................................(b) 16 Solving above two equations we get l = 52.98mm Now considering crushing of the key. We know that shearing strength of the key T =l×

12 60 × 112 × = 20160 l .........................................................(c) 2 2

From equation (b) and (c)

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l = 88.29mm Taking larger of these two we select the length of the key-way used at gear wheel as l = 88.29 Say 90 mm There Fore the two key-ways have following dimensions w = 20 t = 12 l = 90

CHAPTER 08 8. Fabricating of Oil Extractor

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8.1 Main Shaft

20

20

25

50

130

Fig.8.1. Front View of Main Shaft

Manufacturing of the main shaft is the most important part of the manufacturing process because the gear wheel, bearings and handle are mounted on this shaft. To manufacture the shaft we have to use the lathe machine. There we can use the turning, facing & parting operations to make the main shaft to the required dimensions as shown in the Fig.8.1. Then we have to prepare the driven shaft also, there the machining operation is similar to the main shaft only difference is dimensions.

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8.2 Helical Gear

Fig.8.2. Helical Gear Wheel

Manufacturing of helical gear is somewhat difficult but using CNC milling machine can make the gear wheel according to the required profile as given in the design. We have chosen the material as Cast iron so the casting operation also can use to manufacture the gear wheel because this operation does not need very carefully cut teeth.

8.3 Gear housing

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Fig.8.3. Gear Housing

Manufacturing of gear housing is somewhat easier comparing with earlier manufacturing parts because this needs only drilling & boring operations. First we need to cut a metal piece and shaped into required dimensions. Then using CNC milling machine can drill & bore the holes as shown in the Fig.8.3.

8.4 Clamping Plate

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Fig.8.4. Clamping Plate

By using metal plates we can prepare clamping plate to required dimensions as shown in Fig.8.4. This requires welding & drilling operations. First we have to cut two metal plates to required dimensions & then we can drill to make the holes need. After that we can weld the two plates to finish the part.

8.5 Hopper

Fig.8.5. Hopper

Hopper can be made by using alluminium sheet. There we can draw the development of hopper on alluminium sheet. Then cut the development and revert it to a hopper.

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8.6 Other Parts Manufacturing of key is very simple because it need only cut a metal piece & sized it. Handle can be made using two metal pieces & casing by using alluminium sheet. Metal mat can be placed below the machine to collect the crushed seed particles.

CHAPTER 09 9. CONCLUSION AND RECOMMENDATION Designing of a Jatropha Oil Extractor is very important task because here we were concern mainly about poor people in domestic areas. In those areas jatropha planted in their fences. These jatropha seeds not used for any purposes because there poisonous. So by doing this kind of project we can encourage people living in rural areas to cultivate jatropha plant as an energy crop. Finding an alternative fuel to petroleum is world’s trend in these days so jatropha oil also one of a bio-fuel using & researching in nowadays. Some of non- government organizations also make their concern about this area in Sri Lanka. In last few months we had contact with people who are interested in this field and got very important information about the future projects which will be implemented in Sri Lanka. In our design some assumptions were made. Actually the testing of existing machine was very difficult because there were no any facilities to test the performance at Thanamalwila area. How ever we were able to get the some measurements relating to the design from that machine.

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There are more methods of oil extracting available in world. Here we have considered about mechanical method. We hope that in our design we could obtain more oil yield than the existing oil extractor in Sri Lanka also we reduce the size and weight of the extractor which would be very easy for operators. Most importantly we have avoid the removing of husk in our extractor but we couldn’t test the conditions with and without husk as we fail to fabricate the complete oil extractor because of no any fund provided by the university. Our design can develop up to the industrial level by introducing suitable electric motor. Finally we were disappointed because we have no enough money for fabricate the oil extractor which we have design and check whether the performance of our machine.

CHAPTER 10 10. BIBLIOGRAPHY 10.1 Web 1. http://home.t-online.de/home/320033440512-0002/downloads/jcl-manual,30.07.2006 2. www.jatropha.de/zimbabwe/rf-concept-paper.doc,30.07.2006 3. www.jatropha.org,24.07.2006 4. www.wikipedia.org/wiki/Jatropha ,24.07.2006 5. www.jatrophaworld.org/,24.07.2006 6. www.biodieseltoday.com,24.07.2006 7. www.hort.purdue.edu/newcrop/duke_energy,28.07.2006 8. www.svlele.com,28.07.2006 9. www.energy.gov.lk,02.08.2006 10. www.ceb.lk,02.08.2006 11. www.oregonstate.edu/international/outreach/rlc/resources/Jatropha.pdf,04.08.2006 12. www.jatropha.de/documents/jcl-booklet.pdf,04.08.2006

10.2Books

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1. R.S.Khurmi & J.K.Guptha, A Textbook of Machine Design, 1st ed. (S.Chand & Company Ltd, 2004), Ch 28 & 29.

CHAPTER 11 11. ANNEXURE Table 11.1.Values of Allowable Static Stress Material Cast iron, ordinary Cast iron, medium grade Cast iron, highest grade Cast steel, untreated Cast steel, heat treated Forged carbon steel-case hardened Forged carbon steel-untreated Forged carbon steel-heat treated Alloy steel-case hardened Alloy steel –heat treated Phosphor bronze Non-metallic materials Rawhide, fabroil Bakellite, Micarta, Celoron

Allowable static stress ( σ 0 ) MPa or N/mm2 56 70 105 140 196 126 140 to 210 210 to 245 350 455 to472 84 42 56

Table 11.2.Minimum no. of teeth on the pinion in order to avoid interference S. No 1.

System of gear teeth. 14 1/20 composite

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2.

14 1/20 Full depth involutes

32

3.

200 Full depth involutes

18

4.

200 stub involutes

14

Table 11.3.Values of Service Factor (Ks) S.No. 1 2 3 4 5

Type of service Uniform and steady load Light shock load Moderate shock load Heavy shock load Extreme shock load

Service Factor (Ks) for radial ball bearing 1.0 1.5 2.0 2.5 3.0

Table 11.4.Vales of X and Y for Dynamically Loaded Bearing Bearing

Specifications

WA

type X Deep groove ball bearing

WA = 0.025 C0 = 0.04 = 0.07 = 0.13 = 0.25 = 0.50

1

WA

WR < e Y

0

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0.56

e

WR >e Y 2.0 1.8 1.6 1.4 1.2 1.0

0.22 0.24 0.27 0.31 0.37 0.44

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Table 11.5.Principal Dimensions for Radial Ball Bearing Bearing No. 200 300 201 301 202 302 203 303 403 204 304 404 205 305 405 206 306 406 207 307 407 208 308 408 209 309 409 210 310 410

Bore(mm) 10 12 15 17 20 25 30 35 40 45 50

Outside diameter(mm) 30 35 32 37 35 42 40 47 62 47 52 72 52 62 80 62 72 90 72 80 100 80 90 110 85 100 120 90 110 130

Width(mm) 9 11 10 12 11 13 12 14 17 14 15 19 15 17 21 16 19 23 17 21 25 18 23 27 19 25 29 20 27 31

Table 11.6.Basic Static and dynamic capacities of various types of radial ball bearing

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Bearing No.

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Single row deep groove ball bearing

Basic Capacities in kN Single row angular Double row angular contact ball bearing contact ball bearing

Self-aligning ball bearing

Static

Dynamic

Static

Dynamic

Static

Dynamic

Static

Dynamic

(1) 200 300 201 301 202 302 203 303 403 204 304 404 205 305 405 206 306 406 207 307 407 208 308 408 209 309 409 210 310 410 211 311 411

(Co) (2) 2.44 3.60 3 4.3 3.55 5.20 4.4 6.3 11 6.55 7.65 15.6 7.1 10.4 19 10 14.6 23.2 13.7 17.6 30.5 16 22 37.5 18.3 30 44 21.2 35.5 50 26 42.5 60

(C) (3) 4 6.3 5.4 7.65 6.10 8.80 7.5 10.6 18 10 12.5 24 11 16.6 28 15.3 22 33.5 20 26 43 22.8 32 50 25.5 41.2 60 27.5 48 68 34 56 78

(Co) (4) 3.75 4.75 7.2 6.55 8.3 7.8 12.5 11.2 17 15.3 20.4 21.6 34 21.6 34 23.6 40.5 30 47.5 -

(C) (5) 6.3 7.8 11.6 10.4 13.7 11.6 19.3 16 24.5 21.2 28.5 25 35.5 28 45.5 29 53 36.5 62 -

(Co) (6) 4.55 5.6 5.6 9.3 8.15 12.9 11 14 13.7 20 20.4 27.5 28 36 32.5 45.5 37.5 56 43 73.5 49 80 -

(C) (7) 7.35 8.3 8.3 14 11.6 19.3 16 19.3 17.3 26.5 25 35.5 34 45 39 55 41.5 67 47.5 81.5 53 88 -

(Co) (8) 1.80 2.0 3.0 2.16 3.35 2.8 4.15 3.9 5.5 4.25 7.65 5.6 10.2 8 13.2 9.15 16 10.2 19.6 10.8 24 12.7 28.5 -

(C) (9) 5.70 5.85 9.15 6 9.3 7.65 11.2 9.8 14 9.8 19 12 24.5 17 30.5 17.6 35.5 18 42.5 18 50 20.8 58.5 -

212 312 412

32 48 67

40.5 64 85

36.5 55 -

44 71 -

63 96.5 -

65.5 102 -

16 33.5 -

26.5 68 -

Table 11.7.Proportions of Slandered parallel, tapered and gib head keys.

Department of Mechanical & Manufacturing Engineering

57

Faculty of Engineering Galle

Shaft Diameter (mm) up to and including. 6 8 10 12 17 22 30 38 44 50 58 65 75

Final Report

Key cross-section With(mm) Thickness(mm) 2 3 4 5 6 8 10 12 14 16 18 20 22

Department of Mechanical & Manufacturing Engineering

2 3 4 5 6 7 8 8 9 10 11 12 14

58