design and fabrication of soya seed fabrication machine

Design and Fabrication of Soya Seed Harvesting Machine

List of figure

Fig. No description Page No.

Fig. 1.1 Soya bean 3

Fig. 1.2 Hand threshing

Fig. 1.3 Treading of grain under the

feet of animals

Fig. 1.4 Winnowing

Fig. 3.1 Improve bean processing

Fig. 3.2 Classification of motor

Dept of MechEngg. KLE Dr MSSCET, Belagavi


List of Table

Table No. Description Page No.3.1 Morphological Chart for

design of product



Chapter 1

Introduction

The history of agriculture in India dates back to the Rig-Veda, written about 1100 BC. Today

India ranks second worldwide in farm output. Agriculture and allied structures like forestry

and fisheries accounted for 13.7% of the GDP (Gross Domestic Product) in 2013, about 50%

of the total workforce. The economic contribution of agriculture to India’s GDP is steadily

declining with the country’s broad-based economic growth. Still, agriculture is

demographically the broadest economic sector and plays a significant role in overall socio-

economic fabric of India.

As Per the 2010 FAO world agriculture statistics, India is the world's largest producer of

many fresh fruits and vegetables, milk, major spices, select fresh meats, select fibrous crops

such as jute, several staples such as millets and castor oil seed. India is the second largest

producer of wheat and rice, the world's major food staples.

Soyabean continues to be the preferred Kharif crop for farmers due to its high net returns.

The manual harvesting process is tedious and time consuming and moreover the labour costs

are high and also there is lack of laborers. The small scale farmers can’t afford harvesting

machines which are of high costs. Thus there is a need for cost effective low maintenance

soya seed harvesting machine.

Soyabean is grown as a rain fed crop in Kharif Season, asSoyabean is a high yielding crop

compared to other crops, Water Requirement of the crop is very less (110 mm), Time

duration is very less (3 months and 20 Days), Market rates of soyabean are economical.



1.1 Literature Survey

The soybean in North America, also called the soya bean (Glycine max) (fig.1.1) is, a

species of legume native to East Asia, widely grown for its edible bean which has numerous

uses. The plant is classed as an oilseed rather than a pulse by the UN Food and Agriculture

Organization (FAO).

Fat-free (defatted) soya bean meal is a significant and cheap source of protein for animal

feeds and many packaged meals; soya vegetable oils another product of processing the soya

bean crop. For example, soya bean products such as textured vegetable protein (TVP) are

ingredients in many meat and dairy analogues. Soya beans produce significantly more

protein per acre than most other uses of land.

Traditional non fermented food uses of soya beans include soy milk, from

which tofu and tofu skin are made. Fermented foods include soya sauce, fermented bean

paste, natto, and tempeh, among others. The oil is used in many industrial applications. The

main producers of soya are the United States (36%), Brazil (36%), Argentina (18%), China

(5%) and India (4%). The beans contain significant amounts of phytic acid, alpha-linolenic

acid, and isoflavones.

Fig. 1.1 Soya bean



During World War II, soyabeans became important in both North America and Europe

chiefly as substitutes for other protein foods and as a source of edible oil. During the war, the

soyabean was discovered as fertilizer by the United States Department of Agriculture. In the

1960–1 Dillon round of the General Agreement on Tariffs and Trade(GATT), the United

States secured tariff-free access for its soyabeans to the European market. In the 1960s, the

United States exported over 90% of the world's soyabeans. By 2005, the top soyabeans

exporters were Argentina (39% of world soyabean exports), United States (37%) and Brazil

(16%), while top importers were China (41% of world soyabean imports), European Union

(22%), Japan (6%) and Mexico (6%).

1.1.1 Threshing

The prime objective of the threshing process is to detach the sound or undamaged

grainkernels from the plants. In some crops, it also involves the removal of kernels from the

protective cover, called husk or pod. It is achieved by striking, treading, squeezing, tearing,

and rubbing actions or by combinations of these methods. Traditionally, threshing is

performed by treading the grain under the hooves of animals, striking the grains with sticks,

beating them over a log of wood or bamboo grating, or over a ladder, or using a stationary

power thresher of specific design for each crop, or between the rasp-bar and concave of a

combine. The machine used for the purpose of grain detachment and separation is called a

thresher and was introduced in India about 1960.

Timely preparation of seedbed and sowing of seasonal crops immediately after harvest are

the prime desire of all the farmers. To meet these requirements, threshing either needs to be

delayed or the farmers are required to use a stationary thresher. Delayed threshing will cause

not only spoilage of grain, but will also increase the breakage percentage during milling.

Hence, the use of stationary thresher, a faster method of grain detachment and separation for

cereal and pulse crops has become very common among all groups of farmers. Stationary

threshers are conventionally used when the fields are small and conditions are not favorable

for combine operation. For speedy and effective threshing, pedal- and power-operated

threshers are used, respectively, by the small to marginal- and medium-class farmers. With



the use of these threshers, threshing of most crops and separation of grains and seeds from un

threshed debris has become mechanized in all developed and underdeveloped countries.

1.1.1.2 Traditional Threshing

Conventionally, harvested paddy and wheat crops are either dried in the field or on a

cemented floor for 3–5 days to bring down the moisture content from 27–40% to 15–20%

when threshing operations are carried out. Threshing of immatured or moist grain would

result not only in more breakage, but would also require higher impact force for grain

detachment, and cleaning and grain separation from leftovers (broken stalks and chaffs)

would become difficult, requiring more impact power. An average laborer can thresh 15–22

kg/h of grain by hand-beating (Fig 1.2), or 110–140 kg/h by treading the grain under the feet

of animals (Fig 1.3).

Fig 1.2 Hand Threshing

Fig 1.3 Treading of Grain under the Feet of Animals



In either method, sound grains are separated using a winnower operated by human or by a

power unit or dropping the mix against the medium to high natural wind. Thus, the

separation of sound grain and manual bagging require additional labor, making the entire

process tedious, time-consuming, and labor-intensive. It thus brings down the overall

threshing ability of a laborer to 12–18 kg/h in manual threshing and 80–120 kg/h by treading

the grain under the feet of animals. Therefore, traditional methods of threshing are

considered a slow process of grain detachment. Small and marginal farmers of South and

Southeast Asia knowingly follow these methods because of capital constraint and limited

production of cereal and pulse crops.

1.1.1.2 Pedal Threshing

Threshers of different designs and capacities are being manufactured by various

manufacturers in all the countries. They are either throw-in or hold-on type. The Japanese-

type rotary drum thresher, a hold-on type is the first of its kind developed in Japan for

threshing paddy crops. Such a thresher is common with small farmers of paddy-growing

countries. It is cheap, compact, and simple in construction. It consists of a threshing cylinder

(420mm in diameter and 400–700 mm long) with wire loops, driving mechanism, and

supporting frame. The rotary motion to the drum is given by a crank mechanism from a

treadle and two cast iron gears (80 and 20 teeth) with 1:4-speed gain to achieve a cylinder

speed between 300 and 375 rpm (6–7.8 m/s). The threshing drum mounted with a large

number of wireloops at its periphery and at regular intervals shatters grain by impact and

combing actions. Most grains from paddy are detached when the tiller ends of crop bundle is

held over the rotating cylinder along the motion direction. One man can thresh about 1.5–2.0

q/day but additional labor is required to separate grain from chaff and other debris. To

increase the capacity, farmers engage four to six laborers for threshing over a 1.5- to 2.4- m–

long threshing cylinder made locally and operated by a 3.75-kW diesel engine through a flat

belt. An additional two- to four men are engaged for the supply of crop bundles near the

thresher and grain separation. This method in contrast with manual threshing, therefore,

saves time and energy, and at the same time reduces human drudgery to a large extent.



1.1.1.3 Power Threshing

The prime functions of threshing units are to detach sound grain kernels and kernels from

husk or pod; separate them from broken stalks, leftovers, and chaffs; convey and deliver the

sound and unbroken grains or seeds, free from foreign materials, to a delivery outlet and bag

the grains. Because operations such as detachment, separation, conveying, and elevating of

grains or kernels are done simultaneously and in sequence, a prime-mover with a capacity in

the 3.5- to 30.0-kWrange is necessary, depending on the crop parameters, type, and size of

threshing cylinder and feed rate.

Power-driven threshers are very similar to the threshing units used in a combine harvester.

The large-sized threshers are mostly throw-in type and are provided with a belt conveyor as

self-feeder to the threshing cylinder on which the workmen, uniformly and evenly, place the

crop material. Throw-in types are conventionally axial-flow threshers that not only detach

cereal and pulse grain or seeds by impact and combing actions, but also break the leftover

straw during their flow axially against the louvers provided on the inner surface of the

cylinder cover. Effective removal of the grain from tillers and seed separation from husk

occur in an axial-flow thresher, rather than in low-capacity hold-on type threshers in which

crop panicles are held manually for some time against the rotating threshing drum. The

leftovers in the form of bhusa(broken straw and chaffs) obtained from axial-flow thresher are

used as cattle feed or left in the field as fertilizer, whereas the whole crop straw obtained

from the

hold-on threshers is used as the raw material for industries manufacturing straw boards,

Khaskhas, ropes, and are also used to thatch roofs, and as animal feed.

Detachment of seeds and breaking of pods are primarily achieved by impact action, wherein

squeezing, rubbing, combing, and tearing actions are also associated between the threshing

elements and concave grating. Unlike manual threshing, the impact actions inthreshers are

simulated by rotating the cylinder(s) having threshing elements of different designs at their

periphery and along the drum length. When such cylinders are rotated at high speed (7.5–

30.0 m/s), most grains or pods from the straw, which is moving relatively slowly, are



shattered by the repeated impacts. The remaining grains are threshed by the combing,

rubbing, squeezing, and tearing actions as the crops accelerate and pass through the narrow

passages between the cylinder element tip and the concave, as well as with the louvers.

During the separation process, it is assumed that, theoretically, a sheet of crops giving

cushioning effect to the grains rolls over the cylinder when impact shatters most grains.

Increased crop thickness or high feed rate will, therefore, relatively reduce grain damage and

separation from panicle, and vice versa. Proper selection and adjustment of design and

system parameters (discussed later) for effective threshing will primarily depend on the

moisture content and feed rate of the selected crop.

1.1.2 Threshing Cylinder and Concave

The threshing cylinder and the matching concave are the heart of a combine harvester and

stationary power thresher. Most commonly used threshing cylinders are provided with wire-

loop, spiked-tooth, flat-bar, rasp-bar, or angle iron bar as elements called the threshing

elements of the cylinder. Hammer mill- and serrated flywheel-types are also used in axial-

flow threshers. The constructional details as well as the operating principles of each type of

threshing cylinder are discussed in the following.

1.1.2.1 Wire-Loop and Spike-Toothed Cylinders

The elements, such as wire-loops and spike-tooth or studs, are placed at regular intervals

along the drum length, but staggered in subsequent rows around its periphery to provide

impact, rubbing, and combined actions to the crop during its flow through the restricted

passages. The concave grating of steel rods and flats covers one-third to five-twelfth of drum

periphery. It is pivoted at the rear, whereas the front is made adjustable vertically to control

clearance between them. A typical 3.75-kW thresher may have 650 _ 480- mm–diameter

threshing cylinder with 40–50 beaters (6-mm rod for wire-loop or 18- to 20-mm side

square/diameter bar as a spike or stud), designed to be operated at 20.5 and 24.0 m/s for

paddy and wheat crops, respectively. The total number of rows of wire-loop (for paddy) or

spike-tooth (for wheat) on the drum periphery depends on the crop, moisture content, feed



rate, and peripheral velocity. Rubber or plastic-lined loops, spike-tooth, and corrugated

spikes, or studs as beaters are also used for difficult threshing conditions.

1.1.2.2 Rasp-Bar Cylinders

The rasp-bar-type threshing cylinders are provided with left and right rasps, or a raised

configuration alternately along its length and at regular intervals over the drum periphery to

balance the side thrust-with numbers varying between six and ten (even number). Grain

separation is obtained between the corrugated bars and concave grate. Sometimes, a flat-bar

grate, in place of corrugated grates, is used as the concave. Rubbing and tearing actions are

primarily responsible for grain detachment and breakage of straw. Apart from groundnut,

rasp-bar cylinders are adopted for a wide variety of crops and threshing conditions because

the actions of rasps on crops are mild. It is recommended for pulse crop threshing in

stationary threshers and cereal crop threshing at high moisture in a straight-through combine

harvester.

1.1.2.3 Flat-Bar Cylinders

The construction of a threshing cylinder, with or without corrugations in flat-bars, is similar

to that of a spike-tooth cylinder of a stationary thresher, but is made more rigid and strong for

threshing wheat crops. Besides the use of standard concave grating of steel rods and flat-bars,

as in other threshers, the louvers are placed on the inner surface of the cover for axial-flow of

crop materials, effective straw breakage, and grain separation. The grain detachment and

straw breakage are primarily due to impact, and successive grain separation is due to rubbing

and tearing actions against the concave grate and louvers.

1.1.2.4 Angle-Iron-Bar Cylinders

A total of six to ten angle-iron bars in place of rasp-bars are mounted rigidly and regularly

over the drum periphery to form the cylinder, and a concave grating of steel rods and flats is

provided to separate grains from panicles, primarily by impact. Subsequent grain detachment



during its flow through a restricted passage occurs by rubbing and tearing actions in axial-

flow threshers. This type of threshing cylinder is easily adaptable to a wide variety of crop

and threshing conditions, and has less tendency to break up the straw. The angle-bar

cylinders, therefore, are recommended for threshing millets, barley, and other small seeds,

and also in straight-through combines.

1.1.2.5 Hammer-Mill- or Beater-Type Cylinders

Threshers using this type of cylinder are called drummy, hammer-mill-type, or beater type

threshers. They are normally recommended for threshing crops such as wheat, barley,

sorghum, and pearl millet. The threshing drum of such threshers consists of beaters mounted

on a shaft that rotates inside a concave closed casing that is provided with a cleaning system.

Additionally, angle-iron ribs, parallel to the drum axis, are provided at the upper casing for

effective grain separation. A typical 5.6-kW drummy thresher may have 650-mm–diameter

and 460-mm–wide threshing cylinder with 10–16 beaters designed to rotate at a peripheral

speed of 16–20 m/s. The cylinder is rotated counterclockwise when viewed from the feeding

end. Grains are primarily detached by impact action of the beaters, and subsequent separation

is obtained by rubbing and tearing actions against the concave grate and angle-iron ribs. The

cleaning sieves and an aspirator–blower are provided on a separate shaft. The oscillating

sieves placed below the concave receive the threshed material (grains, chaff, and broken

straw). The lighter materials during their fall are sucked by the aspirator–blower and thrown

at a greater distance. The upper sieve receives thick straw (mostly nodes for wheat) and

overflows, while the clean grains are received by the bottom sieve. The lowermost sieve

separates broken and fine materials from clean, sound grains of wheat. This type of thresher

requires more power and can provide fine bruised wheat straw (bhusa).

1.1.2.6 Serrated Flywheel- or Chaff-Cutter-Type Cylinder

Threshers provided with this type of cylinder are also called serrated flywheel-type, chaff

cutter-type, syndicator- or toka-type threshers that are primarily used to thresh wheat crop

that may become wet owing to the postharvest monsoon. Unlike beaters in a hammer-mill

type thresher, the syndicator-type thresher is provided with a flywheel having serrations on



its periphery and sides, closed casing, and concave, and ensilage cutter-type chopping blades

fitted at regular intervals on the flywheel rim. Through the feeding chute, the whole crop is

fed axially into the threshing cylinder. The grain separation is obtained by rubbing actions

between the serrated surfaces of the flywheel and stationary concave grate. Additional

beaters impart impact. The material makes three-quarter turns axially during which threshing

occurs before encountering the chopping knife which cuts the straw into small pieces. A

typical 7.5-kW toka thresher may have 900-580 mm sized threshing drum with closed

concave and two to four chopping knives. They are designed to operate at an optimum

peripheral velocity of 18.2–20.7 m/s. Such threshers are popular among the farmers because

they can thresh moist crop and consume less power, provide chopped straw as animal feed,

and deliver clean grain separately.

1.1.3 Grain or Seed Separation

Separating sound grain or seed from chaff, brokens, and straw is the next important function

of a thresher. Winnowing is the traditional process which is used for seed separation (Fig

1.4).

Fig 1.4 Winnowing

The process begins as the grains, chaff, and straw first leave the concave openings. During

operation, a large portion of threshed grain or seed along with some chaff and straw is

separated from the straw by the threshing unit. Rotary separators and oscillatory straw

carriers are the common forms of grain separators adopted in all stationary threshers and

combine harvesters. Primary separation of most grains is due to the impeller blower (rotary



separator) provided at the other end of the threshing drum or centrifugal blower that blows

off the light materials through the chaff outlet. Subsequent separation of the remaining free

seeds and unthreshed seeds occur as they are agitated and moved over the oscillating straw

carrier. The oscillating straw rack, a one-piece straw carrier, and multiple sections (pieces) of

straw walker are commonly used for the separation process and have been accepted widely

for grain harvesting and threshing machines.

1.1.3.1 Straw Walkers

A multiple piece, oscillating straw walker, having three or four narrow sections placed side

by side in the machine, is commonly used in recent threshers for grain separation. Multiple

throw crankshafts, one at the front and the other at the rear are attached to the individual

section. The crank throw of each section is spaced at equiangular spacing (π/2 or 2π/3

radians) around the circle of motion. The recommended crank speed of the oscillating straw

racks or walkers is between 215 and 260 rpm. Either a too high or too low speed of the crank

will increase seed losses as spilled grain. During its motion, the straw rack accelerates

the straw in rearward and upward directions in one and onehalfcycle of rotation whereas in

the return stroke, the rack tends to leave the straw in midair for a moment. As a result, the

grains heavier than straw fall onto the section near to the discharge end. In the next stroke of

the crank, the grains move one step toward the rear. This process continues and separates the

grain from straw as they walk over the straw rack or walker.



Chapter 2

Objective

1) Surveying and identification of local grain farmers and grain growing associations to

learn more about current harvesting practices, grains produced, and emerging

difficulties in local grain harvesting.

2) Study of harvesting equipment’s being used by the farmers.

3) Conduct archival research and review patents on small-scale combine harvesters,

binders, and threshers from the past.

4) Design and fabrication of soya seed harvesting machine for small scale farmers at

affordable rate.



Chapter 3

Design Methodology

3.1 Conceptual Design through Morphological Chart

Table No. 3.1 Morphological Chart for design of product

Parameters Solutions

Profile Cylindrical Rectangular

bar

Flat

Threshing element

of cylinder

Mild steel

spikes

Canvas spikes Wooden spikes

Principle of

threshing

Rubbing and

beating action

Beating action Rubbing Cutting, Rubbing

and beating action

Concave

construction

material

Mild steel Cast iron wood

Power source Electric motor Diesel engine Tractor

Feed rate 100kg/hr 50kg/hr

The highlighted solutions are selected.



3.2 Factors used for bean processing



Fig. 3.1 Improve bean processing

3.3 Fundamentals of motor



Before we can examine the function of a drive, we must understand the basic operation of the

motor. It is used to convert the electrical energy, supplied by the controller, to mechanical

energy to move the load. There are really two types of motors, AC and DC. The basic

principles are alike for both. Magnetism is the basis for all electric motor operation. It

produces the force required to run the motor. There are two types of magnets the permanent

magnet and the electro magnet. Electro magnets have the advantage over permanent magnet

in that the magnetic field can be made stronger. Also the polarity of the electro magnet can

easily be reversed. The construction of an electro magnet is simple.

When a current passes through a coil of wire, a magnetic field is produced. This magnetic

field can be made stronger by winding the coil of wire on an iron core. One end of the electro

magnet is a north pole and the other end is a south pole. The poles can be reversed by

reversing the direction of the current in the coil of wire. Likewise, if you pass a coil of wire

through a magnetic field, a voltage will be induced into the coil and, if the coil is in a closed

circuit, a current will flow.

3.4 Classification of motor



Fig. 3.2 Classification of motor



Chapter 4

Design Calculation

1. Design of drum

We know peripherial velocity

V= πdN60 …………………Eqn 1.1

From data hand book of post harvest technology

V = 5.5 – 6.5m/s (for spike tooth)

And for soyabean, Drum speed from data handbook of post harvest technology

N = 250 – 800rpm

Now taking,

V = 5.5m/s And

N = 750rpm

We have,

V= πdN60

5.5 = π × d× 750

60

d =60× 5.5750 × π

d = 0.140 m

d = 140 mm

Therefore, taking the available drum size d = 150 mm



2. Tangential force required to crush soya husk

Let, A = crushing area of drum

D = drum diameter

F c= crushing strength for soyabean husk(0.4 kg/cm2)

Therefore, tangential force

F t= F c× A ……….………..Eqn 2.1

Now,A = l × h

A = 150 × 25 = 3750mm2

F c= 0.4 × 9.81

10 ×10 = 0.03924 N/mm2

F c= 0.03924 N/mm2

Therefore,

F t=¿ 3750 × 0.03924 N

F t=¿147.15N



3. Torque required to produce F t

We know,

T = F t× r …………………….Eqn 3.1

T = 147.15 × 106.5

T = 15671.475 N-mm

T = 15.671475 N-m

4. Design of motor

As we know torque required = 15.671475 N-m

We have,

P = 2πNT

60 ……………………Eqn 4.1

P = 2π ×750 ×15.671475

60

P = 1230.834 W

P = 1.24 KW

We know that,

1 Hp = 0.746 KW

Therfore,

P = 1.240.746 = 1.66 Hp

P = 1.66 Hp

Therefore we adopt a motor of 2 Hp



5. Design of shaft

5.1 Design of shaft carrying threshing drum

The maximum shear stress in a circular shaft subjected to torsion

= ح16 ×Tπ ×d3 (solid shaft) …………………….Eqn 5.1

Taking shaft material as carbon steel C50

Syt= 380 Mpa

For shear Ssy = 3802

=190 Mpa

Taking a FOS = 4

190ح = 4 = 47.5 Mpa

We have,

= ح16 Tπ d3

47.5 = 16 ×15671.475

π d3

d = 3√ 16× 15671.475π × 47.5

d = 11.88 mm

Therefore, taking standard shaft of diameter = 30mm

5.2 design of shaft connected to the siever

Force require to reciprocate the sieve = 70 NDept of MechEngg. KLE Dr MSSCET, Belagavi


This is the tangential force acting on the shaft

We know

Torque

T = F t ×r

r = radius of the disc mounted on the shaft and connected eccentrically to the siever

r = 14 mm

therefore,

T = 70 × 14 T = 980 N – mm

We know from Eqn. 5.1 = ح

16 ×Tπ ×d3 (solid shaft)

Taking shaft material as carbon steel C50

Syt= 380 Mpa

For shear Ssy = 3802

=190 Mpa

Taking a FOS = 4

190ح = 4 = 47.5 Mpa

We have,

= ح16 Tπ d3

47.5 = 16 ×980

π d3



d = 3√ 16× 980π × 47.5

d = 4.7 mm

therefore taking available dia. d= 20 mm

6.Design of key

From DDHB,

Syt = 380 Mpa (yield strength of C50 material)

6.1 For d=30 mm

Considering parallel key

b = 10 mm

h = 8 mm

l = 40 mm

Therefore,

σ d = Syt

FOS ……………………Eqn 6.1

σ d= 3803 = 126.66 MPa

σ d= 126.66 MPa

And

τ = σd

2 ………………………...Eqn 6.2

τ=126.662 = 63.33 MPa

τ = 63.33 MPaDept of MechEngg. KLE Dr MSSCET, Belagavi


Design based on shear stress

we know,

τ = 2T

b ×l ×d ………………………..Eqn 6.3

τ = 2× 15671.475

8 × 40 ×30

τ = 3.26 MPaSince,3.26 Mpa < 63.33 Mpa (Design is safe)Design based on crushing strength σ = 4 T

b ×l ×d ………………………………….Eqn 6.4σ = 4 × 15671.475

8 ×40 × 30 = 6.52 MPaσ = 6.52 MPaSince,6.52 < 126 MPa (Design is safe)6.2 For d=20 mm

Considering parallel key



b = 6 mm

h = 6 mm

l = 36 mm

Therefore,

σ d = Syt

FOS ……………………Eqn 6.1

σ d= 3803 = 126.66 MPa

σ d= 126.66 MPa

And

τ = σd

2 ………………………...Eqn 6.2

τ=126.662 = 63.33 MPa

τ = 63.33 MPaDesign based on shear stress

we know,

τ = 2T

b ×l ×d ………………………..Eqn 6.3

τ = 2× 980

6 ×36 ×20

τ = 0.453 MPaSince,0.453 Mpa < 63.33 Mpa (Design is safe)Dept of MechEngg. KLE Dr MSSCET, Belagavi


Design based on crushing strength σ = 4 T

b ×l ×d ………………………………….Eqn 6.4σ = 4 × 980

6 ×36 ×20 = 0.907 MPaσ = 0.907 MPaSince, 0.907 < 126 MPa (Design is safe)7 Design of PulleyTaking std. pulley dia. = 75 mm for the motor shaftWe haveN1

N 2 =d1

d2 …………………………………Eqn.7.1

N1= 1440 rpm (std. 2 Hp motor)N 2 = 750 rpm ( from data handbook of post harvest technology)Therefore,Eqn. 7.1 becomes1440750 = d2

75

d2 = 144 mmDept of MechEngg. KLE Dr MSSCET, Belagavi

Design and Fabrication of Soya Seed Harvesting MachineTherefore,Available std. dia = 150 mm

d2=150 mm , N2=750 rpm d1=75 mm, N1=1440 rpm

Speed required for crank shaft N 4= 400 rpm

And N 2= N3= 750 rpm

Again taking a std, dia. d3= 75 mm

Therefore we have,

N 3

N 4=

d4

d3

750400

=d4

75

d4= 140.62 mm

Therefore,

Taking available std. dia. = 150 mm

d4=150 mm, N 4=400 rpm d3=75 mm, N3=750 rpm



8. Design of V –belt

8.1 Selection of the cross section of the belt

The equivalent pitch diameter from Lingaiah DDHB

De = Fb Dp ………………….Eqn. 8.1

For N 1N 2 =1.92

From DDHB Table 22-25

Small Diameter factor

Fb = 1.13

And we have motor pulley dia.D p = 75 mm

De= 75 ×1.13

De=84.75mm.

From Lingaiah DDHB

For max value of

De = 125 mm

We select A- type cross-section belt.

For A-Type cross – section belt

From Lingaiah DDHB

Nominal top width W = 13 mm



Nominal thickness T = 8 mm

8.2 Angle of Lap

From lingaiah DDHB

θ1= π−(D 2−D1C ) ………………………Eqn. 8.2

Where

D2 & D1 are diameter of larger and smaller pulley respectively and C is the center distance

b/w the pulleys

θ1= π−( 150−75410 )

θ1= 2.958 radians

θ1= 169.5°And also,

θ2= π+( D 2−D 1C )

θ2=π+( 150−75410 )

θ2= 3.324 radians

θ2= 190.48°Dept of MechEngg. KLE Dr MSSCET, Belagavi


8.3 Tension in the belt

We know that,

Ratio of belt tensions is equal to

T1

T2 =

eμ θ

sin α2 ……………………………Eqn. 8.3

Taking standard groove angle α = 34°And μ = 0.3And θ = 2.95 radians We haveT1

T2=

e0.3 2.95

sin 342

T1

T2=19.74 ………………A

Also we know,

Pd= ¿ -T 2) × v ……………………………….Eqn. 8.4

And also,

Pd= K LP

Taking load factor K L= 1.1

Pd= 1.1 × 1230.834

Pd= 1353.91 watts

Also,

v = πdN60



Therefore,

v = π × 0.075× 144060

v = 5.65 m/s

Therefore,

Pd = ¿ -T 2) × 5.65

¿ -T 2) = 1353.91

5.65

¿ -T 2) = 239.63 ……………..B

Solving A & B we get

We get

T 1= 252.41 N

&

T 2 = 12.78 N

8.31 Check calculation

We know that,



Maximum tension in the belt T 1= S ×b× t ……………..Eqn. 8.5

Where S = tensile stress for the belt in N/mm2

We have

b = 13 mm

t = 8 mm

Therefore, Eqn. 7.5 becomes

S = 252.4113 × 8

S = 2.42 N/mm2

For belt material the tensile stress is 8-25 MPa

Therefore,

The design is safe.

8.4 Length of belt

From Lingaiah DDHB

Length of the belt

L =π2 × (d1+d2 )+2 C+

(d2−d1 )2

4 C ………………….Eqn. 8.6

L = π2

× (75+150 )+2× 410+(150−75 )2

4 ×410

L = 1176.85 mm

From Lingaiah DDHB



Table 21-29

Nominal pitch length = 1204 mm

Nominal inside length = 1168 mm

9 Design of Frame

Square cross section as shown below

Moment of inertia

I = (B H3−b h3 )12

………………………..Eqn. 9.1

Where B =32 mm, H = 32 mm, b = 26 mm, h = 26 mm.

Therefore Eqn. 9.1 becomes

I = (32× 323−26 ×263 )12

I = 49300 mm4

We know

Radius of gyration



K = √ IA

……………………………Eqn. 9.2

Where I = moment of inertia

And A = Area of cross section

A = BH−bh

A = 322−262

A = 348 mm2

Therefore,

I = √ 49300348

I = 11.90 mm

Assumed weight of the machine = 200 kg = 2000 N

No. of legs = 4

Weight on each leg = F4

W= 2000

4

W = 500 N

Also we know

Crippling load F cr=n × F

Where n = Factor of safety

Taking n = 3

F cr=3× 500

F cr=1500 N



From Rankine’s formula

F cr=σ × A

1+α L2

K2 ……………………………Eqn. 9.3

L = 532 mm

Taking α = 1

7500

F cr=σ × 348

1+ 17500

5322

11.902

1500= σ ×348

1+ 17500

5322

11.902

Solving the above equation

We get,

σ=5.45 MPa

Taking C 50 material

Yield strength Syt=380 MPa

Taking Fos = 3

Design stress

σ d = S yt

n

σ d = 3803

σ d = 126.66 MPa

5.45 MPa < 126.66 MPaDept of MechEngg. KLE Dr MSSCET, Belagavi


Therefore,

The design is safe

Chapter 5

Diagram

Rotary cutter



Rotary cutter assembly



Drum cover



BlowerDept of MechEngg. KLE Dr MSSCET, Belagavi


Frame



Seive

Pulley

2 – D Design



3 – D Design



Chapter 6

Applications

1. Harvesting of Soya Seed.

2. By changing the sieve size, this machine can be used to harvest other grains also.



Chapter 7

Advantages

1. Reduced harvesting time.

2. By using this machine the problem of labour crises can be reduced. Comparing with

manual harvesting only 18% of labours are required.

3. It increases overall productivity.

4. Efficient work is done by using this machine harvester.

5. Cost of harvesting is comparably less as manual harvesting.

6. Up to 90% of grains are unbroken(good quality grains).



Chapter 8

Disadvantages

1. This harvester requires electricity



Chapter 9

Conclusion



Chapter 10

References

[1] Amalendu Chakraverty, Hand book of Post-Harvest technology, Indian Institute of

Technology, Kharagpur. ISBN: 0-8247-0514-9.

[2] M. C. Siemens and D. E. Hulick, technical paper on “A new Grain Harvesting system for

single‐pass grain harvest”.

[3] K.N Singh, B singh- Journal of agricultural engineering research, July 1981.

[4] Adarsh J Jain , Shashank Karne, Srinivas Ratod , Vinay Thotad and Kiran , “Design and

Fabrication of Small Scale Sugarcane Harvesting Machine”, Vol. 2, No. 3, July 2013, ISSN

2278 – 0149.

[5] H.G. Patil, Machine Design Data Handbook, ISBN: 978-93-80578-96-5.

[6] Lingaiah K, Machine Design Data Handbook Vol. 1, ISBN: 4567142681.

[7] R.S. Khurmi and J.K. Gupta, A Textbook of Machine Design, ISBN: 8121925371.

[8] V.B. Bhandari, Design of Machine Elements, ISBN: 0070611416.

[9] R.K. Rajput, A Textbook of Manufacturing Technology: Manufacturing Processes, ISBN:

9788131802441.

[10] P.N. Rao, Manufacturing Technology, ISBN: 9789332901001.
