Advancement in Onion Harvestor

DOI : 10.17577/IJERTV9IS090529
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Advancement in Onion Harvester

1Deshmukh Priya Chintaman 2Pokale Shubham Balkrushna Department of Mechanical Engineering

P.E.S Modern College of Engineering,Pune Pune, India

3Shetkar Pranav Pralhadrao,

4Thorat Sanket Sandeep

Department of Mechanical Engineering

      1. Modern College of Engineering,Pune Pune, India

        Abstract Onion is one of the most important crop in India. The harvesting of onion crop is a labour intensive operation if a farmers gets workers for manually harvesting the onion crop is costs him about 7000Rs per acre.

        The present research work has been carried out to bring out the reliable solution for harvesting of onion crop. The harvesting of onion crop is a labour intensive operation. The attempt has been made to design the harvester for the low power capacity tractors range in the 15 to 20 hp. The size of the harvester has been decided with respect to the agro technical features of the crop.

        The various designs of onion harvester are available in market but none of them have provided a fully reliable solution to farmers. So in this project we are going to design and manufacture the onion harvester so as to fulfil the demands of Indian Farmers. The harvester manufactured should be cost effective as well as increase the productivity, which would lead to increase in the profit of farmers.

        Keywords Onion crop, harvestor, tractors, productivity

  1. Digging system.
  2. Soil separation system.
  3. Conveyor system.
  4. Windrowing System/Collection unit.
  5. Power transmission.
    1. Digging System

      The Digging system digs out the onion bulb from the soil. The depth of digging varies according to the planting method used and size of onion at the time of harvesting.

      In case of continuous planting method the depth of digging is kept up to 10cm as the bulb is at adept of 5cm.

      1. Need

        Onion is the most important crop in India. The harvesting of onion crop is rigorous and requires huge amount of manpower and time. One of the main reasons of low productivity is insufficient power availability on the farm and low level of farm mechanization. This is especially true for India. The package of modern technology, improved seed and fertilizers, use of efficient and economical farm implements, machines and suitable form of farm power is very important. Production suffers because of improper seed bed preparation, delay in sowing and harvesting. Mechanization enables the conservation of input through precision metering, ensuring better distribution, reducing quantity needed for better response and prevention of losses or wastage of inputs applied. Mechanization reduces unit cost of production through higher productivity.

        Harvesting depends on its type and purpose such as greens, immature bulb & mature bulb. Optimum time of harvesting is one week after 50% of leaves have fallen. Maturities symptoms include yellowing of leave and dry at the top; bulbs turn red and attain their optimum varietal size. Bulbs continue to grow even after the foliage has fallen down.

        Generally the harvester is attached at the back end of tractor from where power is supplied to it through PTO(Power Take-Off) shaft. Also when attached at the back of the tractor it acts a pull type of mechanism rather than push type mechanism which consumes considerably more power.

        A general design of onion harvester consist of following basic systems

        Fig.1 Image showing continuous type of planting

        In case of bed type of planting method the depth of digging is kept upto 5cm as the bulb is comparatively near to the surface.

        Fig.2. Diagram showing bed type of planting method

        The Harvesters currently available in the market have flat triangular type blades made of metal sheet. Care should be taken while designing blades as its sharp corners my damage

        the onion bulb.

    2. Soil Separation System

      Once the onion is digged out of the soil, some soil comes

      along with the incoming onion which needs to be cleaned.


      soil is dry as the water is cutoff nearly a week ago before the

      time of harvesting. Due to this no aggressive cleaning of onion

      is required.

      Fig.3. Image of harvested onion bulb

      As shown in Fig.3. the onion bulb is free from soil. So many

      harvestors are simply provided with a conveyor to remove the


    3. Conveyor System

      Fig.4. Image of conveyor system[3]

      The onion after soil removal is passed to a conveyor which

      moves it to the collection unit. The conveyor can be belt type

      Chain type according to the load of the material to be handled.

    4. Windrowing/Collecting Unit

Fig.5. Windrowing system[3]

The onion after the conveyor goes to the windrowing system where it is made to fall in a straight line on the ground, so that it helps in collection of the onion. Sometimes a collection tray or basket is provided to collect harvested onion.

1.5. Power Transmission

The power it given to the rear conveyor from the PTO shaft. From PTO shaft proper gearing is provided to transmit power to the conveyor. A suitable belt or chain drive be given for transmitting the power to the conveyor shaft.


      In India the average farm size of farmers is less than 3 hectors, hence the large scale machine developed by various agricultural equipment manufacturing firms are not suitable for the Indian market. And also the average monthly income of Indian farmers is Rs 6426, so the machine also needs to be cost effective. Also it should be easily coupled to a small tractor of 15 to 20 HP.

      So in simple words the challenge is to design a compact, cheap yet effective onion harvester suitable for Indian farm conditions.

      Fig.6. Bar charts showing income of farmers

      Fig.7. Average farm size in various states of India

  1. To design a new onion harvester to suit the need of farmers in India.
    • To design new blades to reduce soil resistance.
    • To design an effective soil separation system.
    • To design a system to collect the harvested onion.
  2. To manufacture a cost effective onion harvester.
    • To use cost effective manufacturing methods to manufacturing various components.
    • Selecting cost effective materials.


The onion harvester available in the market have some drawbacks which can be overcome by providing some design modification to the various systems of an onion harvester. The modification are provided by keeping into consideration the requirements of Indian farmers

    1. Analysis Ansys of Blade
      1. Selection of geometry-Blade geometry was selected

        Material- EN8

        Fig.8. Blade geometry

      2. Meshing of blade geometry

        Element type-Triangular shaped Element Size-4mm

        Fig.9. Meshing of blade geometry

      3. Applying boundary conditions

        Fixed support

        Fig.10. Support generation

      4. Force applied

        Fig.11. Force Application

      5. Results

Fig 12. Total deformation

d= Tool depth, (m) C= Cohesion (kPa) Ca= Adhesion (kPa) Draft Calculations


For black cotton soil,

Ny = 1.55 for =0 = Angle of shearing resistance of soil Ny = 1.75 for = = Angleof metal friction

Nc = 1.65 for =0

Nc = 1.6 for = y= 17.68 kN/m3

C= 30.18 kN/m2

Z1= Depth of operation = 10cm = 0.1m

P= 5289.1 N For Black soil

Fig. 13. Maximum stress

    1. Design Calculations
      1. Digging Force:-
        1. Cutting Blade shape: Conical
        2. Blade Material: EN8
        3. Rake Angle: 200
        4. Throat Clearance Calculation: 90 mm Digging force is calculated by



        V= Velocity of tractor/blade, (mm) y= Soil bulk density, (KN/m3)

        w= Tool width, (m)

        = Rake angle, (degree)

      2. Conveyor

        Diameter =12.595 mm

        Weight of sprocket =9.81 N, (3)

        BMmax = 0.9908 Nm =990.8

        thickness =1.7025 mm C = = 0.787

        Mb =44.0489 Nm = 44048.9

        Mt =271520

        Imax =59.4

        d=28.83 mm

        d=28.83 mm CONCLUSION

        After studying the various harvester and testing the newly added design modifications following conclusion were drawn.

        • The conical blades would reduce the chance of onion damage.
        • Simple manufacturing methods involved in the manufacturing of harvester components would reduce the cost considerably.
        • Standard manufacturing components and methods used would help in interchangeability.
        • It would increase productivity, which lead to increase in profit for the farmers.

          FUTURE SCOPE

          The design can evolve further by giving additional attachments to it. The following design inputs can be added if required

        • A attachment can be provided for cutting the onion leaf at the time of harvesting.
        • Collecting baskets can be provided for collecting the harvested onion.
        • In case the soil is stuck to the onion bulb and is not coming off easily in this case a vibrating conveyor

          mechanism can be provided.

        • With some small changes same mechanism can also be used of potato harvesting.


  1. Design of onion harvester ashwini talokar, kanchan wankhade, &

    v. P. Khambalkar, published by international journal & magazine of engineering, technology, management and research.

  2. Design and Fabrication of Underground Vegetable Harvester S.S.Parthipan, Raj parthipans, Department of Mechanical Engineering, Easwari College Of Engineering, Chennai, published by International Journal of Mechanical Civil and Control Engineering.
  3. Design of onion harvester, published by
  4. Survey of Indian agricultural economy, Published by World Economic Forum.
  5. Survey of farm sizes in various states, published by Ministry of Agriculture and Farmers Welfare, Government of India.
  6. Onion Varieties, Submitted by Vinod Kumar, published by agropedia.

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