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How Simple Peanuts (Groundnuts) Shelling Machine Works, Its Parts & How You Can Assemble One

How Simple Peanuts (Groundnuts) Shelling Machine Works, Its Parts & How You Can Assemble One

How Simple Peanuts (Groundnuts) Shelling Machine Works

Peanuts peeling machine also known as peanuts shelling machine is a unique machine with the special task of shelling groundnuts otherwise known as peanuts. It is one of the most sort-after machines in the market due to the increasing need to process groundnuts (peanuts), especially the freshly harvested ones.

Since peanuts (groundnuts) are being used to make some of the processed foods such as groundnut/peanuts butter, peanuts chips, and lots, the processing industries making such products usually depend on the peanuts shelling machine to help in fastening the process.

From the scratch, after washing the peanuts inside water the next action is to separate the nuts from their shell. Using manual means would be very impossible for commercial purposes but the use of a machine can be able to do a ton of peanuts shelling within an hour.

HDC Oil Machinery boasted on their video that their peanuts shelling machine could process from 150kg per hour to 1000kg per hour of peanuts depending on speed and settings. Such capacity cannot be compared by any form of manual method of shelling peanuts.

The above reasons are why the machine is among those selling high in the market. Because of its popularity and high-selling rate, different manufacturers are coming out with varying designs to perfect the operations and counter any lapses found in existing designs as well as adding more features.

Meanwhile, among the numerous designs and brands existing in the market, we are going to focus on the most commonly found design which I refer to as ‘Simple peanuts(groundnuts) shelling Machine’.

Simple peanuts (groundnuts) shelling machines can be found in almost every market selling shelling machines. It has a basic design as well as a simple working principle that can easily be understood by anyone.


Below are parts of the machine, their functions, and how they operate:

Cracker Mechanism

First on the list is the cracker mechanism. It forms the main operating part in the machine because it is the dynamic part of the machine located at the heart of the machine where the shelling operations take place.

By design, the cracker mechanism is a cylindrical-shaped part that has uniform linear spaces created at the section forming the cylindrical shape using metal rods.

As the peanuts (groundnuts) falls into the machine, it will be forced to pass walls thereby being squeezed by the cracker mechanism which makes the shell to crack while the nuts will only have one way of escape which is through the uniform linear space created on the cracker mechanism.

The seed falls through space to the base of the machine where it can exit the machine while the shell which is too big to pass through the uniform space will be forced to escape through an opening created on the machine cover.

The cracker mechanism is the main part that revolves between the cracker shifter and the top cover where the peanuts are feed into the machine and enclosed with bearings at both sides. It is held in position by the bearing carrier which is anchored to the frame structure of the machine.

The right end of the central shaft carrying the cracker mechanism has a pulley fixed on it, the pulley is connected to the next pulley fixed on the electric motor via a teethed belt or a V-belt. As the electric motor turns, it drives the cracker mechanism via the belt connection and causes it to rotate between the cracker shift and the top cover.

Cracker Shifter

The cracker shifter is usually located below the cracker mechanism. It forms an enclosed half-cylindrical shape a few millimeters away from the cracker mechanism but it is not dynamic (it is not a moving part) unlike the cracker mechanism that revolves because it is being turned into an electric motor.

The cracker shifter is fixed on the lower frame structure just below the lower part of the cracker mechanism. Its function is to gather all the peanuts whose shells have been removed and cause them to pass through one channel to the collection unit of the machine.

Top Cover With Input Port

This is just the top casing of the machine. It forms half of the entire size of the working unit of the machine and has opened for feeding or unshelled peanuts (groundnuts) into the working/shelling unit of the machine.

It is usually coupled together with the lower/down cover known as the bottom casing. The coupling joint has rubber seals to prevent fluid penetration and also help to reduce vibration and noise. The protruded ends of both covers have holes that are used to anchor them to frame structure using bolts and nuts.

Down Cover With Output Port

The bottom cover is the lower housing of the machine. It forms half of the entire size of the housing unit of the working unit and it is joined together with the upper casing at the center. Both are fixed on the frame that formed the structure of the machine.

The bottom cover carries the outlet opening where the shelled peanuts fall out as well as where the removed shells fall out of the machine.

In other words, the bottom cover has two outlet openings, one of the openings is for the shelled peanuts while the other opening is for the removed shells.

Frame Structure

The frame structure of the machine forms its main stamina just like in every machine. Frame structure acts as support and standing strength of the machine. It houses the dynamic and static parts and bears all the vibrations coming from the machine.

The frame structure is a simple skeleton of beams joined together via a welding process to carry the electric motor and the working unit.

The electric motor is connected to the bottom part of the frame structure via bolts and nuts while the working unit is connected to the upper part of the frame structure via bolts and nuts. It provides the entire size and shape of the machine, reduces vibrations and noise, and helps to position the machine anywhere it is necessary.


The machine has two bearings. The bearings are positioned in the space available for it in the bearing carrier which is mounted on the frame structure. The bearing carrier alongside the bearing has closed space between the casing and the shaft of the cracker mechanism at both sides of the casing.

Just between the walls of the casing housing cracker mechanism and the bearing carrier, there is no space between them making it have a closed fitting even though no bolt or nut is used to join them together. The bearing seal is used to prevent fluid penetration into the main part of the working unit.

The bearings form an intermediary joint between the moving shaft of the cracker mechanism and the static bearing carrier fixed on the frame structure.

Bearing Carriers

The bearing carrier is the static part that houses the bearing at both sides of the working unit of the machine.

Based on the design, the bearing carrier is meant to contain the bearing as well as the shaft end of the cracker mechanism. It is fixed on the frame structure with bolts and nuts.


There are two pulleys in the machine one is fixed on the shaft of the electric motor while the other is fixed on the end shaft of the cracker mechanism.

By design, the pulley connected to the end shaft of the cracker mechanism is bigger than the one fixed on the end shaft of the electric motor by the ratio of 2:1.

The pulleys carry a belt that is used to transmit rotational motion from the electric motion to the cracker mechanism.

Electric Motor

The electric motor is the engine of the entire unit of the machine. It provides the power needed by the dynamic parts to operate. In other words, it is the machine’s prime mover.

This part of the machine can be detached separately without having any change to the main working unit of the machine. The electric motor can be changed to produce more horsepower for the machine.

The diagram below illustrates the various parts of the machine as discussed above.


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