Human development has allowed great inventions, which have been a great advantage and improvement in the quality of life.
What a few centuries ago was unthinkable today can be achieved at the touch of a button, and that is that electronics has been one of the greatest inventions of mankind.
Washing machines, computers, cars… there are countless devices that we use in our daily lives on which we have become dependent and yet we do not fully know how they work. All these devices are what are called complex machines, which in turn are made with so-called simple machines .
In this article we will deal with what these types of machines consist of, going back to their components and giving some examples to see it more clearly.
What are composite machines?
Composite machines are those mechanical devices which have been formed from two or more simpler machines which are connected in series . Since they are connected in this way, when one of these parts of the composite machine is activated, the rest work in a coordinated way, being able to offer together a function that individually they could not.
Composite machines have evolved as technology has developed. The first ones were mechanical, but with the discovery of electricity they were elaborated from electrical and mixed .
Practically every type of device with a more or less complex mechanism is a composite machine. Whether it’s something as small as a wristwatch or an aerospace ship. The degree of complexity can also be very variable, one example being the trolley, which consists of only two levers.
Every time composite machines are used, their elements are subjected to friction, which generates wear and tear over time. For this reason, this type of machine requires certain care such as good lubrication and being sent to a mechanic in case it does not work properly.
Composition of composite machines
Composite machines work by steps; through which different types of operators work so that the function for which the mechanism was elaborated can be given . There are two types of these operators:
These are the elements that allow the machine to operate by converting force into movement. Their assembly is what is called a mechanism, the main operators of this type being the wheel, axles and gears .
The wheel is a circular piece that rotates around an axis. In itself it is considered a simple machine, being one of the most important inventions of mankind, thanks to the fact that it has been used in an infinite number of more complex machines.
The axles are bars that join the wheels and the pulleys and allow the free movement of these but protected by a support.
Finally, the gears are mechanical operators consisting of two circular toothed pieces in which the larger is called a crown and the smaller a pinion. It allows transmitting the circular movement by means of the movement and contact of its cogwheels.
This type of operator is responsible for storing energy or force and transforming it into another type so that the device can be activated and perform its function. Some examples of these are springs, batteries and motors .
Electric batteries have been made in many shapes and sizes and allow the accumulation of energy that is stored for later use.
Motors are devices that transform energy into another type, so that the machine can use it and perform its function. There are electric, steam and fuel engines.
Simple machines were widely studied during the Renaissance . At that time, the classification for this type of machine consisted of 6 types:
- Inclined plane
Over time, and thanks to technological progress, new machines of this type have been developed, which in turn have made it possible to produce more sophisticated complex machines with specialised functions that would be difficult for ancient people to imagine.
Examples of complex machines
These are several examples of composite machines that show all the typical characteristics of these goods.
This vehicle is a clear example of a composite machine . It is driven by the force of the feet on the pedal, making the wheels attached to the frame turn and allowing the vehicle to move.
It is a machine that allows to raise and lower heavy elements or whose movement can be complicated. The loads are lifted by being placed on a hook at the end of a rope or chain .
This machine was one of the great creations of mankind, since it facilitated the construction of high buildings and its origins date back to Ancient Greece.
3. Car Cat
It is used to lift objects that have a great weight, such as a car or a very heavy piece of furniture. It works using a lever and can be mechanical or hydraulic .
It is a metal mechanism that is incorporated into doors and drawers, which consists of a part that prevents them from being opened.
By incorporating the element that deactivates it, either a key or in the most recent versions a fingerprint, the lock is unlocked and allows access to the interior of the house or the contents of the drawer.
5. Can opener
It’s a device used to open metal cans.
Vehicle in which, when the key is inserted in the ignition, the engine is activated which allows the axles that hold the wheels located at the bottom of the car to move and thus allow the vehicle to be moved.
Also called a cassette recorder, this device that today can be seen as reminiscent of the past music of the eighties works by reproducing the recordings contained in the cassettes.
They are machines through which a fluid passes in a continuous way and this gives kinetic energy to the turbine through the blades that are endorsed in it. Thus, the turbine spins, working in motor quality. Its basic element is the wheel.
It is a self-propelled vehicle used to pull or push trailers. They can be used in different sectors: agriculture, nautical, construction, land movement…
Thanks to its creation, it has made it possible to significantly reduce the labour force as well as increase production, being one of the main elements of the agricultural revolution.
10. Washing machine
This is an electromechanical device , which can be either domestic or industrial, which is used to clean clothes.
In its central part it has a drum with holes that, when the washing machine is activated, spins while water mixed with detergent enters.
The drum moves thanks to the action of an electric motor which transmits the traction to it by means of pulleys.
Some more modern models have improved the washing experience by making the clothes dry already during the process of eliminating residues in the fabrics.
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- Strizhak, V.; Igor P.; Toivo P. (2004). Evolution of design, use, and strength calculations of screw threads and threaded joints. HMM2004 International Symposium on History of Machines and Mechanisms. Kluwer Academic publishers.