The electric motor is an electrotechnical machine that converts electrical energy into mechanical energy. That is, when the electric motor is connected to the proper power source, it begins to rotate, which also begins to rotate the machine or the machine associated with it. That is, it works inversely to the electric generator, which produces electrical energy with mechanical energy.
The electric motor was made possible thanks to the discoveries of Franz Ernst Neumann and James Clerk Maxwell. His discoveries were published in the years 1841 and 1873.
The electric motors can be…
The electric motors can be distinguished between them according to the type of power supply:
- Electric motors of direct current. The DC electric motor can be, in turn, a permanent induction motor or a continuous induction motor. In addition to these more general classifications there are also other more modern types of engines such as stepper motors and linear motors.
- Electric motors of alternating current. The AC motor can be classified as universal motor, synchronous motor or asynchronous motor.
The classic division is between direct current (DC) and alternating…
The universal motor is a type of electric motor that can operate both with direct current and with single-phase alternating current.
Its constitution is similar to that of a direct current series motor, although with some modifications:
The polar nuclei, and the entire magnetic circuit, are built with silicon iron plates isolated and stacked to reduce energy losses by parasitic currents. These currents occur because of magnetic flux variations when connected to an alternating current network.
It has a lower number of turns in the inductor to not magnetically saturate…
Altern current motors are electric motors that are powered by alternating current. Electric motors convert electrical energy into mechanical rotation energy through the mutual action of magnetic fields.
There is a wide variety of altern current motors, among which the following basic types stand out:
- The universal motor that can also be direct current.
- The synchronous motor. In this type of electric motor the speed of rotation is constant and depends on the frequency.
- The asynchronous motor. It is a three-phase motor.
In some cases, such as…
A direct current motor (DC motor), or simply a continuous motor or direct current motor, is a rotating electric malternating currenthine that transforms electrical energy in the form of direct current into mechanical energy through electromagnetic interalternating currenttions.
Virtually all electric motors are reversible, that is, they can transform mechanical energy into electrical energy functioning as dynamos. direct current motors base their operation on the Lorentz law, also called Laplalternating currente's law when it is applied to a conductor, as is the case of motors. Applications…
A motor or motor is a machine designed to convert a form of energy into mechanical energy . An engine can be classified into a category according to two criteria: the form of energy it accepts to create movement and the type of movement it produces.
As a general rule, engines have an axle, which in rotary offset and through mechanical devices such as drive gears. The exceptions are rocket motors and linear motors . Nowadays, combustion engines…
An asynchronous motor is an electric motor powered by alternating current. It is, therefore, what we call an AC motor. This type of engine is also known as an induction motor.
The asynchronous motor is based on the currents induced in the rotor from the rotating magnetic field of the stator. That's why it's called an induction machine. As to be able to induce an electric current in the rotor it is necessary that the rotor is subjected to a variation of the magnetic flux generated by the stator at the frequency of power, or synchronism, the rotor is demagnetized when it reaches the synchronism,…
Traditionally, when we talk about motors, we usually refer to internal combustion engines or electric motors. However, there are other types of motor. Among these types of motor there are the physical power motors.
The so-called physical power motors are motors that take advantage of the kinetic energy or the potential energy of some element.
An example of power motors is found in hydro power plants. In this type of installation the potential energy of the water is used, which, when it falls, becomes kinetic energy and activates a turbine. In this way, a motor,…
Synchronous motors are a type of electric AC motor. Its speed of rotation is constant and depends on the frequency of the voltage of the electrical network to which it is connected and the number of pairs of poles of the motor, the speed is known as "synchronous speed".
The mathematical expression that relates the speed of the machine with the mentioned parameters is:
A linear motor is an asynchronous electric motor that has been developed so that instead of generating a rotating torque it generates a linear displacement. To get it distributes your stator and its rotor distributed differently.
The most common mode of operation is like a Lorentz actuator. In this mode the applied force is linearly proportional to the electric current and to the magnetic field
Linear motors are divided into two main groups:
- Slow acceleration linear motors used in Sky Train transport, Maglev, etc.
- Quick acceleration linear motors used in…
The current carrying excitation winding in the stator generates a magnetic field, which is amplified by the iron sheet package and grouped into defined poles. The same happens in the winding of the armature coil downstream. Depending on how the poles are established, this magnetic field created by the stator of the universal motor causes the rotor to drag behind or push it in front of it. In this case, the coils must be inverted in each half revolution (for machines with a pair of poles), for which a switch is necessary.
Considering a "single pole" version, both magnetic fields are perpendicular…
In some applications, doubts arise as to whether it is better to use an electric motor or to use a thermal motor. One of the important elements in making this decision will be to know the differences in energy efficiency.
Main problems of thermal motors:
- Rising prices of fossil fuels combustibe (oil, coal, etc.)
- Scarce projections of evolution in an immediate future.
- Emission of greenhouse gases.
- Not reversible, when braking, can not generate power.
Main advantages of electric motors:
- You are a clean alternative if we…
The conversion of electrical energy into mechanical energy by means of electro-magnetism was first demonstrated by the British scientist Michael Faraday in 1821. In his pilot he made the end of a free-hanging contact conductor with a pool of mercury in the that a permanent magnet was placed. At the moment when a current flows through the conductor, the driver performs a rotary movement around the magnet. In this way we obtain kinetic energy.
This electric motor is the simplest version of a homopolar motor. An improved form of this is the Barlow wheel. Due to their primitive construction,…
In this website we try to explain the operation of the main types of engines from a theoretical point of view. We present schematically the parts, operating cycles and characteristics of the following types of engines:
- The thermal engine or internal combustion engine. Inside the thermal engines we explain the gasoline engine (or otto engine) and the diesel engine).
- The electric motor. This engine has undergone a great evolution throughout history and right now is one of the most used types of engines and with more projection of the future. We will analyze direct current…
The Otto engine is a type of alternative thermal engine that works through the Otto cycle. It is an alternative engine capable of converting the chemical energy of fuel into mechanical energy through a thermodynamic reaction.
Due to the characteristics of this type of thermal engine it can receive several names.
- Gasoline engine. Due to the fuel used.
- Otto Engine. Because it works through the otto cycle.
- Spark ignition engine. Due to the way to start the ignition of the fuel. The ignition starts through a guspira generated by a spark plug.
The series motor is a type of electric direct current motor in which the armature and the inductor debited or excitation are connected in series. That is why the excitation current or the inductor is also the current of the induced absorbed by the motor.
This type of direct current motor is also called the series excitation motor. The constitution of the electric motor in series is that of having all the elements of the circuit in series, induced windings and inductors. The series engine is characterized by having a high moment of rotation at start-up and its speeds very variable depending…
The endothermic engine, also known as internal combustion engine. The main characteristic of this type of alternative engines is that through the laws of thermodynamics it is able to take advantage of the energy contained in the fuel to obtain a mechanical work.
The endothermic engine is a type of alternative engine by the way of converting chemical energy into mechanical energy. The most popular endothermic engines are the Otto engine or gasoline engine that operates according to the Otto cycle and the diesel engine, which operates according to the diesel cycle. Meaning of the…
A squirrel cage rotor is the rotating part of the common squirrel cage induction motor. The squirrel-cage motor is a type of AC motor.
This type of rotor consists of a cylinder of steel laminations, with aluminum or copper conductors embedded in its surface. In operation, the non-rotating stator winding is connected to an alternating current power source; the alternating current in the stator produces a rotating magnetic field. The rotor winding has a current induced by the stator field, and produces its own magnetic field. The interaction of the two magnetic field sources produces torque…
The heat engines can be classified in many different ways. Then classify heat engines, taking into account six different aspects:
Types of heat engines depending on where combustion takes place
- They Depending on where is combustion.
- Depending on the fuel used and the type of lighting.
- Depending on the movement of moving parts.
- Depending on how realizes the cycle.
- Depending on the number of cylinders
- Depending on the arrangement of the cylinders
Depending on where combustion takes place two types:
Definition of three-phase current
A three-phase current system consists of three single-phase alternating currents of the same frequency and amplitude (and therefore, effective value) that present a certain phase difference between them, around 120 °, and are given in a certain order. Characteristics of the three-phase current
Each of the single-phase currents that make up the system is designated with the phase name.
A three-phase voltage system is said to be balanced when its currents are equal and are symmetrically out of phase. When any of the above conditions…
In this section we describe the different parts of a thermal engine. Of thermal engines have many types, however we will focus on the diesel engine and the gasoline engine (otto cycle).
Despite being different engines share many parts in common, so the scheme presented will serve to indicate the nomenclature of each element.
The most important elements of internal combustion engines, common to diesel and explosion engines, we classify them in two large groups:
- Fixed elements of a heat engine: block, cylinder head, crankcase.
- Moving parts of a heat engine:…
The engine is a machine capable of transforming a source of energy, which can be in chemical form (in the presence of a fuel), electrical or thermal, into a mechanical energy or mechanically continuous work, typically used in the field application purposes. with the propulsion of various types of vehicles.
In a philosophical sense, an engine is the organism that causes movement or change in other affiliated institutions: Aristotle spoke of motionless motor, a term also picked up by other philosophers, to indicate the cause of the universe, that is, the object or subject which (according…
The bench is a generally metallic piece that supports a set of elements, whether mechanical or electrical.
In engines, the bench is the element that constitutes the lower part of the engine. The function of the bench is to support moving parts. In addition, it serves as a retaining wall for the lubricating oil. It is a very resistant element able to withstand the internal stresses inherent to engine operation. Description of the internal combustion engine mainframe
The shape of a motor bed varies depending on the type of motor. In this section we will describe the bench…
What is the indicated diagram?
The indicated diagram is the diagram that represents the real cycle of a heat engine (a diesel engine or an Otto engine).
The actual cycle of a thermal engine reflects the effective operating conditions. These conditions are identified with the diagram of average pressures in the cylinder in correspondence to the different positions of the piston. The pressure shown in a mean pressure diagram is the so-called average pressure indicated. Study of the indicated diagram
The commutator is a component of an electric motor formed by strips of hard electrolytic copper with insulating material in the middle (formerly micanite, nowadays plastic). The assembly is insulated on the rotor shaft and the copper blades are connected to the anchor windings. Permanently installed carbon brushes make contact with the collector and provide power to the anchor windings.
A commutator is a rotary electrical switch in certain types of electric motors and electric generators that periodically changes the direction of the current between the rotor and the external circuit.…
The cylinder of an engine is the enclosure by which a piston moves. The cylinder name comes from its practically cylindrical form.
The materials used to make the cylinders are specific to each type of engine. The way of building and the chosen materials of the cylinder makes vary the performance of the engine. A cylinder made of a gray cast matrix with laminar graphite provides good sliding properties. A motor cylinder made of high quality alloys such as molybdenum, chromium, nickel and manganese, improves hardness and resistance to wear and corrosion.
Engine cylinders are characterized…
Cylinder head, cylinder cap or engine block cover is the top of an internal combustion engine that allows the combustion chamber to close. It constitutes the upper closing of the motor block and in motors on it the valves are seated, having holes for this purpose. The cylinder head has a double wall to allow circulation of the coolant. If the internal combustion engine is ignited (Otto engine), it has threaded holes where the spark plugs are located. In case of being ignition by compression (Diesel engine) in its place it takes the holes for the injectors. The cylinder head is made of cast…
The diesel engine was invented by Rudolf Diesel, in the year 1893. Rudolf Diese was a German engineer, employed by the firm MAN.
Rudolf Diesel studied high thermal efficiency engines, with the use of alternative fuels in internal combustion engines. Diese's goal was to replace the old steam engines that were inefficient, very heavy and expensive. First steps before reaching the diesel engine
In 1806, brothers Claude and Nicéphore Niépce developed the first known internal combustion engine and the first fuel injection system. The two brothers tested systems…
The stator is the fixed part of an electric machine. By electric machine we refer to both electric motors and electric generators. The moving part of an electric motor is called a rotor.
In AC machines the stator is generally in the form of a cylindrical tube, with a certain wall thickness. A based on stacked crowns of magnetic sheet with a toothed on its inner circle are formed the slots where the coils are housed. In the continuous current machines the stator is formed by a solid steel cylindrical frame. This frame has polar poles or pieces with corresponding coils attached to it.…
The rotor is the component that turns on an electric machine. The same definition is valid whether the electric machine is an electric motor or an electric generator. The rotor together with its together with its fixed counterpart, the stator, form the fundamental set for the transmission of power in motors and electrical machines in general.
The rotor is formed by an axis that supports a set of coils wound on a magnetic core. This axis rotates inside a magnetic field created either by a magnet, an electromagnet or by passing through another set of coils, wound on some polar pieces.…
Diesel engines have several advantages over other internal combustion engines: Advantages related to diesel engine fuel
The fuel of a diesel engine has a higher energy density and a smaller volume of fuel is required to perform a specific amount of work.
Diesel engines inject fuel directly into the combustion chamber, have no air intake restrictions other than air filters and intake pipes and have no vacuum in the intake manifold to add parasitic load and pump losses to push the pistons down against the vacuum of the intake system. Cylinder filling is aided by atmospheric…
A first example of the history of the known from rotary to alternative movement is the crank mechanism. The oldest manual cranks appeared in China during the Han Dynasty (202 BC-220 AD). Several sawmills in Roman Asia and Byzantine Syria during the III-VI centuries AD had a connecting rod mechanism that converted the rotary motion of a water wheel into the linear movement of the saw blades. In 1206, the Arab engineer Al-Jazari invented a crankshaft. Piston motor
A free piston engine is a linear internal combustion engine, in which the movement of the piston is not controlled…
Alternative engines can be classified in many different ways. The main forms of classification are the following:
Classification according to the arrangement of the cylinders
- According to the arrangement of the cylinders in the engine
- According to the displacement
- According to the compression ratio
- According to the diameter and stroke ratio
- According to the number of movements of each cycle
A typical way of classifying the reciprocating engine is to use the number and arrangement of the cylinders. In this way we have:
The uses of the steam engine have been changing with the passage of time.
Initially, since the early eighteenth century, steam engines have been used to power a multitude of uses. At first, the steam engine was used as a piston pump. A piston pump is a hydraulic pump that generates movement in it by the movement of a piston.
Subsequently, from the years 1780 began to appear alternative engines. With the alternative motors a new use of the steam engine appears: to give power to the factories and to the industrial one. At the beginning of the 19th century, steam…
Electric motors of direct current work thanks to the properties of the magnets and to the magnetic field that is generated when circulating an electric current by a conductor.
As we well know, the main characteristic of magnets is that they have a south pole (negative) and a north pole (positive). In two different magnets the poles of different sign attract each other and the poles of the same sign repel each other.
Heat engines are a type of alternative engines. Actually, they are the most popular alternative engines.
This type of engine uses the thermal energy caused by the combustion of a fuel (usually gasoil or gasoline) to convert it into mechanical energy. Heat Machines
The concept of a thermal engine is often confused with that of a thermal engine. These terms are related but not exactly the same. A thermal machine is a device or system that works by establishing exchanges of heat and work with its environment. To achieve this, the machine transforms a substance through a cyclic…
The Otto engine and the diesel engine are two types of thermal engines. These are two types of endothermic engines that, through thermodynamic reactions, convert the internal energy of the fuel into mechanical work. However, there are certain differences between them.
The most important difference is found in its theoretical cycle. The Otto engine operates according to the Otto cycle by spark ignition while the diesel engine is controlled according to the diesel cycle by compression ignition.
The other important difference is in the ignition of the fuel. In the Otto engine the ignition…
The actual cycle of a thermal engine is the one that reflects the effective conditions of its operation. These conditions are identified with the diagram of average pressures in the cylinder in correspondence to the different positions of the piston. The pressure shown in a mean pressure diagram is the so-called average pressure indicated.
The indicated diagram is the graph that represents this cycle. Simplified operation of the indicator
The indicator is a device used to obtain the indicated diagram of a thermal engine cycle.
In the indicator of the indicated diagram,…
Steam engines are used to power a wide variety of self-transport applications. These are a few examples:
- Marine applications, naval transport: steamships, steam boats, steam yachts.
- Applications of the steam engine in the field of rail transport: Steam locomotive.
- Agricultural applications: used as traction motor for agricultural machinery. The first tractors in the sector were steam tractors.
- Road transport: Steam vans, steam buses, steam tricycles, steam car.
- Applications in construction machinery: Steam steamroller, steam excavator…
In physics, electricity is a generic term that encompasses a whole set of phenomena that are the manifestation of the presence of a movement of electric charges. We can apply the term electricity to phenomena known as lightning or static electricity but also to other such as the electromagnetic field or electromagnetic induction. The word also serves to designate the branch of physics that studies electrical phenomena and their applications.
In the following sections we will study electricity from a physical point of view…