Engine Creation: There is an old story going around that Wankel invented the miracle engine in 1919. It was always hard to believe in her: how could a 17-year-old guy, albeit talented, do such a thing? He opened his own workshop in the city of Heidelberg, and in 1927 the drawings of a “rotating piston machine” (DKM in German) were born. Felix Wankel received the first DRP patent in 1929, and in 1934 applied for the DKM engine. True, he received a patent two years later. Then, in 1936, Wankel settled in Lindau, where he placed his laboratory.
Then the authorities noticed the promising designer, and work on the DKM had to be abandoned. Wankel worked for BMW, Daimler and DVL, the main aircraft engine companies of Nazi Germany. So it is not surprising that before the onset of 1946, Wankel had to sit in prison as an accomplice of the regime. The laboratory in Lindau was taken out by the French, and Felix was simply left with nothing. Then the authorities noticed the promising designer, and work on the DKM had to be abandoned. Wankel worked for BMW, Daimler and DVL, the main aircraft engine companies of Nazi Germany. So it is not surprising that before the onset of 1946, Wankel had to sit in prison as an accomplice of the regime. The laboratory in Lindau was taken out by the French, and Felix was simply left with nothing. Only in 1951, Wankel got a job at a motorcycle company - already widely known then NSU. Restoring the laboratory, he interested Walter Freude, the designer of racing motorcycles, with his designs. Together, Wankel and Freude pushed the project through the management, and engine development accelerated dramatically. February 1, 1957 earned the first rotary engine DKM-54. He worked on methanol, but by June, the engine that had worked for 100 hours on the stand was switched to gasoline. Only in 1951, Wankel got a job at a motorcycle company - already widely known then NSU. Restoring the laboratory, he interested Walter Freude, the designer of racing motorcycles, with his designs. Together, Wankel and Freude pushed the project through the management, and engine development accelerated dramatically. February 1, 1957 earned the first rotary engine DKM-54. He worked on methanol, but by June, the engine that had worked for 100 hours on the stand was switched to gasoline.
Principles of operation of a rotary engine Wankel engine cycle Wankel engine cycle But then Freude proposed a new concept of a rotary engine! In the Wankel engine (DKM), the rotor rotated around a fixed shaft along with the combustion chamber, which ensured the absence of vibrations. Walter decided to fix the combustion chamber, and let the rotor drive the shaft, that is, use the principle of duality of rotation for a rotary engine. This type of rotary engine was designated KKM. But then Freude proposed a new concept of a rotary engine! In the Wankel engine (DKM), the rotor rotated around a fixed shaft along with the combustion chamber, which ensured the absence of vibrations. Walter decided to fix the combustion chamber, and let the rotor drive the shaft, that is, use the principle of duality of rotation for a rotary engine. This type of rotary engine was designated KKM.
The principle of rotation duality was patented by Wankel himself in 1954, but he still used the DKM principle. It must be said that Wankel did not like the idea of such an inversion, but he could not help it - the engine of his favorite DKM type was time-consuming to maintain, changing the candles required disassembling the engine. So the KKM type engine had much more prospects. His first sample spun on July 7, 1958 (however, it still had candles in the rotor, like on DKM). Subsequently, the candles were transferred to the engine housing, and it acquired its own appearance, which has not fundamentally changed to this day. Now, according to this scheme, all rotary engines are arranged. Sometimes they are called "wankels", after the developer. The principle of rotation duality was patented by Wankel himself in 1954, but he still used the DKM principle. It must be said that Wankel did not like the idea of such an inversion, but he could not help it - the engine of his favorite DKM type was time-consuming to maintain, changing the candles required disassembling the engine. So the KKM type engine had much more prospects. His first sample spun on July 7, 1958 (however, it still had candles in the rotor, like on DKM). Subsequently, the candles were transferred to the engine housing, and it acquired its own appearance, which has not fundamentally changed to this day. Now, according to this scheme, all rotary engines are arranged. Sometimes they are called "wankels", after the developer.
In such an engine, the role of the piston is played by the rotor itself. The cylinder is an epitrochoid-shaped stator, and when the rotor seals move along the stator surface, chambers are formed in which the fuel combustion process takes place. For one revolution of the rotor, this process occurs three times, and thanks to the combination of the shapes of the rotor and stator, the number of cycles is the same as that of a conventional internal combustion engine: intake, compression, power stroke and exhaust. In such an engine, the role of the piston is played by the rotor itself. The cylinder is an epitrochoid-shaped stator, and when the rotor seals move along the stator surface, chambers are formed in which the fuel combustion process takes place. For one revolution of the rotor, this process occurs three times, and thanks to the combination of the shapes of the rotor and stator, the number of cycles is the same as that of a conventional internal combustion engine: intake, compression, power stroke and exhaust.
The rotary engine does not have a gas distribution system - the rotor works for the gas distribution mechanism. He himself opens and closes the windows at the right time. He also does not need balance shafts, a two-section engine can be compared with multi-cylinder internal combustion engines in terms of vibration level. So the idea of a rotary engine in the late fifties seemed like a stepping stone for the automotive industry into a brighter future. The rotary engine does not have a gas distribution system - the rotor works for the gas distribution mechanism. He himself opens and closes the windows at the right time. He also does not need balancer shafts, a two-section engine can be compared with multi-cylinder internal combustion engines in terms of vibration level. So the idea of a rotary engine in the late fifties seemed like a stepping stone for the automotive industry into a brighter future. Into the series! Into the series!
First engine: The engine was developed in cooperation with NSU and in 1957 first gained momentum. One of the 4 experimental engines built stands today in the Deutsches Museum in Munich. Indicators: 250 cm3 and 29 hp at min-1, and in 1963 NSU launched the production of the Spider model - the first production car with rotary piston engine. The motor was developed jointly with NSU and in 1957 gained momentum for the first time. One of the 4 experimental engines built stands today in the Deutsches Museum in Munich. Indicators: 250 cm3 and 29 hp at min-1, and in 1963 NSU launched the Spider model, the first mass-produced car with a rotary piston engine.
Advantages and disadvantages of the engine: The design allows for a four-stroke cycle without the use of a special gas distribution mechanism. This engine can use cheap grades of fuel; it creates almost no vibrations. The design allows for a four-stroke cycle without the use of a special gas distribution mechanism. This engine can use cheap grades of fuel; it creates almost no vibrations. The main advantage of the Wankel engine is its small size for a given power. The engine has few moving parts and is therefore potentially more reliable and cheaper to manufacture. The main advantage of the Wankel engine is its small size for a given power. The engine has few moving parts and is therefore potentially more reliable and cheaper to manufacture.
"Static electricity" - Excess electricity must be removed from the body by grounding. Clothing. Grounding results. For thousands of years, our ancestors walked the earth barefoot, grounding themselves naturally. Normalization of pressure. "Excess" electricity can lead to serious malfunctions of organs and systems.
"Forces of the body" - The force acts on the connection, and the reaction of the connection on the body. Circle. A smooth surface is a surface on which friction can be neglected. d'Alembert principle. Point velocity theorem in complex movement. Force is a sliding vector. Cylindrical hinge. Varignon's theorem. The theorem on the addition of pairs of forces. Rigid closure.
"History of electricity" - XX century - the emergence and rapid development of electronics, micro / nano / pico technologies. The history of the development of electricity. XIX century - Faraday introduces the concept of electric and magnetic fields. XXI century - electrical energy has finally become an integral part of life. XXI century - power outage in household and industrial networks.
"Atomic nuclei" - Scheme of the device of a nuclear power plant. Superheavy nuclei (A > 100). Kernel sizes. Nuclear forces. Nuclear fission. The magnetic field is created by superconducting windings. N? Z diagram of atomic nuclei. Scattering?-particles in the Coulomb field of the nucleus. Rutherford's experience. Models of atomic nuclei. Synthesis of nuclei. Mass and binding energy of the nucleus.
"What does physics study" - Introductory speech of the teacher. Rocket launch. Technique. What does physics study? Eruption. Combustion. Physics. Aristotle is the greatest thinker of antiquity. Thermal phenomena of nature. Magnetic phenomena of nature. Aristotle introduced the concept of "physics" (from the Greek word "fusis" - nature). Acquaintance of students with a new subject of the school course.
"Igor Vasilievich Kurchatov" - His mother was a teacher, his father was a land surveyor. Beloyarsk NPP is named after Kurchatov. IV Kurchatov - Deputy of the Supreme Soviet of the USSR of the third and fifth convocations. Biography of IV Kurchatov as an outstanding Soviet physicist. The Institute of Atomic Energy founded by him was named after Kurchatov in 1960. Who is I.V. Kurchatov?
In total there are 19 presentations in the topic
Electric motors
- Purpose: to study the device and the principle of operation of email. engines of various designs; familiarize yourself with the working principle induction motor(single phase)
- Where are electric motors used in everyday life and industry?
- Electric drill
- Washing machine
- A vacuum cleaner
- electric shaver
- Sewing machine
- Electric transport, etc.
- Electric drill
- The electric drill uses a commutator motor
- electric motor
- Washing machine
- Washing machines use an asynchronous single-phase electric motor.
- electric motor
- a vacuum cleaner
- Vacuum cleaners use a commutator motor
- electric motor
- electric transport
- For the movement of trams, trolleybuses, electric trains, high-power electric motors are used.
- Collector motor device
- The collector electric motor is universal and can work both from direct and from alternating current.
- anchor
- collector
- bed
- inductor
- Features of the collector motor.
- By changing the voltage on the brushes of the motor, you can adjust the speed of rotation of the rotor. Due to this, the collector motor is used in those machines where it is necessary to change the speed of rotation of the mechanisms. (kitchen appliances; electric drill; electric shaver; hair dryer; tape recorders; sewing machine; electrical carpentry tools, etc., as well as electric transport)
- brushes
- collector
- Rotor winding
- How does a collector motor work?
- The principle of operation of the engine is based on the interaction
- conductor ( anchors) with electric current and magnetic field,
- created by an electromagnet (inductor). mechanical force,
- arising from such an interaction, causes to rotate
- anchor (rotor).
- Such engines are divided into:
- AC motors, the frame and core of which are made of sheets of electrical steel;
- DC motors, in which the named parts are made solid.
- The excitation winding of the electromagnet in AC motors is connected in series with the armature winding, which provides a large starting torque.
- Asynchronous motor device
- Next, consider the principle of operation of an asynchronous motor.
- rotor
- stator
- Operation of an induction motor
- The principle of operation of an induction motor is based on the interaction of a rotating magnetic field with currents that are induced by the field in the conductors of a squirrel-cage rotor.
- The rotor is mounted in bearings and therefore moves in the direction of the rotating rotor.
- Structurally, an asynchronous motor consists of two main parts:
- - fixed - stator;
- - movable - rotor.
- The stator has three windings wound at an angle of 120°. The rotor has a winding in the form of a squirrel wheel.
- Operation of an induction motor
- Asynchronous motors have their own:
- * advantages - simple in design, reliable in operation and are used in all sectors of the national economy;
- * disadvantages - the impossibility of obtaining a constant number of revolutions (compared to collectors); at start-up it has a large current, sensitive to voltage fluctuations in the network.
- Of the total number of electric motors produced, 95% are asynchronous.
- Features of the operation of an asynchronous electric motor
- Unlike a commutator motor, where carbon brushes rub against the commutator, in an asynchronous motor, the windings are located in the stator, therefore, without rubbing parts, the service life of an asynchronous motor is much higher than that of a commutator motor, and its range of application is much wider. (washing machines, vacuum cleaners, woodworking and metalworking machines, fans, pumps, compressors, etc.
- Anchor
- windings
- Using a three-phase motor in everyday life
- To use a three-phase motor in everyday life, where there is single-phase electrical wiring, a capacitor must be connected to the circuit. The disadvantage of this method is the use of expensive paper capacitors. (for every 100W of power 10Mkf for a voltage of 250-450V.
- Inclusion of an asynchronous single-phase motor in the network
- In household machines, single-phase asynchronous motors are used that have two windings:
- # working; # launcher; The windings are located at an angle of 90°. When connected to the network, a rotating magnetic field is formed, and the squirrel-cage rotor begins to rotate, after which the starting winding is turned off.
- starting winding
- ~ 220V
- Determine what type of electric motor is used in this household appliance.
- Determine what type of electric motor is used in industrial engineering.
Electric motor - electric machine
(electromechanical converter), in which the electrical
energy is converted into mechanical, side effect
is the release of heat.
Electric motors
Alternating current
Synchronous
Asynchronous
Direct current
Collector
Brushless
Universal
(may eat
both types
current)
principle of electromagnetic induction.
The electric machine consists of:
fixed part - stator (for asynchronous and synchronous
AC machines) or inductor (for machines
direct current)
moving part - rotor (for asynchronous and synchronous
AC machines) or armatures (for DC machines)
current). Usually a rotor is an arrangement of magnets in the shape of a cylinder,
often formed by coils of thin copper wire.
The cylinder has a central axis and is called a "rotor" because
that the axle allows it to rotate if the motor is built
right. When through the rotor coils is passed
electric current, the entire rotor is magnetized. Exactly
you can create an electromagnet. 8.2 AC motors According to the principle of operation, AC motors are divided
for synchronous and asynchronous motors.
Synchronous motor - electric motor
alternating current, the rotor of which rotates synchronously
with the magnetic field of the supply voltage. These engines
are usually used at high powers (from hundreds of kilowatts
and higher).
Asynchronous electric motor - electric motor
alternating current, in which the rotor speed is different
on the frequency of the rotating magnetic field created by the supply
voltage. These engines are the most common
present time. The principle of operation of a three-phase asynchronous electric motor
When connected to the network in the stator, a circular rotating
magnetic field that penetrates a short-circuited winding
rotor and induces an induction current in it. Hence, following the law
Ampere, the rotor comes into rotation. Rotor speed
depends on the frequency of the supply voltage and on the number of pairs
magnetic poles. Difference between speed
stator magnetic field and rotor speed
characterized by slip. The motor is called asynchronous,
since the frequency of rotation of the stator magnetic field does not coincide with
rotor speed. The synchronous motor has a difference in
rotor design. The rotor is either permanent
a magnet, or an electromagnet, or has in itself a part of a squirrel
cells (to run) and permanent or electromagnets. AT
synchronous motor, the rotational speed of the stator magnetic field and
rotor speed match. To run use
auxiliary asynchronous electric motors, or a rotor with
short-circuited winding. Three-phase asynchronous motor To calculate the characteristics of an induction motor and
studies of various modes of its operation is convenient to use
substitution schemes.
At the same time, a real asynchronous machine with electromagnetic
connections between the windings is replaced by a relatively simple
electric circuit, which makes it possible to significantly simplify
calculation of characteristics.
Taking into account the fact that the basic equations of an induction motor
are similar to the same transformer equations,
the equivalent circuit of the motor is the same as that of the transformer.
T-shaped equivalent circuit of an induction motor When calculating the characteristics of an asynchronous motor with
using an equivalent circuit, its parameters should be
known. The T-shaped scheme fully reflects the physical
processes occurring in the engine, but difficult to calculate
currents. Therefore, a great practical application for the analysis
modes of operation of asynchronous machines finds another circuit
substitution, in which the magnetizing branch is connected
directly at the input of the circuit, where the voltage U1 is applied.
This circuit is called L-shaped equivalent circuit. L-shaped scheme
substitution asynchronous
engine (a) and its
simplified version (b) For various mechanisms, it serves as an electric drive
asynchronous motor which is simple and reliable. These engines
easy to manufacture and cheap compared to others
electric motors. They are widely used in
industry, agriculture and construction.
Asynchronous motors are used in electric drives
various construction equipment, in lifting countries.
The ability of such an engine to operate in the intermittent mode makes it possible to use it in
construction cranes. During disconnection from the mains, the motor does not
cools down and does not heat up during operation. 8.3. Electric motors
direct current Collector motor
The smallest motors of a given type (watt units)
are used mainly in children's toys (working
voltage 3–9 volts). More powerful engines(tens of watts)
applied in modern cars(working voltage
12 volts): cooling fan drive and
ventilation, wipers. Collector motors can convert like
electrical energy into mechanical energy, and vice versa. From this
it follows that it can work as an engine and as a generator.
Consider the principle of operation on an electric motor.
It is known from the laws of physics that if through a conductor,
located in a magnetic field to pass the current, then it will start
act force.
Moreover, according to the rule right hand. The magnetic field is directed away from
north pole N to south s, if the palm of the hand is directed to
towards the north pole, and four fingers in the direction of the current
in the explorer, the thumb will indicate the direction
acting force on the conductor. Here is the basis of the work
collector motor. But as we know, small rules create the right things. On the
On this basis, a frame rotating in a magnetic field was created.
For clarity, the frame is shown in one turn. Just like in the past
example, two conductors are placed in a magnetic field, only the current in
these conductors are directed in opposite directions,
so the forces are the same. In sum, these forces give a torque
moment. But it's still a theory. At the next stage, a simple collector engine was created.
It differs from the frame by the presence of a collector. It provides
the same direction of current over the north and south poles.
Flaw this engine in uneven rotation and
inability to work on alternating voltage.
The next step was to eliminate the unevenness of the course by
anchoring a few more frames (coils), and from
DC voltage moved away by replacing permanent magnets
coils wound around the stator pole. When flowing
alternating current through the coils changes the direction of the current, as
in the stator and armature windings, therefore, the torque,
both at constant and at alternating voltage will be
directed in the same direction, which was to be proved. Collector motor device Brushless motor
Brushless DC motors are also called
valve. Structurally, a brushless motor consists of
from a rotor with permanent magnets and a stator with windings. AT
the collector motor, on the contrary, the windings are on the rotor.
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Slides captions:
COLLECTOR ELECTRIC MOTOR Developed by the teacher of technology of the highest category, Honorary Worker of Primary Vocational Education Russian Federation MBOU "Secondary School No. 7", Kaluga Gerasimov Vladislav Aleksandrov
What do these appliances have in common?
COLLECTOR MOTOR
STORY. The first collector electric motor was designed in Russia by the Russian scientist Jacobi Boris Semenovich in 1838. By the 70s of the 19th century, the electric motor had already been improved so much that it remained in this form to this day.
Boris Semyonovich Jacobi
Purpose: Converting electrical energy into mechanical. Mechanical energy drives the working parts of machines and mechanisms.
Principle of operation: Electric current from the source (batteries of galvanic cells) is fed into the winding through special sliding contacts - brushes. These are two elastic metal plates that are connected by conductors to the poles of the current source and pressed against the collector. When an electric current flows through the armature winding, the rotor begins to rotate under the influence of a magnet.
The general arrangement of the electric motor 1-bearings, 2-rear stator cover, 3-winding, 4-armature, 5-core, 6-armature winding, 7-collector, 8-front cover, 9-shaft, 10-impeller.
The smallest engines of this type. three-pole rotor on plain bearings; collector assembly of two brushes - copper plates; bipolar permanent magnet stator. They are mainly used in children's toys (operating voltage 3-9 volts).
Powerful motors (tens of watts), as a rule, have: a multi-pole rotor on rolling bearings; collector assembly of four graphite brushes; four-pole permanent magnet stator. It is this design that most electric motors in modern cars (operating voltage 12 or 24 Volts): drive fans of cooling and ventilation systems, wipers, washer pumps.
Collector motor-wheel, 24 volts 230 watts.
Motors with a power of hundreds of watts Unlike the previous ones, they contain a four-pole stator of electromagnets. The stator windings can be connected in several ways: in series with the rotor (so-called serial excitation), advantage: high maximum torque, disadvantage: high speed idle move that could damage the engine.
in parallel with the rotor (parallel excitation) advantage: greater speed stability when the load changes, disadvantage: lower maximum torque part of the windings in parallel with the rotor, part in series (mixed excitation) to some extent combines the advantages of the previous types, example - car starters. separate power supply (independently excited) the characteristic is similar to parallel connection, but can usually be adjusted.
DC motor with parallel excitation
Series Excited DC Motor
Ways to change the frequency of rotation of the motor shaft By changing the magnitude of the stator excitation current. The greater the current in the stator, the higher the frequency of rotation of the motor shaft
Advantages of electric motors. No harmful emissions during operation Does not require constant maintenance Can be installed anywhere Works in vacuum conditions Does not use flammable substances (gasoline, diesel fuel) Easy to use
Failures in the work of the collector electric motor Operating conditions and service life of motors in household machines are different. The reasons for their failure are also different. It has been established that 85-95% fail due to damage to the insulation of the windings distributed as follows: 90% of turn-to-turn short circuits and 10% of damage and breakdowns of insulation on the case. Then comes the wear of the bearings, the deformation of the steel of the rotor or stator, and the bending of the shaft.
The repair process includes the following main operations:
Pre-repair tests External cleaning from dirt and dust Dismantling into components and parts Removal of windings Washing of components and parts Troubleshooting of components and parts Repair and manufacture of components and parts Assembly of the rotor Manufacturing and laying of windings Drying and impregnation works Machining of the assembled rotor and its balancing Assembly of components and parts Assembly of electric motors Tests after repair External finishing
Summing up the lesson. What is an electric motor? In what devices are collector electric motors used? What parts does a commutator motor consist of? What principle underlies the operation of a collector electric motor?