info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
Electric Motors
6 views
Skip to first unread message
krk...@wp.pl
Apr 16, 2009, 5:45:36 PM4/16/09
to
Electric motors are everywhere! In your house, almost every
mechanical movement that you see around you is caused by an AC or DC
electric motor. By understanding how a motor works you can learn a lot
about magnets, electromagnets and electricity in general. On this page
we hope you will learn what makes an electric motor spin.
An electric motor is all about magnets and magnetism. A motor
uses magnets to create motion. If you have ever played with magnets
you know the law of magnets: Opposites poles attract and like poles
repel. So if you have two bar magnets with their ends marked "north"
and "south," then the north end of one magnet will attract the south
end of the other. On the other hand, the north end of one magnet will
repel the north end of the other. Inside an electric motor, these
attracting and repelling forces create rotational motion.
The armature (or rotor) is an electromagnet. Like the Beakman
rotor above made of copper wound in a circle, the motor below has
copper wound around a soft iron core. The field magnet is still a
permanent magnet, only this time there are two semi-circular magnets
fitted inside a steel casing. In some larger motors and generators
the field magnet could also be an electromagnet. In smaller motors it
usually isn't to save the electricity that would otherwise be needed
to make magnetism and also to reduce complexity. Actually, these days
there are quite a few large motors using magnets to drive cars and the
like. The Solar Navigator catamaran uses permanent magnet motors that
are very efficient.
The motor we have dismantled above is a simple electric toy
motor. Millions of these motors are made every year by Mabuchi and
other famous producers. Mabuchi motors were used on the early 1/10th
and 1/20th development models of Solar Navigator.
If you take apart a small electric motor, you will find that
it contains the same pieces described above: two small permanent
magnets inside casing, two brushes held in a housing, and an
electromagnet made by winding wire around pieces of shaped metal
(laminations) on a steel shaft, known as an armature or rotor. Almost
always the rotor will have three poles or more. There are two good
reasons for a motor to have three poles or more:
It causes the motor to have better dynamics (movement). In a
two-pole motor, if the electromagnet is at the balance point,
perfectly horizontal between the two poles of the field magnet when
the motor starts, you can imagine the armature getting "stuck" there.
That never happens in a three-pole motor, which can start turning from
any starting position.
Each time the commutator hits the point where it flips the
field in a two-pole motor, the commutator shorts out the battery
(directly connects the positive and negative terminals) for a moment.
This shorting wastes energy and drains the battery needlessly. A three-
pole motor solves this problem as well. In fact the timing of an
efficient motor switches on the armature at a point when the magnetic
repulsion is strongest.
It is possible to have any number of poles, depending on the
size of the motor and the specific application it is being used in.
Also, motors come in different shapes and sizes to fit almost
anywhere. Special, very powerful (rare earth) permanent magnets can
be used to boost power - although this increases the cost. Special
brush materials can be used to improve power handling. And these days,
instead of using a mechanical switch like the commutator, electronics
can be used instead to get very accurate timing and sometimes exotic
sine waves. This also eliminates sparking and brush wear problems, so
reducing servicing.
Other efficient dc designs do not have a conventional iron
armature, but an ironless copper winding (a wire cylinder) very close
to a permanent magnet, such as in the Swiss Maxon design motors, also
used on Solar Navigator development models.
mechanical movement that you see around you is caused by an AC or DC
electric motor. By understanding how a motor works you can learn a lot
about magnets, electromagnets and electricity in general. On this page
we hope you will learn what makes an electric motor spin.
An electric motor is all about magnets and magnetism. A motor
uses magnets to create motion. If you have ever played with magnets
you know the law of magnets: Opposites poles attract and like poles
repel. So if you have two bar magnets with their ends marked "north"
and "south," then the north end of one magnet will attract the south
end of the other. On the other hand, the north end of one magnet will
repel the north end of the other. Inside an electric motor, these
attracting and repelling forces create rotational motion.
The armature (or rotor) is an electromagnet. Like the Beakman
rotor above made of copper wound in a circle, the motor below has
copper wound around a soft iron core. The field magnet is still a
permanent magnet, only this time there are two semi-circular magnets
fitted inside a steel casing. In some larger motors and generators
the field magnet could also be an electromagnet. In smaller motors it
usually isn't to save the electricity that would otherwise be needed
to make magnetism and also to reduce complexity. Actually, these days
there are quite a few large motors using magnets to drive cars and the
like. The Solar Navigator catamaran uses permanent magnet motors that
are very efficient.
The motor we have dismantled above is a simple electric toy
motor. Millions of these motors are made every year by Mabuchi and
other famous producers. Mabuchi motors were used on the early 1/10th
and 1/20th development models of Solar Navigator.
If you take apart a small electric motor, you will find that
it contains the same pieces described above: two small permanent
magnets inside casing, two brushes held in a housing, and an
electromagnet made by winding wire around pieces of shaped metal
(laminations) on a steel shaft, known as an armature or rotor. Almost
always the rotor will have three poles or more. There are two good
reasons for a motor to have three poles or more:
It causes the motor to have better dynamics (movement). In a
two-pole motor, if the electromagnet is at the balance point,
perfectly horizontal between the two poles of the field magnet when
the motor starts, you can imagine the armature getting "stuck" there.
That never happens in a three-pole motor, which can start turning from
any starting position.
Each time the commutator hits the point where it flips the
field in a two-pole motor, the commutator shorts out the battery
(directly connects the positive and negative terminals) for a moment.
This shorting wastes energy and drains the battery needlessly. A three-
pole motor solves this problem as well. In fact the timing of an
efficient motor switches on the armature at a point when the magnetic
repulsion is strongest.
It is possible to have any number of poles, depending on the
size of the motor and the specific application it is being used in.
Also, motors come in different shapes and sizes to fit almost
anywhere. Special, very powerful (rare earth) permanent magnets can
be used to boost power - although this increases the cost. Special
brush materials can be used to improve power handling. And these days,
instead of using a mechanical switch like the commutator, electronics
can be used instead to get very accurate timing and sometimes exotic
sine waves. This also eliminates sparking and brush wear problems, so
reducing servicing.
Other efficient dc designs do not have a conventional iron
armature, but an ironless copper winding (a wire cylinder) very close
to a permanent magnet, such as in the Swiss Maxon design motors, also
used on Solar Navigator development models.
Marcin Mały
Apr 18, 2009, 1:59:05 PM4/18/09
to
A ten Twój wpis to ma coś na celu poza kopiowaniem treści ze strony
http://www.solarnavigator.net/electric_motors.htm ???
Ewidentne śmiecenie.
http://www.solarnavigator.net/electric_motors.htm ???
Ewidentne śmiecenie.
Dnia 16-04-2009 o 23:45:36 <krk...@wp.pl> napisał(a):
> Electric motors are everywhere! In your house, almost every
> mechanical movement that you see around you is caused by an AC or DC
> electric motor.
Wojciech Waga
Apr 19, 2009, 4:11:23 PM4/19/09
to
Ostatnio dziwne posty się pojawiają. Trochę wygląda jakby jakiś
nauczyciel(ka) informatyki pokazywał usenet i nie wiedział co to pl.test.
pozdr.
w.
Adam
Apr 20, 2009, 3:43:35 AM4/20/09
to
jest tylko jedna rada
nie odpowiadac, nie zaczepiac, nie komentowac!!!!!!!!!!!!!!!!!!!!!!!!!!
co sam niedawno zrobilem niestety :(
A.
nie odpowiadac, nie zaczepiac, nie komentowac!!!!!!!!!!!!!!!!!!!!!!!!!!
co sam niedawno zrobilem niestety :(
A.
"Wojciech Waga" <adun_...@o2.pl> wrote in message
news:gsg0hb$ds2$1...@achot.icm.edu.pl...
zwge...@gmail.com
Nov 2, 2015, 4:26:50 AM11/2/15
to
Sell:
China Shenzhen ZHAOWEI Machinery & Electronics Co. Ltd engages in designing, manufacturing and marketing all kinds of electric motors. They are mainly suitable for the following applications: smart home application used in smart kitchen and laundry, medical instrument for personal care, smart E-transmission applied in automobile, industry automation applied in telecommunication and a great variety of plastic/metal planetary gearbox in different sizes.
In order to develop the oversea market, we are current seeking new partners around the world to create a bright future together. ZhaoWei is a right choice and excellent partnership with sincere services.
Company: Shenzhen ZHAOWEI Machinery & Electronics Co., Ltd
URL: http://www.zwgearbox.com/
Contact: Anny Liu
Tel：+86-755-27322652
Fax：+86-755-27323949
E-mail:sa...@zwgearbox.com
Add: Blk. 18, Longwangmiao Industry Park, Fuyong Tn., Bao’an Dist., Shenzhen 518103, Guangdong, China
China Shenzhen ZHAOWEI Machinery & Electronics Co. Ltd engages in designing, manufacturing and marketing all kinds of electric motors. They are mainly suitable for the following applications: smart home application used in smart kitchen and laundry, medical instrument for personal care, smart E-transmission applied in automobile, industry automation applied in telecommunication and a great variety of plastic/metal planetary gearbox in different sizes.
In order to develop the oversea market, we are current seeking new partners around the world to create a bright future together. ZhaoWei is a right choice and excellent partnership with sincere services.
Company: Shenzhen ZHAOWEI Machinery & Electronics Co., Ltd
URL: http://www.zwgearbox.com/
Contact: Anny Liu
Tel：+86-755-27322652
Fax：+86-755-27323949
E-mail:sa...@zwgearbox.com
Add: Blk. 18, Longwangmiao Industry Park, Fuyong Tn., Bao’an Dist., Shenzhen 518103, Guangdong, China
0 new messages