(1) Stator (static part)
1, stator core
Function: a part of the magnetic circuit of the motor and stator winding is placed on it.
Structure: The stator core is generally made of silicon steel sheet with a thickness of 0.35~0.5 mm, with insulating layer on the surface, and evenly distributed slots are punched in the inner circle of the core for embedding the stator winding.
Stator core groove types are as follows:
Semi-closed slot: the efficiency and power factor of the motor are high, but the winding is difficult to embed and insulate. Generally used for small low-voltage motors.
Semi-open slot: special-shaped winding can be embedded, which is generally used for large and medium-sized low-voltage motors. The so-called shaped winding means that the winding can be insulated in advance and then put into the slot.
Open slot: it is used to embed the forming winding, and the insulation mode is convenient. Mainly used for high-voltage motors.
2. Stator winding
Function: it is the circuit part of the motor, which is connected with three-phase alternating current to generate rotating magnetic field.
Structure: It consists of three windings with the same structure, which are spaced apart by 120 electrical angle and symmetrically arranged. Each coil of these windings is embedded in each slot of the stator according to certain rules.
The main insulation items of the stator winding are as follows: (Ensure reliable insulation between the conductive part of the winding and the iron core and between the winding itself).
(1) Insulation to ground: insulation between the stator winding as a whole and the stator core.
⑵ Interphase insulation: insulation between stator windings of each phase.
⑶ Turn-to-turn insulation: Turn-to-turn insulation of each phase stator winding.
Wiring in the motor junction box:
There is a terminal board in the motor junction box. Six terminals of three-phase winding are arranged in two rows. The number of three terminals in the upper row from left to right is 1(U 1), 2(V 1) and 3(W 1), and the number of three terminals in the lower row from left to right is 6(W2). All manufacturing and maintenance should be arranged according to this serial number.
3. Basic framework
Function: Fix the stator core and front and rear end covers, support the rotor, and play the role of protection and heat dissipation.
Structure: the frame is generally cast iron, the frame of large asynchronous motor is generally welded with steel plate, and the frame of micro motor is cast aluminum. There are cooling ribs outside the frame of the enclosed motor to increase the cooling area, and the end covers at both ends of the frame to protect the motor have ventilation holes, so that the air inside and outside the motor can directly convection, which is beneficial to heat dissipation.
(2) Rotor (rotating part)
1 rotor core, three-phase asynchronous motor;
Function: As a part of the motor magnetic circuit, the rotor winding is placed in the iron core slot.
Structure: The material used is the same as the stator, and it is made of 0.5 mm thick silicon steel sheets, and the excircle of the silicon steel sheets is stamped with evenly distributed holes for installing rotor windings. Usually, the back inner circle of silicon steel sheet is used to punch the stator core to punch the rotor core. Generally, the rotor core of small asynchronous motor is directly press-fitted on the rotating shaft, and the rotor core of large and medium asynchronous motor (rotor diameter is above 300~400 mm) is press-fitted on the rotating shaft with the help of rotor bracket.
2. Rotor winding of three-phase asynchronous motor
Function: the rotating magnetic field of the cutting stator produces induced electromotive force and current, forming electromagnetic torque to make the motor rotate.
Structure: divided into squirrel cage rotor and wound rotor.
⑴ Squirrel-cage rotor: The rotor winding consists of a plurality of guide rods and two circular end rings inserted into the rotor slot. If the rotor core is removed, the whole winding looks like a squirrel cage, so it is called cage winding. Small-sized cage motor adopts cast aluminum rotor winding, and motors above 100KW are welded with copper bars and copper end rings.
⑵ Wound rotor: The wound rotor winding is similar to the stator winding, and it is also a symmetrical three-phase winding, which is generally connected in a star shape. The three outlet terminals are connected to the three slip rings of the rotating shaft, and then connected to the external circuit through the brush.
Features: The structure is complex, so the wound motor is not as widely used as the squirrel-cage motor. However, in order to improve the starting, braking and speed regulation performance of asynchronous motor, additional resistors and other elements are connected in series in the rotor winding circuit through slip rings and brushes, so it is used in equipment that requires smooth speed regulation within a certain range, such as cranes, elevators, air compressors and so on.
(3) Other accessories of three-phase asynchronous motor.
1, end cover: support function.
2. Bearing: connecting the rotating part and the fixed part.
3. Bearing end cover: protect the bearing.
4. Fan: cooling motor.
Secondly, DC motor adopts octagonal fully laminated structure and series excitation winding, which is suitable for automatic control technology that needs positive and negative rotation. According to the needs of users, it can also be made into series windings. Motors with center height 100 ~ 280mm have no compensation winding, but motors with center heights of 250mm and 280mm can be made according to specific conditions and needs, and motors with center height of 3 15 ~ 450 mm have compensation windings. The installation dimensions and technical requirements of the motor with the center height of 500 ~ 7 10 mm conform to IEC international standards, and the mechanical dimension tolerance of the motor conforms to ISO international standards. Principle of motor classification Commutator with or without commutator. The electromechanical stator coil is driven by voltage. The motor has a commutator, which is used to connect or disconnect the rotor coil by detecting the rotor position, discrete sensors, coil feedback or open loop feedback. The electromechanical commutator electronic switch drives the AC -DC-DC rotor. The iron rotor is ferromagnetic, not permanently magnetized, and has no coil reluctance: hysteresis, synchronous reluctance motor variable magnet group motor/switched reluctance motor variable magnet group motor/switched reluctance motor, stepping motor and accelerator magnet rotor are permanently magnetized. Wireless coil permanent magnet synchronous motor/brushless AC motor brushless DC motor copper (generally with magnetic core) rotor with coil squirrel-cage motor permanent magnet winding stator: general motor (AC -DC dual-purpose motor) is cooled by frequency converter 1): when the motor converts energy, a small part of the loss is always converted into heat, which must be continuously dissipated through the motor housing and surrounding media. This heat dissipation process is called cooling.
2) Cooling medium: gas or liquid medium for transferring heat.
3) Primary cooling medium: the gas or liquid medium whose temperature is lower than that of a certain part of the motor contacts with this part of the motor and takes away the heat released by it.
4) Secondary cooling medium: the gas or liquid medium whose temperature is lower than that of the primary cooling medium takes away the heat released by the primary cooling medium through the outer surface of the motor or the cooler.
5) Final cooling medium: heat is transferred to the final cooling medium.
6) Environmental cooling medium: gas or liquid medium in the environment around the motor.
7) Remote medium: the medium far away from the motor absorbs the heat of the motor through the inlet and outlet pipes or channels, and discharges the cooling medium to the distance.
8) Cooler: a device that transfers the heat of one cooling medium to another and keeps the two cooling media separate. 1, the motor cooling mode code mainly consists of cooling mode symbol (IC), cooling medium loop layout code, cooling medium code and driving mode code of cooling medium movement.
IC+ circuit layout code+cooling medium code+driving method code
2. The symbol code of cooling mode is the abbreviation of English international cooling, which is expressed by IC.
3. The circuit layout code of cooling medium is represented by characteristic number, and our company mainly adopts 0, 4, 6, 8, etc. Let's talk about their meanings respectively.
4. The cooling medium code has the following provisions: cooling medium characteristic code air A hydrogen H nitrogen N carbon dioxide C water W oil U If the cooling medium is air, the letter A describing the cooling medium can be omitted, and the cooling medium we use is basically air.
5. Four methods to promote the movement of cooling medium are mainly introduced. Description of the meaning of feature number 0. Temperature difference 1 free convection of cooling medium. The movement of cooling medium is related to the motor speed, and it can also be driven by the rotor itself, or the rotor can drive the whole fan or pump. 6. Independent components installed on the motor drive the medium to move, and the power required by the components has nothing to do with the speed of the main engine. For example, an external independent component, such as a backpack fan or an independent electrical or mechanical component installed separately from the motor, drives the cooling medium to move, or relies on the pressure in the cooling medium circulation system to drive the cooling medium to move. 6. There are two ways to mark the cooling mode code: simplified way and complete way. We should give priority to simplifying the grading method. The characteristic of simplified marking method is that if the cooling medium is air, A representing the cooling medium code can be omitted from the simplified label. If the cooling medium is water and the driving mode is 7, the number 7 can be omitted from the simplified label.
7. The commonly used heat dissipation methods are IC0 1, IC06, IC41,IC4 16, IC61,IC8 1W, etc.
Example: IC4 1 1 The complete labeling method is IC4A 1A 1.
"IC" is the symbol code of refrigeration mode;
"4" is the layout code of cooling medium circuit (shell surface cooling).
"A" is the code name of cooling medium (air).
The first "1" is the code name of primary refrigerant driving mode (self-circulation).
The second "1" is the code name of secondary refrigerant driving mode (self-circulation).
IC06: External ventilation with blower;
ICl7: The inlet of cooling air is pipeline, and the outlet is louver exhaust;
IC37: cooling air inlet and outlet are all pipes;
IC6 1 1: totally enclosed with air/air cooler;
ICW37A86: totally enclosed with air/water cooler.
And there are many derivative forms, such as self-ventilation, axial flow fan, closed, air/air cooler and so on. Ac motor
induction-motor
Y series (low voltage, high voltage, frequency conversion, electromagnetic braking)
JSJ series (low voltage, high voltage, frequency conversion, electromagnetic braking)
synchro
TD series
TDMK series
continuous current dynamo
Ordinary DC engine
Z2 series
Z4 series
Special DC engine
ZTP railway locomotive company
ZSN cement rotary kiln
The motor is very convenient to use and control, and has the ability of self-starting, accelerating, braking, reversing and braking, which can meet various operation requirements. The motor has high working efficiency, no smoke, no smell, no environmental pollution and low noise. Because of its series of advantages, it is widely used in industrial and agricultural production, transportation, national defense, commercial and household appliances, medical electrical equipment and so on. 1. According to the classification of working power supply and the different working power supply of motor, it can be divided into DC motor and AC motor. Among them, AC motors are divided into single-phase motors and three-phase motors.
2. Classification of motors according to structure and working principle Motors can be divided into DC motors, asynchronous motors and synchronous motors according to structure and working principle. Synchronous motors can also be divided into permanent magnet synchronous motors, reluctance synchronous motors and hysteresis synchronous motors. Asynchronous motors can be divided into induction motors and AC commutator motors. Induction motors are divided into three-phase asynchronous motors and so on.
Phase asynchronous motor and shielded pole asynchronous motor, etc. AC commutator motor is divided into single-phase series motor, AC -DC dual-purpose motor and repulsion motor.
3. Classification of motors according to starting and running modes Motors can be divided into capacitor-started single-phase asynchronous motors, capacitor-operated single-phase asynchronous motors, capacitor-started single-phase asynchronous motors and split-phase single-phase asynchronous motors according to starting and running modes.
4. Motors can be classified into drive motors and control motors according to their uses. The driving motor is divided into electric tools (including drilling, grinding, polishing, slotting, cutting, reaming and other tools) and household appliances (including washing machines, electric fans, refrigerators, air conditioners, tape recorders, video recorders, DVD players, vacuum cleaners, cameras, hair dryers, electric shavers and so on). ) and other general small mechanical equipment (including all kinds of small machine tools, small machinery, medical instruments and electronic instruments). Control motors are divided into stepper motors and servo motors.
5. According to the structure of the rotor, the motor can be divided into squirrel-cage induction motor (called squirrel-cage asynchronous motor in the old standard) and wound induction motor (called wound asynchronous motor in the old standard).
6. Classify motors according to running speed. According to running speed, motors can be divided into high-speed motors, low-speed motors, constant-speed motors and variable-speed motors.
7. According to the protection type, it can be divided into
Open (such as IP 1 1, IP22): The motor has no special protection for the rotating and live parts except the necessary supporting structure.
Enclosed (such as IP44 and IP54): The rotating parts and live parts inside the motor housing have necessary mechanical protection to prevent accidental contact, but it does not obviously hinder ventilation. Protection motor can be divided into:
Mesh cover type: the vent of the motor is covered with a perforated cover, so that the rotating part and live part of the motor can not contact with the outside world.
Anti-dripping: the structure of the motor exhaust port can prevent the liquid or solid falling vertically from directly entering the motor.
Splash prevention: The structure of the motor exhaust port can prevent liquid or solid in any direction from entering the motor at an angle of 100 degrees from the vertical.
Enclosed: The structure of the motor shell can prevent the free exchange of air inside and outside the shell, but it is not required to be completely sealed.
Waterproof: The structure of the motor shell can prevent water with a certain pressure from entering the motor.
Watertightness: when the motor is immersed in water, the structure of the motor shell can prevent water from entering the motor.
Submersible: the motor can run in water for a long time under rated water pressure.
Explosion-proof: the structure of the motor shell is enough to prevent the gas explosion inside the motor from spreading to the outside of the motor, causing the combustible gas explosion outside the motor.
Example: IP44 marking motor can prevent solid foreign matter larger than 1MM from entering and prevent water splashing.
The meaning of the first number after IP
0 No protection, no special protection.
1 It can prevent solid foreign matter with a diameter greater than 50MM from entering the housing, and it can prevent a large area of human body (such as hands) from accidentally contacting charged or moving parts in the housing, but it cannot prevent it from consciously approaching these parts.
2. It can prevent solid foreign matter with a diameter greater than 12MM from entering the casing, and prevent fingers from touching charged or moving parts in the casing.
3 It can prevent solid foreign matter with a diameter greater than 2.5MM from entering the casing, and prevent tools and metals with a thickness (or diameter) greater than 2.5 from contacting live or moving parts in the casing.
4. It can prevent solid foreign matter with a diameter greater than 1MM from entering the casing, and prevent tools and metals with a thickness (or diameter) greater than 1MM from contacting live or moving parts in the casing.
5 It can prevent dust from entering to the extent that it affects the normal operation of the product, and completely prevent contact with live or moving parts in the shell.
6 completely prevent dust from entering and contacting live or moving parts in the housing.
The meaning of the second number after IP
0 No protection, no special protection.
1 drip-proof, vertical drip should not directly enter the product.
2 15゜ is drip-proof, and the dripping water within an angle of 15 degrees from the vertical line should not directly enter the product.
3. Waterproof: Water mist within 60 degrees from the vertical line should not directly enter the product.
4. Anti-splash water, splashing water in any direction should not have adverse effects on the product.
5 water spray prevention, water spray in any direction should not have harmful effects on the product.
Violent waves or strong water spraying should not have harmful effects on the product.
7 anti-soaking, the product is soaked in water under the specified time and pressure, and the water inflow should have no adverse effects on the product.
8 diving, the product is soaked in water for a long time under the specified pressure, and the water inflow should have no harmful effect on the product.
8. According to the ventilation and cooling methods, it can be divided into
1. Self-cooling type: the motor is cooled only by surface radiation and natural airflow.
Self-fan cooling type: the motor is driven by its own fan, which provides cooling air to cool the surface or interior of the motor.
3. Other types of fan cooling: The fan supplying cooling air is not driven by the motor itself, but is driven independently.
2. Duct ventilation type: The cooling air is not directly introduced into the motor from the outside or directly discharged from the inside of the motor, but introduced into or discharged from the motor through the duct. The fan with duct ventilation can be self-fan-cooled or other fan-cooled.
5. Liquid cooling: the motor is cooled by liquid.
Closed-loop gas cooling: the medium cooling the motor circulates in a closed loop including the motor and the cooler, but the medium absorbs heat when passing through the motor and releases heat when passing through the cooler.
7. Surface cooling and internal cooling: the cooling medium does not pass through the inside of the motor conductor, which is called surface cooling, and the cooling medium passes through the inside of the motor conductor, which is called internal cooling.
9. According to the installation structure type:
The type of motor installation is usually indicated by a code. The code name is abbreviated as IM for international installation. The first letter in IM indicates the installation type code, B indicates horizontal installation, and V indicates vertical installation. The second digit represents the feature code and is represented by Arabic numerals.
For example, the IMB5 type indicates that the machine base has no base, the end cover has a large flange, and the shaft extends at the flange end.
The installation types are B3, BB3, B5, B35, BB5, BB35, V 1, V5, V6, etc.
10. According to the insulation grade, it is divided into A, E, B, F, H and C. The working temperature limit of YAEBBF HC with the same grade is 90105120130155/kloc-.
Continuous working system (SI): The motor can run for a long time under the rating specified on the nameplate.
Short-time working system (S2): The motor can only run for a short time in a limited time under the rating specified on the nameplate. There are four standards for short-term operation duration: 10 minutes, 30 minutes, 60 minutes and 90 minutes.
Intermittent working system (S3): The motor can only be used intermittently under the rating specified on the nameplate, expressed as a percentage of each cycle 10 minute. Such as: FC = 25%; Among them, S4-S 10 all belong to intermittent operation systems under several different working conditions. Y(IP44) series asynchronous motors
The motor has a capacity of 0.55 ~ 200 kW, class B insulation and protection grade IP44, reaching the standards of the International Electrotechnical Commission (IEC), and the products have reached the international level in the late 1970s. The weighted average efficiency of the whole series is 0.43% higher than that of JO2 series, and the annual output is about 20 million kilowatts.
Yx series high efficiency motors
Capacity 1.5 ~ 90kW, with 2, 4 and 6 poles. The average efficiency of all series motors is about 3% higher than that of Y(IP44) series, which is close to the international advanced level. It is suitable for one-way operation. When the annual working time is over 3000h h and the load rate is over 50%, the power saving effect is remarkable. The output of this series of motors is not high, and the annual output is about 1 10,000 kilowatts.
Pole-changing speed regulating motor
The main products are YD (90.45 ~ 160 kW), YDT (0. 17 ~ 160 kW), YDB (0.35 ~ 82 kW), YD (0.2 ~ 24 kW) and YFW (630) which have been mass-produced in China.
Electromagnetic slip speed regulating motor
China has mass-produced eight series of products, including YCT (0.55 ~ 90kW), YCT2 (15 ~ 250kW), YCTD (0.55 ~ 90kW), YCTE (5.5 ~ 630kW) and YCTJ (0.55 ~15k).