The structure of three phase asynchronous motor

A,the classification of the three-phase asynchronous motor:Classification:according to the rotor structure Category:squirrel-cage motor and wound rotor motor According to the protection type Categories:open (IP11),protected (IP22 and IP23),closed (IP44),explosion-proof According to the ventilation cooling way Categories:self-cooled,since fan cooled,he fan cooled,pipes,ventilated According to ac synchronous motor the installation structure Categories:horizontal,vertical foot,flange According to the grades of insulation Category:E,B,F,H, According to the work quota Category:continuous,intermittent,intermittent Description:Open (IP11) :cheaper price,the best cooling conditions,due to the rotor windings and exposed to air,can only be used for dry,little dust and no corrosive and explosive gas environment.Protected (IP22 and IP23) :ventilation cooling condition is good,also can prevent the water droplets and iron filings,sundry fall into motor internal,applies only to a few dry and dust and no corrosive and explosive gas environment.Enclosed (IP44) :suitable for damp,dusty,vulnerable to wind and rain erosion,corrosive gases,such as the poor working rotor and stator environment,the most common applications.

Second,the structure of the three-phase asynchronous motor (a) of the stator (static) 1,the stator core Part of motor magnetic circuit,and placed on the stator winding.Structure:the stator iron core by 0.35 ~ 0.5 mm thick surface is commonly insulating layer of silicon steel sheet coining,overlying and become,within the core of the circle has a uniform distribution trough,which embedded in the stator winding.Trough the stator core has the following kinds:Semi-closed type slot:frequency conversion motor efficiency and power factor is higher,but the winding wire and insulation are more difficult.Commonly used in low-voltage motor.Half-open mouth slot:can put molding winding embedded,commonly used in large and medium-sized low-voltage motors.The so-called forming the windings can be treated with insulation in advance and then into the slot.Open rack slot:to put molding winding embedded,insulation method is convenient,mainly used in high voltage motor.2,the stator winding Access is the circuit part of the motor,three-phase alternating current (ac),to produce a rotating magnetic field.Structure:by the three in the space between 120 ° Angle,said arrangement can be connected with the same structure of the winding,the winding of the coil respectively according to certain rule embedded in the stator slot.The main of the stator winding insulation project has the following three:(guarantee between the conductive part of the winding and iron core and reliable insulation and reliable insulation between the winding itself) (1) of insulation:overall between the stator core and stator winding insulation.(2) and white insulation:insulation between each phase of the stator winding.(3) the turn-to-turn insulation:each phase of the stator winding turn-to-turn insulation each wire.

Motor vibration

Motor through a transmission mechanism is connected to a machine.motor vibration can ac electric motor result in mechanical vibration.mechanical vibration also can make the motor vibration.motor and mechanical transmission part release to start the motor.if eliminate vibration is a mechanical failure.or is the motor vibration.vibration reasons:the diesel generator motor seat is not firm.mechanical part of the motor and the driven generator rotor and stator shaft are different.the motor rotor imbalance.motor shaft bending.belt wheel spindle eccentricity.squirrel cage several breaks.bearing damage.unbalanced electromagnetic system.www.dongfeng-motor.com electric JiSao chamber.

The classification of the electromagnetic interference source (disturbance)

Electromagnetic interference,there are many kinds of classification methods,for example,according to the route of transmission,can be divided into the conducted interference and the radiated interference,the conducted interference transmission properties of the electric coupling,magnetic coupling and electromagnetic coupling;According to the transmission properties of radiated interference,can be divided into the near-zone induction coupling and far ground radiation coupling;According to 12v motor the band,can be divided into narrowband and broadband:According to the interference frequency range,and can be subdivided into five kinds of l (table 1);According to the subjective intention of implementation of the intruder,can be divided into intentional interference and has no intention of interference;According to the nature of the interference sources,can be divided into natural interference and man-made interference (figure l - 1),etc.Mainly discuss under the natural disturbance (disturbance) and human disturbance (harassment).1.Natural disturbance.Natural electromagnetic interference sources exist in the earth and the universe,the natural electromagnetic phenomenon produces electromagnetic noise.

The electromagnetic noise generated by the nature of the electromagnetic phenomenon,typically include:(1) atmospheric noise,such as lightning;(2) the sun noise,sunspot activity during geomagnetic storm;(3) NingZhou noise,from the Milky Way;(4) electrostatic discharge (ESI)).2.Human disturbance.Human disturbance from intends to launch interference sources and has no intention of interference sources.Intends to launch the interference source is dedicated to radiate electromagnetic energy equipment,for example,radio,television,communications,radar,navigation,such as transmitting equipment,is a space launch to useful signal of electromagnetic energy to work,they don't require these signals to the electronic system or equipment will form functional disturbance,and is an important single phase induction motor pollution source of electromagnetic environment.There are many devices are unconsciously emission electromagnetic energy,for example,automobile ignition system,different kinds of power device and the device of the motor,lighting,strobe lights advertising,high voltage power line,industrial,scientific and medical didn't prepared,and the receiver local oscillation are unconsciously electromagnetic energy emitted radiation,etc.The launch could be to space radiation,can also be along the conductor conducted emission,electromagnetic energy is emitted by random or regular,generally has a very wide band or discrete spectrum,the power can be emitted from leather tile to mw order of magnitude.

Any electrical and electronic equipment could cause artificial harassment,list some prone to harassment of the equipment.(1) household appliances and and civilian equipment:(1) contact electrical appliances,such as refrigerators,electric iron,electromagnetic switch,relay,etc.(2) use the commutator motor equipment such as electric drill,vacuum cleaners,electric mixer,dental medical equipment,etc.(3) household electric power semiconductor devices,such as silicon rectifier dimmers,switching power supply,etc.(2) the high frequency equipment:(1) high frequency equipment used in industry,such as plastic welder,high frequency welding machine,high frequency heater,etc.(2) high frequency medical equipment,such as VHF and uhf physical therapy device,high frequency knife,electric measuring instrument,etc.

(3) power equipment:(1) power 6v electric motor transmission equipment,such as pay (straight) flow servo motor,stepping motor,solenoid valve,contactor,etc.(2) converter device of power electronic devices,such as controllable rectifier,inverter,inverter,ac voltage regulator,UPs power supply,etc.(3) power transmission equipment,such as high voltage power transmission lines,high voltage circuit breaker,transformer,etc.(4) electrified railway,such as electric locomotive,catenary,etc.(4) the internal combustion engine,including the ignition system,generator,voltage regulator,brush,etc.(5) the radio transmitting and electricalmotor1.blogspot.com receiving devices,including mobile communication system,radio,television,radar,navigation equipment,etc.(6) high speed digital circuit equipment:including computer and related equipment.Various interference

sources may be periodic,its frequency range can be from 0 Hz to tens of thousands of Hector,a few MHZ or even several GHZ or higher.The jamming signal may also is cyclical or pulse form.Energy can also be very weak or megawatt.