2014年9月28日星期日

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.

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