CN2108372U

CN2108372U - Current type protector for motor

Info

Publication number: CN2108372U
Application number: CN 91229240
Authority: CN
Inventors: 石崇满
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-11-22
Filing date: 1991-11-22
Publication date: 1992-06-24

Abstract

The utility model relates to a current type protector for motor which is used for the secondary protection of motors of various specifications in the fields of metallurgy, chemical industry, coal, water conservancy, food processing, etc. The device adopts three mutually separate electromagnetic coils to limit the increase of the operating current of the motor; when the operating current of the motor is over 0.5 times of rated current because of phase interruption, the clamping of towed machinery equipment, the plugging of the towed machinery equipment, the damage of bearings and other phenomena, the current type protector for motor can automatically cut off power supply and effectively protect the motor. The utility model has the advantages of complete function, simple circuit, high reliability and long service life. The utility model is suitable for various occasions as a secondary protector of motor.

Description

Current type protector for motor

The utility model is with the second protection device of contactor control alternating current motor, is widely used in fields such as metallurgy, chemical industry, coal, water conservancy, food processing, and the motor of all size is shielded.

General motor is to adopt full voltage starting, because the complex process of electromagnetic induction can cause very big starting current, is generally about seven times of rated current, and the transient process of starting current continues the 2-60 time of second, and motor just can change stable operation over to.Usually the motor second protection is to adopt thermal relay; and the operating characteristics of thermal relay is to surpass one times current setting; keep being failure to actuate in two hours; current setting above six times moved in 3 seconds; therefore; the current setting of thermal relay; generally adjust at more than 1.05 times of rated current of motor; motor start-up is got into smooth, but, damage of bearings occurs when motor during normal the use; and during other event of overload; when the operating current of motor surpassed 0.5 to 1 times of rated current, thermal relay just can not be cut off the electricity supply automatically, down to causing the overheated motor that burns out of winding.And other second protection device such as threephase asynchronous phase failure protector 85205451 have only single phase failure protection function.And for example the threephase asynchronous comprehensive protection device 89203095, and structure is more complicated also, and itself has ageing process electronic component, and the durability of use is not strong, and cost is also than higher.

The purpose of this utility model is exactly the shortcoming at above-mentioned thermal relay and other second protection dress, provides a kind of multiple functional; the simple device of circuit replaces thermal relay and other second protection device, is active in one's movements; safe and reliable, small investment, long service life.

The utility model is by shell, three electric current input terminals and three electric current outlet terminals, and current-limiting protection device is formed.When the operating current of motor surpass rated current more than 0.5 times the time, the electric current that the solenoid of current-limiting protection device flows through increases, the magnetic field that solenoid produces strengthens; inhale moving armature, make the protection contact disconnect the coil losing electricity of A.C. contactor; the contact disconnects, and effectively protects motor

Fig. 1 is circuit theory diagrams of the present utility model

Fig. 2 is a front view of the present utility model

Fig. 3 is that N of the present utility model is to cutaway view

Among Fig. 1, A, B, C are three-phase alternating-current supplies, and A ', B ', C ' are the electric current input contacts of three solenoids, and A ", B ", C " are the electric current output contacts of three solenoids.J ₁Be ac contactor coil, J _1-1, J _1-2, J _1-3, J _1-4Be contactor J ₁Normally opened contact, J _tBe time relay coil, K _tIt is relay J constantly _tNormally opened contact.L ₁, L ₂, L ₃Be three solenoids by the motor three-phase current, K ₁, K ₂, K ₃It is the protection contact of current mode motor protecting device.In Fig. 2 and Fig. 3, the moving contact short circuit plate, 21,22,23,24,25,26 that 1 insulation board, 2 armature, 3 fixed contacts, 4 moving contacts, 5 solenoids, 6 cylinder iron cores, 7 spring tensions always transfer bar, 8 total supports, 9 insulating pads, 10 armature spring hanging holes, 11,12,13,14,16,18 to be bolt, 15 bayonet sockets, 17 tension springs, 19 fixed contact short circuit plates, 20 Contraband shapes is fixed contact, the 27 tape insulation skin leads that are fixed on the insulation board.

The current mode motor protecting device as shown in Figure 3, and is in the cylinder iron core position of total support 8, fixing three identical cylinder iron core 6 usefulness bolts 12.The high strength enamelled wire that allows to pass through rated current on cylinder iron core 6, is made the identical solenoid L of three number of turns of real core ₁, L ₂, L ₃, three the real electromagnetic wire circle of independence L ₁, L ₂, L ₃ Movable armature 2 is arranged above; be installed on total support 8 by bayonet socket 15; on each armature 2; one and armature 2 insulation are arranged; become the short board 20 of Contraband shape; clamp with two insulation boards 9; be fixed on the armature 2 with bolt 16, be fixed with 4 of moving contacts on the two ends of Contraband shape short board 20, Contraband shape short board 20 does not have wiring; make armature 2 not be subjected to the influence of ambient temperature and wiring external force; flexibly movable, spring always transfers bar 7 to be installed on total support 8, works as axle and location with bolt 13; three performances; the tension spring 17 that length is identical; one end hangs on the spring hanging hole 10 of armature 2, and the other end hangs over spring and always transfers on the bar 7, and spring is always transferred between bar 7 and the total support 8 and cooperated with movable bolt 14; elasticity bolt 14 adjusts armature 2 and spring is always transferred the pulling force of the tension spring 17 between the bar 7, thereby determines the operating current of electric type motor protecting device.Insulation board 1 usefulness bolt 11 is fixed on total support 8; three pairs of fixed contacts 22 and 23 that are fixed on the insulation board; 24 and 25 usefulness short circuit plates, 19 short circuits; three pairs of moving contacts 4 that are fixed on the armature 2 contact with three pairs of fixed contacts 3 on being fixed on insulation board, are three couples protection contact K of current mode motor protection dress ₁, K ₂, K ₃Among Fig. 2 21 is connected with the lead 27 of tape insulation skin with F with G, 26, sees Fig. 1, the coil switch power of A.C. contactor, contactor J when pressing the startup knob ₁Contact J _1-1, J _1-2, J _1-3, J _1-4Closure, motor D starts, because starting current is very big, the protection contact K of current mode motor protecting device ₁, K ₂, K ₃Disconnect immediately, but time relay coil is in parallel with contactor coil, so time relay J _tAlso energized simultaneously of coil, make its normally opened contact K _tClosure, F, the G protection branch, short-circuit with the current mode motor protecting device makes motor finish start-up course, when motor D operating current drops to rated current, the protection contact K of current mode motor protecting device ₁, K ₂, K ₃Closure, motor D is in stable operating condition, time relay J _tNormally opened contact K _tDisconnect, the current mode motor protecting device begins to shield; When motor D the phase failure appears or the machinery equipment that drags occur stuck, stop up; When damage of bearings and other event of overload, motor D running operating current increases the solenoid L in passing through the current mode motor protecting device ₁, L ₂, L ₃Electric current surpasses rated current more than 0.5 times the time, solenoid L ₁, L ₂, L ₃ Top armature 2 will be by adhesive; three any one armature 2 above the solenoid are by adhesive; the capital makes short-circuit contact fixing above the armature 2 and the fixed contact that is fixed on the insulation board disconnect F, the G protection branch circuit break that makes the current mode motor protecting device, A.C. contactor J ₁Last coil losing electricity, its normally opened contact J _1-1, J _1-2, J _1-3, J _1-4Disconnect, realized cutting off the electricity supply automatically, protected motor.

By adjusting the number of turn of solenoid, tension spring coefficient, spring tension always transfer bar to finish the protection operating current of this protective device.

Current type protector for motor, have multiple functional, circuit simple, be active in one's movements, the advantages such as safe and reliable, small investment, saves energy.

Claims

1, a kind of current mode motor protecting device; by shell, three phase mains input and output terminals; current-limiting protection device is formed, and it is characterized in that said current-limiting protection device always transfers bar 7 to be formed by cylinder iron core 6, solenoid 5, armature 2, tension spring 17, spring tension.

2, as right 1 described armature 2, also have on it by two insulation boards 9, the moving contact 4 that Contraband shape moving contact short circuit plate 20 constitutes, it forms protection contact K with the fixed contact 21,22,23,24,25,26 on the insulation board 1 ₁, K ₂, K ₃

3, spring tension as claimed in claim 1 is always transferred bar also to be connected with and is finished the bolt 14 that cut-off current is adjusted.