CN2588639Y - Fully automatic protector with double-centrifugal switch for electric motor - Google Patents

Abstract

The utility model provides a fully automatic protector with a double-centrifugal switch for an electric motor, which mainly comprises a main winding, a starting capacitor which is connected with a secondary winding, a running capacitor, and a normally closed front centrifugal switch. The utility model is characterized in that a relay is arranged in a protective box; a rotor shaft is provided with a normally open centrifugal switch which is mechanically controlled by a rear centrifuge; a normally closed thermal sensitive switch and a normally open centrifugal switch which are arranged in a machine casing are connected in series to a control line of a relay coil. In the utility model, the normally closed thermal sensitive switch which is controlled by temperature and the normally open centrifugal switch which is controlled by the rear centrifuge are connected in series to the control line of the relay coil, and the main power source of the motor is controlled by the normally open contact of the relay, forming duplicate protection, so the utility model has the advantages of simple structure, low cost, safe operation, and strong protection function.

Description

Two centrifugal switch motor full-automatic protection devices

Technical field:

The utility model relates to a kind of full-automatic protection device with motor and protective device thereof, particularly a kind of single-phase motor of full-automatic defencive function, specifically a kind of pair of centrifugal switch motor full-automatic protection device.

Background technology:

In general: alternating current motor can be divided into threephase asynchronous and monopole asynchronous motor two big classes, threephase asynchronous need use three-phase alternating-current supply to work, has significant limitation in the use, and monopole asynchronous motor can directly be worked on single phase alternating current power supply, therefore, monopole asynchronous motor uses very extensive in industries such as agricultural machinery product and household appliances, particularly serve various types of agricultural machinery products of vast rural area, almost all being to use monopole asynchronous motor is that engine comes work, existing monopole asynchronous motor mainly is made of with the auxiliary winding that is installed on rotor the main winding that is installed in the casing, on auxiliary winding, be equipped with starting capacitance, running electric capacity, the centrifugal switch that is installed on the armature spindle is serially connected with on the starting capacitance circuit, after the normal startup of monopole asynchronous motor, motor speed reaches 80% o'clock of rated value, the sedimentator that is installed on the armature spindle disconnects centrifugal switch under action of centrifugal force, throw off the starting capacitance circuit and enter normal operating conditions, but the monopole asynchronous motor that uses exists the low critical defect of anti-overload ability at present, particularly under the general on the low side and unsettled actual conditions of vast rural cities and towns area power grid voltage, monopole asynchronous motor usually takes place in running owing to brownout causes the too high accident that burns out equipment of temperature rise, also usually take place because the phenomenon of stall appears in excess load, when speed drop to 80% when following of rated value, centrifugal switch can insert the starting capacitance circuit by auto-closing, cause electric current sharply to increase, cause the accident that punctures capacitance short-circuit scaling loss equipment, have a strong impact on the normal useful life of monopole asynchronous motor, cause great economic loss.Though also released some single-phase motors technical scheme of protection automatically at present; but adopt comparatively complicated controllable silicon electronic switching circuit technology mostly; because the manufacturing cost height, the user is difficult to accept, and is difficult on the lower monopole asynchronous motor of price own and promotes the use of.

Summary of the invention:

The utility model be propose on the basis of existing technology a kind of simple in structure; safe and reliable to operation; long service life; manufacturing cost is cheap; have under-voltage; two centrifugal switch motor full-automatic protection devices of kinds of protect functions such as overload stall; it mainly comprises the main winding that is installed in the casing; be installed on the auxiliary winding and the starting capacitance that is connected in auxiliary winding of armature spindle; running electric capacity; preceding sedimentator is installed on armature spindle; the normally closed centrifugal switch equipped in the position that adapts with preceding sedimentator is serially connected with on the branched line of starting capacitance; it is characterized in that: be fixedly installed on the protection box body of casing and be equipped with normally open push button switch; device has relay in the protection box body; the normally open contact access main power circuit of relay is directly controlled motor to be got electric or dead electricity; the back sedimentator is installed on armature spindle; be connected in parallel in normally open push button switch with the equipped centrifugal switch of often opening in the position that adapts of sedimentator, back, what be installed on the normally closed thermoswitch in the casing and become parallel connection often drives centrifugal switch; normally open push button switch is serially connected with on the control circuit of relay coil.When motor brownout occurs and causes temperature rise too high in running, normally closed thermoswitch is heated and disconnects, the relay coil dead electricity, relay normally open contact disconnects the power supply of timely cut-out motor thereupon, motor is effectively protected, because normally closed thermoswitch is to be serially connected with on the control circuit of relay coil, the electric current that passes through is very little, and normally closed thermoswitch contact is not easy-sintering damage in the course of the work; When the motor overload operation stall occurs rotating speed is sharply descended, back sedimentator reduces because of rotating speed, centrifugal force sharply descends the centrifugal switch of often opening on the control circuit that is serially connected with relay coil is disconnected rapidly, at this moment relay coil dead electricity, relay normally open contact disconnects the power supply of timely cut-out motor thereupon, can prevent from effectively the accident that stall causes temperature rising scaling loss motor to occur because of overload operation.The utility model adopts by the normally closed thermoswitch of temperature control and often opening on the control circuit that centrifugal switch is serially connected with relay coil by back sedimentator machinery control; main power source by the normally open contact of relay control motor forms duplicate protection again, has advantage safe and reliable to operation, that defencive function is strong.

Description of drawings:

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is an electrical schematic diagram of the present utility model.

Embodiment:

The two centrifugal switch motor full-automatic protection devices that the utility model proposes, it mainly comprises the main winding 7 that is installed in the casing 1, be installed on the auxiliary winding 8 and the starting capacitance C1 that is connected in auxiliary winding 8 of armature spindle 6, running capacitor C 2, casing 1 has been done wiring hole 4 and binding post 3, sedimentator 5 before on armature spindle 6, being equipped with, the normally closed centrifugal switch K3 equipped in the position that adapts with preceding sedimentator 5 is serially connected with on the branched line of starting capacitance C1, be fixedly installed on the protection box body 2 of casing 1 and be equipped with normally open push button switch K1, done entrance hole 10 on the protection box body 2, device has relay J in the protection box body 2, the normally open contact access main power circuit of relay J is directly controlled motor and is got electric or dead electricity, back sedimentator 9 is installed on armature spindle 6, be connected in parallel in normally open push button switch K1 with the equipped centrifugal switch K2 that often opens in the position that adapts of sedimentator 9, back, what be installed on the normally closed thermoswitch Q in the casing 1 and become parallel connection often opens centrifugal switch K2, normally open push button switch K1 is serially connected with on the control circuit of relay J coil, it is work like this: during actuating motor, press normally open push button switch K1, the coil of relay J gets, insert the normally open contact closure of main power circuit, the normal startup of motor enters operating state, at this moment normally closed thermoswitch Q and the centrifugal switch K2 that often opens that is controlled by back sedimentator 9 machineries all are in closure state, the coil of relay J all the time the electric main circuit that makes is in closure state, even unclamp normally open push button switch K1, motor also is in normal operating conditions, when motor brownout occurs and causes temperature rise too high in running, being installed on normally closed thermoswitch Q in the casing 1 is heated and disconnects, the coil losing electricity of relay J, the normally open contact that inserts the relay J of main power circuit disconnects the power supply of timely cut-out motor thereupon, can prevent to cause temperature rising scaling loss motor because of brownout, temperature in casing 1 is reduced under the normal condition, when normally closed thermoswitch Q returns to closure state, also must press normally open push button switch K1 once more and just can restart motor; If the temperature in the casing 1 does not reduce, normally closed thermoswitch Q is under the off-state all the time, even press normally open push button switch K1 once more by mistake, motor can not start, have and well protect effect automatically, because normally closed thermoswitch Q is serially connected with on the control circuit of relay J coil, the electric current that passes through on the contact of normally closed thermoswitch Q is very little, and the contact of normally closed thermoswitch Q not easy-sintering is damaged, and can prolong its working life effectively; When stall appears in the motor overload operation, when rotating speed sharply descends, even inserting under the situation of starting capacitance C1 circuit with the equipped normally closed centrifugal switch K3 auto-closing of preceding sedimentator 5, back sedimentator 9 also can reduce because of rotating speed, centrifugal force sharply descends the centrifugal switch K2 that often opens on the control circuit that is serially connected with the relay J coil is disconnected rapidly, at this moment relay coil J dead electricity, the normally open contact that inserts the relay J of main power circuit disconnects the power supply of timely cut-out motor thereupon, can prevent from effectively the accident that stall causes temperature rising scaling loss motor to occur because of overload operation.

Claims (1)

1. two centrifugal switch motor full-automatic protection device; it mainly comprises the main winding (7) that is installed in the casing (1); be installed on the auxiliary winding (8) of armature spindle (6) and be connected in the starting capacitance (C1) of auxiliary winding (8); running electric capacity (C2); preceding sedimentator (5) is installed on armature spindle (6); the normally closed centrifugal switch (K3) equipped in the position that adapts with preceding sedimentator (5) is serially connected with on the branched line of starting capacitance (C1); it is characterized in that: be fixedly installed on the protection box body (2) of casing (1) and be equipped with normally open push button switch (K1); device has relay (J) in the protection box body (2); back sedimentator (9) is installed on armature spindle (6); be connected in parallel in normally open push button switch (K1) with the equipped centrifugal switch (K2) of often opening in the position that adapts of back sedimentator (9), what be installed on the normally closed thermoswitch (Q) in the casing (1) and become parallel connection often drives centrifugal switch (K2); normally open push button switch (K1) is serially connected with on the control circuit of relay (J) coil.

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