CN88210053U - Large capacity centrifugal switch - Google Patents

Abstract

The utility model discloses a large capacity centrifugal switch, which relies the centrifugal force to start and reset in the rotating state; the capacity of the contact can communicate or cut off the electric current 500 amp hereafter under the alternating current-direct current voltage of 380 volt; the designed rotation speed of the given operation is guaranteed, and the capacity of the contact can also have the appropriate adjustment to the operation rotation speed within a small range, simultaneous ensuring the working thermal stability and the arc extinguishing performance, reducing the power loss and accidents to ensure the safety.

Description

Large capacity centrifugal switch

The utility model relates to appliance switch, specifically a kind of centrifugal switch.

At present, the centrifugal switch that adopts on the motor is to be installed in series on the starting winding in machine, by centrifugal force make the starting winding closed with turn-off.This kind switch is because its physical dimension is too little and electrical quantity can only be limited in the squirrel-cage asynchronous motor and uses, and its rated voltage is 220 volts, and electric current is below 10 amperes, 370 watts of rated power.This centrifugal switch be physical dimension and electrical quantity all can not to satisfy voltage be 380 volts, electric current is more than 100 amperes, power needs at the big capacity wound rotor asynchronous motor more than 35 kilowatts.After electric motor starting is over, so both inconvenient, dangerous again by manually using manual manipulation rotor loop short circuit in machine, also can bring unnecessary trouble.

The purpose of this utility model provides a kind of can depressing 380 volts alterating and direct current, switches on or off the electric current below 500 amperes, and can be contained on the slewing, by centrifugal force starting with reset that it is often opened or the big capacity centrifugal switch of normally closed interlock.

The utility model is grouped into by contact mechanism, transmission mechanism, fixed underpan and trimming part.Contact mechanism comprises dynamic and static contact, the spring of moving, return spring.Hold-down support.Fixed contact is fixed under the bearing loam cake, with moving contact at a distance of the 6-8 millimeter, moving contact when the drive link in the transmission mechanism is moved spring, thereby moves moving contact by the spring supporting of moving, and makes, contact closure, finishes the connection task.Transmission mechanism comprises centrifugal, towing bracket, cross-tie, drive link.Centrifugal links to each other with towing bracket, and towing bracket links to each other with cross-tie.Cross-tie links to each other with drive link again.Fixed disk comprises chassis and slide block, and centrifugal is slided in slideway.The trimming part branch comprises the fine setting spring and adjusts spring, adjusts rated speed among a small circle.

Starting of the present utility model and to return be function decision by the size of centrifugal force and spring, irrelevant with the length of motor starting process time, only reach the given starting speed of centrifugal switch, switch could start, just can reset during less than the re-entry speed of centrifugal switch, can guarantee that rotating speed of motor reaches after the set-point, just the starting equipment short circuit with rotor loop gets rid of, can be because of the operation short-circuited conducting sleeve yet cause various accidents accidentally.Because centrifugal switch when the electric motor rotation resistant square increases back reduction of speed or stall, can automatically insert rotor loop to starting equipment, thereby can significantly reduce the rotor current of motor, can reduce the generation of burn-out motor accident again.Because after the centrifugal switch action, on the spindle nose of rotor,, stopped rotor current in cable and the power loss in power supply and the A.C. contactor directly the rotor loop short circuit.

Concrete structure of the present utility model is provided by following embodiment and accompanying drawing thereof.In the accompanying drawing: fixed contact 1, the spring 2 of moving, moving contact 3, return spring 4, drive link 5, towing bracket 6, transverse link 7, chassis 8, centrifugal 9, slideway 10, rotating speed is adjusted spring 11.

The example commonly used of this programme is that centrifugal switch is contained on the spindle nose of wound type asynchronous motor slip ring end, and three lead-in wires of rotor are connected on after the normally open contact of switch, connects the starting equipment (frequency sensitive resistor or start resistor) to motor again.Before wound motor was finished the starting task, contact was in open-circuit condition, and rotor current has only through starting equipment could constitute path.After waiting to finish the starting task, moving contact has been connected fixed contact under the driving of centrifugal force after, with make rotor current on the spindle nose of motor by direct short-circuit.Like this, motor just can move under the NATURAL MECHANICAL PROPERTIES state.

When the motor of operation cut off the power supply stoppage in transit or remarkable reduction of speed, the moving contact of UNICOM's fixed contact can deflect from the disappearance or the minimizing of mental and physical efforts again, after automatically reseting starting equipment is inserted automatically the rotor loop of motor.For the starting once more of motor or under the slow-speed of revolution, produce the bigger electromagnetic torque condition of having put forward merit.

This switch in use, the rotation rotating speed that needs given artificially action and return only in servicely need not manual operation.

Accompanying drawing is a supporting embodiment of this switch and wound rotor asynchronous motor.Needs according to construction of switch size (thickness), after the spindle nose lengthening with wound rotor asynchronous motor slip ring end, the centrifugal switch that is matched with the diameter of axle in the center chassis hole is sleeved on the spindle nose of motor sliding ring end again, and then three lead-out wires of rotor are connected on three fixed contacts of this switch, after treating that motor rotates, this switch can move by centrifugal traction moving contact by the given rotating speed of design, has been switched on or switched off fixed contact.Before arbor did not rotate, the fixed contact of switch was in the position of disconnection as shown in drawings.When motor shaft was begun rotation by static state after, centrifugal with certain mass will be moved to abaxial direction along slideway.Therefore, all will be pulled to the abaxial direction moving linearly of slide block when centrifugal joining towing bracket, drive link, transverse link.Meanwhile, move spring, return spring and rotating speed adjusted spring and all is compressed because of stressed.When the rotating speed of arbor increased to the given rotating speed of switch, two springs of moving were compressed to collinear critical localisation by the pulling force of transverse link just.After this,, increase under the action of centrifugal force little as long as the rotating speed of arbor has an increment slightly, centrifugal and will arrive at final make position apace with the member of its interlock, thus finished the task of connecting fixed contact.

After the running speed of arbor is reduced to the re-entry speed of switch, because the reducing of centrifugal force, moving contact will be adjusted under the effect of natural expansion force of spring at return spring and rotating speed, and the dynamic and static contact of switch is disconnected rapidly.

This switch is adjusted when moving rotating speed significantly, needs to change centrifugal and return spring, interior among a small circle the adjustment when moving rotating speed, and adjustable rotational speed is adjusted spring.Can adopt the contact of button vacuum bubbles to the bigger centrifugal switch of capacity.

Claims (2)

1, a kind of big capacity centrifugal switch, it is characterized in that being grouped into by contact mechanism, transmission mechanism, fixed underpan and trimming part, contact mechanism comprises moving contact, fixed contact, the spring of moving, return spring and hold-down support, fixed contact is fixed under the bearing loam cake and moving contact at a distance of the 6-8 millimeter, moving contact is by the spring supporting of moving; Transmission mechanism comprises that centrifugal, towing bracket, cross-tie, drive link, drive link link to each other with towing bracket, and towing bracket links to each other with cross-tie, and cross-tie links to each other with drive link again; Fixed disk comprise chassis and slide block, centrifugal in slideway, slide.

2, centrifugal switch according to claim 1 is characterized in that can adopting the contact of detaining vacuum bubbles to the bigger centrifugal switch of capacity.