CN2218409Y

CN2218409Y - Open-phase overload protector for three phase motor

Info

Publication number: CN2218409Y
Application number: CN 95230642
Authority: CN
Inventors: 刘宗和
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-03-26
Filing date: 1995-03-26
Publication date: 1996-01-24
Anticipated expiration: 2005-03-26

Abstract

The utility model relates to an open-phase overload protector for a three phase motor, comprising a spindle and a board hook on the spindle. An insulating plate is sheathed with the spindle, and hooks both sides of the board hook, via t-shaped claw hook posts on the insulating plate on the spindle; simultaneously, each of the T-shaped claw hook posts of the insulating plate respectively hooks the middle part of a spring; the middle part of a centrifugal rod is connected with the board hook; the two bent ends of the centrifugal rod are respectively inserted in the centre holes of two springs on the same side. The protector is connected with the alternating current contactor of the power supply of a motor in series; in the overload or the phase failure of the motor, the centrifugal rod on the protector is retracted to drive the insulating plate to push and shut a contact to cut off the power supply of the motor, in order to achieve the aim of protection. The utility model has the advantages of a low failure rate, high sensitivity, low cost, and a wide range of application.

Description

Three-phase alternating-current motor overload of loss of phase protector

The utility model discloses a kind of three-phase alternating-current motor overload of loss of phase protector.

Three-phase alternating-current motor overload of loss of phase protector generally adopts electronic control circuit in background technology; control the electric electromechanics source circuit according to the malfunction electric current; when the phase failure, overload, in time cut off motor power; make motor avoid burning out; its deficiency is the electronic control circuit complex structure; the element rapid wear, failure rate height, inconvenient maintenance.

The utility model purpose is to provide a kind of three-phase alternating-current motor overload of loss of phase protector that relies on motor rotation speed to control motor power.

The utility model purpose is achieved in that three-phase alternating-current motor overload of loss of phase protector is interconnected by axle, insulation board, spring and centrifugal bar and forms.Plate that has two eave tiles of edge cover colludes on the axle, the T type pawl post that two symmetries are arranged on the insulation board, two T type pawl post inboards are embraced plate and are colluded side, and a spring is respectively caught in the outside by the waist, the plate eave tile respectively catches on a centrifugal bar middle part, and centrifugal bar two bending ends are inserted in respectively in the two spring homonymy centre bores.

Below in conjunction with accompanying drawing the utility model is described in further detail:

Fig. 1 is the utility model structure diagram.

Fig. 2 is the vertical view of Fig. 1.

Fig. 3 is the motor power circuit schematic diagram.

Fig. 4 is the utility model control circuit schematic diagram.

Referring to Fig. 1, three-phase alternating-current motor outage overload protective device comprises an axle 1, is with the plate that rectangle, a upper and lower side is eave tile 8 on it and colludes 5.

Referring to Fig. 2, insulation board 2 is annular, has T type pawl post 6, two pawl posts 6 inboards of two symmetries to catch on plate on it and colludes 5 avris, and a fixing spring 3 is respectively caught in the outside by the waist.Centrifugal bar 4 middle parts are caught on by eave tile 8, and its two bendings end 7 is inserted in respectively in the spring 3 end centre bores, makes spring 3 bendings, two of centrifugal bar 4 symmetric arrangement.

During use, whole device is twisted by the centre bore on bolt and the motor output shaft by the centre bore on the axle 19 and is connect, or axle 1 is set on the motor shaft.Referring to Fig. 3, Fig. 4, connect in the contact of the A.C. contactor C on this device and the motor power circuit, and it draws contact arrangement in insulation board 2 plate face inboards, and is normally opened contact.When motor did not start, its normally opened contact disconnected, when actuating motor; press starting button QA, A.C. contactor C gets electric and self-locking, and motor rotates; centrifugal bar 4 on the protector is subjected to centrifugal action and outer opening at this moment; when it was subjected to centrifugal force greater than the elastic force of the spring 3 of case of bending, centrifugal bar 4 was a hinge with eave tile 8, and spring 3 is straightened; force insulation board 2 to move right by pawl post 6; promotion normally opened contact closure is decontroled button QA, and motor should run well.In case motor overload; or the phase failure; motor speed can descend; when centrifugal bar 4 suffered centrifugal force during less than the elastic force of its suffered spring 3, insulation board 2 is moved to the left, and the normally opened contact of original closure is opened; A.C. contactor C outage; cut off motor power circuit, in time avoided burn-down of electric motor, reached the purpose of protection motor.

The utility model advantage and good effect are; 1, is subjected to centrifugal masterpiece according to rotating object With principle, be designed to centrifugal mechanical structural defence device, reasonable in design, compactness, zero Parts are few, not only reduced fault rate, and cost is low, for ease of maintenaince. 2, protector peace Be contained on the motor output shaft, can be equipped with on the motor in use, but also can be at motor Just mix protective device when dispatching from the factory, be conducive to this protector and apply. 3, this protector and The number of poles of motor is relevant, as required can be on centrifugal bar counterweight, adapting to the motor speed needs, Centrifugal bar is active in one's movements, so can reduce the protector specification, makes the protector scope of application wider.

Claims

A kind of three-phase alternating-current motor overload of loss of phase protector; it is characterized in that it is interconnected by axle (1), insulation board (2), spring (3) and centrifugal bar (4) forms; axle (1) goes up plate that has two eave tiles (8) of edge cover and colludes (5); the T type pawl post (6) that two symmetries are arranged on the insulation board (2); the inboard holding board of two T type pawl posts (6) colludes (5) side; a spring (3) is respectively caught in the outside by the waist; plate eave tile (8) respectively catches on a centrifugal bar (4) middle part, and the last two bending ends (7) of centrifugal bar (4) are inserted in respectively in two springs (3) the homonymy centre bore.