CN209981104U - Three-phase protector and electrical equipment - Google Patents

Abstract

Three-phase protector and electrical equipment. The three-phase protector includes: the first static terminal is provided with a first static contact and the second static terminal is provided with a second static contact; the movable arm is provided with a free end and a fixed end, the free end is provided with a first movable contact and a second movable contact, the first fixed contact and the first movable contact form a first pair of electric contacts, and the second fixed contact and the second movable contact form a second pair of electric contacts; a disk configured to actuate the movable arm when a temperature exceeds a predetermined value; and a housing for accommodating the first and second stationary terminals, the movable arm, and the disc, wherein the three-phase protector further includes an arc isolating portion provided between the first and second pairs of electrical contacts, the arc isolating portion being configured to isolate an arc generated by the first pair of electrical contacts from an arc generated by the second pair of electrical contacts. An electrical apparatus includes the three-phase protector. The disclosed three-phase protector realizes a long life with a simple structure.

Description

Three-phase protector and electrical equipment

Technical Field

The utility model relates to a three-phase protector and electrical equipment, electrical equipment includes this three-phase protector.

Background

The protector is a protector for connecting or disconnecting a circuit connection by deformation and/or inversion of a disk when a predetermined temperature is exceeded.

Three-phase protectors are often used in various conventional electrical apparatuses (e.g., motors) using alternating current. Three-phase protectors generally have two pairs of electrical contacts, which are deformed and/or flipped to open the two pairs of electrical contacts when the current and/or temperature of the electrical apparatus exceeds a predetermined value, thus protecting the electrical apparatus.

The existing small three-phase protector (such as a three-phase protector bound on a motor winding) is very easy to burn out in a short time (such as hundreds of cycles), so that the service life is short.

SUMMERY OF THE UTILITY MODEL

To address the above-described deficiencies in the prior art, it is an object of the present invention to provide an improved three-phase protector with a simple structure for achieving a long service life.

In one aspect, the utility model provides a three-phase protector, three-phase protector includes: the first static terminal is provided with a first static contact, and the second static terminal is provided with a second static contact; the movable arm is provided with a free end and a fixed end, the free end is provided with a first movable contact and a second movable contact, the first fixed contact and the first movable contact form a first pair of electric contacts, and the second fixed contact and the second movable contact form a second pair of electric contacts; a disc configured to actuate the movable arm when a temperature exceeds a predetermined value; and a housing for accommodating the first stationary terminal, the second stationary terminal, the movable arm, and the disc, wherein the three-phase protector further includes an arc isolation portion provided between the first pair of electrical contacts and the second pair of electrical contacts, the arc isolation portion being configured to isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other.

In some configurations, the three-phase protector further includes a first wire, a second wire, and a third wire, the first and second wires electrically connected to the first and second stationary terminals, respectively, and the third wire electrically connected to the movable arm.

In some configurations, the arc isolation is an insulating barrier.

In some configurations, the insulating partition is molded as one piece with the housing, the insulating partition extending vertically upward within the housing from a bottom wall of the housing by a height that is greater than or equal to a height of the two pairs of electrical contacts.

In some configurations, the insulating partition extends vertically upward within the enclosure from a bottom wall of the enclosure to a top wall of the enclosure.

In some constructions, the housing and the arc chute are both made of plastic.

In some constructions, the plastic is a polyphenylene sulfide plastic.

In another aspect, the present disclosure provides an electrical device comprising the above-described three-phase protector.

With the above-described structure, the three-phase protector of the present disclosure achieves a high service life with the simplest structure.

Drawings

The various objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention, taken in conjunction with the accompanying drawings. The drawings are merely exemplary of the invention and are not necessarily drawn to scale. In the drawings, like reference characters designate the same or similar parts throughout the different views.

Fig. 1 is a schematic diagram showing an internal structure of a three-phase protector according to the present disclosure;

fig. 2 is a schematic top view of a three-phase protector according to the present disclosure, with a portion of the upper surface of the housing omitted to more clearly show the internal structure; and

fig. 3 is a sectional view taken along line a-a of fig. 2.

Detailed Description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred embodiments of the disclosure are shown. It should be understood, however, that the present disclosure can be embodied in many different forms and is not limited to the embodiments described below; rather, the embodiments described below are intended to provide a more complete disclosure of the present disclosure, and to fully convey the scope of the disclosure to those skilled in the art. It is also to be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

It should be understood that like reference numerals refer to like elements throughout the several views. In the drawings, the size of some of the features may be varied for clarity.

Unless otherwise defined, terms (including technical and scientific terms) used herein shall have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains. Unless otherwise indicated, the terms "comprising" and "including" as used in the specification and claims should be interpreted in an open-ended fashion, that is, the terms "comprising" and "including" should be interpreted as being synonymous with the terms "including at least" or "including at least".

As used herein, unless otherwise noted, the terms "upper", "lower", "top", "bottom", "left", "right", and the like, are relative orientations of the protector in the state shown in fig. 1-3.

The term "disc" as used in the present invention refers to a heat sensitive element that is capable of deforming and/or flipping when the temperature exceeds a predetermined value.

It is to be understood that the terminology used in the description is for the purpose of describing particular embodiments only, and is not intended to be limiting of the disclosure. Well-known functions or constructions may not be described in detail for brevity and/or clarity.

To the above-mentioned defect among the prior art, the utility model provides a three-phase protector. Referring to fig. 1-3, one embodiment of a three-phase protector 100 according to the present disclosure is shown.

As shown in fig. 1, a three-phase protector 100 according to the present disclosure includes a first stationary terminal 1 and a second stationary terminal 2. The first stationary terminal 1 and the second stationary terminal 2 are provided with a first stationary contact and a second stationary contact, respectively (not shown in the figure).

As shown in fig. 1, the three-phase protector 100 according to the present disclosure further includes a movable arm 3. The movable arm 3 has a fixed end and a free end. The free end of the movable arm 3 is provided with a first movable contact 31 and a second movable contact 32. The first movable contact forms a first pair of electrical contacts with the first stationary contact, and the second movable contact forms a second pair of electrical contacts with the second stationary contact. In one example, the fixed end is a common end and the free end is a bifurcated structure. The bifurcation structure may be a U-shaped bifurcation structure, a V-shaped bifurcation structure, or other form of bifurcation structure. The first and second movable contacts 31 and 32 are provided on the two prongs, respectively.

As shown in fig. 1, the three-phase protector 100 according to the present disclosure further includes a first wire 41, a second wire 42, and a third wire 43. The first and second wires 41 and 42 are electrically connected to the first and second fixed terminals 1 and 2, respectively, and the third wire 43 is electrically connected to the movable arm 3.

The three-phase protector 100 according to the present disclosure further includes a disc (not shown). The disc is a heat sensitive element. A disc may be provided under the movable arm 3 (for example for a normally closed three-phase protector). A disc may also be provided on the movable arm 3 (for example for a normally open three-phase protector). When the temperature exceeds a predetermined value, the disc deforms and/or flips, exerting a force on the movable arm 3, causing the movable arm 3 to act, opening the two pairs of electrical contacts (for example for a normally closed three-phase protector) or closing the two pairs of electrical contacts (for example for a normally open three-phase protector). In one example, the disc may be a bimetal. A "bimetal" is a metal element obtained by combining two or more layers of alloys having different thermal expansion coefficients, which is deformed by heat generation when a temperature exceeds a predetermined value.

As shown in fig. 2 to 3, the three-phase protector 100 according to the present disclosure further includes a housing 5. The housing is used for accommodating the first fixed terminal 1, the second fixed terminal 2, the movable arm 3 and the disc. The housing 5 may be made of any suitable material, such as plastic, metal or the like. The plastic is Preferably Polyphenylene Sulfide (PPS) plastic or similar material. Polyphenylene Sulfide (PPS) has excellent high temperature resistance, corrosion resistance, and insulating properties. In the case of adopting the plastic shell, compared with the metal shell, the insulating sleeve does not need to be arranged outside the shell, so that the parts are reduced, and the rapid transmission of the temperature is facilitated.

Fig. 2 is a schematic top view of a three-phase protector according to the present disclosure, with a portion of the upper surface of the housing omitted to more clearly show the internal structure. Fig. 3 is a sectional view taken along line a-a of fig. 2.

As shown in fig. 2 and 3, the three-phase protector 100 may further include an arc isolation portion 10. The arc isolation is disposed between the first pair of electrical contacts and the second pair of electrical contacts. The arc isolation 10 is configured to isolate an arc generated between the first pair of electrical contacts and an arc generated between the second pair of electrical contacts from each other. The arc barrier 10 may be made of any insulating material capable of isolating an arc. For example, the arc chute 10 may be made of PPS plastic or similar material.

In one example, the arc chute 10 may be an insulating barrier, as shown in fig. 2 and 3. Although the example in the drawings illustrates one embodiment of the arc isolation part in the form of an insulating barrier, it may be appreciated by those skilled in the art that the arc isolation part may not be limited to an insulating barrier as long as it can isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other. For example, the arc isolation part may be an arc isolation cover, an arc isolation sleeve, or the like.

In a preferred embodiment, the insulating spacer is formed in one piece with the housing 5, for example by moulding. The insulating barrier can be of the same material as the plastic housing 1 (e.g. polyphenylene sulfide (PPS) plastic). An insulating partition is provided within the housing 1 between the two pairs of electrical contacts and extends vertically upwards from the bottom wall of the housing 1 to a certain height. The height is greater than or equal to the height of the two pairs of electrical contacts. In one example, the insulating partition extends from the bottom wall of the housing 1 up to the top wall of the housing 1. The length of the insulating spacer in the length direction is sufficiently long to isolate an arc generated between the first pair of electrical contacts from an arc generated between the second pair of electrical contacts. For example, the length of the insulating spacer in the length direction exceeds the extent of the area in which the two pairs of electrical contacts are located.

Although some embodiments of the insulating spacer have been exemplified above, it will be appreciated by those skilled in the art that the number, shape, arrangement, etc. of the insulating spacers are not limited as long as they can isolate the arc generated by the first pair of electrical contacts from the arc generated by the second pair of electrical contacts. For example, the insulating spacer may also be a separate component or molded integrally with the other components.

In the current small-size three-phase protector that can bind on motor winding, because three-phase protector's space is limited, can't set up parts such as arc control device among the large-scale circuit breaker, consequently current small-size three-phase protector is often burnt out easily, therefore life is lower. The applicant of the present disclosure has found that the fundamental reason that small three-phase protectors are often easily burnt is that, due to the small size of the product, the contacts are very close to each other, so that the electric arc between two pairs of contacts is very easily brought together due to electromagnetic forces, thus causing a short circuit in the circuit and burning the three-phase protector. Based on the above findings, the three-phase protector according to the present disclosure eliminates the risk of the arc breaking the three-phase protector to burn out by merely providing the above-described arc isolation portion (for example, by merely molding the partition integrally inside the plastic case), thereby greatly improving the service life of the three-phase protector by a simple structure.

In another aspect, the present invention also provides an electrical apparatus on which a three-phase protector 100 of the type described above can be mounted and used. This can improve the safety performance of the electrical device.

The three-phase protector 100 according to the present disclosure can be applied to various motors, for example, motors for electric devices such as water pumps, juice makers, soymilk makers, mixers, dust collectors, and electric tools.

The operation principle of the three-phase protector 100 according to the present disclosure will be described below. When the motor protected by the three-phase protector has overlarge current and/or overhigh temperature, the heat generated by the motor is transmitted to the disc through the shell and/or the movable arm through which the overlarge current flows enables the movable arm to generate heat and transmits the heat to the disc, and when the temperature of the disc exceeds a preset value, the disc deforms and/or turns over, so that acting force is applied to the movable arm, the movable arm moves, the two pairs of electric contacts are opened or closed, and the effect of protecting electric equipment is achieved.

Although the present disclosure has been described with reference to exemplary embodiments, those skilled in the art will appreciate that various modifications and variations can be made to the exemplary embodiments of the present disclosure without materially departing from the spirit and scope of the disclosure. Accordingly, all such modifications and variations are intended to be included herein within the scope of this disclosure as defined by the following claims. The scope of the disclosure is defined by the appended claims, and equivalents of those claims are intended to be embraced therein.

Claims (8)

1. A three-phase protector, the three-phase protector comprising:

the first static terminal is provided with a first static contact, and the second static terminal is provided with a second static contact;

the movable arm is provided with a free end and a fixed end, the free end is provided with a first movable contact and a second movable contact, the first fixed contact and the first movable contact form a first pair of electric contacts, and the second fixed contact and the second movable contact form a second pair of electric contacts;

a disc configured to actuate the movable arm when a temperature exceeds a predetermined value; and

a housing for accommodating the first stationary terminal, the second stationary terminal, the movable arm, and the disc,

characterized in that the three-phase protector further comprises an arc isolation portion disposed between the first pair of electrical contacts and the second pair of electrical contacts, the arc isolation portion being configured to isolate an arc generated by the first pair of electrical contacts and an arc generated by the second pair of electrical contacts from each other.

2. The three-phase protector of claim 1, further comprising a first lead, a second lead, and a third lead, the first lead and the second lead being electrically connected to the first stationary terminal and the second stationary terminal, respectively, and the third lead being electrically connected to the movable arm.

3. The three-phase protector of claim 1, wherein the arc splitter is an insulating barrier.

4. A three-phase protector according to claim 3 wherein the insulating barrier is moulded integrally with the housing, the insulating barrier extending vertically upwardly within the housing from a bottom wall of the housing to a height greater than or equal to the height of the two pairs of electrical contacts.

5. The three-phase protector of claim 4, wherein the insulating partition extends vertically upward within the housing from a bottom wall of the housing to a top wall of the housing.

6. A protector according to any one of claims 1-5 wherein the housing and the arc barrier are both made of plastic.

7. The protector of claim 6, wherein the plastic is polyphenylene sulfide plastic.

8. An electrical apparatus, characterized in that it comprises a three-phase protector according to any one of claims 1-7.

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