EP4331000A1

EP4331000A1 - Electromagnetic relay

Info

Publication number: EP4331000A1
Application number: EP22712891.5A
Authority: EP
Inventors: Loganadhan V; Uthayakumar M; Shambhulingappa S; Manjunath AJ
Original assignee: Hitachi Energy Ltd
Current assignee: Hitachi Energy Ltd
Priority date: 2021-04-30
Filing date: 2022-03-01
Publication date: 2024-03-06
Also published as: CN117203735A; AU2022266021A1; WO2022228751A1

Abstract

An electromagnetic relay is provided. The electromagnetic relay includes: at least two parts, being stacked along a first direction and fixedly connected with each other in a second direction, wherein the first direction is substantially perpendicular to the second direction; and at least one movable contact spring, each having a first portion; the first portion of each movable contact spring is sandwiched between two adjacent ones of the parts; and the parts are made of insulating material.

Description

ELECTROMAGNETIC RELAY

TECHNICAL Mi l l)

[0001] The present disclosure relates to a relay, and more particularly to an electromagnetic relay.

BACKGROUND

[0002] A relay is an electrically operated switch. It includes a set of input terminals for single or multiple control signals, and a set of operating contact terminals. Relays are used where it is necessary to control a circuit by an independent low-power signal, or where several circuits must be controlled by one signal. Electromagnetic relays are those relays which operate on the principle of electromagnetic attraction. It is a type of a magnetic switch which uses a magnet for creating a magnetic field. The magnetic field is then used for opening and closing the switch and for performing a mechanical operation.

[0003] In the industry, a relay could be used as a protective means which is designed to trip circuit breaker when a fault is detected. Factors such as compactness and robustness of a relay are oftentimes valuable considerations for its application. Currently, those factors are still demand further developments.

[0004] The apparatus or devices described in this section are not necessarily apparatus or devices that have been previously conceived or employed. It should not be assumed that any of the apparatus or devices described in this section are considered to be the prior art just because they are included in this section, unless otherwise indicated expressly. Similarly, the problem mentioned in this section should not be considered to be universally recognized in any prior art, unless otherwise indicated expressly.

SUMMARY

[0005] According to an aspect of the present disclosure, an electromagnetic relay is provided. The electromagnetic relay includes: at least two parts, being stacked along a first direction and fixedly connected with each other in a second direction, wherein the first direction is substantially perpendicular to the second direction; and at least one movable contact spring, each having a first portion. The first portion of each movable contact spring is sandwiched between two adjacent ones of the parts, and the parts are made of insulating material.

[0006] More features and advantages of the present disclosure will become apparent from the exemplary embodiments described below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The drawings exemplarily show embodiments and form a part of the specification, and are used to explain exemplary implementations of the embodiments together with a written description of the specification. The embodiments shown are merely for illustrative purposes and do not limit the scope of the claims. Throughout the drawings, like reference signs denote like but not necessarily identical elements.

[0008] Fig. 1 is an overview of an electromagnetic relay from one perspective according to an exemplary embodiment of the present disclosure;

[0009] Fig. 2 is an overview of one insulation washer according to an exemplary embodiment of the present disclosure; [0010] Fig. 3 is a cross sectional view taken along line A-A’ in Fig. 1 according to an exemplary embodiment of the present disclosure;

[0011] Fig. 4 is a side view of the electromagnetic relay of Fig. 1 according to an exemplary embodiment of the present disclosure;

[0012] Fig. 5 is another side view of the electromagnetic relay of Fig. 1 according to an exemplary embodiment of the present disclosure;

[0013] Fig. 6 is a top view of the electromagnetic relay of Fig. 1 according to an exemplary embodiment of the present disclosure;

[0014] Fig. 7 is a cross sectional view taken along line B-B’ in Fig. 1 according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

[0015] In the present disclosure, unless otherwise stated, the terms “first”, “second”, etc., used to describe various elements are not intended to limit the positional, temporal, or importance relationship of these elements, but rather only to distinguish one component from another. In some examples, the first element and the second element may refer to the same instance of the element, and in some cases, based on contextual descriptions, the first element and the second element may also refer to different instances.

[0016] The terms used in the description of the various examples in the present disclosure are merely for the purpose of describing particular examples, and are not intended to be limiting. If the number of elements is not specifically defined, it may be one or more, unless otherwise expressly indicated in the context. Moreover, the term “and/or” used in the present disclosure encompasses any of and all possible combinations of the listed items.

[0017] Spatially relative terms, such as “beneath”, “below”, “lower”, “under”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary terms “below” and “under” can encompass both an orientation of above and below. Terms such as “before” or “preceding” and “after” or “followed by” may be similarly used, for example, to indicate an order in which light passes through the elements. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.

[0018] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

[0019] It will be understood that when an element or layer is referred to as being “on”, “connected to”, “coupled to”, or “adjacent to” another element or layer, it can be directly on, connected, coupled, or adjacent to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to”, “directly coupled to”, or “immediately adjacent to” another element or layer, there are no intervening elements or layers present. In no event, however, should “on” or “directly on” be construed as requiring a layer to completely cover an underlying layer.

[0020] Embodiments of the invention are described herein with reference to schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Accordingly, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the invention.

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present specification and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0022] The present disclosure relates to voltage transformers supply routing to control and relay panels in substations and specifically to a voltage selection relay for synchronizing scheme and interlocking logics for feeders and buses in substation automation and also for general control where multiplication of contacts is desired.

[0023] In the related art, an auxiliary bistable relay is used primarily for tripping application and also used as Potential Transformer (PT) selection and contact multiplication. The form factor, number of contacts and price of the relay are considerations for the application of the relay in the substations. The industry desires auxiliary relays for PT selection and contact multiplication function, which are in a reduced form and without compromising on the robust build, preferably having at least 14 contacts and a flag for position indication.

[0024] In order to solve the abovementioned problem and meet the industry desires, the present disclosure provides an electromagnetic relay through a compact arrangement of its elements, thereby reducing the size of the relay and improving its robustness simultaneously. [0025] Embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings.

[0026] Fig. 1 is an overview of an electromagnetic relay 100 from one perspective according to an exemplary embodiment of the present disclosure. As shown in Fig. 1, electromagnetic relay 100 comprises at least two parts, e.g., part 110 and part 120, being stacked along a first direction and fixedly connected with each other in a second direction. The first direction is substantially perpendicular to the second direction. Exemp lardy, part 100 and part 120 can be vertically stacked with each other along a Z direction. In some variants, part 110 and 120 are fixedly connected in an X direction. In some embodiments, the phrase “fixedly connected” means that there is no horizontal play between the two parts, and that the two parts will not have any movements relative to each other when electromagnetic relay 100 is in operation.

[0027] In some embodiments, electromagnetic relay 100 comprises at least one movable contact spring, e.g., movable contact springs 130 and 140, each having a first portion. The first portion of each movable contact spring is sandwiched between two adjacent ones of the parts. Exemplarily, each of movable contact springs 130 and 140 may comprise a first portion on one end and a second portion on the other end. In some variants, a movable contact is located on the second portion of each of movable contact springs 130 and 140, and the first portion is sandwiched between adjacent parts 110 and 120. In some embodiments, parts 110 and 120 are made of insulating material such as plastic.

[0028] In some embodiments, electromagnetic relay 100 comprises a plurality of fixed contacts, e.g., fixed contacts 150, to contact the movable contact located on the second portion of movable contact spring 130. In some variants, electromagnetic relay 100 comprises a block 160 for holding the fixed contacts 150 and the at least two parts 110 and 120.

[0029] In some implementations, electromagnetic relay 100 comprises a coil of wire wrapped around a soft iron core, an iron yoke which provides a low reluctance path for magnetic flux, and a movable iron armature, all of which are not shown for clarity of illustration. In some variants, the armature may hinge to the yoke and mechanically link to one or more sets of moving contacts. In some variants, the armature is held in place by a spring so that when the relay is deenergized there is an air gap in the magnetic circuit. Exemplarily, when an electric current passes through the coil it generates a magnetic field that activates the armature, and consequent movement of the movable contacts located on movable contact spring 130 either makes or breaks a connection with fixed contact 150. If electromagnetic relay 100 is de energized, then the movement opens the contacts and breaks the connection. Alternatively, when the electric current to the coil is switched off, the armature is returned by a force such as spring to its relaxed position.

[0030] Overall, the at least two parts inside electromagnetic relay 100 is implemented in a way that there is no horizontal play between the parts. Moreover, a first portion of each of movable contact springs 130 and 140 is sandwiched between two adjacent parts, making movable contact springs 130 and 140 less likely to drift laterally, e.g., along a Y direction. Thus, electromagnetic relay 100 can be constructed in a compact form due to the elimination of intervals between the at least two parts and it also helps to keep the movable contact portions in right alignment with the fixed contacts.

[0031] In some embodiments, parts 110 and 120 comprise respective insulation washers. In some variants, each of parts 110 and 120 itself is an insulation washer made of plastic or other insulating materials.

[0032] In some embodiments, each of the insulation washers comprises substantially along the first direction a protrusion structure on an upper end surface of the insulation washer and a recession structure on a lower end surface of the insulation washer. Reference is now made to

Fig. 2. [0033] Fig. 2 is an overview of one insulation washer 200 according to an exemplary embodiment of the present disclosure. Insulation washer 200 comprises a protrusion structure 210 on the upper end surface 220 and a recession structure 230 on the lower end surface 240. [0034] In some embodiments, the protrusion structure of a first insulation washer is engaged with the recession structure of an adjacent, second insulation washer such that the first and second insulation washers are fixedly connected with each other in the second direction. Exemplarily, referring back to Fig. 1, the first part 110 and the second part 120 may be the first insulation washer 110 and the second insulation washer 120 respectively, and are fixedly connected with each other in the X direction through the engagement between the protrusion structure of the first insulation washer 110 and the recession structure of the second insulation washer 120.

[0035] Overall, insulation washer 200 provides isolation between circuits. Also, the stop features such as protrusion structure 210 and recession structure 230 can prevent the insulation washer from laterally drifting, e.g., drifting in the X direction. Thus, through the engagement between the insulation washers, electromagnetic relay 100 is able to keep the movable contact portions in right alignment with the fixed contacts.

[0036] In some embodiments, a lower insulation washer of every two adjacent ones of the insulation washers comprises at least one slot at the upper end surface of the lower insulation washer, and the first portion of each movable contact spring is conformally fit in a respective one of the at least one slot of the lower insulation washer.

[0037] Fig. 3 is a cross sectional view taken along line A-A’ in Fig. 1 according to an exemplary embodiment of the present disclosure. Referring to Fig. 3, a lower insulation washer of every two adjacent ones of the insulation washers comprises slots 310 and 330. A first potion 320 of movable contact spring 350 is conformally fit into slot 310. Similarly, a first portion 340 of movable contact spring 360 is conformally fit into slot 330. In some embodiments, the phrase “conformally fit” means that there is no play between the first portion (e.g., 320 or 340) and the lower insulation washer. In some embodiments, the lower insulation washer comprises two slots opposite to each other. Exemplarily, slots 310 and 330 are arranged to opposite to each other. [0038] Accordingly, by fitting a first portion of the movable contact spring into the slot located on the upper end surface of the lower insulation washer, there is no play between the movable contact spring and the insulation washer. It will reduce or prevent the lateral movement along the Y direction of movable contact springs 350 and 360. Movable contact portions 350 and 360 are in a right alignment with the corresponding fixed contacts after assembly or calibration. Due to the restriction to lateral movement, movable contact springs 350 and 360 will be less likely to drift away from the calibrated right alignment position, making electromagnetic relay 100 more robust.

[0039] In some embodiments, electromagnetic relay 100 may comprise two pairs of contact blocks on two opposite lateral sides of the electromagnetic relay. Each pair of contact blocks comprises two contact blocks, each contact block comprising a plurality of terminals electronically connected to respective ones of the plurality of fixed contacts.

[0040] Fig. 4 is a side view of electromagnetic relay 100 according to an exemplary embodiment of the present disclosure. Referring to Fig. 4, electromagnetic relay 100 comprises two pairs of contact blocks (one pair is indicated by 410, and the other pair is on the opposite lateral side and is not shown). The pair of contact blocks 410 comprises two contact blocks 420 and 430, each contact block comprising a plurality of terminals electronically connected to respective ones of the plurality of fixed contacts. Exemplarily, contact block 420 comprises 8 terminals 422, 424, etc., and contact block 430 comprises 8 terminals 432, 434, etc. In some embodiments, the terminals are in electronical connection with the fixed contacts such as fixed contacts 150. In some variants, each of the terminals is one end of a respective fixed contact. [0041] In some embodiments, devices such as potential sensors may be connected to electromagnetic relay 100 through any one of the terminals, such that an electronic circuit will complete when the armature is operated to move the movable contact to contact the corresponding fixed contact.

[0042] In some embodiments, each contact block further comprises ribs separating the plurality of terminals from each other to provide electrical resistance between the plurality of terminals. Exemplarily, contact block 420 includes ribs 440, and contact block 430 includes ribs 450. In some variants, ribs 440 and 450 may be made of materials with high dielectric constant such as plastic in order to provide high dielectric strength.

[0043] Overall, in some applications of electromagnetic relay 100 like PT selection application, the potential involved therein may be significantly high such as tens of thousands of volts. Ribs 440 and 450 with high dielectric strength can provide more protection for the device, making electromagnetic relay 100 more robust.

[0044] In some implementations, electromagnetic relay 100 may further comprise two cable supports, each between the two contact blocks of a respective pair of the two pairs of contact blocks. Exemplarily, cable support 460 is located on one side of electromagnetic relay 100 and between contact blocks 420 and 430 of the pair of contact blocks 410. Alternatively, the other cable support (not shown) is located on the other side opposite to cable support 460.

[0045] In some embodiments, the two cable supports are arranged such that the coil is separated from cables electrically connected to the plurality of terminals. Exemplarily, cable support 460 may be a plate that is located between the cables and the coil. In some implementations, cables are routed through the inner side of the cable support 460. In some variants, cable support 460 can be made of insulating materials such as plastic.

[0046] Accordingly, with cable support 460, electromagnetic relay 100 is less likely to have loose or cut strands that affect the basic function of relay. Cable support 460 provides a support to reduce the dispersibility of cables and makes them firmly arranged. Furthermore, it separates cables from the coil area, thereby reducing the possibility of malfunction caused by the impact from the coil.

[0047] In some embodiments, electromagnetic relay 100 further comprises one or more shorting links for short-circuiting corresponding ones of the plurality of fixed contacts.

[0048] Fig. 5 is another side view of electromagnetic relay 100 according to an exemplary embodiment of the present disclosure. Referring to Fig. 5, electromagnetic relay 100 further comprises shorting link 510 for changing over contacts through short-circuiting terminals 520 and 530. In some embodiments, terminals 520 and 530 are in electronical connection with respective fixed contacts. Therefore, shorting link 510 is able to short-circuit the respective fixed contacts. In some implementations, terminals 520 and 530 may be a common terminal for both terminals 540 and 550, with terminal 540 being a Normal Open (NO) contact and terminal 550 being a Normal Close (NC) contact. It should be noted that although short link 510 is shown as between two fixed contacts, other number of fixed contacts may be short-circuited by one or more short links. The present disclosure does not limit the number or position of the short links. [0049] In some implementations, the contact configuration varies from application purposes. Accordingly, with internal shorting links like 510, electromagnetic relay 100 may offer flexibility for contact configuration. It also eliminates the need for additional wirings for change over contact, resulting in lesser effort during engineering.

[0050] In some embodiments, the electromagnetic relay may further comprise a magnetic circuit module comprising an armature; and a flag indicator. The flag indicator comprises one or more indication slots and a movable flag underneath the one or more indication slots to visibly indicate a motion of the armature.

[0051] Fig. 6 is a top view of electromagnetic relay 100 according to an exemplary embodiment of the present disclosure. Referring to Fig. 6, electromagnetic relay 100 further comprises a flag indicator 610 on connection block 160. Flag indicator 610 comprises three indication slots, 620, 630 and 640. Movable flag 650 is located underneath the three indication slots 620, 630 and 640.

[0052] In some embodiments, electromagnetic relay 100 further comprises a lever configured to drag the movable flag in response to the motion of the armature to change a visibility of the movable flag through at least one of the indication slots.

[0053] Fig. 7 is a cross sectional view taken along line B-B’ in Fig. 1 according to an exemplary embodiment of the present disclosure. Referring to Fig. 7, electromagnetic relay 100 comprises a coil 710, an armature 720 and a lever 730. In some embodiments, when relay 100 is energized, coil 710 generates a magnetic field that activates armature 720. In some embodiments, armature 720 is operated to move the movable contact spring between a contacting position at which the fixed contact contacts the movable contact, and a non-contacting position at which the fixed contact and the movable contact are not in contact with each other. In some variants, the motion caused by armature 720 between the contacting position and the non-contacting position may be visibly indicated by flag indicator 610. In some implementations, armature 720 is connected to lever 730, causing lever 730 to move in response to the motion of armature 720. In some implementations, lever 730 is mechanically connected to movable flag 650 and will drag movable flag 650 in response to the motion of armature 720. In some embodiments, the movement of lever 730 during the operation of relay 100 switches the contact position from one side to other, causing movable flag 650 connected to be also driven and resulting in a change of visibility of movable flag 650 through at least one of indication slots 620, 630 and 640.

[0054] Accordingly, in the present disclosure, flag indicator 610 is controlled based on the motion of armature 720. By configuring the movable flag and slots 620, 630 and 640, the user can better visually perceive the operation of electromagnetic relay 100. This also improves the fail proof during installation.

[0055] Although the embodiments or examples of the present disclosure have been described with reference to the drawings, it should be understood that the methods, systems and devices described above are merely exemplary embodiments or examples, and the scope of the present disclosure is not limited by the embodiments or examples, and is only defined by the scope of the granted claims and the equivalents thereof. Various elements in the embodiments or examples may be omitted or substituted by equivalent elements thereof. Moreover, the steps may be performed in an order different from that described in the present disclosure. Further, various elements in the embodiments or examples may be combined in various ways. It is important that, as the technology evolves, many elements described herein may be replaced with equivalent elements that appear after the present disclosure.

Claims

We Claim:

1. An electromagnetic relay, comprising: at least two parts, being stacked along a first direction and fixedly connected with each other in a second direction, wherein the first direction is substantially perpendicular to the second direction; and at least one movable contact spring, each having a first portion; wherein: the first portion of each movable contact spring is sandwiched between two adjacent ones of the parts; and the parts are made of insulating material.

2. The electromagnetic relay of claim 1, wherein the parts comprise respective insulation washers.

3. The electromagnetic relay of claim 2, wherein each of the insulation washers comprises substantially along the first direction a protrusion structure on an upper end surface of the insulation washer and a recession structure on a lower end surface of the insulation washer.

4. The electromagnetic relay of claim 3, wherein the protrusion structure of a first insulation washer is engaged with the recession structure of an adjacent, second insulation washer such that the first and second insulation washers are fixedly connected with each other in the second direction.

5. The electromagnetic relay of claim 3 or 4, wherein a lower insulation washer of every two adjacent one of the insulation washers comprises at least one slot at the upper end surface of the lower insulation washer, and wherein the first portion of each movable contact spring is conformally fit in a respective one of the at least one slot of the lower insulation washer.

6. The electromagnetic relay of claim 5, wherein the lower insulation washer comprises two slots opposite to each other.

7. The electromagnetic relay of any of preceding claims, further comprising: a plurality of fixed contacts; and two pairs of contact blocks on two opposite lateral sides of the electromagnetic relay, wherein each pair of contact blocks comprises two contact blocks, each contact block comprising a plurality of terminals electronically connected to respective ones of the plurality of fixed contacts.

8. The electromagnetic relay of claim 7, wherein each contact block further comprises ribs separating the plurality of terminals from each other to provide electrical resistance between the plurality of terminals.

9. The electromagnetic relay of claim 7 or 8, further comprising two cable supports, each between the two contact blocks of a respective pair of the two pairs of contact blocks.

10. The electromagnetic relay of claim 9, further comprising: a magnetic circuit module comprising a coil, wherein the two cable supports are arranged such that the coil is separated from cables electrically connected to the plurality of terminals.

11. The electromagnetic relay of any of claim 7-10, further comprising one or more shorting links for short-circuiting corresponding ones of the plurality of fixed contacts.

12. The electromagnetic relay of any of preceding claims, further comprising: a magnetic circuit module comprising an armature; and a flag indicator, wherein the flag indicator comprises one or more indication slots and a movable flag underneath the indication slots to visibly indicate a motion of the armature.

13. The electromagnetic relay of claim 12, further comprising a lever configured to drag the movable flag in response to the motion of the armature to change a visibility of the movable flag through at least one of the indication slots.

14. The electromagnetic relay of any of preceding claims, further comprising a block for holding the at least two parts.