US2013836A - Induction relay - Google Patents

Description

Sept. 10, 1935. J, PARSONS 2,013,836

INDUCTION RELAY Filed Nov. 13, 1954 Z-Sheets-Sheet 1 WITNESSES: INVENTOR v Q f0/7/7 si/ arsorzs.

T RNEY P 1935. J. s. PARSONS 2,013,836

DUCTION RELAY Filed Nov. 13, 1934 2 Sheets-Sheet 2 WITNESSES: INVENTOR m John 5 Parsons.

i 'atented Sept. 10, 1935 PATENT OFFICE INDUCTION RELAY John S. Parsons, Swissvale, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 13, 1934, Serial No. 752,897

9 Claims. (Cl. 175 294) My invention relates to induction relays and particularly to such relays for use in applications requiring an unusual degree of compactness without sacrifice of torque or accuracy. Although 5 my invention is of general utility in the relay art, it is particularly applicable to power directional network relays and other induction relays which are operated within an outer casing whose dimensions may be dependent upon the dimen- 10 sions of the relay.

In the smaller sizes of network protectors as used in network distribution systems, the size of a polyphase relay. as ordinarily constructed 'may impose undesirable limitations on the height 15 or depth or the protector casing, particularly where the more compact forms of circuit Dl3l er are used. The usual form of polyphase relay consists of a plurality of discs mounted on a common shaft, with three electromagnetic ele- 20 ments and one or two damping magnets arranged to act on the discs. There are commonly two or three discs-used in such a construction.

In accordance with my invention, the disc construction is avoided and the armature element 25 is made in the form of a single conducting drum which is acted upon by all of the electromagnetic elements and one or more damping magnets. However, the drum is not located entirelyoutside of the electromagnetic elements nor entirely in- 30 side, but preferably part of the-iron and coils of each element are included within the drum and the remainder arranged outside.

With such an arrangement, I have found that the volume of the relay may be reduced more 35 than 50% and weight to a value approximately 40% less than present designs, while maintaining an equal or higher torque.

Itis accordingly an object of my invention to provide a novel induction relay in which the 40 secondary or armature member is cylindrical in form and encloses one polar electromagnetic system, whereas a second polar electromagnetic vsystem is arranged outside of the armature member.

45 Another object of my invention is to provide a novel induction relay which shall produce a maximum mechanical output for a given relay weight operated at a given efiiciency.

Other objects of my invention will become evi- 5 dent from the following detailed description taken in conjunction with the accompanying drawings, in which Figure 1 is a plan view of a relay embodying my invention with parts broken away and parts 55 shown in section,

Fig. 4 is a fragmentary plan view with parts 5 in section of a' modified arrangement of electromagnets embodying my invention.

Referring to Figs. 1 and 2, which show an application of my invention to a three-phase network relay, the operating parts of the relay are enclosed in a case comprising a base plate I of cast iron or other suitable metal and a glass cover 2 fitted by means of a gasket 2a to the base plate I and removably secured thereto by means of posts 3 and thumbscrews 4 in the usual manner.

The base-plate I is formed to have a fiat portion la and a plurality of internally raised bosses lb for supporting the relay magnetic structure and for providing suitable external space for the attachment of conductors to the relay terminals. The relay is provided with the usual terminals 5 mounted upon the base plate .I and insulated therefrom by means of suitable insulating spacers 6 and terminal blocks 1 (one of which is shown in the lower left corner of Fig. 2), in the usual manner.

The terminals 5 comprise internally threaded conducting bushings 5a embedded in the terminal block I for engagement with externally threaded connecting screws 5b and 5c. The connecting screws 5b' pass through insulated terminal assemblies 5d supported by the spacers 6. The spacers 6 are secured to the base plate I by means of suitable machine screws 6a.

The relay is provided with three similar electro-magnetic elements 8, two of which are shown in Fig. 1, secured to the base-plate I and preferably symmetrically disposed about a common center as indicated. As mentioned above, the induction member of the relay is made in the form of a cylinder or drum 9, subject to the influence of the three elements '8. In accordance with my invention, the magnetic structure comprising the three elements 8 is so arranged that at least one pole of each element, with its associated coil, is mounted within the drum 9, and at least one of the remaining poles of each element with its associated coil is mounted outside of the drum. In the construction shown, each element consists of separate current magnets I0 and potential magnets I l, but, obviously, the invention may be practiced with other arrangements.

The construction of one of the elements 8 is best shown in the upper part of Fig. 1 where parts are broken away and the coils shown in section. The potential magnet II is preferably of the iron-clad type and comprises a laminated magnetic core I la having a main pole II b and a potential coil I Ic mounted thereupon. A lag loop (1 of copper or other suitable conducting material is mounted in the surface-of the core Ila around the main pole II b. The lag loop M11 is designed to produce a suflicient phase-angle lag in the main pole flux to cause it to be in quadrature to the voltage applied to thecoil II c, in a manner well understood in the art.

The current magnet I 0 comprises a C-shaped magnetic core Illa, arranged to provide two pole faces pole [lb and preferably symmetrically arranged with reference thereto. Suitable coils for obtaining power-directional and phasing operation of the relay are mounted upon the core Illa. the embodiment shown, these coils consist of separate current coils Ind and phasing coils IIle mounted upon each leg of the C-shaped core, but obviously other well known equivalent arrangements could be used. For example, the phasing coils We could be omitted entirely by arranging the current coils Illd for phasing operation as well as power-directional operation, in wellknown manner.

The drum 9 is secured to a suitable metallic wheel or spider I2, which in turn is rigidly secured to a main shaft I3. The main shaft I3 is drilled at either end to receive steel bearing pins I4 which are preferably press-fitted into the holes thus formed.

A frame I5, preferably of inverted U-shape is secured to the base plate I for supporting one end of the main shaft I3. For this purpose, an adjustable main bearing I 6, having a ring jewel I6a and a cup jewel I6b, is centrally mounted in the fame I5. A similar main bearing I1 is mounted in the base-plate I in alignment with the bearing I6. The bearing arrangement shown is that preferred where the relay is mounted in such position that the main shaft I3 is horizontal. If the relay is operated with its main shaft vertical, the forms of bearings commonly used in vertical shaft relays would, of course, be substituted.

The frame I is also provide with an insulated bearing I8 for a contact shaft 20. The inner end of the contact shaft is mounted in a sec- 7 0nd insulated bearing 22 supported by means of a metallic member 24 in alignment with the bearing I8. The member 24 is preferably mounted on the frame I5.

The moving contact of the relay is preferably in the form of a flat contact spring 25, rigidly secured to the contact shaft 20 and arranged to make contact with an adjustable tripping contact 21 or an adjustable closing contact 29.

The contact spring 25 is made somewhat longer than necessary to engage the contac s 21 and 29, in order to engage a reverse current adjuster 30. The reverse current adjuster 3D is provided for exerting a biasing torque opposing engagement of the contact spring 25 with the tripping contact 21, to thereby set an adjustable minimum value to the directional power flow which will effect operation of the relay.

The closing and tripping contacts 29 and 21 respectively and the reverse current adjuster 30 are supported by means of a U-shaped member 3I of insulating material secured to the frame I5. A spiral spring 33 is secured to the contact shaft 20 and to the frame I5 for biasing the contact spring 25 into engagement with the clos- IIJb angularly displaced from the main' ing contact 29. Movement of the main shaft I3 is transmitted to the contact shaft 20 by means of a pinion 35 press-fitted on the main shaft I3 and arranged to engage a gear wheel 31 secured to the contact shaft 29.

A permanent damping magnet 38 is secured to the base-plate I for damping movements of the induction member 9 in a wellknown manner.

An overvoltage adjuster is mounted in any suitable manner for arcuate movement concentric to the main shaft I3. Although only one overvoltage adjuster 40 is shown in Fig. 1, it will be understood that one is provided for each relay element 8. The overvoltage adjuster 4D is provided with a flat conducting loop portion 40a which extends upward between the drum 9 and the potential pole III). The construction of the overvoltage adjuster 40 is best shown in Fig. 3.

A suitable adjusting device 40b is provided for moving the loop 4011 through a range of positions in front of the potential pole 'I lb. The loop 40a acts to produce a quadrature component of potential pole flux which exerts an adjustable biasing force on the drum 9, as long as the potential magnet He is energized. The overvoltage adjusters 40 are normally adjusted to produce a total bias slightly greater than that produced by the spring 33 and acting in the opposite direction. In the absence of current flow in the coils llld or Ille, therefore, the spring contact 25 is biased into engagement with the reverse current adjuster 30 when the potential coils IIc are energized. When the potential coils IIc are deenergized, the spring 33 maintains the contact spring 25 in engagement with the closing conr tact 29 as shown.

Inasmuch as the electrical connections of the network relay shown in Figs. 1 and 2 are known in the art and form no part of the present invention, they have not been illustrated. Such connections and the associated auxiliary apparatus are shown and described in the United States patent to Bostwick 1,955,940 for example.

However, it will be understood that the relay is used in network protectors associated with polyphase circuits, and causes the network circuit breaker to open in response to directional power flow in excess of a predetermined value in the polyphase circuit and to reclose when the polyphase voltage on the two sides of the circuit breaker bear a predetermined relationship of magnitude and phase position.

Fig. 4 shows an alternative arrangement of the electromagnets used in the practice of my in vention. In the Fig. 4 modification, the poten- ,1,

than inside as in Figs. 1 and 2.

I do not intend that the present invention shall be restricted to the specific structural details, arrangement of parts or circuit connections herein set forth, as various modifications thereof may be efiectcd without departing from the spirit and scope of my invention. I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

, I claim as my invention:

1. In an altemating-current relay of the induction type, magnetic structure including a first polar portion and a second polar portion, a first coil means inductively associated with said first polar portion, a second coil means inductively associated with said second polar portion, and an induction member including a conducting portion having the form of a surface of revolution surrounding said first polar portion and said first coil means, saidconducting portion being inductively subject to magnetic fields produced by both of said polar portions.

2. In an alternating-current relay of the induction type, a first electromagnet including a core and a coil inductively associated therewith, an induction member including a conducting portion having the form of a surface of revolution surrounding said first electromagnet and subject to the magnetic field produced thereby, and a second electromagnet external to said conducting portion and positioned to magnetically influence said conducting portion, said second electromagnet including a core and a coil inductively associated therewith.

3. In an alternating-current relay of the induction type, magnetic structure including a "rst polar portion and a second polar portion, a first coil means inductively associated with said first polar portion, a second coil means inductively associated'with said second polar portion, and an induction member mounted for rotation about an axis, said member including a conducting portion having the form of a surface of revolution centered on said axis and surrounding said first polar portion and said first coil means, said conducting portion being inductively subject to magnetic fields produced by both of said polar portions, said polar portions being angularly displaced about said axis.

4. In an alternating-current relay of the induction type, a plurality of electromagnetic elements each comprising magnetic structure including a first polar portion and a second polar portion, a first coil means inductively associated with the corresponding first polar portion, and a second coil means inductively associated with the corresponding second polar portion, and an induction member including a conducting portion having the form of a surface of revolution surrounding all of said first polar portions and all of said first coil means, said conducting portion being inductively subject to magnetic fields produced by all of said first polar portions and all of said second polar portions.

5. In an alternating-current relay of the induction type, a plurality of electromagnetic elementseach comprising an inner electromagnet 6. In an alternating-current relay of the in- 10 duction type, a plurality of symmetrically disposed electromagnetic elements each comprising an inner electromagnet and an outer electromagnet, each of said electromagnets including a core and a coil inductively associated therewith,

an induction member including a conducting cylindrical portion surrounding all of said inner electromagnets and subject to the magnetic fields produced thereby, said outer electromagnets be ing positioned to inductively influence said conducting portion.

7. In an induction relay, an induction member including a conducting portion of substantially cylindrical form, electromagnetic energizing means including a polar portion arranged to inductively influence said conducting portion, a shading device having an electrically closed shad- .ng circuit, and adjustable mounting means for said shading device arranged to permit arcuate movement of said shading circuit between said 3 polar portion and said conducting portion along a path substantially concentric to the axis of said conducting portion.

8. In a network relay of the induction type.

electromagnetic energizing means including a 3,-

first polar portion and a second polar portion.

' an induction member including a conducting portion having the form of a surface of revolution surrounding said first polar portion, said conducting portion being inductively subject to mag- 40 netic fields produced by both of said portions. a shading device having an electrically closed shading circuit, and adjustable mounting means for said shading device arranged to permit arcuatc movement of said shading circuit between one of said polar portions and said conducting portion along a path substantially concentric to the axis of said conducting portion.

9. In a network relay having a potential pole.

an overvoltage adjuster comprising a conducting loop portion inductively associated with said. pole and an arcuate rack portion concentric with a point fixed with reference to said pole. an :'d justing pinion in mesh with said rack, and means for confining movement of said adjuster to an arcuate path concentric with said point.

JOHN ,S. PARSONS.

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