DE2445671A1 - ACTUATOR FOR CIRCUIT BREAKERS - Google Patents

Description

I r. t it «ι ι ι

DIPL.-ING. KLAUS NEUBECKER

Patent attorney 9AARR71

4 Düsseldorf 1 Schadowplatz 9

44, 353 Düsseldorf , Sept. 24, 1974

Westinghouse ELectrio Corporation
Pittsburgh, Pa., V. St. A. __

Actuator for circuit breaker

The present invention relates generally to a circuit breaker with an actuator and in particular a pneumatic actuator.

From US-PS 3,624,329 a pneumatic actuator for a circuit breaker is known, in which a spring-loaded closing piston is actuated pneumatically, to rotate a circuit breaker release lever and thereby to close the breaker contacts · After If there is no pressurization of the bottom piston, a compression spring located in the working cylinder brings the Closing piston back to its initial position, whereby the Piston rod disengaged from a roller connected to the pivoting lock lever. The bottom flask uses a normally closed three-way valve with the valve having the piston on its working side. exposed to slight pressure in its retracted position. The working side of the piston is actuated of the three-way valve applied in order to exert the required closing force on the piston to the interrupter close. In addition, in the closing style.

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Telephone (O211) 32 O8 58 Telegrams Custopat

the one on the side of the not acted upon by pressure medium Piston provided a compression spring to allow the piston to return to its retracted position, so that the The piston does not interfere with the switching of the circuit breaker after a bottom closing operation has been carried out. It also switches a lock control switch off the solenoid valve after the actuator is fully closed, in addition A so-holder is required to prevent the breaker from tripping, until the locking piston is in its original withdrawn position has returned.

The object of the present invention is to provide an actuator for a circuit breaker that does the Closing a circuit breaker against strongly accelerating opening spring pressure, which contacts the breaker trying to open, allowing, with the plunger in a non-obstructive position during a subsequent trip in the normal locked closed position of the breaker is · The invention is in particular for actuating members of circuit breakers of relitiν Higher voltage and high current carrying capacity suitable. To solve this problem, a circuit breaker comprises • an actuating member, releasable contacts, a moving part, Means do delivering the opening and closing movements of the loetoaren contacts responsive to the movement of the movable file, a pneumatic actuator with a Trelbkelben, which can be actuated in a pneumatic, actuated Cylinder is located and has a piston rod that »I retreokt outside of the pneumatically operated cylinder, wherein the piston rod is connected to the movable part in order to actuate it, the piston rod moving at one end of the actuating cylinder on a working side of the propulsion piston extended out, means to normal-

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times in both the pneumatically operated cylinder of the driven rather than the non-driven side of the drive piston under high pressure, and valve means for withdrawing (Jas from the non-driven side of the drive piston, around the drive piston and the movable part move to close the breaker contacts.

The pulp control valve is expediently deactivated or switched over to allow the piston to reverse a movement cause, whereby on both sides of the drive piston below high pressure medium is brought. Due to the pressure difference that acts across the cross-sectional area of the piston rod that extends out of the actuating cylinder, gas under high pressure does not affect the piston rod driving side of the piston and normal atmospheric pressure on the outside of the cylinder actuating the piston acts, the necessary pressure differential force is supplied over the cross-sectional area of the piston rod to bring about the return of the piston to its normal deactivated back position, in which both sides of the sabot are pressurized · The normally open pulp control valve is then in its switched Position.

The invention is explained in more detail below with reference to an exemplary embodiment shown in the accompanying figures.

Fig. 1 shows in section a circuit breaker with closed contacts and with dea Kelben in his retracted Bücketellpoeitlon.

FIG. 2 shows a view similar to FIG. 1, with calibration however the circuit breaker in open

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Position.

Fig. 3 shows the position of various parts during a closing stroke.

Figure 4 shows a partial end view along line IV-IY of Figure 3.

Figure 1 shows an actuator 1 for closing and opening circuit breaker contacts 2, 3 and 4 of a circuit breaker 5. The three sets of circuit breaker contacts 2, 3 »4 are shown schematically in FIG. The actuator 1 is connected to a circuit breaker 5 as described in US Pat. No. 3,624,329 is. Although the view shown in Figure 1 shows a direct mechanical connection to the contacts, can because the actuator also operates control valves, which in turn control a flow of gas to pistons that are connected to the contacts are connected.

A switching magnet unit 7 is for releasable magnetic locking of the circuit breaker 5 is provided in the closed position. As described in the aforementioned patent, the holding magnet unit 7 has a holding magnet 11 and a shift lever 13 pivotally mounted on a fixed pin 15 while its tail portion • in toggle lever-ββstange 19 in a slightly reduced position Holding position · As shown in Figure 1, the toggle linkage 19, a pair of toggle levers 21, 23, the toggle lever 21 being pivotably mounted on a stationary pin 25 is, while the other toggle lever 23 can be shaken with a movable pin 27 at the outer free end of a Main operating lever unit 29 »which can be pivoted on a

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stationary »Ii pin 30 is mounted, is attached.

An operating rod 31 can be pivoted between the ends the main control lever unit 29 hinged at 32 and also connected to the movable contacts 2a, 3a, 4a of the circuit breaker 5, as shown schematically, by a spring 34 with a large spring force in the circuit bottom closing position for effecting the opening. the Contacts biased, as shown in Figure 1 »is. Specifically, there are one or more acceleration springs 34 between a fixed transverse plate 36 »which is across extends to heavy side support plates 38 and with these for example through. Welding is connected in which the various fixed pins 25 »30 and 37 of the actuator 1 and a movable spring plate 40 arranged ». . which is connected to the contact operating rod 31 and is movable.

A pair of dampers 42, 43 serve to dampen the ends of the opening and closing movements of the main operating lever unit 29, while an auxiliary bracket unit is provided, which via an angle lever 46 and a connecting piece 48 with a rope 50 of the lift control lever unit 29 is connected to effect the desired actuation of the auxiliary switch 44. As known to those skilled in the art, the auxiliary holder 44 controls electrical circuits (not shown), which point to the positions of the interrupter 5 respond to open and close the circuit.

As shown in Figure 1, the main operating lever unit 29 urged by the spring 34 to open the contacts 2, 3, 4, but in their closed position below the application of this spring 3.4 held by the locking action of the switching magnet unit 7. Switching windings 52, 53 are located in the magnet unit 7, which is held in the

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th state the magnetic flux within the holding magnet 11 derive and thereby cause the release of the magnet armature, which in turn kinks the lever linkage enabled, whereby the spring opening operation of the contacts 2a, 3a, 4a of the circuit breaker 5 is enabled.

circle
In order to effect the closing action of the circuit breaker 5, an improved bottom piston device 57 is provided which has a drive piston 59 which is reciprocable in a pneumatically operated cylinder 60 with air normally under high bridge on both sides of the piston or gas 61 is located. The pressure medium 61 does not need to be air and can be a suitable gas that is even suitable for having an arc-extinguishing effect in the interrupter 5 , “This is particularly relevant when the interrupter 5 contains sulfur hexafluoride (SFg) , whereby it is not desirable to use two different gases such as SFg and compressed air in the same interrupter 5. In this way, the sulfur hexafluoride gas can serve not only to release the arc at the contacts 2, 3, 4, but also to actuate the piston device 57 .

The retort piston 59 is connected to a piston rod 63 which has an actuation element 65 with a longitudinal slot 67. This provides a stroke loss yerMndiang 64 between piston rod 63 and Holl® 68 that is carried by lever 29. When the breaker 5 is in the open circuit position, as shown in Figure 2, the roller 68, which is movable with the main operating lever unit 29, is in a position adjacent to the end 67a of the longitudinal slide 67. In this case, that will Discharge of gas 61 from the right end 71 of the cylinder 60 to the high pressure gas 61 on the

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allow left drive side 73 of the piston 59, one after

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to effect right-directed / left actuation of the piston 59, and "here inevitably the roller 68 and therefore the main control lever unit 29 in a clockwise direction, as in FIG Figure 2 and 3 can be seen, move in order to do a closing operation of the breaker 5. to effect. FIG. 3 shows such a closing actuation of the interrupter 5 in more detailed form.

The present invention is suitable for use with conventional three-way normally open control valves 75 which, when actuated, vent fluid from area 71 to the right of the non-driving surface of drive piston 59. After switching the normally-open three-way control valve 75, the gas 61 can again through the conduits 77, flow 78 in the right chamber 71 of the Betätigungszyjinders 60, the following compensation of the gas pressure on both sides of the piston 59 this in its left end position, as shown in Figure 1 shown, in view of the pressure difference prevailing at the piston unit 59. As is known to those skilled in the art, this pressure difference exists due to the cross-sectional area "A" (FIG. 4) of the piston rod 63 itself. With regard to the cross-sectional area "A" (FIG acts, that the piston rod 63 to the left AUB the cylinder 60 as shown in Figure 1, is pushed, as is outside of the cylinder 60 only atmospheric pressure or low pressure gas. There is therefore an unbalanced pressure force on the piston rod 63 of the piston unit $ 9

Equalization of the gas pressure on both sides of the piston will push the piston 59 to the left, where it will eventually stop at an annular stop 72.

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High pressure gas 61 is passed through a high pressure feed line 81, which is fed from a suitable high-pressure container 85, is fed into the cylinder space 76.

In order to avoid a leakage loss at the cylinder 60, a bellows 80 is provided for example to prevent grass from escaping to prevent the opening 82 in the end plate 84 of the cylinder 60. However, other seals can also be used will. The use of a bellows 80, however, ensures that a long life without the occurrence of Leakage at the opening 82 in the end plate 84 of the cylinder 60 is achieved.

The electrical control 86 for actuating the three-way control valve 75 is shown in Figure 1, due to the pressing down or the bottom of a button the control valve 75 is actuated, whereby pressure medium is discharged from the area 71. This is how it usually works existing high pressure gas 61 in area 76 on the other side of piston 49, whereby the Piston rod 63 is driven to the right, whereby the interrupter 5 is closed. The closed position of the contacts 2, 3, 4 of the sub-burner naturally act as loading acceleration springs 34, which are normally provided in a circuit breaker, to a subsequent To bring about a no-nonsense opening of the contacts.

In such an interrupter with the improved closing piston device 57, a normally open three-way valve 75 is used. This valve supplies both sides of the drive piston 49 with gas under pressure. The valve 75 empties one side 71 of the piston 59, while the pressure medium 61 on the other side 76 of the piston 59 empties the required closing force to close the interrupter

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supplies. The return of the drive piston 59 to its normal return position, as shown in Figure 1, does not require a spring. As stated, the area ^11A ″ (Figure 4) of the piston rod 63 together with the high pressure gas that is on the inside of the piston unit 61 in the area 71 and the normal atmospheric air pressure that exists outside the cylinder 60, the force required to return the piston 59 to its left return position, as shown in FIGS.

The / valve assembly is designed accordingly and in their Technically very flawless operation in a wide pressure range. This makes it possible to dispense with the usual interlock test switch and switching the valve through auxiliary contacts, which are also used for other purposes The switch that has been used so far to ensure that the piston 59 has completely returned before a switching process is also no longer required. The full retraction stroke of the piston 49 before a switching process can without Use of this switch.

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Claims (1)

Claim it lejStromkreieunterbreoher with an actuating element, releasable contacts, a movable part, means for performing the opening and bottom closing movements of the releasable contacts in response to the movement of the movable part, a pneumatic actuator with a driving piston _r which can be actuated in a pneumatic actuating cylinder and a © piston rod which extends out of the pneumatic actuation cylinder, the piston rod being connected to the movable part in order to actuate it, the piston rod protruding from one end of the actuating cylinder on the working side of the drive train, indicated by means normally (60) both on the driving and on the non treibendta side of the driving piston (59) © in high pressure gas _y httlt in the pneumatic actuation "yliiider and by valve means (75) for discharging gas from the non-driving side of the driving piston, around the rotary piston and there to move eglich® part (29) to the tMt <9? te @ eh®rk®ntakte (2, 3, _f 4) to close. 2 · -Stromkreennttrforeoher according to claim 1, characterized. aeiohnet that there is a "movable" part (29) © in a pivotable one The main control lever is, which can be operated on a fixed Pin (32) mounted and connected to the piston rod (63). 3, circuit breaker according to claim 1 or 2 _S, characterized in that the connection between the piston rod (63) and the pivotable main operating lever (29) is a lost stroke connection, the drive piston (59) 509814/0876 its reset position without affecting the main operating lever can take. 4. Circuit breaker according to one of claims 1 to 3, characterized in that the movable part (29) by a collapsible toggle linkage (19) in held in its closed position. 5 · Circuit breaker according to Claim 4, marked by means (Ti) for holding the toggle linkage (19) in a squat position with a magnetic actuated switch arm (13). 6. Circuit breaker according to Anspruoh 4 or 5, characterized by acceleration springs (34) for biasing the moving contacts (2, 3> 4) of the breaker in the opening direction and a loss of stroke connection between the movable file (29) and the piston rod (63) of the pneumatic actuator (60). 7. Circuit breaker naoh one of claims 1 to 6, characterized in that the valve means (75) is a normally comprise open three-way control valve, wherein the movable! ax (29) a sohsMnkbaren. Operating lever has, which can be pivoted on. is mounted on a stationary pivot, 8. Circuit breaker naoh one of the claims! 3 * to 7, characterized in that the stroke loss connection consists of a longitudinal slot (67) in the piston rod (63). 9 · circuit breaker according to one of claims 1 to 8, 509814/0876 «· 12 ·» characterized in that it is the normal reset position dt * driving piston (59), in the one on both sides of this Gae existed under high pressure, Ewiaohen den Ends dta pntuaatiaohtn actuating cylinders (60) lies and by which an ineohlagEylindtr is determined 10 »ßtromkrtisausbruchtr naoh Anapruoh 9, daduroh gtktnnzelöft that the valve means (35) da» Hoohdzhickgaa from the non-driving side dta driving piston (59) nourishing dta closing process dta circuit interruption to effect dtr 3ohlie8btwtgung dta piston · ablateen, whereby the Drttokdifferenii, Ait on the Quertohnittsbereioh of the piston rod • acts, the Hüoketell movement dta drive piston (59) causes and the Hulrrtrlutt connection the Eolbenatang in a dtn eohwenkbaren main lever (29) is arranged in a non-impairing position. 11 * Stromkrtieuaterbrtoher NaOH Inapruoh 10, characterized gekennteiohnet, dai tin pair tone Dttepfungagliedern (42, 43) opening to the llbKpfen represents · - and Sohlieflbewegungen of Hauptbetätigungahtbtle (29) rtrgtsehen i «t _# 11 * itramkreiaunterstreühtr naoh Antpruoh 11, daduroh gtktnnitithnet, "al Ineohlafmittel in dt" Eylinder (60) attached *, where a l & it da · tylindert and the propellant (19) inks occurred lertioh and daa other lndt dta l / lltintnect iweit Btrtioh dtfi- »Ι«] Τ · »| because * means anti hold one aaset with height * Druok ΪΜ btidtn itrtithtÄ * o * ftttHtn are, te tafi die Druoktlfftrt & t tittr dta Oiertoluiitttbereith tar Ktlbtnatangt in twtikalwtn gtitn the Ameohlag and 4a Xitttl sum Int It er en dt β second itrtioht by actuation of the three-way control valves forward 509814/0876 - 13 - - ■ "ν are seen, so that the gas with high pressure in the first area pushes the piston (59) to the other side of the cylinder the (60) presses 13. Circuit breaker according to claim 12, characterized by a bellows (8o) fence sealing the opening in one end of the cylinder (60), which at one end on the piston rod (63) and at the other bath at one end of the Actuating cylinder (60) is attached 14 · Circuit breaker according to claim 13, characterized in that there is a permanent pneumatic Hoohdruok connection with the first area in order to keep the first area permanently at high pressure * 15 · Circuit breaker according to claim 14, characterized in that the pneumatic actuator does not act on the alternating uptake and discharge of gas with high pressure in the pneumatic actuating cylinder (βθ) on the non-driving side of the driving piston (59), 16. Circuit interruption near claim 15, characterized in that the pneumatic BreiwegeYe & til (75) there » alternating printing and emptying dee oaeei the non-driving side of the driving piston (59) is adjusted, about the back and forth movement of the Kelbenetange (63) to effect. 509814/0876 «Η Blank page