EP0755564B1 - Device for tensioning the cut-in spring in actuator units for circuit breakers, in particular vacuum circuit breakers - Google Patents

Abstract

The invention concerns a device for tensioning the cut-in spring in actuator units for circuit breakers, in particular vacuum circuit breaker, the cut-in spring (7) being designed as a tensioning spring which is in contact with a cam (2) mounted on the cut-in shaft (5) and which can be tensioned both by an electric motor (20) and by a hand-turned shaft (21) through a spur-gear train, the last spur gearwheel (1) also being mounted on the cut-in shaft (5). The aim of the invention is to design a tensioning device in which the spur-gear train operates without overrunning, and reversing of the cam (2) is prevented or limited by the cut-in spring (7). This is achieved by virtue of the fact that the last spur gearwheel (1) in the spur-gear train is disposed over an overrunning bearing (6) on the cut-in shaft (5) in such a way that, when cut-in spring tensioning begins, the cam (2) and hence also the cut-in shaft (5), are carried directly by the last spur gearwheel (1) out of a position in which they are located past the bottom dead centre position (9) of the shaft (5) as the cam (2) rotates upwards, while, during the cut-in phase, the last spur gearwheel (1) is locked in position, when the cut-in shaft (5) turns through bottom dead centre (9), by the overrunning bearing (6) and by the operative connection with the other spur gearwheels in the spur-gear train.

Description

The invention relates to a device for tensioning the closing spring of drive devices for electrical circuit breakers, especially vacuum circuit breakers where the formed as a tension spring with the on the Starting shaft applied eccentric is connected and both by an electric motor and by a manual wind shaft with the interposition of a spur gear is exciting, with its last spur gear also on the Einschaltwelle is arranged, which is also the jack for release a switch-on process by the switch-on shaft and with the cam in operative connection with the cam wearing.

Is with electrical switching devices, so with circuit breakers high voltage, especially vacuum circuit breakers, the closing process finished, it depends on the vacuum circuit breaker prepare again for the next switch-on process, so that a switching sequence OFF - ON - OFF ensures becomes. This presupposes that after the switch-on process has ended the closing spring effecting the switch-on process is tensioned again so that the next switch-on process is prepared is. It stands in known drive devices for vacuum circuit breakers, the closing spring with an open an eccentric shaft in connection, so that upon release also arranged on the switch-on shaft Jack one that is still provided on the switch-on shaft Cam when rotating by about 180 °, conditional through the action of the switch-on spring designed as a tension spring, those in operative connection with the cam Pushes the switch lever into a position that corresponds to the switch-on position corresponds.

The preparation of the switch-on spring designed as a tension spring for the next switch-on process, that is, you can tension it such as the VEM company lettering "Low oil indoor circuit breaker" Hn / 65 / 77- 10000-7.77-IV / 1 / 17-565 - April 1976, taken from the VEB Schaltgerätewerk Muskau can be by applying a control voltage to a electric motor with the interposition of a gearbox that works with a push rod, a ratchet disc is rotated so that the eccentric on this ratchet disc attached closing spring is tensioned. Such a transmission is also for actuating the movable switch contact in High-voltage switchgear provided according to DD 296 378 A5.

In the known drive device for vacuum circuit breakers, where the closing spring with one on the closing shaft located eccentric is in between the electric motor and the switch-on shaft Gear is a spur gear, the last spur gear on the Starting shaft is loosely mounted. Will with this drive device the pawl arranged on the switch-on shaft released, the associated release of the tensioned closing spring of the eccentric and thus also the Starting shaft with the cam disc rotated by approx. 180 °. At this movement sequence of the switch-on shaft runs on this eccentric located on the pawl of a backstop, limited through the kinetic energy, over, so that the The closing spring is partially tensioned again. At that subsequent reversal of movement of the switch-on shaft and so that the eccentric also relaxes the partially tense Closing spring again and accelerates the closing shaft with their eccentric in the opposite direction of rotation, and for as long as until the eccentric strikes the pawl of the backstop.

In order to switch on the spring in this known drive device prepare for the next switch-on process the last spur gear of the Helical gearbox in the area of the engagement shaft one in axial Direction, circular segment-shaped projection. After Passing through an idle area beats the circular segment Projection of the loosely mounted spur gear on a fixed the drive pin connected to the switch-on shaft, takes the Starting shaft and thus the eccentric by turning it again 180 ° with and the closing spring is tensioned so that the vacuum circuit breaker for the next switch-on process is prepared.

The positions of the switch-on shaft and thus the eccentric are not considering the use of an electrical Motors bound, but these positions take up the engagement shaft and thus the eccentric and that on the switch-on shaft arranged pawl even when the operation of the Helical gearbox and thus the last one, on the closing shaft arranged spur gear for tensioning the closing spring a manual winding shaft is actuated, its additional arrangement not only necessary to carry out revisions but also by many operators of a vacuum circuit breaker, in addition to the electric motor as the drive becomes.

The invention has for its object a device for Tensioning the closing spring of drive devices for electrical Circuit breakers, especially vacuum circuit breakers, with the switch-on spring designed as a tension spring the eccentric mounted on the switch-on shaft stands and both by an electric motor and by a manual winding shaft with the interposition of a spur gear is tensionable, with its last spur gear also is arranged on the switch-on shaft, which is also the Pawl to release a switch-on process by the switch-on shaft as well as in operative connection with the switch lever standing cam, to create the spur gear works without idling and turning back the Eccentric prevented by the closing spring after switching on or limited and a clamping of the switch on the pawl connected to the switch-on shaft preparing the circuit breaker for the next one Switching on is avoided.

According to the invention this is achieved in that the last Spur gear of the spur gear via a freewheel bearing on the Einschaltwelle is arranged such that at the start of tensioning the closing spring of the eccentric and thus the closing shaft from a position in which they are in a position in the direction of rotation of the eccentric upwards behind the lower one Dead center of the switch-on shaft lies directly through the last spur gear can be taken while in the phase of switching on when the switch-on shaft rotates above its lower one Dead center the last spur gear through the freewheel bearing as well as through the operative connection with the other spur gears of the Helical gear is locked in position.

It is useful to ensure a long functional reliability of the Free wheel bearing and thus a long service life of the drive device to ensure for the circuit breaker when the freewheel bearing from the actual freewheel and one each Support bearings arranged on both sides of the freewheel consists. Both the freewheel and the two support bearings of the Freewheel bearings are preferably needle bearings, each also other bearings can be used without the function of Restrict free-wheel bearing.

In a further embodiment of the invention, the inner ring of the Freewheel of the freewheel bearing through the outer peripheral surface the switch-on shaft and the diameter of the needles of the freewheel is smaller than the distance between the outer peripheral surface the switch-on shaft and the inner circumference of the Outer ring of the freewheel, and they are evenly distributed on inner circumference of the outer ring arranged sawtooth-shaped surfaces, such that its greatest distance from the inner circumference of the Outer ring always on the opposite in the direction of rotation Side of the sawtooth-shaped surfaces is provided. To ensure functional reliability to secure this freewheel, have on arranged inner circumference of the outer ring of the freewheel sawtooth-shaped surfaces a slight slope.

According to a further feature of the invention, the needles of Freewheel of the freewheel bearing, when the closing spring is tensioned act against the sawtooth-shaped surfaces with a slight slope, under the force of spring elements, such that they on the sawtooth-shaped surfaces of the outer ring of the freewheel, that is in the clamping direction, can be pressed so that it is ensured that immediately when actuating the multi-stage spur gear by an electric motor or by a manual wind shaft through the last gear that sits on the engagement shaft that Starting shaft and thus also the one arranged on the starting shaft Eccentric is taken, so that with the eccentric related closing spring to prepare the next switch-on process. Because of the immediate Driving the switch-on shaft and thus the eccentric result not only shorter for tensioning the closing spring Clamping times, but because now the spur gear starts under load, i.e. no longer idles wear of the same is also reduced.

As a spring body on the needles of the freewheel of the freewheel bearing spring clips are preferably used, which is on the outer ring of the freewheel of the freewheel bearing support. Of course, the invention excludes the use any other spring body that is on the needles of the Freewheel acts and deviates from the spring clip.

This is a device for tensioning the invention Closing spring of drive devices for electrical circuit breakers, in particular vacuum circuit breakers, in which the last spur gear of the spur gear via Freewheel bearing is connected to the switch-on shaft. Thereby become shorter clamping times for tensioning the closing spring achieved and also achieved that the spur gear starts under load so that its wear is reduced.

The last spur gear rotates during the switch-on process, taking into account the free wheel bearing over which it is on the Einschaltwelle is arranged, but also in that the teeth this spur gear with the teeth of the next spur gear of the spur gear are engaged, not with.

A preferred embodiment of the device is that with the last one, over the freewheel bearing on the engagement shaft arranged spur gear a single-stage spur gear in connection stands, the spur gear with the largest diameter, with a spur gear attached to the manual wind shaft with a smaller one Diameter is engaged, and on the manual wind shaft a free-wheel bearing is also arranged, the one with receives a collar provided on its outer circumference a return spring is arranged, one end of which at one on the stop element arranged with a collar and the second end of a stop element, from two stop elements arranged on the rear wall of the switch drive is attached.

While the return spring, which is advantageously a torsion spring, arranged on the shaft of the collar provided with a collar can be, the two on the rear wall of the switch drive attached stop elements by, for example, 180 ° be staggered. It is possible to go through the staggered arrangement of the stop elements achieved To achieve effect at a different angle, for example, if they are offset by 30 ° to each other are. Preferably in the rear wall of the switch drive and the manual winding shaft is also mounted in its front wall.

To turn on the circuit breaker, in particular Vacuum circuit breaker, a turning back of the eccentric through the Switch-on spring in the direction of the bottom dead center of the switch-on shaft to avoid, or at least to limit it so that at the start of tensioning the closing spring, the eccentric and thus the switch-on shaft take a position in the direction of rotation of the eccentric upwards behind the bottom dead center the switch-on shaft is located, but especially also after the stop the pawl connected to the switch-on shaft, at which Preparation of the vacuum circuit breaker for the next switch-on process to prevent the catch from jamming, is both after opening the circuit breaker the return angle of the eccentric as well as after the stop of the pawl connected to the switch-on shaft on the switch-on shaft the return angle of the pawl is limited.

This is done in that after the stop with the a collar-provided socket connected stop element on the one lying in the direction of rotation of the socket stop element arranged on the rear wall of the switch drive, both stop elements together with the freewheel bearing and the collar with a collar, for the single-stage Helical gearbox and thus a backstop for the engagement shaft form. It is with the attack of the Socket-related stop element on the in Direction of rotation of the socket initially lying on the rear wall of the Switch drive arranged stop element, the return spring curious; excited.

By creating a backward rotation angle through the backstop is limited, not only after the switch-on process a possible reversal of movement of the Einschaltwelle with their Components prevented, but it is also ensured that after the pawl hard hit the on pawl, the pawl connected to the switch-on shaft can turn back a small angle. By the resulting Relaxing the impact force is not just one The pawl is unlocked, but it will also ensured that the lift spring when the elevator by the electric motor or when winding by hand crank No faults occur via the manual winding shaft.

It is advantageous that in the device according to the invention the freewheel bearing when preparing the circuit breaker for the next switch-on, by actuation of the single-stage spur gear via the electric motor as an elevator motor or the manual winding shaft with a collar provided socket releases, so that by relaxing the return spring the socket can be rotated in the opposite direction until the stop element connected to the socket arranged on the second, on the rear wall of the switch drive Stop element strikes.

Taking into account the tensioning of the closing spring a low engine torque can be made, but also at a low speed of the last spur gear and thus To reach the switch-on shaft, the single-stage gearbox a big reduction on.

It is useful that as a single-stage spur gear a large reduction gearbox is used that from an elliptical, attachable to the shaft of the electric motor There is a socket on its outer circumference Ball bearing receives an externally toothed elastic ring that in its large ellipse axis concentric with the wave of the electric motor arranged internal teeth of two one above the other engages rings, one of which Ring is attached to the housing of the electric motor and the second ring carries a double spur gear, of which the spur gear the smallest diameter with the last on the closing shaft arranged spur gear is engaged, the externally toothed elastic ring has fewer teeth than one the two with an internal toothing, one above the other arranged rings, the other with internal teeth provided ring has the same number of teeth as the externally toothed elastic ring.

The invention is intended to be based on an exemplary embodiment are explained in more detail.

Fig. 1

die Einschaltwelle mit dem auf ihr aufgebrachten letzten Stirnrad eines Stirnradgetriebes in der Ausschaltstellung,

Fig. 2

die Einschaltwelle mit dem auf ihr aufgebrachten letzten Stirnrad nach Fig. 1 in der Einschaltstellung,

Fig. 3

eine schematische Darstellung des Freilaufes eines Freilauflagers, über das das letzte Stirnrad auf der Einschaltwelle angeordnet ist,

Fig. 4

eine weitere schematische Darstellung des Freilaufes nach Fig. 3 in der Vorderansicht in Verbindung mit an den Stirnseiten angeordneten Stützlagern,

Fig. 5

die Einschaltwelle in der Ausschaltstellung nach Fig.1 in Wirkverbindung mit einem einstufigen Stirnradgetriebe sowie der Handaufzugswelle,

Fig. 6

die Einschaltwelle nach Fig. 5 in der Einschaltstellung,

Fig. 7

die Draufsicht auf die Einschaltwelle nach Fig. 6.

In the accompanying drawing:

Fig. 1

the switch-on shaft with the last spur gear of a spur gear set in the off position,

Fig. 2

1 in the switch-on position, with the last spur gear according to FIG. 1 applied to it,

Fig. 3

1 shows a schematic illustration of the freewheel of a freewheel bearing, via which the last spur gear is arranged on the switch-on shaft,

Fig. 4

3 shows a further schematic illustration of the freewheel according to FIG. 3 in front view in connection with support bearings arranged on the end faces,

Fig. 5

the switch-on shaft in the switch-off position according to FIG. 1 in operative connection with a single-stage spur gear and the manual winding shaft,

Fig. 6

5 in the switch-on position,

Fig. 7

6 shows the top view of the switch-on shaft according to FIG. 6.

1 shows, in addition to the last spur gear 1 not shown multi-stage spur gear also Eccentric 2, a cam 3 and a pawl 4, over the the switch-on process is triggered on the switch-on shaft 5 a drive device for an electrical circuit breaker, in particular vacuum circuit breakers arranged. While the eccentric 2, the cam 3 and the pawl 4 fixed are arranged on the switch-on shaft 5, the last spur gear 1 of the multi-stage spur gear via a freewheel bearing 6, which is shown in more detail in FIGS. 3 and 4, on the switch-on shaft 5 arranged. In the switch-off position shown here is the one connected to the eccentric 2, as Tension spring trained closing spring 7 tensioned, i.e. that the Drive device for triggering a switch-on process on Vacuum circuit breaker is prepared. The triggering of the switch-on process is done by releasing the pawl 4 by a further jack, also not shown, which for Drive device belongs. Is the switch-on process through Release of the pawl 4 is triggered by the closing spring 7 not only the pawl 4, but also the eccentric 2 and so that the switch-on shaft 5 and the cam 3, which with a switch lever also not shown in Active connection is brought about 180 ° in the direction of arrow 8 turned. The eccentric 2 passes through, due to the Kinetic energy, the bottom dead center 9 of the switch-on shaft 5, until finally the switch-on shaft 5, the eccentric 2 and the Pawl 4 assume the position shown in Fig. 2, in which the closing spring 7 is relaxed.

If the closing spring 7 is now to be tensioned in order to trigger it to prepare another switch-on process thus the switch-on shaft 5, the eccentric 2 with the switch-on spring 7, the cam plate 3 and the pawl 4 from that of FIG. 2 apparent position are brought into the position shown in Fig. 1, in which the closing spring 7 is tensioned by the last spur gear 1 of the multi-stage spur gear immediately at the start of actuation of the multi-stage spur gear via the freewheel 6, the switch-on shaft 5 and thus the Eccentric 2 taken along until the eccentric 2 corresponds to the position 1, in which the closing spring 7 is tensioned, So prepared to trigger the next switch-on process is. The fact that the switch-on shaft 5 and the eccentric 2 immediately carried by the multi-stage spur gear the clamping times of the closing spring 7 are shortened. The multi-stage helical gearbox starts up under load there is no idling and the wear becomes significant reduced. When using a single-stage spur gear the same advantages result.

4 there is the freewheel bearing 6, via which the last Spur gear 1 of the multi-stage spur gear according to FIGS. 1 and 2 is arranged on the switch-on shaft 5, from the actual Freewheel 10 and the two support bearings 11, the freewheel 10th limit at the front. Both the freewheel 10 and the Support bearings 11 are needle bearings. As can be seen in connection with FIG. 3 is the inner ring of the freewheel 10 of the freewheel bearing 6 through the outer peripheral surface of the switch-on shaft 5 formed, and in the space 12 between this peripheral surface and the inner circumference of the outer ring 13 of the freewheel 10 needles 14 are arranged, the diameter of which is smaller than the distance between the outer peripheral surface of the switch-on shaft 5 and the inner circumference of the outer ring 13 of the freewheel 10. These needles 14 have sawtooth-shaped surfaces 15 low gradient in active connection, evenly distributed arranged on the inner circumference of the outer ring 13 of the freewheel 10 are so that their greatest distance to the inner The circumference of the outer ring 13 is always in the direction of rotation (arrow direction 8 - Figs. 1 and 2) opposite side of the sawtooth Surfaces 15 is provided. The needles are there 14 of the freewheel 10 of the freewheel bearing 6 under the force of Spring bodies 16, which are designed as spring clips, so that the needles 14 on the sawtooth-shaped surfaces 15 of the outer ring 13 of the freewheel 10, that is to say in the clamping direction, can be pressed are. This creates the conditions for immediately upon initiation of multi-stage operation Helical gearbox, i.e. also the rotation of the last spur gear 1 for the purpose of tensioning the closing spring 7, the closing shaft 5 and thus also the eccentric 2 taken along by the last spur gear 1 the clamping process until after turning by approx. 180 ° the closing spring 7 is completed.

In the device according to Fig.5; 6 and 7 is first of the Started using a single-stage spur gear 17. In addition to the last spur gear 18 of the same are on the closing shaft 5 of the switching drive also an eccentric 2, one Cam 3 and a pawl 4 on the switch-on after release by a latch 19 is arranged. The eccentric 2, the cam 3 and the pawl 4 fixedly arranged on the switch-on shaft 5 while the last spur gear 18 of the single-stage spur gear 17th Arranged via the freewheel bearing 6 on the switch-on shaft 5 is.

While in the switch-off position shown in FIG. 5, the connected to the eccentric 2, designed as a tension spring Closing spring 7 is tensioned so that the drive device to trigger a switch-on process at the vacuum circuit breaker is prepared from Fig. 6 that the Switch-on spring 7 is relaxed, the switch-on spring 7, the Eccentric 2 and thus the switch-on shaft 5 are in one position located in the direction of rotation of the eccentric 2 upwards lies behind the bottom dead center 9 of the switch-on shaft 5.

If, starting from the position shown in FIG Switch-on spring 7, this to trigger a further switch-on process to be excited, it is necessary the Starting shaft 5, the eccentric 2 with the closing spring 7, the Cam 3 and the pawl 4 of the one shown in Fig. 6 Bring position in the position shown in FIG. 5. To do this through the last spur gear 18 of the single-stage spur gear 17 immediately after its actuation by an electric Motor 20 as an elevator motor after this has a control voltage received, or through the manual wind shaft 21 (Fig.7) the switch-on shaft 5 and thus the eccentric 2 taken along. This entrainment takes place until the eccentric 2 as shown in FIG. 5 Has assumed the position in which the closing spring 7 so excited to trigger the next switch-on process is prepared.

But now to ensure that after the hard attack the Jack 4 on the pawl 19, the one with the switch-on shaft 5 related pawl 4 through a small angle can turn back, there is also a backstop 22, as shown in Fig.7, provided by the for turning back the pawl 4 has a limited reverse rotation angle is provided. But that means that the impact force can relax and thus blocking the pawl 19 is canceled. The backstop 22 is simultaneously but also achieved that after switching on a possible Reversal of movement of the switch-on shaft 5 with its components, thus also the closing spring 7, at least prevents it to a limited extent becomes.

As shown in Figure 7, the spur gear 23 is the largest Diameter of the single-stage spur gear 17 with a the manual winding shaft 21 fixed spur gear 24 with a small Diameter engaged. It is also on the manual wind shaft 21 a one-way bearing 25 is arranged, one with a Bund 26 provided socket 27 receives on its outer circumference a return spring 28 is arranged. While one end 29 the return spring 28 on one arranged on the socket 27 Stop element 30 is attached, the second end 31 is the return spring 28 arranged on the shaft 32 of the bushing 27, with a stop element 33, two offset by 180 ° to each other stop elements attached to the rear wall 34 of the switch drive 33; 35. In this training is the Manual winding shaft 21 not only in the rear wall 34 but also stored in the front wall 36 of the switch drive.

Through the, essentially through the bushing 27, the return spring 28, the stop elements 30; 33; 35 and by the Freewheel bearing 25 backstop 22 is both after the turning angle of the vacuum circuit breaker of the eccentric 2 and after the stop with the switch-on shaft 5 connected pawl 4 on the pawl 19 the reverse rotation angle is limited. This is done by after the Stop of the stop element connected to the socket 27 30 on the closest in the direction of rotation of the socket 27 Stop element 33, both stop elements 30; 33 together with the freewheel bearing 25 and the bushing 27 for that single-stage spur gear 17 and thus for the engagement shaft 5 form a backstop 22. Both stop elements stand 30; 33 in contact with one another, then the return spring 28 curious; excited.

In contrast, in the preparation phase of the vacuum circuit breaker for the next switch-on process by actuating the single-stage spur gear 17 via the electric motor 20 as an elevator motor or the manual winding shaft 21 the freewheel bearing 25 which is provided with a collar 26 Bushing 27 free, so that by relaxing the return spring 28th the socket 27 is rotated in the opposite direction. This Rotation continues until it connects to the socket 27 standing stop element 30 on the second, on the rear wall 34 of the switch drive arranged stop element 35, strikes.

As a single-stage spur gear 17, one with a large one Reduction provided, as is also the case as a harmonic drive gear is known. The one ring 37 of two is one above the other arranged rings 37; 38 of this transmission on the housing 39 of the electric motor 20 and the second ring 38 carries a double spur gear 40, the spur gear 41 with the smallest Diameter with the last arranged on the switch-on shaft 5 Spur gear 18 is engaged. By using it of the single-stage spur gear 17 and its adaptation the conditions of the switch drive for a circuit breaker, especially a vacuum circuit breaker under Consideration of the manual winding shaft 21, but also the backstop 22 is by the device according to the invention at the same time influenced a reduction in the conversion Space in relation to the spur gear and thus on the Costs.

Claims (17)

1. Device for tensioning the closing spring of drive devices for electrical circuit breakers, in particular vacuum circuit breakers, in the case of which the closing spring (7), which is designed as a tension spring, is connected to the eccentric (2) which is fitted on the closing shaft (5), and can be tensioned both by an electric motor (20) and by a manual tightening shaft (21) with the interposition of spur gearing, the last spur gear (1) of the latter likewise being arranged on the closing shaft (5), which is also fitted with the catch (4) for initiating a closing process by means of the closing shaft (5) and with the cam disc (3) which is operatively connected to the closing lever, characterized in that the last spur gear (1) of the spur gearing is arranged via a freewheeling bearing (6) on the closing shaft (5), in such a manner that, at the start of tensioning of the closing spring (7), the eccentric (2) and thus the closing shaft (5) can be driven directly by the last spur gear (1) from a position in which they are located after the bottom dead centre (9) of the closing shaft (5) in the rotation direction of the eccentric (2) towards the top, while, in the phase of the closing process during rotation of the closing shaft (5) beyond its bottom dead centre (9), the last spur gear (1) is locked in its position by the freewheeling bearing (6) and by the operative connection to the other spur gears of the spur gearing.
2. Device according to Claim 1, characterized in that the freewheeling bearing (6) is composed of the freewheeling mechanism (10) and of in each case one supporting bearing (11), which supporting bearings are arranged on both sides of the freewheeling mechanism (10).
3. Device according to Claims 1 and 2, characterized in that both the freewheeling mechanism (10) and the supporting bearings (11) of the freewheeling bearing (6) are needle bearings.
4. Device according to Claims 1 to 3, characterized in that the inner ring of the freewheeling mechanism (10) of the freewheeling bearing (6) is formed by the outer circumferential surface of the closing shaft (5), in that the diameter of the needles (14) of the freewheeling mechanism (10) is less than the distance between the outer circumferential surface of the closing shaft (5) and the inner circumference of the outer ring (13) of the freewheeling mechanism (10), and in that sawtooth-shaped surfaces (15) are arranged distributed uniformly on the inner circumference of the outer ring (13), in such a manner that their greatest distance from the inner circumference of the outer ring (13) is always provided on the side of the sawtooth-shaped surfaces (15) which is opposite in the rotation direction.
5. Device according to Claim 4, characterized in that the sawtooth-shaped surfaces (15) which are arranged on the inner circumference of the outer ring (13) of the freewheeling mechanism (10) have a shallow gradient.
6. Device according to Claims 1 to 5, characterized in that the needles (14) of the freewheeling mechanism (10) of the freewheeling bearing (6) are subject to the force of spring bodies (16) in such a manner that they can be pressed onto the sawtooth-shaped surfaces (15) of the outer ring (13) of the freewheeling mechanism (10), that is to say in the clamping direction.
7. Device according to Claim 6, characterized in that the spring bodies (16) are spring clips which are supported on the outer ring (13) of the freewheeling mechanism (10) of the freewheeling bearing (6).
8. Device according to Claims 1 to 7, characterized in that a single-stage spur gearing (17) is connected to the last spur gear (18), which is arranged above the freewheeling bearing (6) on the closing shaft (5), and its spur gear (23) having the largest diameter engages with a spur gear (24) which is mounted on the manual tightening shaft (21) and has a small diameter, and in that a freewheeling bearing (25) is furthermore arranged on the manual tightening shaft (21) and holds a bush (27), which is provided with a collar (26), on whose outer circumference a restoring spring (28) is arranged, one of whose ends (29) is mounted on a stop element (30), arranged on the bush (27) which is provided with a collar (26), and the second end (31) of which is mounted on a stop element (33) of two stop elements (33; 35) which are arranged on the rear wall (34) of the circuit breaker drive.
9. Device according to Claim 1, characterized in that the restoring spring (28) is arranged on the shank (32) of the bush (27) which is provided with a collar (26).
10. Device according to Claims 8 and 9, characterized in that the restoring spring (28) is designed as a rotating spring.
11. Device according to Claims 8 to 10, characterized in that the two stop elements (33; 35) which are mounted on the rear wall (34) of the circuit breaker drive are arranged offset with respect to one another through a predetermined angle, preferably of 180°.
12. Device according to Claims 8 to 11, characterized in that the manual tightening shaft (21) is mounted at one end in the rear wall (34) and at the other end in the front wall (36) of the circuit breaker drive.
13. Device according to Claims 8 to 12, characterized in that, not only is the backlash angle of the eccentric (2) limited after the closing of the circuit breaker, but the backlash angle of the catch (4) is also limited after said catch (4), which is connected to the closing shaft (5), stops on the closing catch (19), in that, after the stop element (30), which is connected to the bush (27) which is provided with a collar (26), has stopped on the stop element (33) which is located first in the rotation direction of the bush (15) and is arranged on the rear wall (34) of the circuit breaker drive, the two stop elements (30; 33) form a non-return stop (22), together with the freewheeling bearing (25) and the bush (27), for the single-stage spur gearing (17), and thus for the closing shaft (5).
14. Device according to Claims 8 to 13, characterized in that the restoring spring (28) is stressed when the stop element (30) which is connected to the bush (27) stops on the stop element (33) which is located first in the rotation direction of the bush (27) and is arranged on the rear wall (34) of the circuit breaker drive.
15. Device according to Claims 8 to 14, characterized in that, during the preparation of the circuit breaker for the next closing process by operation of the single-stage spur gearing (17) via the electric motor (20), as a tightening motor, or of the manual tightening shaft (21), the freewheeling bearing (25) releases the bush (27) which is provided with a collar (26), so that the bush (27) can be rotated in the opposite direction as a result of the relief of the stress on the restoring spring (28), until the stop element (30), which is connected to the bush (27), stops on the second stop element (35), which is arranged on the rear wall (34) of the circuit breaker drive.
16. Device according to Claims 8 to 15, characterized in that the single-stage spur gearing (17) has a high step-down ratio.
17. Device according to Claims 8 to 16, characterized in that the single-stage spur gearing (17) having a high step-down ratio is composed of an elliptical bush which can be fitted onto the shaft of the electric motor (20) and holds on its outer circumference, via a ball bearing, an elastic ring which has external teeth and on its major ellipse axis engages in the internal tooth system, which is arranged concentrically with respect to the shaft of the electric motor (20), of two rings (37; 38) which are arranged one above the other, one ring (37) of which is mounted on the housing (39) of the electric motor (20) and the second ring (38) is fitted with a double spur gear (40), of which the spur gear (41) having the smallest diameter engages with the last spur gear (18) arranged on the closing shaft (5), the elastic ring which has external teeth having fewer teeth than one of the two rings (37; 38) which are provided with an internal tooth system and are arranged one above the other, the other ring which is provided with an internal tooth system having the same number of teeth as the elastic ring which has external teeth.

Images