WO2015181087A1

WO2015181087A1 - Circuit breaker comprising an improved actuating shaft

Info

Publication number: WO2015181087A1
Application number: PCT/EP2015/061436
Authority: WO
Inventors: Volker Heins
Original assignee: Eaton Electrical Ip Gmbh & Co. Kg
Priority date: 2014-05-30
Filing date: 2015-05-22
Publication date: 2015-12-03
Also published as: DE112015002576A5; DE102014107628A1

Abstract

Disclosed is a circuit breaker (1) comprising a housing (2) and an actuating shaft (7) which is rotatably mounted therein and which includes a first shaft bearing surface (11) corresponding to a first housing bearing surface (13) in the housing (2), and a second shaft bearing surface (12) corresponding to a second housing bearing surface (14) in the housing (2). The two shaft bearing surfaces (11, 12) extend coaxially, and the radius of the first shaft bearing surface (11) is smaller than the radius of the second shaft bearing surface (12). In addition, the first shaft bearing surface (11) has the shape of a cylinder sleeve segment.

Description

Circuit breaker with improved selector shaft

TECHNICAL AREA

The invention relates to a circuit breaker comprising a housing and a rotatably mounted therein switching shaft, wherein the switching shaft has a first shaft bearing surface which corresponds to a first Gehäuselagerfiäche in the housing, and a second

Shaft bearing surface, which corresponds to a second Gehäuselagerfiäche in the housing, and wherein the two shaft bearing surfaces are arranged coaxially and wherein the radius of the first shaft bearing surface is smaller than the radius of the second shaft bearing surface.

STATE OF THE ART

EP 0 209 058 A2 discloses a circuit breaker with a housing and a switching shaft rotatably mounted therein. In the shift shaft, a contact arm is rotatably mounted, which has at its free end a contact in the ON state of

Circuit breaker is pressed against a fixed contact in the housing. Thus, the shift shaft is mechanically stable, the bearing seats formed by externally cylindrical shaft bearing surfaces are relatively large. The disadvantage is that the torque required to rotate the selector shaft is relatively large because of the frictional forces acting far on the outside.

From EP 0 619 590 AI another circuit breaker of the above type is known, however, the bearing seats formed by externally cylindrical shaft bearing surfaces are relatively small. This reduces the torque required to rotate the selector shaft, but this procedure also considerably reduces the mechanical stability of the selector shaft.

Finally, WO 2006/120149 A1 discloses a circuit breaker with a

Switch shaft and a rotatably mounted therein contact arm. The contact arm has a contact at its free end, which is fixedly arranged in the housing Contact is pressed. The circuit breaker has fixed, bolted to the housing tabs, which in the assembly of the shift shaft in pockets of

Submerse shift shaft. The tabs have at their end facing the switching shaft bores, in which axes for rotatable mounting of the shift shaft is introduced. The axes and tabs are made of steel for reasons of strength and thus cause additional costs, especially because they must be isolated from live parts.

DISCLOSURE OF THE INVENTION

An object of the invention is therefore to provide an improved circuit breaker.

In particular, the shift shaft is easy to turn, mechanically stable and yet

be inexpensive and can be easily installed in the housing of the circuit breaker.

This object is achieved with a circuit breaker of the type mentioned, in which the first shaft bearing surface is formed in the form of a cylinder jacket segment. In other words, the first shaft bearing surface does not comprise a full cylinder jacket or encloses an angle of <360 °.

As a result, the shift shaft can also be supported centrally, without thereby

Torque for actuating the shift shaft would increase significantly. At the same time, the switching shaft is extremely stable due to the special construction, since the cross section and thus the axial area moments of inertia and the polar area moment of inertia are comparatively large. Finally, the assembly of the switching shaft in the housing is also very simple, since this only has to be used between two housing halves, without causing a complicated threading of an axle (as in WO

2006/120149 AI) would be necessary.

Further advantageous embodiments and modifications of the invention will become apparent from the dependent claims and from the description in conjunction with the figures.

It is particularly advantageous if, in the ON state of the circuit breaker or during a movement into this state, a bearing force directed onto the first shaft bearing surface acts. This is the circuit breaker during the turn-on

relatively easy. It is particularly advantageous if, in the OFF state or in the TRIPPED state of the circuit breaker or during a movement into this state / in these states, a bearing force directed onto the second shaft bearing surface acts. As a result, the circuit breaker is also during the turn-off or during the

Tripping process relatively smooth.

It is advantageous, although the second shaft bearing surface in the form of a

Cylinder shell segment is formed. Thus, both shaft bearing surfaces are formed in the form of cylinder jacket segments. In other words, includes the second

Shaft bearing surface no full cylinder shell or encloses an angle of <360 °. As a result, the shift shaft can be structurally simpler under certain circumstances.

In particular, in the above context, it is advantageous if the first shaft bearing surface extends at least in sections in an angle region which is free of the second shaft bearing surface. Thereby, the two shaft bearing surfaces can be arranged substantially opposite each other, in particular at the same axial position. It is furthermore advantageous if the first shaft bearing surface is concave and the second

Shaft bearing surface are convex. Thus, the switching shaft has a formed as a partial surface of an inner cylinder first shaft bearing surface which cooperates with a partial surface of an outer cylinder of the housing. In addition, the switching shaft designed as a (part) surface of a coaxially arranged outer cylinder second

Shaft bearing surface which cooperates with a (part) surface of an inner cylinder.

In the above context, it is particularly advantageous if the cylinder jacket segment assigned to the first shaft bearing surface has an angle of at most 180 °. This allows the shift shaft in a simple manner to a housing projection with the first

Housing bearing surface are placed. It is also advantageous if both shaft bearing surfaces are convex. Thus, the switching shaft has a formed as a partial surface of an outer cylinder first shaft bearing surface which cooperates with a partial surface of an inner cylinder of the housing. In addition, the switching shaft on a (part) surface of a coaxially arranged outer cylinder formed second shaft bearing surface, which also cooperates with a (part) surface of an inner cylinder. It is particularly advantageous in the above context, if one of the first

Housing bearing surface associated cylinder jacket segment has an angle of 180 ° maximum. This allows the shift shaft in turn easily to a

Housing projection to be fitted with the first housing bearing surface.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will be explained in more detail with reference to the exemplary embodiments indicated in the schematic figures of the drawing. It shows:

Fig. 1 is an oblique view of an exemplary circuit breaker;

FIG. 2 shows the circuit breaker from FIG. 1 with the housing cover lifted off; FIG.

Fig. 3 seen the shift shaft from the circuit breaker of Figures 1 and 2 obliquely from below;

Fig. 4, the lower housing part of the circuit breaker of Figures 1 and 2 viewed obliquely from above;

5 shows a longitudinal section through the circuit breaker in the region of the switching shaft.

6 shows a first cross section through the circuit breaker in the region of the switching shaft.

7 shows a second cross section through the circuit breaker in the region of the switching shaft.

Fig. 8 is a schematic representation of the switching shaft contact arrangement at

closed contact switch and

Fig. 9 is a schematic representation of the switching shaft contact arrangement with open

Schaltontakt.

DETAILED DESCRIPTION OF THE INVENTION

1 shows an oblique view of an exemplary circuit breaker 1, which has a housing 2 which comprises a housing lower part 3 and a housing upper part 4. Furthermore, the circuit breaker 1 includes terminals 5 and an actuator 6 for switching on and off of the circuit breaker 1 respectively for displaying the switching state of

Circuit breaker 1. Fig. 2 shows the circuit breaker 1 of FIG. 1 with lifted housing upper part 4, whereby the view is released into the interior of the circuit breaker 1. In the circuit breaker 1 is a

Shift shaft 7 rotatably mounted. In turn, a plurality of contact arms 8 are rotatably mounted in the switching shaft 7, which each have a switching contact 9 at its end. In the

Closed position, the contact arm 8 and the switch contact 9 is pressed against a housing-fixed contact, so that the terminals 5 and 10 are electrically connected. When excessive current through the terminals 5 and 10 of the contact arm 8 is spun by electrodynamic forces and remains after the triggering until the rotation of the switching shaft 7 in the OFF position in the OPEN position. Fig. 3 now shows the switching shaft 7 seen from the circuit breaker 1 of Figures 1 and 2 obliquely from below. Well visible are the recesses for the contact arms 8 and a plurality of first shaft bearing surfaces 11 and second shaft bearing surfaces 12th

Fig. 4 shows the housing lower part 3 shown separately of the circuit breaker 1 of

Figures 1 and 2 viewed obliquely from above. In particular, 4 projections with first housing bearing surfaces 13 can be seen from FIG.

5 shows a longitudinal section through the circuit breaker 1 in the region of the switching shaft 7. From FIG. 5 it is apparent, in particular, that the first shaft bearing surface 11 with the first housing bearing surface 13 and the second shaft bearing surface 12 with a second

Housing bearing surface 14 in the housing 2 corresponds. Fig. 6 also shows a first cross section AA through the circuit breaker 1 in the region of the switching shaft 7 at the level of a connecting lever 15, which connects the switching shaft 7 with a known per se and therefore not shown switching mechanism. On the

Switching mechanism, the actuating element 6 and the switching shaft 7 are coupled together. The connecting lever 15 is connected by means of a bolt 16 with the switching shaft 7 and by means of a bolt 17 with the switching mechanism.

Fig. 7 also has a second cross-section BB through the circuit breaker 1 in the region of the switching shaft 7, from which in particular the interaction of the first

Shaft bearing surface 11 with the first housing bearing surface 13 and the second

Shaft bearing surface 12 with the second housing bearing surface 14 can be seen. In summary, this results in a circuit breaker 1, comprising a housing 2 and a rotatably mounted therein switching shaft 7,

wherein the switching shaft 7 has a first shaft bearing surface 11, which corresponds to a first housing bearing surface 13 in the housing 2, and a second

Shaft bearing surface 12, which corresponds to a second housing bearing surface 14 in the housing 2,

wherein the two shaft bearing surfaces 11, 12 are arranged coaxially (about the axis x), wherein

wherein the radius of the first shaft bearing surface 11 is smaller than the radius of the second shaft bearing surface 12, and wherein

the first shaft bearing surface 11 is formed in the form of a cylinder jacket segment.

In the example shown concretely in the figures, the second shaft bearing surface 12 is also designed in the form of a cylinder jacket segment. The two shaft bearing surfaces 11 and 12 therefore each enclose an angle of <360 °. In particular, the cylinder jacket segment assigned to the first shaft bearing surface 11 has an angle of <180 °.

The first shaft bearing surface 11 extends in the example shown also at least

in sections in an angle region free of the second shaft bearing surface 12 and is arranged substantially opposite the second shaft bearing surface 12. The two shaft bearing surfaces 11 and 12 are in particular at the same axial position. Another feature of the arrangement shown in the figures is that the first

Shaft bearing surface 11 is concave and the second shaft bearing surface 12 is convex. That is, the first shaft bearing surface 11 is formed as a partial surface of an inner cylinder, and the first housing bearing surface 13 is formed as a partial surface of an outer cylinder. In addition, the second shaft bearing surface 12 is formed as a partial surface of an outer cylinder, and the second housing bearing surface 14 is formed as a partial surface of an inner cylinder.

The proposed measures have a number of advantages:

In particular, from Fig. 7 it can be seen that the switching shaft 7 with the first

Shaft bearing surface 11 on the first housing bearing surface 13 having projection in

Housing base 3 can be placed. That is, the threading of a separate axis is eliminated, whereby the assembly process of the shift shaft 7 is very easy. Essentially, the assembly of the switching shaft 7 is completed by placing the upper housing part 4.

In particular, from Fig. 7 is further apparent that the shift shaft also on Height of the first shaft bearing surface 11 has a comparatively large cross-section, whereby the axial area moments of inertia and the polar

Area of inertia are relatively large. That is, the shift shaft 7 is extremely stable to bending and torsional loads.

From Figures 4 and 5 is also apparent that the shift shaft 7 is not only supported at the ends, but also centrally. This is another measure that counteracts excessive deformation of the shift shaft 7. Due to the great rigidity of the shift shaft can be waived in principle but also outside bearings.

The torque for actuating the shift shaft 7 is very small because of the small radius of the first shaft bearing surface 11. At least, this relates to the ON state and the power-on process. Figures 8 and 9 illustrate what is meant by it.

8 shows a schematic representation of the switching shaft contact arrangement in the ON state with the switching contact closed, that is to say the switching mechanism (not shown) generates a counterclockwise torque on the switching shaft 7 via the connecting lever 15. This makes the contact arm 8 with the contact 9 against the

Connection 5 is pressed. It act the schematically represented forces, namely the

Contact force F _K , the lever force F _R and the bearing force F _L. From Fig. 8 it can be seen that the bearing force F _{L is directed} in this state on the first shaft bearing surface 11. Due to the lever lengths, the bearing force F _{L is} relatively large. However, this hardly interferes because the frictional force caused by the bearing force F _L due to the small radius of the first shaft bearing surface 11 causes only a small torque, which counteracts the lever force F _R. This means that the circuit breaker 1 is comparatively smooth during the switch-on process.

Fig. 9 shows the arrangement of Fig. 8 now open or opening contact, that is, the OFF state of the circuit breaker 1 and the RELEASE state. In this state act on the shift shaft 7 because of the omission of the

Contact force F _K only comparatively small forces, specifically the lever force F _R and the bearing force F _L. From Fig. 9 it can be seen that the bearing force F _{L is directed} in this state on the second shaft bearing surface 12. Although attacks by the bearing force F _L

caused frictional force significantly further out than in the state shown in FIG. 8, but this is also much smaller because of the low bearing force F _L.

All in all, said frictional force calls only a small amount of leverage F _R

counteracting torque, which remains in a manageable frame. The means that the circuit breaker 1 is relatively smooth even in this switching state and during the turn-off.

By the proposed measures, the shift shaft 7 is therefore on the one hand very stable, easy to install and well stored, but on the other hand also remains in the various

Switching states of the circuit breaker 1 always smoothly.

In the examples shown in the figures, it has always been assumed that the first shaft bearing surface 11 is concave. But this is not a necessary condition for the invention. Similarly, it is conceivable that both shaft bearing surfaces 11, 12 are convex. The switching shaft 7 then has a partial surface of an outer cylinder formed as the first shaft bearing surface 11, which cooperates with a partial surface of an inner cylinder of the housing 2. The bearing the first housing bearing surface 13

Projection (see Fig. 4) then has a corresponding hollow cylindrical recess. This advantageously has the first housing bearing surface 13 associated

Cylinder shell segment at an angle of <180 °, so that the shift shaft 7 can be mounted by simply assembling the housing halves 3 and 4.

It is also generally conceivable that the first shaft bearing surface 11 and the second

Shaft bearing surface 12 are not located at the same axial position. The first

Shaft bearing surface 11 thus does not necessarily extend at least in sections in an angle region free of the second shaft bearing surface 12 and is therefore not necessarily disposed substantially opposite the second shaft bearing surface 12.

Finally, it is noted that the circuit breaker 1 and its components are not necessarily shown to scale and therefore may have other proportions. Furthermore, a circuit breaker 1 may also comprise more or fewer components than illustrated. Location information (for example, "top", "bottom", "left", "right", etc.) are based on the respective figure described and are in a change in position of the circuit breaker 1 mutatis mutandis to adapt to the new situation. Finally, it is noted that the above embodiments and developments of the invention in any way

combine.

Claims

claims

A circuit breaker (1) comprising a housing (2) and a control shaft (7) rotatably mounted therein,

- Wherein the switching shaft (7) has a first shaft bearing surface (1 1), which with a first housing bearing surface (13) in the housing (2) corresponds, and a second

Shaft bearing surface (12) which corresponds to a second housing bearing surface (14) in the housing (2),

wherein the two shaft bearing surfaces (1 1, 12) are arranged coaxially and

- wherein the radius of the first shaft bearing surface (1 1) is smaller than the radius of the second shaft bearing surface (12),

characterized in that

the first shaft bearing surface (1 1) is designed in the form of a cylinder jacket segment.

2. Circuit breaker (1) according to claim 1, characterized in that in its ON state or during a movement in this state one on the first

Shaft bearing surface (1 1) directed bearing force (F _L ) acts.

3. Circuit breaker (1) according to claim 1, characterized in that in its OFF state respectively the RELEASE state or during a movement in this state / in these states on the second shaft bearing surface (12) directed bearing force (F _L ) acts ,

4. Circuit breaker (1) according to one of claims 1 to 3, characterized in that the second shaft bearing surface (12) is formed in the form of a cylinder jacket segment.

5. Circuit breaker (1) according to claim 4, characterized in that the first

Shaft bearing surface (1 1) at least in sections in one of the second

Shaft bearing surface (12) free angle range runs.

6. Circuit breaker (1) according to one of claims 1 to 5, characterized in that the first shaft bearing surface (11) is concave and the second shaft bearing surface (12) is convex.

7. Circuit breaker (1) according to claim 6, characterized in that the first shaft bearing surface (11) associated with the cylinder jacket segment has an angle of at most 180 °.

8. Circuit breaker (1) according to one of claims 1 to 5, characterized in that both Wellenlagerfiächen (11, 12) are convex.

9. Circuit breaker (1) according to claim 8, characterized in that one of the first Gehäuselagerfiäche (13) associated cylinder jacket segment at an angle of

has a maximum of 180 °.