Vacuum switch

Abstract

The invention relates to a vacuum switch (1). The vacuum switch (1) comprises a vacuum interrupter (3) having a tube housing (5) and two contact elements (7, 9) which protrude into the tube housing (5) and of which a first contact element (7) can be moved relative to the tube housing (5) and the second contact element (9) between a first switch position, in which the first contact element (7) rests against the second contact element (9), and a second switch position, in which the first contact element (7) is separated from the second contact element (9). Furthermore, the vacuum switch (1) comprises a braking unit (11) which is designed to brake a movement of the first contact element (7) from the first switch position into the second switch position, and which is arranged in the vicinity of the tube housing (5).

Description

[0001] Description

[0002] Vacuum switch

[0003] The invention relates to a vacuum switch.

[0004] A vacuum switch, as used here, is an electrical switching device comprising a vacuum switching tube with a tube housing and two contact elements projecting into the tube housing. In the first switching state of the vacuum switch, the contact elements are in contact with each other, and in the second switching state, they are separated. To move the contact elements relative to each other, the vacuum switch has a drive mechanism for at least one contact element, to which the contact element is coupled by a kinematic chain. For a vacuum switch, precise adjustment of a motion characteristic, which describes the distance between the contact elements per unit time, is crucial for the switching operations. In particular, a switching-off process, in which contact elements move relative to each other from the first switching state to the second switching state, must occur very rapidly.On the other hand, a contact element at the end of the switching-off process must not move too quickly relative to the tube housing, so as not to destroy or damage the vacuum switch. Therefore, the contact element must be sufficiently braked, especially at the end of the switching-off process. This is usually achieved using a braking unit, which is located in the kinematic chain in or near the drive unit.

[0005] The invention is based on the objective of providing a vacuum switch that is improved, in particular with regard to the braking of a contact element during the switching-off process. This objective is achieved according to the invention by a vacuum switch having the features of claim 1.

[0006] Advantageous embodiments of the invention are the subject of the dependent claims.

[0007] A vacuum switch according to the invention comprises

[0008] - a vacuum switching tube with a tube housing and two contact elements projecting into the tube housing, of which a first contact element is movable relative to the tube housing and the second contact element between a first switching position in which the first contact element rests against the second contact element and a second switching position in which the first contact element is separated from the second contact element and

[0009] - a braking unit which is designed to brake a movement of the first contact element from the first switching position to the second switching position, and which is located near the tube housing.

[0010] The braking of the movement of the first contact element is understood to mean a reduction in the magnitude of the speed of the first contact element relative to the tube housing.

[0011] The statement that the vacuum switch has a movable contact element and a brake unit with the aforementioned features does not preclude the possibility that the vacuum switch has more than one contact element and a brake unit with these features for each of these contact elements. The statement should therefore be understood to mean that the vacuum switch has at least one contact element and one brake unit with these features.

[0012] A vacuum switch according to the invention thus has a braking unit arranged near the tube housing, which is configured to brake the movement of the first contact element from the first switching position to the second switching position. By arranging the braking unit near the tube housing, the movement characteristic of the first contact element can be influenced directly at the vacuum switching tube. This allows for a significantly more complex movement characteristic of the first contact element to be set than with a braking unit arranged in or on the drive for the first contact element, since the movement characteristic is not influenced by a kinematic chain via which the first contact element is coupled to the drive. For example, the influence of connecting rods, lever elements, and / or joints of the kinematic chain on the braking effect of the braking unit is eliminated.

[0013] In one embodiment of the vacuum switch, the braking unit has a gas-filled gas chamber with a first opening, which is closed by a first sealing element rigidly connected to the first contact element. This opening is reduced in size as the first contact element moves from the first to the second switching position. The closure of the gas chamber by the first sealing element and the reduction in size of the gas chamber during the movement of the first contact element compress the gas within the chamber. This increases the pressure of the gas in the chamber, opposing the movement of the first contact element and thus braking it. The gas chamber therefore provides pneumatic braking of the movement of the first contact element.

[0014] In a further embodiment of the vacuum switch, the gas chamber of the brake unit has a second opening through which a drive element is guided. This drive element is rigidly connected to the first closing element and closes the second opening. The drive element is, for example, coupled to a drive for the first contact element and configured to couple the drive to the first contact element in order to move the first contact element between its switching positions. The drive element is thus guided through the gas chamber and rigidly connected to the first closing element and therefore also to the first contact element. This allows the first contact element to be coupled to the drive element through the gas chamber and driven by a drive via the drive element.

[0015] In a further embodiment of the vacuum switch, the gas chamber of the brake unit has at least a third opening, and the brake unit has a second closing element configured to close each third opening when the first contact element moves from the first switching position to the second switching position, and to open it when the first contact element moves from the second switching position to the first switching position. According to this embodiment of the vacuum switch, when the first contact element moves from the first switching position to the second switching position, the gas chamber of the brake unit is closed by the second closing element, so that, as described above, it brakes the movement of the first contact element by increasing the pressure in the gas chamber.When the first contact element moves from the second switching position to the first switching position, the gas space is opened by the second closing element, allowing gas from the vicinity of the brake unit to flow into the gas space.

[0016] In a further embodiment of the vacuum switch, the second closing element is arranged within the gas chamber of the brake unit. For example, the second closing element is designed as a disc or a flap. This allows for a simple and compact design of the brake unit, as the second closing element is moved within the gas chamber by pressure changes in the gas chamber. In a further embodiment of the vacuum switch, the second closing element has a recess through which the actuating element is guided. This embodiment of the vacuum switch implies, in particular, that every third opening of the gas chamber is arranged near the second opening of the gas chamber. If the gas chamber has several third openings, these are thus arranged distributed around the second opening.

[0017] In a further embodiment of the vacuum switch, the gas chamber of the brake unit has a fourth opening, which is permanently open during movements of the first contact element. This fourth opening regulates the gas pressure in the gas chamber, allowing predefined movement characteristics to be set for the movements of the first contact element. In particular, the fourth opening counteracts pressure increases in the gas chamber and excessive braking effect of the gas chamber when the first contact element moves from the first switching position to the second switching position.

[0018] In a further embodiment of the vacuum switch, the brake unit has an encapsulated brake element that is coupled to the movements of the first contact element.

[0019] For example, the braking element is coupled to a drive element, which is coupled to a drive for the first contact element and is configured to couple the drive to the first contact element in order to move the first contact element between its switching positions. This configuration of the vacuum switch is an alternative to the configurations mentioned above. Instead of a gas chamber that is directly coupled to the first contact element via the first closing element, in this configuration of the vacuum switch the first contact element is coupled to the drive element via an encapsulated braking element.

[0020] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more readily understandable in connection with the following description of exemplary embodiments, which are explained in more detail in conjunction with the drawings. These show:

[0021] FIG 1 shows a schematic sectional view of a first embodiment of a vacuum switch in a first switching state,

[0022] FIG 2 shows a schematic sectional view of the vacuum switch shown in Figure 1 in a second switching state,

[0023] FIG 3 shows a schematic side view of components of a second embodiment of a vacuum switch.

[0024] Corresponding parts in the figures are marked with the same reference symbols.

[0025] Figure 1 (FIG 1) and Figure 2 (FIG 2) show a schematic sectional view of a first embodiment of a vacuum switch 1 in two different versions.

[0026] Switching states. Non-invention-relevant components and details of the vacuum switch 1 are not shown.

[0027] The vacuum switch 1 comprises a vacuum switching tube 3 with a tube housing 5, a first contact element 7, and a second contact element 9. The contact elements 7 and 9 project into the tube housing 5. A first contact element 7 is movable relative to the tube housing 5 and the second contact element 9 between a first switching position, in which the first contact element 7 is in contact with the second contact element 9, and a second switching position, in which the first contact element 7 is separated from the second contact element 9. Figure 1 shows the vacuum switch 1 in the first switching position of the first contact element 7. Figure 2 shows the vacuum switch 1 in the second switching position of the first contact element 7. The vacuum switch 1 also includes a braking unit 11, which is configured to brake the movement of the first contact element 7 from the first switching position to the second switching position.

[0028] The brake unit 11 has a gas-filled gas chamber 13 with a first opening 15, which is closed by a first closing element 17 firmly connected to the first contact element 7, except for an opening 44 in the first closing element 17.

[0029] Furthermore, the gas chamber 13 of the brake unit 11 has a second opening 19 through which a drive element 21 is guided, which is rigidly connected to the first closing element 17 and closes the second opening 19. The drive element 21 is coupled to a drive 23 (see Figure 3) for the first contact element 7 and is configured to couple the drive 23 to the first contact element 7 in order to move the first contact element 7 between its switching positions.

[0030] Furthermore, the gas chamber 13 of the brake unit 11 has several, for example three, third openings 25, which are arranged distributed around the second opening 19 (only one third opening 25 is visible in Figures 1 and 2). For the third openings 25, the brake unit 11 has a second closing element 27 arranged in the gas chamber 13, which is configured to close the third openings 25 when the first contact element 7 moves from the first switching position to the second switching position and to open them when the first contact element 7 moves from the second switching position to the first switching position.

[0031] In the embodiment shown in Figures 1 and 2, the brake unit 11 is arranged in a gas-filled housing 29 and fixed in the housing 29 by at least one screw connection 31. The second opening 19 and the third openings 25 of the gas chamber 13 of the brake unit 11 are, in this embodiment, openings in a wall 33 of the brake unit 11, which is opposite the first opening 15 and is perpendicular to a longitudinal axis 35 of the housing 29, which defines an axial direction. The second closure element 27 is, in this embodiment, a disc with a first disc opening 37 through which the drive element 21 passes. Furthermore, the disc has at least a second disc opening 39, through which a positioning lug 41 is guided, projecting from the wall 33 in the axial direction.A spring element 43 is arranged on each positioning nose 41, which exerts a spring force on the disk in the axial direction towards the wall 33.

[0032] The disk is aligned parallel to the wall 33 by at least one positioning lug 41 and the disk is pressed against the wall 33 by the spring element 43 of each positioning lug 41, so that the third openings 25 of the gas space 13 are closed by the disk in the first switching position and in the second switching position of the first contact element 7.

[0033] The gas chamber 13 of the brake unit 11 further has a fourth opening 44, which is permanently open when the first contact element 7 moves. In the embodiment shown in Figures 1 and 2, the fourth opening 44 is an opening in the first locking element 17. In other embodiments, however, the fourth opening 44 can also be arranged differently, for example in the drive element 21 or the second locking element 27.

[0034] When the first contact element 7 moves from the first switching position to the second switching position, the gas chamber 13 is reduced in size and the gas in the gas chamber 13 is compressed. This increases the pressure of the gas in the gas chamber 13, and the third openings 25 remain closed by the disc, as the increased pressure presses the disc even more firmly against the wall 33. The compression of the gas in the gas chamber 13 slows the movement of the first contact element 7. The fourth opening 44 regulates the gas pressure in the gas chamber 13, allowing predefined movement characteristics to be set for the movements of the first contact element 7. In particular, the fourth opening 44 counteracts an overpressure in the gas chamber 13 and excessive braking of the gas chamber 13 when the first contact element 7 moves from the first switching position to the second switching position.

[0035] When the first contact element 7 moves from the second switching position to the first switching position, the gas chamber 13 is enlarged, causing the pressure of the gas in the gas chamber 13 to decrease. With a suitable design of the gas chamber 13 and each spring element 43, the resulting negative pressure in the gas chamber 13, relative to the pressure in the housing 29 surrounding the brake unit 11, lifts the disc from the wall 33, opening the third openings 25 of the gas chamber 13 and allowing gas to flow from the housing 29 into the gas chamber 13.

[0036] Figure 3 ( FIG 3 ) shows a schematic side view of components of a second embodiment of a vacuum switch 1, wherein again only components relevant to the invention of the vacuum switch 1 are shown purely schematically.

[0037] Figure 3 shows a drive 23, a connecting rod 45, a lever element 47, a drive element 21, a first contact element 7 and a brake unit 11 of the vacuum switch 1.

[0038] As shown in Figures 1 and 2, the vacuum switch 1 comprises a vacuum switching tube 3 with a tube housing 5, a first contact element 7, and a second contact element 9, the tube housing 5 and the second contact element 9 of the vacuum switching tube 3 not shown again in Figure 3. The first contact element 7 is positioned relative to the tube housing 5 and the second contact element 9 between a first switching position, in which the first

[0039] The first contact element 7 rests against the second contact element 9, and is movable in a second switching position in which the first contact element 7 is separated from the second contact element 9. The first contact element 7 is also connected to the drive element 21.

[0040] Furthermore, the vacuum switch 1 includes a brake unit 11, which is configured to brake the movement of the first contact element 7 from the first switching position to the second switching position. In contrast to the embodiment shown in Figures 1 and 2, the brake unit 11 in the embodiment shown in Figure 3 has an encapsulated brake element 49, which is coupled to the movements of the first contact element 7.

[0041] The drive 23 is configured to move the connecting rod 45 (in the illustrated embodiment, in a vertical direction). The connecting rod 45 is coupled to the lever element 47 by a first joint 51. The lever element 47 is rotatably mounted about a pivot axis 53, so that movements of the connecting rod 45 cause rotations of the lever element 47 about the pivot axis 53. The drive element 21 is coupled to the lever element 47 by a second joint 55, so that rotations of the lever element 47 about the pivot axis 53 (horizontal in the illustrated embodiment) cause movements of the drive element 21 and thus also of the first contact element 7. The brake element 49 is designed in a piston-like manner in the embodiment shown in Figure 3, so that it counteracts a force acting along its longitudinal axis, for example, like a shock absorber.A first end 57 of the brake element 49 is rigidly connected to a stationary component 59 of the vacuum switch 1. A second end 61 of the brake element 49 is coupled to the lever element 47 by a third joint 63, so that forces acting along the longitudinal axis of the brake element 49 counteract rotations of the lever element 47 about the axis of rotation 53 and thereby brake movements of the drive element 21 and the first contact element 7. Although the invention has been further illustrated and described in detail by preferred embodiments, the invention is not limited by the disclosed examples and other variations can be derived from them by those skilled in the art without departing from the scope of protection of the invention.

Claims

Patent claims 1. Vacuum switch (1) , comprising, - a vacuum switching tube (3) with a tube housing (5) and two contact elements (7, 9) projecting into the tube housing (5), of which a first contact element (7) is movable relative to the tube housing (5) and the second contact element (9) between a first switching position in which the first contact element (7) rests against the second contact element (9) and a second switching position in which the first contact element (7) is separated from the second contact element (9) and - a braking unit (11) which is configured to brake a movement of the first contact element (7) from the first switching position to the second switching position and which is located near the tube housing (5).

2. Vacuum switch (1) according to claim 1, wherein the brake unit (11) has a gas-filled gas chamber (13) which has a first opening (15) which is closed by a first closing element (17) which is firmly connected to the first contact element (7), and which is reduced in size when the first contact element (7) moves from the first switching position to the second switching position.

3. Vacuum switch (1) according to claim 2, wherein the gas space (13) of the brake unit (11) has a second opening (19) through which a drive element (21) is guided, which is rigidly connected to the first closing element (17) and closes the second opening (19).

4. Vacuum switch (1) according to claim 3, wherein the drive element (21) is coupled to a drive (23) for the first contact element (7) and is configured to couple the drive (23) to the first contact element (7) in order to move the first contact element (7) between its switching positions.

5. Vacuum switch (1) according to one of claims 2 to 4, wherein the gas space (13) of the brake unit (11) has at least one third opening (25) and the brake unit (11) has a second closing element (27) which is configured to close each third opening (25) when the first contact element (7) moves from the first switching position to the second switching position and to open it when the first contact element (7) moves from the second switching position to the first switching position.

6. Vacuum switch (1) according to claim 5, wherein the second closure element (27) is arranged within the gas space (13) of the brake unit (11).

7. Vacuum switch (1) according to claim 5 or 6, wherein the second closure element (27) is designed as a disk or a flap.

8. Vacuum switch (1) according to one of claims 5 to 7, wherein the second locking element (27) has a recess (37) through which the drive element (21) is guided.

9. Vacuum switch (1) according to one of the preceding claims, wherein the gas space (13) of the brake unit (11) has a fourth opening (44) which is permanently open during movements of the first contact element (7).

10. Vacuum switch (1) according to claim 1, wherein the brake unit (11) has an encapsulated brake element (49) which is coupled to the movements of the first contact element (7).

11. Vacuum switch (1) according to claim 9, wherein the brake element (49) is coupled to a drive element (21) which is coupled to a drive (23) for the first contact element (7) and is configured to couple the drive (23) to the first contact element (7) in order to to move the first contact element (7) between its switching positions.

Images