In the following, the invention is shown schematically in a drawing and described in more detail with reference to an exemplary embodiment.
In the drawing,
FIG. 1 shows the schematic construction of an input shaft and an output shaft with a magnetic coupling, and
FIG. 2 shows the sequence involved in a method according to the invention.
FIG. 1 shows a drive device with an input shaft 1 and an output shaft 2. The input shaft 1 and the output shaft 2 are each rotatably mounted. A rotational movement can be imposed upon the input shaft 1 by means of a drive lever 3. A blocking lever 4 is arranged on the output shaft 2. The input shaft 1 and the output shaft 2 are arranged coaxially with respect to one another so that their faces are opposite to one another. A magnetic coupling 5 is arranged on their facing ends. The magnetic coupling 5 has an input drive-side coupling element 6 and an output drive-side coupling element 7. The input drive-side coupling element 6 is arranged on the input shaft 1. The output drive-side coupling element 7 is arranged on the output shaft 2. The input drive-side coupling element 6 is designed as a hollow cylinder. A multiplicity of magnets is arranged radially on the circumference of the input drive-side coupling element 6. These magnets are preferably permanent magnets. At the same time, the radial distribution is chosen in such a way that north and south poles of the magnets are arranged alternately radially around the inner sheath surface of the hollow-cylindrical input drive-side coupling element 6. The output drive-side coupling element is cylindrical and has a diameter such that it can be moved into the hollow-cylindrical input drive-side coupling element 6. The output drive-side coupling element 7 has north and south poles of magnets each radially distributed alternately on its outer sheath surface. At the same time, the radial distribution of the magnets on the input drive-side coupling element 6 and the output drive-side coupling element 7 is chosen to be in the form of sectors in such a way that, when the output drive-side coupling element 7 is moved into the input drive-side coupling element 6, a multiplicity of magnet pairs is formed which are clearly associated with one another by means of the magnetic forces.
FIG. 1 shows the magnetic coupling 5 in a decoupled state. The two coupling elements 6, 7 must be inserted one into the other for the magnetic coupling 5 to become effective. The coupling elements 6, 7 can be designed, for example, in accordance with the magnetic coupling disclosed in the KTR publication “Dauermagnetische Synchronkupplung” [Permanent magnet synchronous coupling].
In addition, it is also conceivable for other different embodiments of magnetic couplings to be used. For example, it is possible to use coupling elements that to be arranged so as to face one another in order to achieve a coupling effect, and else coupling elements that enable an arrangement of the axes of rotation of the coupling elements other than a coaxial arrangement. Examples of arrangements of this kind are parallel axes of rotation (the magnet poles are then each located radially on the external circumference of the coupling elements) or else axes of rotation that are at an angle to one another in the manner of a bevel gear.
FIG. 2 shows a sectional view through the magnetic coupling 5 wherein the input drive-side coupling element 6 encloses the output drive-side coupling element 7, as a result of which the respective magnet pairs can exert a force effect on one another. The coupling of a drive device 8 to the drive lever 3 is shown schematically. The drive device 8 can be an electric motor drive, for example, in particular an electromagnetic linear drive. An electrical switching device 9 is also shown symbolically in FIG. 2. The electrical switching device 9 has a movable contact piece, which is connected to the blocking lever 4, shown schematically. The translation of the driving movement to the switching movement can be adjusted by changing the lengths of the drive lever 3 as well as the lever arm on the blocking lever 4. The electrical switching device 9 can in particular be a grounding switch or a high-speed grounding switch in the field of electrical high-voltage engineering. A rotational movement of the output shaft 2 in a first direction of rotation 11 is limited by means of a first blocking device 10 via the blocking lever 4. The ability of the output shaft to move in a second direction of rotation 13 is limited by means of a second blocking device 12. The first blocking device 10 and the second blocking device 12 are designed in the form of mechanical stops against each of which the blocking lever 4 strikes alternately. The possible angle of rotation of the output shaft 2 is limited by the arrangement of the blocking devices 10, 12.
In the interests of simplifying the diagram, only the poles of the magnet pairs necessary for transmitting the movement are shown. In the coupling elements 6, 7 shown in FIG. 2, six magnet pairs have been evenly distributed radially on the circumferences. This results in a switching angle of 60°. As a deviation from this, four magnet pairs, five magnet pairs or eight magnet pairs can also be used, resulting in switching angles of 90°, 72° and 45°. A movement sequence of the drive arrangement shown in FIG. 2 is described in the following wherein the movable contact piece of the electrical switch 9 is moved suddenly from an off position “0” into an on position “1”. The drive device 8 moves the drive lever 3 and thus the input shaft 1 as well as the input drive-side coupling element 6 in the first direction of rotation 11. The blocking lever 4 fixed to the output shaft 2 bears against the first blocking device 10. Owing to the attractive force effect between the magnet pairs on the input drive-side coupling element 6 and on the output drive-side coupling element 7, the blocking lever 4 is pressed against the first blocking device 10. The input shaft 1 is moved further by means of the drive lever 3. When half the switching angle has been reached, 30° in the present example, a transition position of the magnetic coupling 5 is reached. This means that the magnet pairs are arranged so as to be displaced with respect to one another by approximately half of the effective pole faces. If the drive lever 3 is moved further in the first direction of rotation 11, pole faces of the same polarity overlap one another to an ever-increasing extent. Magnets of the same polarity repel one another. When a critical position is reached, the repelling forces are sufficiently large that the blocking lever 4 with the output shaft 2 is moved suddenly in the second direction of rotation 13. The blocking lever 4 strikes against the second blocking device 12 in this direction of rotation.
During the movement, the blocking lever 4 is initially pressed against the first blocking device 10 owing to the attractive magnetic forces of the magnet pairs of unequal polarity. The repelling forces of pole faces of the same polarity are utilized during a further phase of the movement of the input shaft 1.
The blocking lever 4 moves back from the second blocking device 12 to the first blocking device 10 in the same manner.
Magnet pairs with different magnet poles lie opposite one another in the end positions of the blocking lever 4 both when the blocking lever 4 strikes the first blocking device 10 and also when the blocking lever 4 bears against the second blocking device 12, with the result that a stable position of the output shaft is automatically produced owing to the force effect of the magnetic coupling.
When a split case is used which is placed in the gap between the input drive-side coupling element 6 and the output drive-side coupling element 7, the driving movement can also be transmitted through a closed wall. At the same time, the wall can be an encapsulated housing of a compressed gas-insulated switchgear assembly or a compressed gas-insulated switching device, for example. In this case, the split case is part of the wall.
Patent Application
20080047374
