KR20130028714A - Rotary switches - Google Patents

Abstract

An improved rotary switch (eg a two pole double brake switch) comprises a first pole and second poles 2, 4. Each pole includes a rotatable bridging member 24 and a pair of fixed busbars 6a, 6b; 8a, 8b. Each busbar has one or more main contacts 14 and may also include a contact arm 12 having an arc contact 28. This rotary switch is configured such that the direction of current flow through the first pole 2 is opposite to the direction of current flow through the second pole 4. In this way, the arcs set on the first pole 2 are deflected away from the arcs set on the second pole 4.

Description

Rotary switch {ROTARY SWITCHES}

The present invention relates to rotary switches, in particular double pole (or multi pole) double break rotary switches for current interruption.

Dual brake rotary switches with a convenient number of poles are well known as disconnect switches or off-load switches and typically have fixed contacts or contacts at both ends thereof. And a bridging member that can rotate to be in direct physical contact with the busbars.

Summary of the Invention

The present invention provides an improved rotary switch comprising a first pole and a second pole, each pole having a pair of fixed busbars having a rotatable bridging member and one or more primary contacts. And the rotary switch is configured such that the direction of current flow through the first pole is opposite to the direction of current flow through the second pole such that arcs set in the first pole are set in the second pole. Configured to deflect away from them.

The rotary switch is particularly useful when applied to direct current distribution systems designed to have low L / R time constants (eg, as off-load switches) and when high power density is the primary goal. However, the high arc voltage achieved by the rotary switch is also effective for breaking direct current and alternating current circuits with fairly large L / R time constants.

Rotary actuators of any suitable configuration are preferably used to rotate the rotatable bridging members between the closed and open positions. In the closed position, both ends of each of the rotatable bridging members are in direct physical contact with associated fixed busbars such that current can flow between the busbars through the rotatable bridging member. In the open position both ends of the rotatable bridging member are spaced apart from the associated busbars. The rotary actuator is preferably a rotatable brit in both directions (ie in a first direction moving from the closed position toward the open position to open the rotary switch and in a second direction moving from the open position towards the closed position to open the rotary switch). The gong members are rotated. The rotary actuator can rotate the rotatable bridging members under the control of a regulator or control means such as an electronic control unit. As in other conventional rotary switches, a spring-detent or other snap action rotary drive coupling mechanism is rotatable bridging at the main contact "contact" and "disconnect". It can be inserted between the rotary actuator and the rotatable bridging members to maximize the rotational speed of the members.

The rotatable bridging members are preferably configured to rotate in tandem, and thus can be rotated by the same rotary actuator. In practice, rotatable bridging members can be mounted to a common drive shaft such that each of the respective pole contact systems is synchronized in phase with respect to a common rotational operation.

The rotatable bridging member and the fixed busbars of each pole are preferably spaced axially to avoid potential flashover between the poles.

When each arcing contacts are physically separated, full arcing between the rotatable bridging member of each pole and the fixed busbars is initiated. The interaction of the generated magnetic flux with the current loops flowing through each pole creates a radial repulsive force that deflects each arc away from the center of the current loop. This increases the arc length and arc voltage during the process. This also accelerates the rotatable bridging member of each pole towards the open position away from the associated busbars. This increases the separation between each arc discharge contact which further increases the arc length.

The current loops flowing through the two poles are in opposite directions. This can be achieved by proper connection of fixed busbars to external circuits. The current loops are coupled to each other, and the magnetic flux generated when the current flows in the opposite direction interacts with the current loops in a manner that generates a repulsive force between the current loops. This causes the arcs to repel each other in the connection systems of the two poles, thus reducing the risk of flashover between the poles.

It is preferable that the entire rotary switch is impregnated with the liquid insulator. It will be readily understood that the term "liquid insulator" is intended to include any liquid having sufficient dielectric withstand as well as a proprietary liquid that is specifically commercially available. This will include deionized water, FLUORINERT and other equivalent perfluorocarbon fluids, mineral transformer oils, silicone transformer oils, synthetic oils and esters, methylene chloride and the like. Particularly preferred coolant fluids are proprietary transformer insulating fluids such as MIDEL and their equivalents. The liquid insulator improves the cooling and generation of arc voltages of the rotary switch as described in detail below. The liquid insulator may be stationary or, depending on the device, may flow past the rotary switch.

 In a preferred configuration, the rotatable bridging members have both ends, each end comprising an arc contact. Each fixed busbar has a contact arm comprising an arc contact and one or more main contacts. The rotatable bridging members are then in a closed position where both ends of each rotatable bridging member are in direct physical contact with the main contact of the contact arm and associated busbars, and both ends of the rotatable bridging members are contact arm. And an open position spaced apart from the main contact of the associated busbars. The bridging members rotatable between the open and closed positions are in direct physical contact with the arc contacts on the contact arms of the busbars in which the arc contacts on both ends of the rotatable bridging member are associated, but no longer with the main contact. It takes an intermediate position without direct physical contact.

The contact arm of each fixed busbar is preferably formed as an integral part of the busbar, with the associated rotatable bridging member sliding contact therewith as it rotates between the closed and open positions. In, it can be shaped and sized appropriately to move past it.

The main contacts of the fixed busbars of each pole preferably comprise one or more elastic contact members in sliding contact with each end of the associated rotatable bridging member when the rotatable bridging member is in the closed position. The main contacts represent the main flow path of current between the fixed busbars of each pole and the opposite ends of the associated rotatable bridging member when the rotatable bridging member is in the closed position.

The fixed busbars of each pole may comprise a plurality of main contacts. Thus, when the associated rotatable bridging member is in an intermediate position, the rotatable bridging member preferably still has only a flow path for the current between the busbars and both ends of the rotatable bridging member directly to each other. It is important to know that it is spaced apart from all main contacts of the busbars so that each arc contact is in physical contact. When a plurality of main contacts are used by a particular busbar, they preferably form a group of parallel connected electrical circuits between the busbars and each end of the associated rotatable bridging member. As such, the continuous current rating of the rotary switch is affected by the degree of current sharing between the paralleled electrical circuits, which is advantageous if the contact wear, corrosion and synthetic contact resistance can be as constant as possible. Moreover, the "contact" (close) and "disconnect" (open) rated current of the rotary switch is affected by the corresponding sequential "contact" and "disconnect" behavior. For this reason, the rotatable bridging member of each pole is preferably made to allow almost synchronized "contact" and "disconnect" of all parallel connection circuits. The rotational speed of the rotatable bridging member of each pole is also made as technically practicable as possible to minimize the elapsed time associated with non-synchronization. It will be appreciated that each arc contact also acts as an electrical circuit parallel to the main contacts at their respective “contacts” and “disconnects”. This synchronization characteristic is particularly advantageous when arc contact wear and corrosion occurs during use and as a result the arc contact resistance is increased. This is because the arc contact resistance directly affects the "contact" and "disconnect" currents that occur at the respective main contacts.

The contact system formed by the rotatable bridging member and the main contacts of each pole benefits from sliding or "wiping" contact operation and is considerably used to ensure that the mating contact surfaces are cleaned during relative movement. Large contact pressures can be used in the main contact. In addition, these facing contact surfaces do not enter into the problem of electrical corrosion when parallel connection arc contacts are used. These two factors lead to a low contact resistance and the resulting voltage drop when the rotary switch is in the closed position.

The rotary switch is preferably a two-pole (or multi-pole) double brake rotary switch.

1 is a plan view of a two-pole double brake rotary switch in accordance with the present invention;
2 is a side view of the rotary switch of FIG. 1;
3 is an end view of the rotary switch of FIG. 1;
4 is a schematic view of the rotary switch of FIG. 1;
5 is a top view of the rotary switch of FIG. 1 in a closed position;
6 is a schematic view of the rotary switch of FIG. 5;
7 is a top view of the rotary switch of FIG. 1 in a partially open position;
8 is a schematic view of the rotary switch of FIG. 7;
9 is a plan view of the rotary switch of FIG. 1 in the closed position showing the current loop at one pole;
FIG. 10 is a plan view of the rotary switch of FIG. 1 in an intermediate (pre-arcing) position, showing the current loop at one pole; FIG.
FIG. 11 is a plan view of the rotary switch of FIG. 1 in an incompletely open (arc discharge) position, showing a current loop at one pole; FIG.
12 is a plan view of the rotary switch of FIG. 1 in an incompletely open (arc discharge) position, showing a current loop at two poles;
FIG. 13 is a cross sectional view of the rotary switch of FIG. 1 in an incompletely open (arc discharge) position showing a current loop at two poles; FIG.
FIG. 14 is a schematic diagram showing how the rotary switch of FIG. 1 can be integrated into an external electrical circuit for unidirectional direct current flow between a voltage source and a load.

The basic configuration of the two-pole double brake rotary switch will now be described with reference to FIGS. 1 to 3. Rotary switches with three poles can be used in three-phase alternating current circuits, and the present invention includes rotary switches having this configuration.

The rotary switches of FIGS. 1-3 are intended for use with external circuitry such as a dc distribution architecture, providing an extremely compact and reliable off-road switch for switchgear. This rotary switch can also serve as an off-load isolator while the external circuit is powered down. The direct current distribution architecture may form part of a power transmission system for, for example, ship power and propulsion distribution systems, or renewable energy devices such as wind turbines or subsea generators. Rotary switches generally open after the current and the prospective open circuit voltage have been reduced to an acceptable level by other means (eg, application of external electronic means and / or foldback characteristics). . For example, the rotary switch can be opened after the current and intrinsic open circuit voltage are reduced to <20 A and <50 V, respectively. Once the rotary switch breaks the circuit, the intrinsic current and voltage can be increased by other means. Preferably, sufficient time will be given between opening and closing of the rotary switch to cause arc extinction.

These rotary switches can easily energize 3kA when closed and can easily withstand 300kV when opened. The main advantage of the rotary switch is the inherent separation of the arc through the liquid insulator during the opening, ie during the subsequent opening step shortly after opening, and thus the risk of flashover between the poles as a result. Rotary switches are also further helped by the cooling effect of the liquid insulator and have essentially high arc voltages and rapid and complete arc extension behavior, which are the result of electromagnetic repulsion between arcs and contact systems.

The rotary switch comprises an anode and a cathode 2, 4 which are axially spaced from each other as most clearly shown in FIGS. 2 and 3. 1 is a plan view of the anode 2, but it will be readily appreciated that the cathode 4 has exactly the same configuration.

 Each of the poles 2, 4 comprises first and second fixed busbars spaced apart on the same plane. More specifically, anode 2 comprises first and second fixed busbars 6a and 6b and cathode 4 comprises first and second fixed busbars 8a and 8b. . Each busbar is generally L-shaped. The first part 10 of each busbar defines the inlet or outlet point of the current loop and the second part 12 is directly with the end of the rotatable bridging member (see below) when the rotary switch is in the closed position. It defines a contact arm that is shaped and sized to be in physical contact.

The first portion 10 of each busbar can be connected to an external direct current circuit (external circuit) as shown schematically in FIG. 14 and described in more detail below. Connection with an external direct current circuit can be made by any suitable means, such as a fixed busbar with slotted holes such that bolted joints are fitted to geometrical tolerances. Alternatively, flexible links of laminated copper foil or multiple wire strand structures can be used. External busbar connections can be made using insulated bushings or molded busbar seals, in which case these connections must pass through a wall of a reservoir containing a liquid insulator impregnated with a rotary switch.

When the contact 14 is "contacted" or "disconnected" with the associated rotatable bridging member 24, the first priority requirement is that the corresponding arc contacts 28, 30 must be in sliding contact in the intermediate position. Second portion or contact arm 12 of each busbar such that there is sufficient clearance to receive both ends of the rotatable bridging member 24 as the rotatable bridging member 24 moves past the contact arm. Is slightly angled (ie, its free end is thicker than where it engages with the first part 10) or otherwise shaped.

As most clearly shown in FIG. 3, each fixed busbar is axially spaced apart by spacers 18 and a pair of resilient inwardly biased by leaf springs 20. A contact 14 having contact members (calipers) 16. The ends 22 of the contact members 16 are designed to be in sliding contact with the rotatable bridging member 24 and may be made of copper and plated or surface treated with silver or copper-tungsten alloy to provide sliding contact. It can provide resistance to wear and corrosion. This thus provides a low and stable contact resistance throughout the operating life of the rotary switch. In general, although each contact 14 preferably comprises a pair of contact members 16, it will be readily appreciated that a single contact member may also be used. Each fixed busbar also includes a plurality of contacts (each having one or two elastic contact members) arranged in the same place that can be connected together in parallel to ensure that the desired thermal limit current rating for the rotary switch is achieved. can do.

Components assembled to form the contact 14 are fixed to the first portion 10 of the respective fixed busbars 6a, 6b by bolt fastenings. Clearance holes at the fixed end of each contact 14 are shown in FIG. 1, which is an alternative assembly method that maintains the correct alignment of the contacts while fixed to an assembly jig or a fixed busbar. It may include provisions for use.

In order to improve the clarity of FIG. 3, the drive shaft 26 portion and the second fixed busbars 6b, 8b have been omitted.

Each of the poles 2, 4 also includes a rotatable bridging member (moving blade) 24. The rotatable bridging members 24 are mounted to the drive shaft 26 in a manner that provides electrical insulation between the rotatable bridging members and the common rotary actuator, and always have the same contact relationship with their respective fixed busbars ( mechanically rotated simultaneously by a common rotary actuator (not shown) to maintain a physical relationship. The rotatable bridging members 24 can be rotated between the closed position and the open position.

The rotatable bridging members 24 are a pair of notches at the edges facing the first portion 10 of the associated busbars when the rotatable bridging members are in the closed position. (24a, 24b). Notches 24a and 24b are designed to enable generally synchronized "contact" and "disconnect" of all circuits connected in parallel when each fixed busbar includes a plurality of contacts 14.

The busbars and rotatable bridging members 24 are generally made of copper. The busbars can be electroplated with a corrosion resistant metal and the rotatable bridging members can be silver plated to provide a low and stable contact resistance.

A general arrangement of fixed busbars and rotatable bridging members 24 of a two-pole double brake rotary switch is schematically shown in FIG. 4.

When the rotatable bridging members 24 are in the closed position, the opposite ends of each rotatable bridging member are elastic contact members of each contact 14 as well as the arc contact 28 of each fixed busbar. It is also in direct physical contact with (16). This is shown in FIGS. 5 and 6.

When the rotatable bridging members 24 are in the open position, both ends of each rotatable bridging member are no longer elastic contacts of each contact 14 or the arc contact 28 of each fixed busbar. There is no direct physical contact with the members 16. This is illustrated in FIGS. 7 and 8. When the rotary switch is fully open, the rotatable bridging members 24 will generally be rotated approximately 90 degrees from its closed position. However, the term "open position" herein does not necessarily mean a fully open position, but includes all positions where there is no direct physical contact between the rotatable bridging members and the respective fixed busbars.

Both ends of each rotatable bridging member 24 are in direct physical contact with the arc contacts 28 of the respective fixed busbars, but not with the elastic contact members 16 of each contact 14. There is also a (or pre-arking) position.

Both ends of each rotatable bridging member 24 have an arc contact 30 designed to be in direct physical contact with the arc contact 28 of each fixed busbar when the rotatable bridging members are in an intermediate position. Include. The arc contacts 28, 30 of the fixed busbars and the rotatable bridging members are located at such extremities in which arc discharge can be predicted as the rotary switch moves from the closed position to the open position. Corrosion of arc contacts can be minimized by the use of suitable sacrificial arcing members or arcing horns.

The rotary switch can be closed by rotating the rotatable bridging members 24 from the open position to the closed position. This rotates the drive shaft 26 in a first direction for moving the rotatable bridging members 24 from the closed position to the open position and in a second direction for rotating the rotatable bridging members from the open position to the closed position. Can be achieved by a common rotary actuator (not shown). As the rotary switch moves to the closed position, both ends 32, 34 of each rotatable bridging member 24 come into contact with the ends 22 of the elastic contact members 16, and the leaf springs The contact members can be pushed slightly apart against the inner deflection of 20 (when sliding contact with each end of each rotatable bridging member 24 falls as it moves from the closed position to the open position, the contact It will be readily appreciated that the members 16 may move slightly towards each other under the inner deflection of the leaf springs 20).

When the rotary switch is closed, the corresponding arc contacts 28, 30 come into contact with each other before the contact 14 contacts the rotatable bridging members 24. Thus in some applications with high inrush current, arc discharge may occur between arc contacts 28, 30 in a capacitive system, for example. During the closing of the rotary switch, its purpose is to sink the inrush current and the associated arc discharge while the arc contacts 28, 30 are in close proximity to each other.

The flow passage of direct current when the rotary switch is closed will now be described in more detail with reference to FIG. 9. When the rotary switch is closed, the rotatable bridging members 24 are in the closed position, and direct current can flow between the busbars 6a, 6b of the anode 2 as indicated by the arrow. More specifically, in the case of the anode 2, a direct current can flow from the first portion 10b of the busbar 6b, which defines the entry point of the current loop, to the contact 14b. The direct current in the contact 14b is the first of the bridging member 24 rotatable along the contact members 16 and through the ends 22 of the contact members in sliding contact with the first end 32. Flow to the end 32. Direct current flows into the contact 14a along the rotatable bridging member 24 and through the ends 22 of the contact members 16 in sliding contact with the second end 34 of the rotatable bridging member. Flow. Finally, a direct current flows from the contact 14a to the first portion 10a of the busbar 6a which defines the exit point of the current loop. Indeed, some of the direct current may also flow directly between the busbars and the contact arms 12a, 12b of the rotatable bridging member 24, but this direct current is relatively relatively between the fixed busbar and the rotatable bridging member. As a result of the high contact resistance will be much lower than flowing through the respective contacts 14a, 14b. There will be a similar current loop between the busbars 8a, 8b of the cathode 4, but the direction of the current flow will be reversed as described in more detail below.

The flow path of direct current when the rotary switch is in the intermediate (or pre-arking) position will now be described in more detail with reference to FIG. 10. When the rotary switch is in the intermediate position, there is no longer direct physical contact between the contacts 14a, 14b and the rotatable bridging member 24. However, the direct current will continue to flow between the busbars 6a, 6b of the anode 2 as indicated by the arrow. More specifically, in the case of the anode 2, the direct current flows from the first portion 10b of the busbar 6b, which defines the inlet of the current loop, to the fixed arc contact 28b along the contact arm 12b. Then through the sliding contact resistance between the arc contact 28b and the moving arc contact 30b to the arc contact 30b and then to the first end 32 of the rotatable bridging member 24. (If the rotary switch is in the intermediate position, it will be readily appreciated that the arc contacts 28, 30 are in direct physical contact with both ends 24 of the rotatable bridging member). Direct current flows along the rotatable bridging member 24 and through the sliding contact resistance made by the fixed and moving arc contacts 28a, 30a to the contact arm 12a. Finally, a direct current flows along the contact arm 12a to the first portion 10a of the busbar 6a which defines the outlet of the current loop. The flow of direct current between the busbars 6a, 6b is determined by an external circuit controlled by the rotary switch, and each pair of arc contacts 28a, 30a and 28b, 30b during direct physical contact with each other. The voltage drop in between has a slight effect on the current in the external circuit, provided that the arc contact is not severely worn. There may be a similar current loop between the busbars 8a, 8b of the cathode 4, but the direction of current flow will be in the opposite direction as described in more detail below.

The flow path of direct current when the rotary switch is in the incompletely open (or arc discharge) position will now be described in more detail with reference to FIG. When the rotary switch is in the incompletely open position, there is no longer direct physical contact between the contacts 14a, 14b and the rotatable bridging member 24. Also between the contacts 12a, 12b of the respective busbars 6a, 6b and the ends of the rotatable bridging member 24 (or more specifically between each pair of arc contacts 28a, 30a and 28b, 30b). There is no direct physical contact at all. However, the direct current continues to flow between the busbars 6a, 6b of the anode 2 as indicated by the arrow. More specifically, in the case of the anode 2, a direct current can flow from the first portion 10b of the busbar 6b, which defines the inlet of the current loop, along the contact arm 12b to the arc contact 28b. have. Direct current from the fixed arc contact 28b flows into the moving arc contact 30b of the first end 32 of the rotatable bridging member 24 as an arc. Direct current flows along the rotatable bridging member 24 to the arc contact 30a of the second end 34 of the rotatable bridging member 24. The direct current from the arc contact 30a flows as an arc to the fixed arc contact 28b of the contact arm 12a of the busbar 6a. Finally, a direct current flows along the contact arm 12a to the first portion 10a of the busbar 6a which defines the outlet of the current loop. The flow of direct current between the busbars 6a, 6b is now only partially determined by the external circuitry controlled by the rotary switch, and as their arc lengths increase due to the disconnection of the arc contacts, the arc contacts 28a , The specific gravity determined by the arc voltages appearing between the opposing pairs of 30a, 28b, and 30b). There may be a similar current loop between the busbars 8a, 8b of the cathode 4, but the direction of current flow will be in the opposite direction as described in more detail below.

The inlets and outlets 10a, 10b of the current loop of the anode 2 are defined by correspondingly spaced adjacent ends of the busbars 6a, 6b and corresponding busbar connections to the external circuit. These are the arc discharge zones (denoted “arc discharge” in FIGS. 11 to 13) between the arc contacts 28a, 28b and 30a and 30b of the busbars 6a and 6b and the rotatable bridging member 24, respectively. Provide a slight magnetic flux density to the field. This means that the magnetic flux density of each arc discharge zone is the current loop of the portion comprising busbars 6a, 6b, arc contacts 28a, 28b and 30a, 30b, arc discharge zones and rotatable bridging member 24. It means that what is generated by the direct current flowing in the main body. The magnetic flux density interacts with the direct current in the arc to create a radial repulsive force, which deflects each arc away from the center of the current loop as a result of the relatively low mass in the arc and the properties of the liquid insulator surrounding the arcs. . This extends the arc and increases the arc voltage during the process. This electromagnetic behavior pushes both ends 32, 34 of the rotatable bridging member 24 from the fixed busbars 6a, 6b, whereby the rotary actuator fully opens the rotatable bridging member. It helps to move towards the location and increases the arc length and arc voltage even more. The arc voltage will be enough to quickly cut off the current in the DC circuit. This improves the current breaking capability of the rotary switch and makes the rotary switch physically smaller and more compact. As a result, the rotary switch can have an exceptionally high power density (volts x amps / size).

Rotary switches are entirely impregnated with liquid insulators such as MIDEL. More specifically, the rotary switch may include various forms of pressure relief systems, insulation monitoring devices and other associated control systems for receiving pressure waves generated by the opening of the rotary switch. It may be located in a tank or reservoir (not shown) of the liquid insulator. A series of rotary switches can be located in the same tank in which insulator barriers are inserted to minimize the risk of flashover between adjacent rotary switches.

Impregnation of the rotary switch in the liquid insulator enhances the cooling of the metal conductors, and more specifically, the arc's cooling, deionization and arc extinction performance.

When the rotary switch is in the incomplete open (or arc discharge) position, the flow path of the direct current of the two poles 2 and 4 will be described in more detail with reference to FIGS. 12 and 13. The drive shaft 26 and the second fixed busbars 6b and 8b have been omitted for the sake of clarity of FIG. 13.

It will be appreciated that in the case of the anode 2 a direct current flow flows from the second busbar 6b to the first busbar 6a as described above and as indicated by the solid arrows. In the case of the cathode 4, however, the direct current flows from the first busbar 8a to the second busbar 8b as indicated by the dashed arrows. Thus in both poles direct currents flow in opposite directions in parallel planes. The electromagnetic interaction between the direct current flowing in the current loops and the magnetic flux density produces a repulsive force parallel to the axis of rotation of the rotary switch, which causes the arcs of the respective arc discharge zones of the positive and negative poles 2 and 4 to each other. Deflect off. This deflection is in the opposite direction to electrostatic attraction which would otherwise result in flashovers between the poles 2, 4.

Why in the case of the anode 2 the direct current cannot flow from the first busbar 6a to the second busbar 6b and in the case of the cathode 4 the direct current is removed from the second busbar 8b. There is no practical reason why it cannot flow into one busbar 8a. The direction of direct current flow at the poles 2, 4 will depend on how it is connected to the busby external circuit.

 All current loops are coupled to each other between the poles 2, 4, which must be spaced apart by a sufficient distance if the axial repulsion provides a valid advantage. If flashover is to be avoided, some separation is necessary in any case for electrostatic reasons.

FIG. 14 shows a direct current circuit in which current flows in one direction between the voltage source V and the load L. FIG. A two pole double brake rotary switch is shown in the electrical circuit by four separate switches. Switches A and B generally correspond to busbars 6a and 6b of anode 2 and switches C and D generally correspond to busbars 8a and 8b of cathode 4. It will be easy to see. When the rotatable bridging members 24 are rotated by a common rotary actuator (not shown), all four switches open at the same time, blocking the direct current flowing through each arm of the direct current circuit. Indeed, in the case of a direct current circuit of the type shown in Fig. 14, the rotary switch is a single pole (i.e., switches A and B or switches C and D) such that the current is cut off only on one arm of the direct current circuit. Only need to have, but having two poles provides better performance as a result of the sum of the four arc voltages. Rotary switches of suitable configuration can also be used for bidirectional current flow or alternating current (ac) operation.

Claims (15)

Rotary switch comprising first and second poles (2, 4), each of which has a rotatable bridging member (24) and at least one primary contact (14) A pair of fixed busbars 6a, 6b; 8a, 8b, wherein the rotary switch has a direction in which current flows through the first pole 2 through the second pole 4; A rotary switch configured to be reversed in the direction of current flow through such that the arc set on the first pole (2) is deflected away from the arc set on the second pole (4). The method of claim 1,
And a rotary actuator for rotating the rotatable bridging members (24) between an open position and a closed position. The method of claim 2,
And the rotatable bridging members (24) are configured to rotate in tandem. The method according to claim 2 or 3,
The rotatable bridging members (24) are mounted to a common drive shaft (26). 5. The method according to any one of claims 1 to 4,
Arcs set between the rotatable bridging member 24 of the first pole 2 and the associated fixed busbars 6a, 6b are arranged in the rotatable bridging member of the second pole 4. A rotary switch biased away from the arcs set between 24) and the associated fixed busbars (8a, 8b). 6. The method according to any one of claims 1 to 5,
The rotatable bridging members (24) having both ends (32, 34), each of which comprises an arc contact (30). The method according to claim 6,
Rotary switch, each fixed busbar (6a, 6b; 8a, 8b) comprises a contact arm (12) having an arc contact (28). The method of claim 7, wherein
Arc contacts 30 of the rotatable bridging member 24 and arc contacts of the contact arms 12a, 12b of the associated fixed busbars 6a, 6b at the first pole 2. Arcs set between 28a and 28b are arc contacts of the contact arms of the associated fixed busbars 8a and 8b with the arc contacts of the rotatable bridging member 24 at the second pole 4. A rotary switch biased away from the arcs set between them. 9. The method according to any one of claims 1 to 8,
The interaction of the generated magnetic flux with the current loop flowing through the respective poles 2, 4 is such that the fixed busbars 6a, associated with the rotatable bridging member 24 of the first pole 2, 6b) generates a radial repulsive force that deflects the arcs set between 6b away from the center of the current loop flowing through the first pole 2 to move the rotatable bridging member 24 to the associated fixed busbars 6a. Rotary switch for accelerating away from 6b) towards the open position. The method of claim 9,
The interaction of the generated magnetic flux with the current loop flowing through the respective poles 2, 4 is such that the fixed busbars 8a, associated with the rotatable bridging member 24 of the second pole 4, 8b) generates a radial repulsive force that deflects the arcs set between 8b) away from the center of the current loop flowing through the second pole 4 to move the rotatable bridging member 24 to the associated fixed busbars 8a. Rotary switch accelerating away from 8b) towards the open position. 11. The method according to any one of claims 1 to 10,
Rotary switch impregnated with liquid insulator. The method according to any one of claims 1 to 11,
Rotary switch, 2-pole double brake rotary switch. The rotatable bridging members 24 are placed between the associated fixed busbars 6a, 6b of the first pole 2 and the associated fixed busbars 8a, 8b of the second pole 4. Maintaining in a closed position for current to flow; And
Opening the rotary switch by rotating the rotatable bridging members 24 to an open position when a current should be interrupted,
A method for interrupting current in a circuit using the rotary switch according to any one of claims 1 to 12. The method of claim 13,
Reducing the current in the circuit to an acceptable level before the rotary switch is opened. The method according to claim 13 or 14,
Closing the rotary switch by rotating the rotatable bridging members (24) toward the closed position once the current is cut off.

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