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(11) | EP 4 258 306 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A SWITCHING SYSTEM |
| (57) A switching system comprises two stationary contacts and a movable contact; the movable
contact switches between the two stationary contacts; the movable contact is provided
with a contact zone which can contact with the stationary contacts; an oil reservoir
is provided in the contact zone.
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TECHNICAL FIELD
BACKGROUND
[0002] Plug-in contact structure is a common contact in the field of low-voltage switch. In the existing low-voltage switch with double open positions, the contact spring force (resultant force) is concentric with the contact rotation center to ensure that the pressures of the contact at the two open positions are substantially equal. When the switch is closed, both ends of the movable contact clamp the first stationary contact and the second stationary contact respectively.
[0003] When the switch is open, the arc burns between the open positions until it extinguishes, and the high temperature generated by the arc combustion will melt the contact surface material. When the switch is repeatedly opened and closed for many times, the contact surface between the movable contact and the stationary contacts will become uneven, which will increase the resistance of the switch closing and opening and affect the switch performance.
[0004] In order to solve the above technical problems, one attempt is to provide an electrical switch, which includes a first fixed contact and a second fixed contact, and a movable blade contact that includes at least a pair of longitudinal blades flexibly connected to each other, whereby the blades come into contact with contact portions of the first fixed contact and/or the second fixed contact in a switching event. The opposite surfaces of the contact portions of the first and second fixed contacts include rough areas, while the inner surface of each blade includes protruding areas or the opposite surfaces of the contact portions of the first and second fixed contacts include protruding areas, while the inner surface of each blade includes rough areas. However, this solution still has the problems of complex structure and unsatisfactory arc extinguishing effect.
SUMMARY
[0005] In order to remedy one or more defects in the prior art, according to one aspect of the present disclosure, a switching system is proposed, which comprises two stationary contacts and one movable contact.
[0007] The movable contact is provided with a contact zone which can contact with the stationary contact.
[0009] According to the above aspect of the present disclosure, the movable contact includes a first bracket and a second bracket in the form of a clamping structure.
[0011] A movable contact arc contact area, a first main contact area and a second main contact area are respectively arranged in the contact zone at the one end of the first bracket and of the second bracket.
[0012] The other end of the first bracket and of the second bracket are respectively provided with a load-side bulge.
[0013] According to the above aspect of the present disclosure, the first main contact area and the second main contact area are arranged side by side in the width direction (lateral direction) of the first bracket and the second bracket.
[0014] In the longitudinal direction of the first bracket and the second bracket, the movable contact arc contact area is arranged adjacent to the first main contact area and the second main contact area and closer to an outer edge of the one end of the first bracket and the second bracket than the first main contact area and the second main contact area.
[0015] According to the above aspect of the present disclosure, an oil reservoir is provided between the first main contact area and the second main contact area.
[0016] An oil reservoir is arranged between the movable contact arc contact area and the first main contact area and between the movable contact arc contact area and the second main contact area.
[0017] According to the above aspect of the present disclosure, the movable contact arc contact area has a flat contact surface and chamfers located at either side of the contact surface.
[0018] According to the above aspect of the present disclosure, the first main contact area, the second main contact area and the load-side bulge all have arc-shaped outer surfaces.
[0019] The height of the contact surface of the movable contact arc contact area is lower than the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge, that is, there is a height difference h between the contact surface of the movable contact arc contact area and the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge;
[0021] The highest point of the arc-shaped outer surface of the first main contact area, the highest point of the arc-shaped outer surface of the second main contact area and the highest point of the arc-shaped outer surface of the load-side bulge have the same height.
[0022] According to the above-mentioned aspect of the present disclosure, the highest points of the arc-shaped outer surfaces of the first main contact area and of the second main contact area have a position difference s compared with a corresponding edge of the corresponding movable contact arc contact area.
[0023] According to the above aspect of the present disclosure, the position difference s is between 1 mm and 6 mm, preferably 4 mm.
[0025] According to the above aspect of the present disclosure, the other end of the first bracket and of the second bracket are pivotally connected to an output terminal via the load-side bulge.
[0026] According to the above aspect of the present disclosure, the movable contact further comprises a sleeve, a pressure spring and a holder for holding the pressure spring.
[0027] The first bracket and the second bracket are held in the sleeve under the combined action of the sleeve, the pressure spring and the holder.
[0028] The holder is of ring shape with a rectangular cross section and is held in the sleeve, and the first bracket, the second bracket and the pressure spring pass through the holder.
[0029] The pressure spring acts between the holder and the first bracket and between the holder and the second bracket, thereby pressing the first bracket and the second bracket toward each other.
[0031] According to the above-mentioned aspect of the present disclosure, a sleeve partition is provided inside the sleeve.
[0032] Under the action of the pressure spring, the first bracket and the second bracket respectively abuts against one side of the sleeve partition.
[0033] According to another aspect of the present disclosure, the movable contact arc contact area extends respectively from the highest point of the first main contact area and the highest point of the second main contact area in the form of a ramp.
[0034] According to the above-mentioned another aspect of the present disclosure, the oil reservoir extends into the movable contact arc contact area in the form of a ramp.
[0035] According to another aspect of the present disclosure, the first main contact area, the second main contact area and the load-side bulge all have arc-shaped outer surfaces.
[0036] According to another aspect of the present disclosure, the movable contact arc contact area in the form of a ramp is lower than the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge.
[0037] The plane where the highest points of the first main contact area and the second main contact area are located has an angle difference a relative to the movable contact arc contact area in the form of a ramp.
[0038] The highest point of the arc-shaped outer surface of the first main contact area, the highest point of the arc-shaped outer surface of the second main contact area and the highest point of the arc-shaped outer surface of the load-side bulge have the same height.
[0039] According to another aspect of the present disclosure, the angle difference a is between 1 and 5°, preferably 3°.
[0040] According to another aspect of the present disclosure, the highest points of the arc-shaped outer surfaces of the first main contact area and of the second main contact area have a position difference s compared with a corresponding edge of the corresponding movable contact arc contact area.
[0042] According to another aspect of the present disclosure, the position difference s is between 1 mm and 6 mm, preferably 4 mm.
[0043] According to another aspect of the present disclosure, the movable contact arc contact area, the first main contact area and the second main contact area are all made of conductive metal materials and are arranged on the one end of the first bracket and of the second bracket by welding and/or electroplating.
[0044] According to another aspect of the present disclosure, the movable contact arc contact area is made of alloy material with high melting point.
[0045] The melting point of the alloy material of the movable contact arc contact area is higher than that of the materials of the first main contact area and the second main contact area.
[0046] According to the above-mentioned another aspect of the present disclosure, a plurality of oil reservoirs may be provided in the movable contact arc contact area in the form of a ramp.
[0047] The plurality of oil reservoirs extend along the length direction of the first bracket and the second bracket. Or the plurality of oil reservoirs extend substantially along the width direction of the first bracket and the second bracket.
[0048] According to the above aspect of the present disclosure, one end of the stationary contact is provided with a stationary contact arc striking portion, a stationary contact arc contact area and a stationary contact notch.
[0049] A gradually changing chamfered portion is arranged on one end of the stationary contact, and the stationary contact arc contact area is arranged on the gradually changing chamfered portion and adjacent to the stationary contact arc striking portion
[0050] The one end of the stationary contact is provided with a main contact area of the stationary contact, and the main contact area of the stationary contact is located below the stationary contact notch and the stationary contact arc contact area.
[0051] According to the above-mentioned aspect of the present disclosure, gaps exist between the movable contact arc contact area, the first main contact area and the second main contact area of the first bracket and the movable contact arc contact area, the first main contact area and the second main contact area of the second bracket, respectively.
[0052] According to the above-mentioned aspect of the present disclosure, when the switching system is closed, it is convenient to insert the gradually changing chamfered portion of the stationary contact into the gaps.
[0053] According to the above-mentioned aspect of the present disclosure, the stationary contact arc striking portion is arranged for the combustion of an arc, and the stationary contact arc contact area and the main contact area of the stationary contact are protected by burning the stationary contact arc striking portion.
[0054] According to the above aspect of the present disclosure, the stationary contact arc contact area is located between the stationary contact arc striking portion and the main contact area of the stationary contact.
[0055] During the relative motion of the stationary contact and the movable contact, the contact of the stationary contact arc contact area with the movable contact arc contact area and the contact of the main contact area of the stationary contact with the first main contact area and the second main contact area meet the following timing sequence:
during the closing operation, the contact between the stationary contact arc contact area and the movable contact arc contact area is earlier than that between the main contact area of the stationary contact and the first main contact area and the second main contact area; when completely closed, because of the existence of the height difference h, the main contact area of the stationary contact contacts at least one of the first main contact area and the second main contact area, while the stationary contact arc contact area is separated with the movable contact arc contact area;
during the opening operation, because of the position difference s and the height difference h, the separation of the stationary contact arc contact area from the movable contact arc contact area is later than the separation of the main contact area of the stationary contact from the first main contact area and the second main contact area.
[0056] According to the above-mentioned aspect of the present disclosure, the main contact area of the stationary contact is located in the lowermost region of the stationary contact.
[0057] The stationary contact notch of the stationary contact is provided such that when the switching system cuts off the current, the arc between the stationary contact arc contact area of the stationary contact and the movable contact arc contact area can be subjected to a magnetic blowing force in the direction of the arc-extinguishing grid, thereby the arc can be quickly transferred to the latter to protect the movable contact arc contact area and the stationary contact arc contact area from less erosion by the arc.
[0058] According to the above-mentioned aspect of the present disclosure, when the switching system is in the closed position, at least one of the first main contact area and the second main contact area keeps in contact with the main contact area of the stationary contact for carrying rated current and short-circuit current under special working conditions.
[0059] The movable contact arc contact area and the stationary contact arc contact area are kept separate.
[0060] According to another aspect of the present disclosure, one end of the stationary contact is provided with a stationary contact arc striking portion, a stationary contact arc contact area and a stationary contact notch.
[0061] A gradually changing chamfered portion is arranged on one end of the stationary contact, and the stationary contact arc contact area is arranged on the gradually changing chamfered portion and adjacent to the stationary contact arc striking portion
[0062] The one end of the stationary contact is provided with a main contact area of the stationary contact, and the main contact area of the stationary contact is located below the stationary contact notch and the stationary contact arc contact area.
[0063] According to another aspect of the present disclosure, there are gaps between the movable contact arc contact area, the first main contact area and the second main contact area of the first bracket and the movable contact arc contact area, the first main contact area and the second main contact area of the second bracket, respectively.
[0064] According to another aspect of the present disclosure, when the switching system is closed, it is convenient to insert the gradually changing chamfered portion of the stationary contact into the gaps.
[0065] According to the above-mentioned another aspect of the present disclosure, the stationary contact arc striking portion is provided for the combustion of an arc, and the stationary contact arc contact area and the main contact area of the stationary contact are protected by burning the stationary contact arc striking portion.
[0066] According to another aspect of the present disclosure, the stationary contact arc contact area is located between the stationary contact arc striking portion and the main contact area of the stationary contact.
[0067] During the relative motion of the stationary contact and the movable contact, the contact of the stationary contact arc contact area with the movable contact arc contact area and the contact of the main contact area of the stationary contact with the first main contact area and the second main contact area meet the following timing sequence:
During the closing operation, due to the position difference s, the contact between the stationary contact arc contact area and the movable contact arc contact area is earlier than the contact between the main contact area of the stationary contact and the first main contact area and the second main contact area of the movable contact, and when completely closed, due to the angle difference α, only the main contact area of the stationary contact contacts at least one of the first main contact area and the second main contact area, while the stationary contact arc contact area is separated from the second act contact area.
[0068] During the opening operation, due to the position difference s and the angle difference α, the separation between the stationary contact arc contact area and the movable contact arc contact area is later than the separation between the main contact area of the stationary contact and at least one of the first main contact area and the second main contact area.
[0069] According to another aspect of the present disclosure, the main contact area of the stationary contact is located in the lowermost region of the stationary contact.
[0070] The stationary contact notch is provided such that when the switching system cuts off the current, the arc between the stationary contact arc contact area and the movable contact arc contact area can be subjected to a magnetic blowing force in the direction of the arc-extinguishing grid, thereby the arc can be quickly transferred to the latter to protect the movable contact arc contact area and the stationary contact arc contact area from less erosion by the arc.
[0071] According to another aspect of the present disclosure, when the switching system is in the closed position, at least one of the first main contact area and the second main contact area keeps in contact with the main contact area of the stationary contact for carrying rated current and short-circuit current under special working conditions.
[0072] The movable contact arc contact area and the stationary contact arc contact area are kept separate.
[0073] In the technical solutions according to the present disclosure, the zone where the movable contact arc contact area and the main contact areas of the movable contact are located is the contact zone, and a plurality of oil reservoirs are arranged in the contact zone, so that when the contact zone contacts with the stationary contact, there is a certain contact point to ensure the electrical performance of the switching system. At the same time, the oil reservoir can store grease, which is used for lubrication when the movable and stationary contacts slide relatively, that is, in the process of closing and opening the switching system every time, and thus the contact portions of the movable and stationary contacts are supplemented with grease, and therefore, the wear of the contacts is reduced.
[0074] In the above two different layout structures of the movable contact arc contact area and the main contact areas of the movable contact, the movable contact arc contact area and the stationary contact arc contact area are made from different material than that of the main contact areas of the movable contact and the main contact areas of the stationary contacts and embedded (such as welding, powder metallurgy, etc.) in the movable contact and the stationary contacts. Generally, the movable contact arc contact area and the stationary contact arc contact area are made of high-melting-point alloy (the melting point is higher than that of the material of the main contact areas of the movable contact and the main contact areas of the stationary contacts), which can reduce the wearing speed of the movable contact arc contact area and the stationary contact arc contact area, providing better protection for the main contact areas of the movable contact and the main contact areas of the stationary contacts and thus further improving the electrical performance of the switching system.
[0075] In the technical scheme according to the present disclosure, the stationary contact arc striking portion is provided for the combustion of the arc, and the purpose of protecting the stationary contact arc contact area and the main contact area of the stationary contact is achieved by burning the stationary contact arc striking portion.
[0076] In the technical scheme according to the present disclosure, the main contact area of the stationary contact is located in the lowermost region of the stationary contact. Due to the protection realized by the stationary contact arc contact area and the stationary contact arc striking portion, the switching system is protected from electrical wearing or from suffering less electrical wearing resulted by electrical operation in the whole life cycle, thus always showing excellent current carrying capacity (lower temperature rise).
[0077] In the technical solution according to the present disclosure, the stationary contact notch is provided such that when the switching system cuts off the current, the arc between the stationary contact arc contact area of the stationary contact and the movable contact arc contact area can be subjected to a magnetic blowing force in the direction of the arc-extinguishing grid, thereby the arc can be quickly transferred to the latter to protect the movable contact arc contact area and the stationary contact arc contact area from less erosion by the arc.
[0078] In the technical solution according to the present disclosure, when the switching system is in the closed position, the first main contact area and the second main contact area are kept in contact with the main contact area of the stationary contact for carrying rated current and short-circuit current under special working conditions, while the movable contact arc contact area and the stationary contact arc contact area are kept separated, so as to ensure good contact between the main contact areas and realize excellent performance of the switch with lower temperature rise.
[0079] In the technical solution according to the present disclosure, due to the existence of the position difference s and the height difference h, in the closing process of the switching system, the conduction of the corresponding arc contact areas of the movable and stationary contacts is always earlier than that of the corresponding main contact areas of the movable and stationary contacts (as shown in Fig. 2), until the corresponding main contact areas of the movable and stationary contacts are completely contacted (as shown in Fig. 3), since the height difference h between the main contact areas of the movable contact and the movable contact arc contact area will raise the movable contact arc contact area, separating it from the stationary contact arc contact area. In the opening process of the switching system, each corresponding main contact area of the movable contact slides on each corresponding main contact area of the stationary contact firstly. At this time, the movable contact arc contact area is not in contact with the stationary contact arc contact area, until the corresponding main contact area of the movable contact slides into the chamfered portion, the gap begins to decrease, and the movable contact arc contact area contacts with the stationary contact arc contact area, and each corresponding main contact area is separated. As further sliding, the movable contact arc contact area is separated from the stationary contact arc contact area. At this time, the arc burns between the stationary contact arc contact area and the movable contact arc contact area and quickly transfers to the arc-extinguishing grid and the movable contact arc contact area to burn until it is extinguished.
[0080] The movable contact arc contact area and the stationary contact arc contact area can protect the main contact areas of the movable contact and the stationary contacts from arc ablation and improve the service life of the switching system. the conduction of each corresponding arc contact area of the movable and stationary contacts is always earlier than that of each corresponding main contact area of the movable and stationary contacts (as shown in Fig. 2), and the contact point between the movable contact and the stationary contact first moves from point b to point a (as shown in Fig. 13). When the switching system is closed (as shown in Fig. 3), because of the angle difference α between the main contact area of the movable contact and the movable contact arc contact area, the main contact area of the movable contact is kept in contact with the main contact area of the stationary contact, and all the zones where the main contact areas of the movable contact extend outward (including the movable contact arc contact area) are kept separated from the stationary contact. During the opening process of the switching system, the main contact areas of the movable contact first slide on the main contact area of the stationary contact. At this time, all the zones (including the movable contact arc contact area) where the main contact areas of the movable contact extend outward are not in contact with the stationary contact, until the main contact areas of the movable contact slide into the chamfered portion, the gap between the paired movable contacts begins to decrease, and the contact point between the movable contact and the stationary contact moves from point a to point B until they finally separate at point b (as shown in Fig. 13). The arc burns between the stationary contact arc contact area 12 and the movable contact arc contact area, and quickly transfers to the arc-extinguishing grid and the movable contact arc contact area to burn until it extinguishes. The movable contact arc contact area and the stationary contact arc contact area can protect the corresponding main contact areas of the movable contact and the stationary contact from arc ablation, and improve the service life of the switching system.
[0081] So far, in order that the detailed description of the disclosure herein can be better understood and the contribution of the disclosure to the prior art can be better realized, the disclosure has outlined the contents of the disclosure quite broadly. Of course, embodiments of the present disclosure will be described below and will form the subject of the appended claims.
[0082] Likewise, those skilled in the art will recognize that the concept on which this disclosure is based can be easily used as a basis for designing other structures, methods and systems for carrying out the several purposes of this disclosure. Therefore, it is important that the appended claims should be regarded as including such equivalent structures as long as they do not exceed the spirit and scope of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0083] Those skilled in the art will have a better understanding of this disclosure through the following drawings, and the advantages of this disclosure can be more clearly reflected. The drawings described here are only for illustrative purposes of selected embodiments, not all possible implementations, and are not intended to limit the scope of the present disclosure.
Fig. 1 shows a switching system in an open state (double open state) according to an embodiment of the present disclosure,
Fig. 2 shows the switching system in the closed state according to the above embodiment of the present disclosure, in which the stationary contact arc contact area is in contact with the movable contact arc contact area, and the main contact of the stationary contact is not in contact with the main contact areas of the movable contact;
Fig. 3 shows the switching system in the closed state according to the above embodiment of the present disclosure, in which the main contact of the stationary contact is in contact with the main contact areas of the movable contact, and the stationary contact arc contact area is not in contact with the movable contact arc contact area;
Fig. 4 shows a perspective schematic view of a stationary contact according to the present disclosure;
Fig. 5 shows the section taken along the line A-A in Fig. 4;
Fig. 6 shows a perspective schematic view of one embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Fig. 7 shows a side view of one embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Fig. 8 shows a top view of one embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Fig. 9 shows the section taken along the line B-B in Fig. 3;
Fig. 10 shows an enlarged view of a part of Fig. 9;
Fig. 11 shows a perspective schematic view of another embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Fig. 12 shows a side view of another embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Fig. 13 shows a top view of another embodiment of a first bracket and a second bracket of a movable contact according to the present disclosure;
Figs. 14 and 15 respectively show cross-sectional profiles at two ends of the movable contact arc contact area in the form of a ramp of the first bracket and the second bracket according to the present disclosure;
Fig. 16 shows another embodiment of the first bracket and the second bracket of the movable contact according to the present disclosure based on the section taken along the line B-B in Fig. 3;
Fig. 17 shows an enlarged view of a part of Fig. 16;
Fig. 18 shows that a plurality of oil reservoirs extend substantially along the length direction of the first bracket and the second bracket;
Fig. 19 shows that a plurality of oil reservoirs substantially extend along the width direction of the first bracket and the second bracket.
DETAILED DESCRIPTION
[0084] In the following, specific embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings.
[0085] Fig. 1 shows a switching system in an open state according to one embodiment of the present disclosure. Figs. 2 and 3 show a switching system in a closed state according to the above embodiment of the present disclosure. In Figs. 2 and 3, a stationary contact 1 and an arc-extinguishing grid in Fig. 1 are omitted for simplicity.
[0086] In Fig. 1, the switching system includes two stationary contacts 1 and one movable contact 2. One of the stationary contacts 1 can be connected to a first power supply (not shown), the other of the stationary contacts 1 can be connected to a second power supply (not shown), and the movable contact 2 can be connected to a load (not shown). The arc-extinguishing grid is arranged between the two stationary contacts 1.
[0087] In Fig. 1, the movable contact 2 is in a dual-open position (the movable contact 2 is in open position for the two stationary contacts 1), so that the movable contact 2 is not in contact with any of the stationary contacts 1. In Figs. 2 and 3, the movable contact 2 is in a closed position, and the movable contact 2 is in contact with one of the stationary contacts 1 (for the other stationary contact 1, the movable contact 2 is in the opening position), and the first power supply supplies power to the load.
[0089] When the movable contact 2 is in contact with the other one of the stationary contacts 1, the second power supply supplies power to the load.
[0090] Figs. 4 and 5 show the stationary contact 1 according to one embodiment of the present disclosure.
[0091] One end of the stationary contact 1 is provided with a stationary contact arc striking portion 11, a stationary contact arc contact area 12 and a stationary contact notch 13. On said one end of the stationary contact 1, there is also a gradually changing chamfer portion 14, and the stationary contact arc contact area 12 is arranged on the gradually changing chamfer portion 14 and adjacent to the stationary contact arc striking portion 11. On the one end of the stationary contact 1, there is also a main contact area 15 of the stationary contact, which is located below the stationary contact notch 13 and the stationary contact arc contact area 12.
[0092] The other end of the stationary contact 1 can be connected with the first power supply through a power supply input terminal (not shown).
[0093] As shown in Figs. 9 and 16, the movable contact 2 has a clamping structure, which includes a first bracket 21 and a second bracket 22.
[0094] The first bracket 21 and the second bracket 22 are arranged face to face with respect to each other and separated from each other at one of their ends.
[0095] As shown in Fig. 6 to Fig. 8, a movable contact arc contact area 211, 221, a first main contact area 212, 222 and a second main contact area 213, 223 are respectively arranged at one end of the first bracket 21 and of the second bracket 22, and a load-side bulge 214, 224 is arranged at the other end of the first bracket 21 and of the second bracket 22.
[0096] In the width direction (transverse direction) of the first bracket 21 and the second bracket 22, the first main contact area 212, 222 and the second main contact area 213, 223 are arranged side by side.
[0097] In the longitudinal direction of the first bracket 21 and the second bracket 22, the movable contact arc contact area 211, 221 is arranged adjacent to the first main contact area 212, 222 and the second main contact area 213, 223, and closer to an outer edge of the one end of the first bracket 21 and of the second bracket 22 than the first main contact area 212, 222 and the second main contact area 213, 223.
[0098] In Fig. 6, for each of the first bracket 21 and the second bracket 22, there is one movable contact arc contact area, but there may be two or more. In Fig. 6, for each of the first bracket 21 and the second bracket 22, there are one first main contact and one second main contact, but there may be more than two respectively.
[0099] Gaps exist between the movable contact arc contact area 211, the first main contact area 212 and the second main contact area 213 of the first bracket 21 and the movable contact arc contact area 221, the first main contact area 222 and the second main contact area 223 of the second bracket 22, respectively.
[0100] An oil reservoir 217, 227 is provided between the first main contact area 212, 222 and the second main contact area 213, 223.
[0101] Oil reservoirs 217, 227 are provided between the movable contact arc contact area 211, 221 and the first main contact area 212, 222 and between the movable contact arc contact area 211, 221 and the second main contact area 213, 223.
[0102] As shown in Figs. 6 to 7, the first main contact areas 212, 222, the second main contact areas 213, 223 and the load-side bulge 214, 224 all have arc-shaped outer surfaces, such as spherical outer surfaces.
[0103] The movable contact arc contact area 211, 221 has a flat contact surface 215, 225 and a chamfer 216, 226 located at either side of the contact surface 215, 225.
[0104] In Fig. 7, the height of the contact surface 215, 225 of the movable contact arc contact area 211, 221 is lower than the highest point of the arc-shaped outer surfaces of the first main contact area 212, 222, the second main contact area 213, 223 and the load-side bulge 214, 224, for example, by a mount of 0.1 mm to 0.5 mm, preferably by 0.3 mm.
[0105] The highest point of the arc-shaped outer surface of the first main contact area 212, 222, the highest point of the arc-shaped outer surface of the second main contact area 213, 223 and the highest point of the arc-shaped outer surface of the load-side bulge 214, 224 have the same height.
[0106] As shown in Fig. 7, for the first bracket 21, the thickness of the first main contact area 212 and of the second main contact area 213 is greater than that of the arc contact area 211, that is, the first main contact area 212 and the second main contact area 213 are higher than the movable contact arc contact area 211, and that is, the first main contact area 212 and the second main contact area 213 have a height difference h with respect to the movable contact arc contact area 211. The first main contact area 212 and the second main contact area 213 have the same thickness.
[0107] As shown in Fig. 7, for the second bracket 22, the thickness of the first main contact area 222 and the second main contact area 223 is greater than that of the arc contact area 221, that is, the first main contact area 222 and the second main contact area 223 are higher than the movable contact arc contact area 221, and that is, the first main contact area 222 and the second main contact area 223 have a height difference h relative to the movable contact arc contact area 221. The thickness of the first main contact area 222 is equal to that of the second main contact area 223.
[0109] As shown in Fig. 8, for the first bracket 21, the highest points of the arc-shaped outer surfaces of the first main contact area 212 and of the second main contact area 213 have a position difference s compared with a corresponding edge of a corresponding movable contact arc contact area 211, the edge being formed at the joint between the contact surface 215, 225 and the chamfer 216, 226.
[0110] Also as shown in Fig. 8, for the second bracket 22, the highest point of the arc-shaped outer surfaces of the first main contact area 222 and of the second main contact area 223 has a position difference s compared with a corresponding edge of a corresponding movable contact arc contact area 221, the edge being formed at the joint between the contact surface 215, 225 and the chamfer 216, 226.
[0112] The movable contact arc contact area 211, 221, the first main contact area 212, 222 and the second main contact area 213, 223 are all provided for conducting current, wherein when the movable contact 2 is in contact with one of the stationary contacts 1, the movable contact arc contact area 211, 221 and the first main contact area 212, 222 can successively contact with one of the stationary contacts 1. Thereafter, the second main contact area 213, 223 may be or may be not electrically connected to one of the stationary contacts 1 as required. When the movable contact 2 is in contact with the other one of the stationary contacts 1 (not shown), the movable contact arc contact area 211, 221 and the second main contact area 213, 223 can be successively conducted with the other one of the stationary contacts 1. Thereafter, the first main contact area 212, 222 may be or may be not electrically connected to the other one of the stationary contacts 1 as required.
[0113] The movable contact arc contact area 211, 221, the first main contact area 212, 222 and the second main contact area 213, 223 are all made of conductive metal materials and are arranged on one end of the first bracket 21 and of the second bracket 22 by welding, electroplating and/or other methods.
[0114] As shown in Figs. 1 to 3, the other end of the first bracket 21 and of the second bracket 22 are pivotally connected to the output terminal 3 via the load-side bulge 214, 224.
[0116] As shown in Figs. 1 to 3, 9 and 10, 16 and 17, the movable contact 2 further includes a sleeve 4, a pressure spring 5 and a holder 6 for holding the pressure spring.
[0117] The first bracket 21 and the second bracket 22 are held in the sleeve 4 under the combined action of the sleeve 4, the pressure spring 5 and the holder 6.
[0118] The holder 6 has a ring shape with a rectangular cross section and is held in the sleeve 4, and the first bracket 21, the second bracket 22 and the pressure spring 5 pass through the holder 6.
[0119] The pressure spring 5 acts between the holder 6 and the first bracket 21 and acts between the holder 6 and the second bracket 22, thereby pressing the first bracket 21 and the second bracket 22 toward each other.
[0121] As shown in Figs. 1 to 3, a sleeve driving member 41 is provided outside the sleeve 4. A driving mechanism (not shown) drives the sleeve driving member 41 to actuate the first bracket 21 and the second bracket 22 to rotate between the open position and the closed position.
[0122] The sleeve driving member 41 is substantially in the shape of an oblate cylinder. The center of the top surface of the sleeve driving member 41 is provided with a spline-shaped depression 412.
[0123] As shown in Fig. 9, a sleeve partition 42 is provided inside the sleeve 4. Under the action of the pressure spring 5, the first bracket 21 and the second bracket 22 respectively abut against a side of the sleeve partition 42.
[0124] As shown in Fig. 11 to Fig. 15, the first main contact area 212, 222, the second main contact area 213, 223 and the movable contact arc contact area 211, 221 in the form of a ramp are respectively arranged on one end of the first bracket 21 and of the second bracket 22. On the other end of the first bracket 21 and of the second bracket 22, a load-side bulge 214, 224 is provided.
[0125] Different from the movable contact arc contact area 211, 221 shown in Figs. 6 to 8, the movable contact arc contact area 211, 221 shown in Figs. 11 to 15 extend obliquely from the highest point of the first main contact area 212, 222 (as shown by dots in Fig. 13) and the highest point of the second main contact area 213, 223 (as shown by dots in Fig. 13), respectively.
[0126] Figs. 14 and 15 show cross-sectional profiles at both ends of the movable contact arc contact area 211, 221 in the form of a ramp, respectively.
[0127] The first main contact area 212, 222 and the second main contact area 213, 223 are arranged side by side.
[0128] In the longitudinal direction of the first bracket 21 and the second bracket 22, the movable contact arc contact area 211, 221 in the form of a ramp is arranged adjacent to the first main contact area 212, 222 and the second main contact area 213, 223 and closer to the outer edge of one end of the first bracket 21 and the second bracket 22 than the first main contact area 212, 222 and the second main contact area 213, 223.
[0129] In Fig. 11, for each of the first bracket 21 and the second bracket 22, there is one movable contact arc contact area in the form of a ramp. In Fig. 11, for each of the first bracket 21 and the second bracket 22, the first main contact and the second main contact are one respectively, but they may be more than two respectively.
[0130] Gaps exist between the movable contact arc contact area 211, the first main contact area 212 and the second main contact area 213 of the first bracket 21 and between the movable contact arc contact area 221, the first main contact area 222 and the second main contact area 223 of the second bracket 22.
[0131] In the above two different layout structures of the movable contact arc contact area and the main contact areas of the movable contact, the movable contact arc contact area and the stationary contact arc contact area are made from different material than that of the main contact areas of the movable contact and the main contact areas of the stationary contacts and embedded (such as welding, powder metallurgy, etc.) in the movable contact and the stationary contacts. Generally, the movable contact arc contact area and the stationary contact arc contact area are made of high-melting-point alloy (the melting point is higher than that of the material of the main contact areas of the movable contact and the main contact areas of the stationary contacts), which can reduce the wearing speed of the movable contact arc contact area and the stationary contact arc contact area, providing better protection for the main contact areas of the movable contact and the main contact areas of the stationary contacts and thus further improving the electrical performance of the switching system.
[0132] As shown in Fig. 11, oil reservoirs 217, 227 are provided between the first main contact area 212, 222 and the second main contact area 213, 223.
[0133] As shown in Fig. 11, the oil reservoir 217, 227 may extend into the movable contact arc contact area 211, 221 in the form of a ramp.
[0134] As shown in Fig. 11, the first main contact area 212, 222, the second main contact area 213, 223 and the load-side bulge 214, 224 all have arc-shaped outer surfaces, such as spherical outer surfaces.
[0135] As shown in Fig. 11, the movable contact arc contact area 211, 221 in the form of a ramp has a flat contact surface 215, 225 and a chamfer 216, 226 located at either side of the contact surface 215, 225.
[0136] In Fig. 12, the movable contact arc contact area 211, 221 in the form of a ramp is lower than the highest points of the arc-shaped outer surfaces of the first main contact area 212, 222, the second main contact area 213, 223 and the load-side bulge 214, 224.
[0137] The highest point of the arc-shaped outer surface of the first main contact area 212, 222, the highest point of the arc-shaped outer surface of the second main contact area 213, 223 and the highest point of the arc-shaped outer surface of the load-side bulge 214, 224 have the same height.
[0138] As shown in Fig. 12, for the first bracket 21, the plane where the highest points of the first main contact area 212 and the second main contact area 213 are located has an angle difference α with respect to the movable contact arc contact area 211 in the form of a ramp.
[0139] As shown in Fig. 12, for the second bracket 22, the plane where the highest points of the first main contact area 222 and the second main contact area 223 are located has an angle difference α with respect to the movable contact arc contact area 221 in the form of a ramp.
[0141] As shown in Fig. 13, for the first bracket 21, the highest point of the arc-shaped outer surfaces of the first main contact area 212 and the second main contact area 213 has a position difference s compared with the corresponding edge of the corresponding movable contact arc contact area 211, and the edge is formed at the joint of the contact surface 215, 225 and the chamfer 216, 226.
[0142] As shown in Fig. 13, for the second bracket 22, the highest points of the arc-shaped outer surfaces of the first main contact area 222 and the second main contact area 223 have a position difference s compared with the corresponding edge of the corresponding movable contact arc contact area 221, and the edge is formed at the joint of the contact surface 215, 225 and the chamfer 216, 226.
[0144] In Fig. 13, the movable contact arc contact area 211, 221 in the form of a ramp, the first main contact area 212, 222 and the second main contact area 213, 223 are all provided for conducting current, wherein when the movable contact 2 is in contact with one of the stationary contacts 1 (as shown in Figs. 2 and 3), the movable contact arc contact area 211, 221 and the first main contact area 212, 222 can contact the one of the stationary contacts 1 one after another. Thereafter, the second main contact area 213, 223 may be or may be not electrically connected to one of the stationary contacts 1 as required. When the movable contact 2 is in contact with the other one of the stationary contacts 1 (not shown), the movable contact arc contact area 211, 221 and the second main contact area 213, 223 can be successively conducted with the other one of the stationary contacts 1. Thereafter, the first main contact area 212, 222 may be or may be not electrically connected to the other one of the stationary contacts 1 as required.
[0145] The movable contact arc contact area 211, 221 in the form of a ramp, the first main contact area 212, 222 and the second main contact area 213, 223 are all made of conductive metal materials and are arranged on one end of the first bracket 21 and of the second bracket 22 by welding, electroplating and/or other methods.
[0146] As shown in Figs. 18 and 19, a plurality of oil reservoirs 217, 227 can be provided in the movable contact arc contact area 211, 221 in the form of a ramp, wherein in Fig. 18, the plurality of oil reservoirs 217, 227 extend substantially along the length direction of the first bracket 21 and the second bracket 22; while in Fig. 19, the plurality of oil reservoirs 217, 227 extend substantially along the width direction of the first bracket 21 and the second bracket 22.
[0147] Next, the operation state of the switching system according to the present disclosure will be explained by taking the closing (contacting) and opening (not contacting) of the movable contact 2 and one of the two stationary contacts 1 as examples.
[0148] The overall layout of a switching system according to the present disclosure, such as a dual power changeover switch, is shown in Fig. 1. As shown in Fig. 2 and Fig. 3, when the movable contact 2 rotates counterclockwise, it can be connected with the first power supply (not shown). When the movable contact 2 rotates clockwise (not shown), it can be connected with the second power supply.
[0149] As shown in Figs. 6 to 10, on the first bracket 21 and the second bracket 22, the zone where the movable contact arc contact area 211, 221, the first main contact area 212, 222 and the second main contact area 213, 223 are located is the contact zone. A plurality of oil reservoirs 217, 227 are arranged in the contact zone, so that the movable contact 2 has a defined contact point when contacting with the stationary contact 1, and the electrical performance of the switching system is guaranteed. At the same time, the oil reservoirs 217, 227 can store grease for lubrication when there is relative slide between the main contact area of the movable contact and main contact area of the stationary contact, that is, in each closing and opening process of the switching system, for grease to be supplemented to the contact portions of the movable contact and the stationary contacts, thereby reducing the wearing of the contacts and resistance in opening and closing processes, and thereby improving the mechanical and electrical life of the switching system.
[0150] As shown in Figs. 4 and 5, the gradually changing chamfer portion 14 of the stationary contact 1 is easy to be inserted into the contact gaps of the movable contact 2. The stationary contact 1 also has the following functional features:
- (a) a stationary contact arc striking portion 11, provided for combustion of electric arc, and thus, the purpose of protecting the stationary contact arc contact area 12 and the main contact area 15 of the stationary contact is achieved by burning the stationary contact arc striking portion 11;
- (b) a stationary contact arc contact area 12, located between the stationary contact arc striking portion 11 and the main contact area 15 of the stationary contact. During the relative motion of the stationary contact 1 and the movable contact 2, the contact of the stationary contact arc contact area 12 with the movable contact arc contact area 215, 225 and the contact of the main contact area15 of the stationary contact meet the following timing sequence: during the closing operation, the contact between the stationary contact arc contact area 12 and the movable contact arc contact area 215, 225 is earlier than that between the main contact area of the stationary contact 15 and the first main contact area 212, 222 and the second main contact area 213, 223; when completely closed, the main contact area of the stationary contact 15 contacts the first main contact area 212, 222 and the second main contact area 213, 223, while the stationary contact arc contact area 12 is separated with the movable contact arc contact area 215, 225; during the opening operation, the separation of the stationary contact arc contact area 12 from the movable contact arc contact area 215, 225 is later than the separation of the main contact area of the stationary contact 15 from the first main contact area 212, 222 and the second main contact area 213, 223. This timing requirement of this scheme is realized by the height difference h and position difference s (angle difference α and position difference s) of the movable contact 2. Of course, it can also be realized by setting the corresponding position parameters of the arc contact areas on the stationary contacts.
- (c) a main contact area 15 of the stationary contact, located in the lowest area of the stationary contact 1. Due to the protection achieved by the stationary contact arc contact area 12 and the stationary contact arc striking portion 11, the switching system is protected from electrical wearing or from suffering less electrical wearing resulted by electrical operation in the whole life cycle, thus always showing excellent current carrying capacity (lower temperature rise).
- (d) a stationary contact notch 13: when the switching system cuts off the current, the arc between the stationary contact arc contact area 12 and the movable contact arc contact area 211, 221 can be subjected to a magnetic blowing force in the direction of the arc-extinguishing grid, so that the arc can be quickly transferred to the latter to protect the movable contact arc contact area and the stationary contact arc contact area from less erosion by the arc.
[0151] When the switching system is in the open position, under the action of the pressure spring 5, the gap between the arc contact area 211 of the first bracket 21 and the arc contact area 221 of the second bracket 22 and the gap between the main contact area 212 of the first bracket 21 and the main contact area 222 of the second bracket 22 are smaller than the thickness of the stationary contact 1, as shown in Figs. 9 and 10; while when the switching system is closed, the paired first bracket 21 and second bracket 22 can be pushed apart by the stationary contact 1.
[0152] When the switching system is in the closed position, the first and second main contact area 212, 222 and 213, 223 are kept in contact with the main contact area of the stationary contact 15 for carrying rated current and short-circuit current under special working conditions, while the movable contact arc contact area 215 and 225 and the stationary contact arc contact area 12 are kept disengaged to ensure good contact between the main contact areas, thus achieving excellent performance of the switching system with lower temperature rise.
[0153] Due to the existence of the position difference s and the height difference h, in the closing process of the switching system, the conduction of the corresponding arc contact areas of the movable and stationary contacts is always earlier than that of the corresponding main contact areas of the movable and stationary contacts (as shown in Fig. 2), until the corresponding main contact areas of the movable and stationary contacts are completely contacted (as shown in Fig. 3), since the height difference h between the main contact area of the movable contact and the movable contact arc contact area 215, 225 will raise the movable contact arc contact area 215, 225, separating it from the stationary contact arc contact area 12. During the opening process of the switching system, each corresponding main contact area of the movable contact 2 slides on each corresponding main contact area of the stationary contact 1. At this time, the movable contact arc contact area 215, 225 is not in contact with the stationary contact arc contact area 12, until the corresponding main contact area of the movable contact slides into the chamfered portion 14, the gap begins to decrease, and the movable contact arc contact area 215, 225 contacts with the stationary contact arc contact area 12, and each corresponding main contact area is separated. As further sliding, the movable contact arc contact area 215, 225 is separated from the stationary contact arc contact area 12. At this time, the arc burns between the stationary contact arc contact area 12 and the movable contact arc contact area 215, 225 and quickly transfers to the arc-extinguishing grid and the movable contact arc contact area 215, 225 to burn until it is extinguished.
[0154] The movable contact arc contact area and the stationary contact arc contact area can protect the main contact areas of the movable contact and the stationary contacts from arc ablation and improve the service life of the switching system.
[0155] Because of the above position difference s and angle difference α, the conduction of each corresponding arc contact area of the movable and stationary contacts is always earlier than that of each corresponding main contact area of the movable and stationary contacts (as shown in Fig. 2), and the contact point between the movable contact 2 and the stationary contact 1 first moves from point b to point a (as shown in Fig. 13). When the switching system is closed (as shown in Fig. 3), because of the angle difference α between the main contact area of the movable contact and the movable contact arc contact area 215, 225, the main contact area of the movable contact is kept in contact with the main contact area 15 of the stationary contact, and all the zones where the main contact areas of the movable contact extend outward (including the movable contact arc contact area) are kept separated from the stationary contact. During the opening process of the switching system, the main contact area of the movable contact first slides on the main contact area 15 of the stationary contact. At this time, all the zones (including the movable contact arc contact area) where the main contact area of the movable contact extend outward are not in contact with the stationary contact 1, until the main contact area of the movable contact slides into the chamfered portion 14, the gap between the paired movable contacts begins to decrease, and the contact point between the movable contact 2 and the stationary contact 1 moves from point a to point b until they finally separate at point b (as shown in Fig. 13). The arc burns between the stationary contact arc contact area 12 and the movable contact arc contact area 215, 225, and quickly transfers to the arc-extinguishing grid and the movable contact arc contact area 215, 225 to burn until it extinguishes.
1. A switching system, comprising two stationary contacts and one movable contact;
the movable contact is configured to switch between the two stationary contacts;
the movable contact is provided with a contact zone which can contact with the stationary contacts;
an oil reservoir is provided in the contact zone.
2. The switching system according to claim 1, wherein
the movable contact comprises a first bracket and a second bracket in the form of a clamping structure;
the contact zone is arranged on one end of the first bracket and of the second bracket;
a movable contact arc contact area, a first main contact area and a second main contact area are arranged in the contact zone on the one end of the first bracket and of the second bracket respectively;
the other end of the first bracket and of the second bracket are respectively provided with a load-side bulge.
3. The switching system according to claim 2, wherein
the first main contact area and the second main contact area are arranged side by side in the width direction of the first bracket and the second bracket;
in the longitudinal direction of the first bracket and the second bracket, the movable contact arc contact area is arranged adjacent to the first main contact area and the second main contact area, and closer to an outer edge of the one end of the first bracket and the second bracket than the first main contact area and the second main contact area;
an oil reservoir is arranged between the first main contact area and the second main contact area;
an oil reservoir is arranged between the movable contact arc contact area and the first main contact area and between the movable contact arc contact area and the second main contact area.
4. The switching system according to claim 3, wherein
the first main contact area, the second main contact area and the load-side bulge all have arc-shaped outer surfaces;
the height of the contact surface of the movable contact arc contact area is lower than the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge, that is, there is a height difference h between the contact surface of the movable contact arc contact area and the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge;
the highest point of the arc-shaped outer surface of the first main contact area, the highest point of the arc-shaped outer surface of the second main contact area and the highest point of the arc-shaped outer surface of the load-side bulge have same height.
5. The switching system according to claim 4, wherein
the highest point of the arc-shaped outer surfaces of the first main contact area and of the second main contact area has a position difference s compared with a corresponding edge of the corresponding movable contact arc contact area;
the edge is formed at the joint of the contact surface and the chamfer.
6. The switching system according to claim 2, wherein
the other end of the first bracket and of the second bracket are pivotally connected to an output terminal via the load-side bulge;
the movable contact further comprises a sleeve, a pressure spring and a holder for holing the pressure spring;
under the combined action of the sleeve, the pressure spring and the holder, the first bracket and the second bracket are held in the sleeve;
the holder is of ring shape with a rectangular cross section and is held in the sleeve, and the first bracket, the second bracket and the pressure spring pass through the holder;
the pressure spring acts between the holder and the first bracket and between the holder and the second bracket, thereby pressing the first bracket and the second bracket toward each other;
The one end of the first bracket and of the second bracket protrudes from the sleeve.
7. The switching system according to claim 2, wherein
the movable contact arc contact area extends respectively from the highest point of the first main contact area and the highest point of the second main contact area in the form of a ramp;
the oil reservoir extends into the movable contact arc contact area in the form of a ramp.
8. The switching system according to claim 7, wherein
the first main contact area, the second main contact area and the load-side bulge all have arc-shaped outer surfaces;
the movable contact arc contact area in the form of a ramp is lower than the highest points of the arc-shaped outer surfaces of the first main contact area, of the second main contact area and of the load-side bulge;
the plane where the highest points of the first main contact area and the second main contact area are located has an angle difference α relative to the movable contact arc contact area in the form of a ramp;
the highest point of the arc-shaped outer surface of the first main contact area, the highest point of the arc-shaped outer surface of the second main contact area and the highest point of the arc-shaped outer surface of the load-side bulge have the same height.
9. The switching system according to claim 8, wherein
the highest point of the arc-shaped outer surfaces of the first main contact area and of the second main contact area has a position difference s compared with a corresponding edge of the corresponding movable contact arc contact area;
the edge is formed at the joint of the contact surface and the chamfer.
10. The switching system according to claim 2, wherein
the movable contact arc contact area is made of alloy material with high melting point;
the melting point of the alloy material of the movable contact arc contact area is higher than that of the materials of the first main contact area and the second main contact area.
11. The switching system according to claim 9, wherein
a plurality of oil reservoirs are arranged in the movable contact arc contact area in the form of a ramp;
the plurality of oil reservoirs extend along the length direction of the first bracket and the second bracket; or the plurality of oil reservoirs extend along the width direction of the first bracket and the second bracket.
12. The switching system according to claim 5, wherein
one end of the stationary contact is provided with a stationary contact arc striking portion, a stationary contact arc contact area and a stationary contact notch;
a gradually changing chamfered portion is arranged on one end of the stationary contact, and the stationary contact arc contact area is arranged on the gradually changing chamfered portion and adjacent to the stationary contact arc striking portion;
the one end of the stationary contact is also provided with a main contact area of the stationary contact, and the main contact area of the stationary contact is located below the stationary contact notch and the stationary contact arc contact area.
13. The switching system according to claim 12, wherein
gaps exist between the movable contact arc contact area, the first main contact area and the second main contact area of the first bracket and the movable contact arc contact area, the first main contact area and the second main contact area of the second bracket, respectively;
the stationary contact arc contact area is located between the stationary contact arc striking portion and the main contact area of the stationary contact.
14. The switching system according to claim 9, wherein
one end of the stationary contact is provided with a stationary contact arc striking portion, a stationary contact arc contact area and a stationary contact notch;
a gradually changing chamfered portion is also arranged on one end of the stationary contact, and the stationary contact arc contact area being arranged on the gradually changing chamfered portion and adjacent to the stationary contact arc striking portion;
the one end of the stationary contact is also provided with a main contact area of the stationary contact, and the main contact area of the stationary contact is located below the stationary contact notch and the stationary contact arc contact area.
15. The switching system according to claim 14, wherein
gaps exist between the movable contact arc contact area, the first main contact area and the second main contact area of the first bracket and the movable contact arc contact area, the first main contact area and the second main contact area of the second bracket, respectively.
gaps exist between the movable contact arc contact area, the first main contact area and the second main contact area of the first bracket and the movable contact arc contact area, the first main contact area and the second main contact area of the second bracket, respectively.