High-capacity contact system and use method

Abstract

The invention relates to the technical field of electrical switch equipment, and particularly discloses a high-capacity contact system and a use method, and the system comprises a static contact assembly, a moving contact assembly which is matched with the static contact, an elastic assembly which is connected with the moving contact assembly, and a fixed rotating shaft which is in running fit with the moving contact assembly. A connecting point of the elastic assembly is arranged between the fixed rotating shaft and the top surface of the moving contact assembly; the moving contact assembly is provided with a waist-shaped through hole which is used in cooperation with the fixed rotating shaft and has a waist-shaped cross section. According to the invention, the requirements of extremely high short-time endurance capability and extremely low contact resistance of the contact can be effectively met; according to the invention, the long contact is matched with the middle contact piece, the side contacts are matched with the side contact pieces, gaps exist between two adjacent groups of contacts and are mutually independent, and multiple groups of contact fingers are mutually independent and do not influence the closing effect, so that HOLM force generated by current contraction can be overcome; and the electric power generated by the conductive loop is fully utilized to improve the short-time endurance capability of the contact system.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical switchgear, and more particularly to a large-capacity contact system and a method of using the same. Background Art

[0002] In the prior art, conventional contact systems with a certain capacity are mostly single-finger structures with large HOLM force and weak electrodynamic compensation effect in the conductive circuit, which makes the short-term tolerance of the contact system extremely limited. Such contacts are only suitable for electrical switches with current limiting capabilities, but their disadvantages will be highlighted in DC magnetic field circuit breakers.

[0003] Conventional contact systems with arc contacts are attached to main contacts and their function is only to transfer the arc, but their current carrying capacity is extremely limited and their contact resistance is relatively large, which makes it impossible to effectively reduce the contact resistance of the entire contact system.

[0004] In conventional contact systems, the relative independence of multiple contact fingers is not obvious. When the contact breaks the arc, some contact fingers may stick together due to electrical erosion. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a large-capacity contact system and a method of use;

[0006] The solution adopted by the present invention to solve the technical problem is:

[0007] A large-capacity contact system is installed in a DC magnetic field circuit breaker, comprising a stationary contact assembly, a moving contact assembly used in conjunction with the stationary contact, an elastic assembly having one end connected to a side of the moving contact assembly close to the stationary contact assembly, and a fixed rotating shaft installed in the DC magnetic field circuit breaker and rotatably matched with the moving contact assembly;

[0008] The connection point of the elastic component is arranged between the fixed rotating shaft and the top surface of the moving contact component; and a waist-shaped through hole which is used in conjunction with the fixed rotating shaft and has a waist-shaped cross section is arranged on the moving contact component.

[0009] In some possible embodiments, the moving contact assembly includes a long contact sleeved on the outside of a fixed rotating shaft, two groups of side contacts located on both sides of the long contact and sleeved on the outside of the fixed rotating shaft, the top of the long contact is located above the top of the side contact and cooperates to form a convex structure; the long contact and the side contact are close to each other to form a gap on one side.

[0010] In some possible implementations, an elastic member is provided between the long contact and the side contact.

[0011] In some possible implementations, the moving contact assembly further includes a power shaft disposed parallel to the fixed rotating shaft and passing through the long contact and the side contact;

[0012] The distance between the power shaft and the top of the side contact is L, and the distance between the power shaft and the bottom of the side contact is H, L=0.45-0.55H.

[0013] In some possible implementations, two sets of needle roller bearings are mounted on the outer side of the power shaft; the two sets of needle roller bearings are located in the gap formed by the long contact and the side contact and move in the gap along the axial direction of the power shaft.

[0014] In some possible implementations, each group of elastic members between the side contacts and the long contacts includes two groups, one group of elastic members is arranged between the power shaft and the fixed rotating shaft, and the other group is arranged on a side of the fixed rotating shaft away from the power shaft.

[0015] In some possible embodiments, the elastic component includes an elastic unit 1 connected to the long contact and the side contact close to the static contact group, and an elastic unit 2 connected to both ends of the power shaft; the elastic unit 1 is arranged between the power shaft and the fixed rotating shaft and the distance between the connection point and the axis of the fixed rotating shaft is smaller than the distance between the connection point and the axis of the power shaft; the stiffness of the elastic unit 1 is greater than the stiffness of the elastic unit 2.

[0016] In some possible embodiments, the elastic unit 2 includes two groups of springs A with the same structure and connected to the two ends of the power shaft respectively; the elastic unit 1 includes three groups of springs B with the same structure and arranged one by one corresponding to the long contacts and the side contacts; the stiffness of the spring A is A, the stiffness of the spring B is B, and B=2.5-3A.

[0017] In some possible embodiments, the stationary contact assembly includes a conductive block, an intermediate contact piece installed on the conductive block and used in conjunction with the long contact, and two groups of side contact pieces located below the contact piece and used in conjunction with the two groups of side contacts; the side contact piece and the intermediate contact piece are close to each other on one side to form a gap, and a gap is formed between the two groups of side contact pieces.

[0018] A method for using the large-capacity contact system described above specifically comprises the following steps:

[0019] When closing the switch, firstly, a closing force is applied to the moving contact assembly, pushing the moving contact assembly to move around the axis of the fixed shaft toward the side close to the stationary contact assembly until the moving contact assembly contacts the stationary contact assembly; wherein, the long contact contacts the middle contact piece first, and then the side contact contacts the side contact piece; at this time, the elastic assembly is in a compressed state;

[0020] Subsequently, under the continuous push of the closing force, the elastic component continues to be compressed, and the moving contact component moves toward the side close to the static contact component around the contact line formed when it contacts the static contact component, until the side contact in the moving contact component is completely in contact with the static contact component, completing the closing;

[0021] When opening the circuit breaker, the moving contact assembly is not subjected to the closing force, and the elastic assembly recovers from the compressed state to the initial state. The side contacts and the side contact pieces are separated first, and then the middle contacts and the middle contact pieces are separated to complete the opening of the circuit breaker.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention can effectively meet the requirements of extremely high short-time tolerance and extremely low contact resistance;

[0024] The present invention can overcome the HOLM force generated by current contraction and make full use of the electromotive force generated by the conductive circuit to improve the short-time tolerance of the contact system by matching the long contact with the middle contact piece, matching the side contact with the side contact piece, and having gaps between two adjacent groups of contacts and being independent of each other, and multiple groups of contact fingers are independent of each other and do not affect the closing effect.

[0025] The present invention has good main arc timing, and ensures that the contact is not seriously burned by the arc through the arrangement of the long contact and the side contact; the contact pressure between the multiple contact fingers is relatively independent, and ensures that the contact system has good contact during its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 It is a schematic diagram of the connection relationship among the needle bearing, the power shaft, the elastic member, the elastic assembly and the long contact in the present invention;

[0028] Figure 3 It is a front view of the moving contact assembly in the present invention;

[0029] Figure 4 It is a back view of the moving contact assembly in the present invention;

[0030] Figure 5 It is a front view of the stationary contact assembly of the present invention;

[0031] Figure 6 This is a schematic diagram of the force and movement of the moving contact assembly when the present invention is used to close the circuit breaker;

[0032] Figure 7 This is a schematic diagram of the long contact and the static contact assembly just coming into contact when the circuit breaker of the present invention is closed;

[0033] Figure 8 This is a schematic diagram of the closing process of the present invention;

[0034] Among them: 1. static contact assembly; 11. conductive block; 12. middle contact piece; 13. side contact piece; 14. static arcing angle; 2. moving contact assembly; 21. long contact; 22. side contact; 23. power shaft; 24. elastic unit one; 25. elastic unit two; 26. needle roller bearing; 27. elastic part; 28 waist-shaped through hole; 3. fixed rotating shaft. DETAILED DESCRIPTION

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. The "first", "second" and similar words mentioned in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one" or "one" and other similar words do not indicate a quantity restriction, but indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "multiple" refers to two or more. For example, multiple positioning columns refer to two or more positioning columns. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The present invention is described in detail below.

[0037] like Figure 1-Figure 8 As shown:

[0038] A large-capacity contact system is installed in a DC magnetic field circuit breaker and used in conjunction with an electromagnetic mechanism, the electromagnetic mechanism is used to provide a closing force, and includes a static contact assembly 1, a moving contact assembly 2 used in conjunction with the static contact, an elastic assembly having one end connected to a side of the moving contact assembly 2 close to the static contact assembly 1, and a fixed rotating shaft 3 installed in the DC magnetic field circuit breaker and rotatably matched with the moving contact assembly 2;

[0039] The connection point of the elastic component is arranged between the fixed rotating shaft 3 and the top surface of the moving contact component; a waist-shaped through hole 28 which cooperates with the fixed rotating shaft 3 and has a waist-shaped cross section is arranged on the moving contact component 2;

[0040] The static contact assembly 1 and the fixed rotating shaft 3 are fixedly installed in the DC magnetic field circuit breaker, and the moving contact assembly 2 is sleeved on the outer side of the fixed rotating shaft 3 through the waist-shaped through hole 28 and can rotate around the fixed rotating shaft 3; the electromagnetic mechanism is used to apply a closing force to the moving contact assembly 2;

[0041] One end of the elastic component is connected to the moving contact component 2, and the other end is fixed in the DC magnetic field circuit breaker. The elastic component is in a compressed state when the circuit is closed, and when the circuit is opened, it will recover from the compressed state to the initial state to drive the moving contact component 2 to separate from the static contact component 1;

[0042] When closing the circuit, the electromagnetic mechanism applies a closing force to the moving contact assembly 2, so that the moving contact assembly 2 moves around the fixed rotating shaft 3 toward the side close to the static contact assembly 1; after the moving contact assembly 2 contacts the static contact assembly 1, the moving contact assembly 2 will move around the contact line formed by it and the static contact assembly 1 toward the side close to the static contact assembly 1. At this time, the elastic component will provide sufficient contact pressure. When the electromagnetic mechanism connected to the moving contact assembly 2 moves to the final stage, the air gap gradually decreases, and it has a larger closing thrust, which can ensure that the closing force is sufficient to overcome the reaction force generated by the elastic component, while ensuring that a relatively fast speed is maintained during closing.

[0043] In some possible implementations, such as Figure 1-Figure 4 As shown, the moving contact assembly 2 includes a long contact 21 sleeved on the outside of the fixed rotating shaft 3, and two groups of side contacts 22 located on both sides of the long contact 21 and sleeved on the outside of the fixed rotating shaft 3. The top of the long contact 21 is located above the top of the side contact 22 and cooperates to form a convex structure; the long contact 21 and the side contact 22 are close to each other to form a gap; the two groups of side contacts 22 are symmetrically arranged;

[0044] Specifically, a group of long contacts 21 and two groups of side contacts 22 are respectively provided with waist-shaped holes, and the three groups of waist-shaped holes are connected to form a waist-shaped through hole 28;

[0045] The top of the long contact 21 is located above the top of the side contact 22. When closing the circuit breaker, the long contact 21 will first contact the static contact assembly 1; when opening the circuit breaker, the side contact 22 will first separate from the static contact assembly 1; so that the arc mainly burns at the long contact 21;

[0046] By setting the side contact 22, the long contact 21, and the side contact 22, and forming a gap between the two adjacent ones, the contact pressure is relatively independent; when there is wear, they are not affected by each other, which can ensure a good contact effect of the contact system; at the same time, when closing the switch, the long contact 21 first contacts the static contact assembly 1, and when the long contact 21 first contacts the static contact assembly 1, there is a gap T between the side contact 22 and the static contact assembly 1;

[0047] It should be noted that the distance between the top surface of the long contact 21 and the top surface of the side contact 22 can be set according to the time interval requirement for the long contact 21, the side contact 22 and the stationary contact assembly 1 to contact; the present invention does not make any requirements here;

[0048] In some possible implementations, the moving contact assembly 2 further includes a power shaft 23 arranged in parallel with the fixed rotating shaft 3 and passing through the long contact 21 and the side contact 22; the power shaft 23 is transmission-connected to the electromagnetic mechanism, and the electromagnetic mechanism applies a closing force to the power shaft 23, thereby driving the long contact 21 and the side contact 22 to move around the fixed rotating shaft 3 toward one side of the stationary contact assembly 1;

[0049] The long contact 21 and the side contact 22 are rotatably matched with the power shaft 23 respectively, and the relative rotation range between the two is the moving distance of the fixed shaft 3 in the waist-shaped through hole 28; nuts are provided at both ends of the power shaft 23; the long contact 21 and the side contact 22 are pre-tightened by the nuts.

[0050] like Figure 3 As shown, the distance between the power shaft 23 and the top of the side contact 22 is L, and the distance between the power shaft 23 and the bottom of the side contact 22 is H, L = 0.45-0.55H;

[0051] The power shaft 23 cooperates with the side contact 22 and the long contact 21 to realize multi-contact finger parallel current diversion, which greatly reduces the HOLM force caused by current concentration. The position of the power shaft 23 enables the electrodynamic torque under the contact structure to overcome the torque generated by the HOLM force, further improving the short-circuit withstand capability of the contact system.

[0052] In some possible implementations, such as Figure 2 As shown, two sets of needle bearings 26 are mounted on the outer side of the power shaft 23; the two sets of needle bearings 26 are located in the gap formed by the long contact 21 and the side contact 22 and move along the axial direction of the power shaft 23 in the gap;

[0053] By utilizing the high dynamic load capacity of the needle bearing 26 to reduce the impact of the strong closing force on the power shaft 23, the closing reliability and life of the contact system can be greatly improved.

[0054] In some possible implementations, such as Figure 2 As shown, an elastic member 27 is provided between the long contact 21 and the side contact 22; each group of elastic members 27 between the side contact 22 and the long contact 21 is two groups, one group of elastic members 27 is provided between the power shaft 23 and the fixed shaft 3, and the other group is provided on the side of the fixed shaft 3 away from the power shaft 23;

[0055] Preferably, the elastic member 27 is a compression spring, and its axis is parallel to the axis of the fixed shaft 3;

[0056] By arranging two groups of elastic members 27 between the side contact 22 and the long contact 21 respectively, the electric attraction force generated between the side contact 22 and the long contact 21 when the contacts (side contact 22 and long contact 21) are connected to a large current is overcome, thereby ensuring that the contact system does not suffer structural damage.

[0057] In some possible implementations, such as Figure 4 As shown, the elastic component includes an elastic unit 1 24 connected to the long contact 21 and the side contact 22 close to the stationary contact component 1, and an elastic unit 2 25 connected to both ends of the power shaft 23; the elastic unit 1 24 is arranged between the power shaft 23 and the fixed rotating shaft 3, and the distance between the connection point of the elastic unit 1 24 and the moving contact component 2 and the axis of the fixed rotating shaft 3 is d, and the distance between the connection point of the elastic unit 1 24 and the moving contact component 2 and the axis of the power shaft 23 is D; D>d;

[0058] The stiffness of the elastic unit 1 24 is greater than the stiffness of the elastic unit 2 25;

[0059] Specifically, Figure 1 , Figure 2 As shown, the elastic unit 25 includes two groups of springs A with the same structure and connected to the two ends of the power shaft 23 respectively; the elastic unit 1 24 includes three groups of springs B with the same structure and arranged one by one with the long contacts 21 and the side contacts 22; the stiffness of the spring A is A, the stiffness of the spring B is B, and B=2.5-3A.

[0060] like Figure 6 As shown, when the circuit breaker is closed, the needle bearing 26 mounted on the power shaft 23 is subjected to the closing force F1, and rotates counterclockwise around the axis of the fixed shaft 3 until the long contact 21 and the side contact 22 just contact the stationary contact assembly 1; the spring A and the spring B are converted from the pre-compression state to the compression state;

[0061] like Figure 7 , Figure 8 As shown, thereafter, the long contact 21 and the side contact 22 will transfer the swinging shaft to the contact line with the static contact assembly 1; under the continuous push of the closing force F1, the moving contact assembly 2 will rotate clockwise around the contact line, and the moving contact assembly 2 will greatly compress the spring B. At the same time, the fixed shaft 3 will swing to the right in the waist-shaped through hole 28 relative to the moving contact assembly 2, and finally the switch will be closed in place. At this time, the pressure F21 of the long contact 21 and the pressure F22 of the side contact 22 are guaranteed by the spring force F3 of the spring B.

[0062] In some possible implementations, such as Figure 5As shown, the static contact assembly 1 includes a conductive block 11, an intermediate contact piece 12 installed on the conductive block 11 and used in conjunction with the long contact 21, two groups of side contact pieces 13 located below the contact piece and used in conjunction with the two groups of side contacts 22, and a static arc-starting angle 14 in contact with the intermediate contact piece 12; the side contact piece 13 and the intermediate contact piece 12 are close to each other to form a gap on one side, and a gap is formed between the two groups of side contact pieces 13;

[0063] Furthermore, the structure and size of the middle contact piece 12 and the side contact piece 13 are the same, and the structure and size of the contact fingers arranged on the long contact 21 and the contact fingers arranged on the side contact 22 are the same; so that the long contact 21 located in the middle has the same pressure and contact area as the side contact 22, which can also greatly improve the current carrying capacity and further reduce the contact resistance of the present invention.

[0064] A method for using the large-capacity contact system described above specifically comprises the following steps:

[0065] When closing the switch, the electromagnetic mechanism first applies a closing force to the moving contact assembly 2, pushing the long contact 21 and the side contact 22 in the moving contact assembly 2 to move around the axis of the fixed shaft 3 to the side close to the stationary contact assembly 1, until the moving contact assembly 2 contacts the stationary contact assembly 1, and the contact is just released at this time; wherein, the long contact 21 contacts the middle contact piece 12 first, and then the side contact 22 contacts the side contact piece 13; at this time, the elastic assembly is in a compressed state;

[0066] Subsequently, under the continuous push of the closing force, the elastic component continues to be compressed, and the long contact 21 and the side contact 22 in the moving contact component 2 respectively move toward the side close to the stationary contact component 1 around the contact line formed when they contact with the stationary contact component 1, until the long contact 21 in the moving contact component 2 is in full contact with the middle contact piece 12 in the stationary contact component 1, and the side contact 22 in the moving contact component 2 is in full contact with the side contact piece 13 in the stationary contact component 1;

[0067] Complete closing;

[0068] When opening the switch, the moving contact assembly 2 is not subjected to the closing force, and the elastic assembly (spring A and spring B) recovers from the compressed state to the initial state, first separating the side contact 22 from the side contact piece 13, and then separating the middle contact from the middle contact piece 12, ensuring that the final arc burns in the long contact 21 and the middle contact piece 12, which can greatly reduce the ablation amount of the side contacts 22 and the side electrical contact pieces on both sides;

[0069] Complete the gate opening.

[0070] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A large-capacity contact system installed in a DC field circuit breaker, characterized in that: It includes a stationary contact assembly, a moving contact assembly used in conjunction with the stationary contact, an elastic assembly having one end connected to a side of the moving contact assembly close to the stationary contact assembly, and a fixed rotating shaft installed in the DC magnetic field circuit breaker and rotatably matched with the moving contact assembly; The connection point of the elastic component is arranged between the fixed rotating shaft and the top surface of the moving contact component; and a waist-shaped through hole which is used in conjunction with the fixed rotating shaft and has a waist-shaped cross section is arranged on the moving contact component.

2. A large-capacity contact system according to claim 1, characterized in that: The moving contact assembly includes a long contact sleeved on the outside of a fixed rotating shaft, and two groups of side contacts located on both sides of the long contact and sleeved on the outside of the fixed rotating shaft. The top of the long contact is located above the top of the side contact and cooperates to form a convex structure; the long contact and the side contact are close to each other to form a gap on one side.

3. A large-capacity contact system according to claim 2, characterized in that: An elastic member is arranged between the long contact and the side contact.

4. A large-capacity contact system according to claim 3, characterized in that: The moving contact assembly also includes a power shaft arranged parallel to the fixed rotating shaft and passing through the long contact and the side contact; The distance between the power shaft and the top of the side contact is L, and the distance between the power shaft and the bottom of the side contact is H, L=0.45-0.55H.

5. A large-capacity contact system according to claim 4, characterized in that: Two sets of needle bearings are sleeved on the outer side of the power shaft; the two sets of needle bearings are located in the gap formed by the long contact and the side contact and move along the axial direction of the power shaft in the gap.

6. A large-capacity contact system according to claim 4, characterized in that: Each group of elastic members between the side contacts and the long contacts includes two groups, one of which is arranged between the power shaft and the fixed rotating shaft, and the other is arranged on a side of the fixed rotating shaft away from the power shaft.

7. A large-capacity contact system according to claim 4, characterized in that: The elastic component includes an elastic unit 1 connected to the long contact and the side contact close to the static contact component, and an elastic unit 2 connected to both ends of the power shaft; the elastic unit 1 is arranged between the power shaft and the fixed rotating shaft, and the distance between the connection point and the axis of the fixed rotating shaft is smaller than the distance between the connection point and the axis of the power shaft; the stiffness of the elastic unit 1 is greater than the stiffness of the elastic unit 2.

8. A large-capacity contact system according to claim 7, characterized in that: The elastic unit 2 includes two groups of springs A with the same structure and connected to the two ends of the power shaft respectively; the elastic unit 1 includes three groups of springs B with the same structure and arranged one by one corresponding to the long contacts and the side contacts; the stiffness of the spring A is A, the stiffness of the spring B is B, and B=2.5-3A.

9. A large-capacity contact system according to any one of claims 2 to 8, characterized in that: The stationary contact assembly includes a conductive block, an intermediate contact piece installed on the conductive block and used in conjunction with the long contact, and two groups of side contact pieces located below the contact piece and used in conjunction with the two groups of side contacts; the side contact piece and the intermediate contact piece are close to each other to form a gap on one side, and a gap is formed between the two groups of side contact pieces.

10. A method for using a large-capacity contact system according to any one of claims 1 to 9, characterized in that: The specific steps include: When closing the switch, firstly, a closing force is applied to the moving contact assembly, pushing the moving contact assembly to move around the axis of the fixed shaft toward the side close to the stationary contact assembly until the moving contact assembly contacts the stationary contact assembly; wherein, the long contact contacts the middle contact piece first, and then the side contact contacts the side contact piece; at this time, the elastic assembly is in a compressed state; Subsequently, under the continuous push of the closing force, the elastic component continues to be compressed, and the moving contact component moves toward the side close to the static contact component around the contact line formed when it contacts the static contact component, until the side contact in the moving contact component is completely in contact with the static contact component, completing the closing; When opening the circuit breaker, the moving contact assembly is not subjected to the closing force, and the elastic assembly recovers from the compressed state to the initial state. The side contacts and the side contact pieces are separated first, and then the middle contacts and the middle contact pieces are separated to complete the opening of the circuit breaker.

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