Permanent magnetic mechanism of direct-current magnetic field circuit breaker

Abstract

The invention relates to the technical field of magnetic field circuit breakers, and particularly discloses a direct-current magnetic field circuit breaker permanent magnet mechanism which comprises a magnetic shielding shell with a U-shaped mounting cavity, a permanent magnet holding assembly mounted in the U-shaped mounting cavity, an iron core assembly sleeved with the permanent magnet holding assembly and an electromagnetic coil sleeved with the outer side of the iron core assembly. The permanent magnet maintaining assembly and the iron core assembly are matched to form a closed magnetic loop. The iron core assembly comprises a driving shaft, and a static iron core and a movable iron core which sleeve the outer side of the driving shaft; the static iron core is fixedly arranged in the magnetic shielding shell and is elastically connected with the movable iron core; two ends of the driving shaft penetrate through the magnetic shielding shell; in an opening state, an air gap I is formed between the movable iron core and the top of the top magnet yoke; and an air gap II is formed between the movable iron core and the static iron core. A two-way closed magnetic loop exists in the magnetic field circuit breaker, the closing holding force meeting the requirement of the magnetic field circuit breaker is provided, the internal space is fully utilized, the electromagnetic coil can be demagnetized rapidly in the opening process, and the response speed is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic field circuit breakers, and more specifically to a permanent magnet mechanism of a DC magnetic field circuit breaker. Background Art

[0002] The DC field circuit breaker is one of the key devices in the excitation system and plays a key role in the demagnetization of the generator set due to an accident. With the continuous increase in the capacity of newly built hydropower, thermal power and nuclear power generating units, it has now reached the 1000MW level, and the excitation current is close to 8000A. Therefore, the rated current of the DC field circuit breaker should be set at no less than 8000A to meet the current excitation requirements.

[0003] For DC magnetic field circuit breakers, their contact systems must have good breaking capacity and short-time tolerance, and be able to withstand the impact of short-circuit currents of tens of kiloamperes. In order to meet the requirements of reliable closing and opening of DC magnetic field circuit breakers and rapid establishment of arc voltage, the operating mechanism of the magnetic field circuit breaker must have the characteristics of large closing holding force, fast response speed and high reliability in complex electromagnetic environments.

[0004] The permanent magnetic operating mechanisms currently used in the field of DC circuit breakers are mostly cylindrical structures. This type of permanent magnetic operating mechanism often has problems such as being too heavy, slow opening response speed, and low space utilization when improving the closing holding force. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a permanent magnet mechanism of a DC magnetic field circuit breaker;

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

[0007] A permanent magnet mechanism of a DC magnetic field circuit breaker, comprising a magnetic shielding shell with a square structure and a U-shaped mounting cavity, a permanent magnet holding component mounted in the U-shaped mounting cavity, an iron core component sleeved in the permanent magnet holding component and forming an annular cavity therewith, and an electromagnetic coil located in the annular cavity and sleeved on the outer side of the iron core component; the permanent magnet holding component cooperates with the iron core component to form a closed magnetic circuit;

[0008] The iron core assembly comprises a driving shaft coaxially arranged with the electromagnetic coil, a static iron core and a moving iron core sleeved on the outside of the driving shaft; the static iron core is fixedly installed in the magnetic shielding shell and elastically connected to the moving iron core; both ends of the driving shaft pass through the magnetic shielding shell;

[0009] When in the open state, an air gap 1 is formed between the moving iron core and the top of the top magnetic yoke; and an air gap 2 is formed between the moving iron core and the static iron core.

[0010] In some possible embodiments, the permanent magnet retaining assembly includes two groups of side magnetic yokes fixed in a magnetic shielding shell and symmetrically arranged, a top magnetic yoke installed on the top of the side magnetic yoke and sleeved on the outside of the iron core, two groups of permanent magnets installed on the inner side surfaces of the side magnetic yokes and located below the electromagnetic coil, and an inner magnetic yoke sleeved on the outside of the static iron core and connected to the permanent magnet; the permanent magnet, side magnetic yoke, top magnetic yoke, air gap one, moving iron core, air gap two, static iron core, and inner magnetic yoke form a closed magnetic circuit.

[0011] In some possible implementations, the moving iron core is fixedly sleeved on the outside of the driving shaft and has a T-shaped cross-section, including a large end located above the top magnetic yoke, and a small end coaxially connected to the large end and located in the magnetic shielding shell; the small end is elastically connected to the static iron core;

[0012] When closing the circuit breaker, the moving iron core is attracted by the magnetic field generated by the electromagnetic coil and the magnetic field generated by the permanent magnet, and the moving iron core drives the driving shaft to move toward the side close to the static iron core until the bottom of the large end of the moving iron core overlaps the upper surface of the top magnetic yoke, providing closing holding force for the contact system connected to the driving shaft, and the closing process is completed.

[0013] In some possible implementations, a groove coaxial with the drive shaft is provided on the static iron core, a spring is installed in the groove, the spring is sleeved on the outside of the drive shaft and one end of the spring passes through the groove and abuts against the bottom of the moving iron core.

[0014] In some possible implementations, a cover plate is further provided above the top magnetic yoke; one end of the drive shaft passes through the cover plate;

[0015] The cover plate and the top magnetic yoke form a space for the moving iron core to expand and contract along the axial direction of the driving shaft;

[0016] The cover plate and the magnetic shielding shell are respectively provided with through holes for the driving shaft to pass through.

[0017] In some possible embodiments, the electromagnetic coil includes a frame that is sleeved on the outside of the core assembly and abuts against the lower surface of the top magnetic yoke and the upper surface of the inner magnetic yoke, respectively, and a winding sleeved on the outside of the frame; a gap is formed between the frame and the inner surface of the side magnetic yoke.

[0018] In some possible implementations, the outer diameter of the winding is smaller than the distance between the two sets of side yokes.

[0019] In some possible implementations, a base plate made of non-magnetic material is installed in the magnetic shielding shell, and the permanent magnet, side magnetic yoke, and static iron core are installed on the base plate; a limiter is provided on the side magnetic yoke to prevent the corresponding permanent magnet from shifting its position.

[0020] In some possible implementations, the magnetic shielding shell has a three-layer structure, including an inner layer, a middle layer and an outer layer, and the bottom plate is installed in the inner layer; a magnetically conductive flat pad is arranged between two adjacent layers.

[0021] In some possible implementations, grooves for the lead wires of the electromagnetic coil to pass through are respectively provided on the inner layer and the middle layer, a mounting hole is provided on the outer layer, and a lead wire mounting seat is provided on the outer layer.

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

[0023] The present invention changes the shape of the permanent magnet mechanism and reasonably arranges the arrangement of the permanent magnet, the side magnetic yoke, the top magnetic yoke, the moving iron core, the static iron core and the inner magnetic yoke in the permanent magnet mechanism, so that a bidirectional closed magnetic circuit exists inside the permanent magnet mechanism, providing a closing holding force that meets the requirements of the magnetic field circuit breaker. At the same time, due to the full use of the internal space, the electromagnetic coil can be quickly demagnetized during the opening process, thereby improving the response speed of the permanent magnet mechanism.

[0024] The magnetic shielding shell provided in the present invention can not only effectively prevent magnetic leakage, but also reduce the influence of the external complex electromagnetic environment on the permanent magnet mechanism, thereby improving the reliability of the permanent magnet mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is an explosion schematic diagram of the present invention;

[0026] Figure 2 It is a schematic cross-sectional view of the structure of the present invention in the open state;

[0027] Figure 3 It is a schematic cross-sectional structural diagram of the present invention in a closed state;

[0028] Figure 4 is a side view of the present invention;

[0029] Wherein: 1-drive shaft, 2-cover plate, 21-limiting groove, 3-self-lubricating bearing, 4-moving iron core, 41-big end, 42-small end, 5-top magnetic yoke, 6-side magnetic yoke, 7-frame, 8-winding, 9-static iron core, 10-spring, 11-permanent magnet, 12-inner magnetic yoke, 13-bottom plate, 14-magnetic shielding shell, 141-inner layer, 142-middle layer, 143-outer layer, 15-magnetic flat pad, 16-external fixing screws, 17-air gap one, 18-air gap two. DETAILED DESCRIPTION

[0030] 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.

[0031] The present invention is described in detail below.

[0032] like Figure 1-Figure 4 As shown;

[0033] A permanent magnet mechanism of a DC magnetic field circuit breaker, comprising a magnetic shielding shell 14 with a square structure and a U-shaped mounting cavity, a permanent magnet holding component mounted in the U-shaped mounting cavity, an iron core component sleeved in the permanent magnet holding component and forming an annular cavity with the permanent magnet holding component, an electromagnetic coil located in the annular cavity and sleeved on the outside of the iron core component, and a bottom plate 13 mounted in the U-shaped mounting cavity and used for grasping the permanent magnet holding component and the iron core component; a self-lubricating bearing 3 used in conjunction with a drive shaft 1 and sleeved on the outside of the drive shaft 1 is installed in the bottom plate 13; the provision of the self-lubricating bearing 3 effectively realizes the bearing of radial magnetic field force;

[0034] The iron core assembly includes a drive shaft 1 coaxially arranged with the electromagnetic coil, a static iron core 9 and a moving iron core 4 sleeved on the outside of the drive shaft 1; the static iron core 9 is fixedly installed in the magnetic shielding shell 14 and elastically connected to the moving iron core 4, specifically, the elastic connection is realized by a spring 10; both ends of the drive shaft 1 pass through the magnetic shielding shell 14;

[0035] A cover plate 2 is arranged above the permanent magnetic holding assembly; one end of the driving shaft 1 passes through the cover plate 2;

[0036] Specifically, the permanent magnetic holding component is installed in the U-shaped installation cavity, the iron core component is installed in the permanent magnetic holding component and an annular cavity is formed between the permanent magnetic holding component, and the electromagnetic coil is sleeved on the outside of the iron core component and installed in the annular cavity;

[0037] When in the open state, an air gap 17 is formed between the moving iron core 4 and the top of the top magnetic yoke 5; an air gap 2 18 is formed between the moving iron core 4 and the static iron core 9;

[0038] The permanent magnetic holding assembly cooperates with the iron core assembly to form two closed magnetic circuits to cooperate with the electromagnetic coil to generate a magnetic field, providing a closing holding force that meets the requirements of the magnetic field circuit breaker; by providing a magnetic shielding shell 14 assembly, not only can magnetic leakage be effectively prevented, but also the influence of the external complex electromagnetic environment on the permanent magnetic mechanism can be reduced, thereby improving the reliability of the permanent magnetic mechanism;

[0039] When in the open state, the moving iron core 4 is separated from the permanent magnetic holding assembly, and the upper surface of the moving iron core 4 contacts the inner surface of the cover plate 2. At this time, there is an air gap 17 between the moving iron core 4 and the top magnetic yoke 5, and an air gap 2 18 between the bottom of the moving iron core 4 and the top of the static iron core 9. The spring 10 can overcome the magnetic field force generated by the closed magnetic circuit formed by the permanent magnet 11, the side magnetic yoke 6, the top magnetic yoke 5, the air gap 17, the moving iron core 4, the air gap 2 18, the static iron core 9, and the inner magnetic yoke 12, so that the moving iron core 4 is kept in the current position;

[0040] When in the closed state, the moving iron core 4 overlaps the permanent magnetic holding assembly, the moving iron core 4 contacts the upper surface of the top magnetic yoke 5, the air gap 1 17 is reduced to zero, and the air gap 2 18 is reduced to a smaller value. At this time, the permanent magnet 11, the side magnetic yoke 6, the top magnetic yoke 5, the moving iron core 4, the air gap 2 18, the static iron core 9, and the inner magnetic yoke 12 form a closed magnetic circuit, and the magnetic field force generated can overcome the reaction force generated by the buffer spring 10 and the circuit breaker mechanism, so that the moving iron core 4 remains in the current position.

[0041] In some possible implementations, in order to enable the permanent magnetic holding component to generate two closed magnetic circuits;

[0042] The permanent magnet holding assembly includes two groups of side yokes 6 fixed in a magnetic shielding housing 14 and symmetrically arranged, a top yoke 5 installed on the top of the side yokes 6 and sleeved on the outside of the iron core, two groups of permanent magnets 11 respectively installed on the inner side of the side yokes 6 and located below the electromagnetic coil, and an inner yoke 12 sleeved on the outside of the static iron core 9 and connected to the permanent magnet 11; the permanent magnet 11, the side yokes 6, the top yoke 5, the air gap 17, the moving iron core 4, the air gap 2 18, the static iron core 9, and the inner yoke 12 form a closed magnetic circuit;

[0043] Furthermore, the static iron core 9 and the inner magnetic yoke 12 are transitionally matched; the static iron core 9 and the inner magnetic yoke 12 can also be an integrally formed structure, which can reduce the difficulty of assembly;

[0044] Two groups of side yokes 6 are installed in the U-shaped installation cavity and are symmetrically arranged. Two groups of permanent magnets 11 are respectively installed on the side of the two groups of side yokes 6 close to each other. Two groups of inner yokes 12 are also installed on the side of the two groups of permanent magnets 11 close to each other. The top yoke 5 is installed on the top surface of the side yokes 6; the electromagnetic coil will be located in the space between the permanent magnet 11 and the top surface of the inner yoke 12, and the lower surface of the top yoke 5; the end of the moving iron core 4 away from the static iron core 9 passes through the top yoke 5;

[0045] The moving iron core 4 will drive the drive shaft 1 connected thereto to move along the axial direction of the drive shaft 1 under the action of the magnetic field. When the switch is changed from the open state to the closed state, that is, when the switch is closed, the electromagnetic coil is energized to generate a magnetic field with the same direction as the magnetic field of the two closed magnetic circuits. The moving iron core 4 is attracted by the magnetic field generated by the electromagnetic coil and the magnetic field generated by the permanent magnet 11. The air gap 17 disappears, and the air gap 2 18 becomes a minimum value. The electromagnetic coil stops being energized. The moving iron core 4 and the drive shaft 1 can overcome the reaction force generated by the elastic connection and the contact system only under the action of the magnetic field generated by the permanent magnet 11, providing a larger closing holding force for the contact system, and the closing process is completed.

[0046] On the contrary, when the gate is opened, the electromagnetic coil is energized to generate a magnetic field in the opposite direction to the magnetic fields of the two closed magnetic circuits. During the current flow process, the electromagnetic coil can quickly demagnetize the permanent magnet 11 to reverse the overall magnetic field. At this time, the moving iron core 4 is subjected to a repulsive force under the action of the overall magnetic field. Under the action of the magnetic field repulsive force, the spring 10 repulsive force and the contact system reaction force, the moving iron core 4 drives the drive shaft 1 to move rapidly away from the static iron core 9 until the upper surface of the moving iron core 4 overlaps the inner surface of the cover plate 2. During this process, air gap 1 17 and air gap 2 18 gradually increase, and the electromagnetic coil stops being energized. The moving iron core 4 and the drive shaft 1 can overcome the attraction provided by the magnetic field generated by the permanent magnet 11 only under the action of the reaction force generated by the spring 10, maintain the open state, and the opening process is completed.

[0047] In some possible implementations, the moving iron core 4 is fixedly sleeved on the outside of the driving shaft 1 and has a T-shaped cross-section, including a large end 41 located above the top magnetic yoke 5, and a small end 42 coaxially connected to the large end 41 and located in the magnetic shielding shell 14; the small end 42 is elastically connected to the static iron core 9; the large end 41 and the small end 42 are both cylindrical;

[0048] A through hole coaxial with the driving shaft 1 is provided on the top magnetic yoke 5 , and the inner diameter of the through hole is larger than the outer diameter of the small end 42 and smaller than the outer diameter of the large end 41 .

[0049] Specifically, the gap formed between the bottom of the large end 41 and the upper surface of the top magnetic yoke 5 is an air gap 17; the gap between the small end 42 and the static iron core 9 is an air gap 2 18;

[0050] When closing the switch, the electromagnetic coil is energized to generate a magnetic field, and the direction of the magnetic field is the same as the direction of the magnetic field of the two closed magnetic circuits generated by the permanent magnet 11, the side magnetic yoke 6, the top magnetic yoke 5, the air gap one 17, the moving iron core 4, the air gap two 18, the static iron core 9, and the inner magnetic yoke 12; the moving iron core 4 is attracted by the magnetic field generated by the electromagnetic coil and the magnetic field generated by the permanent magnet 11, and the moving iron core 4 drives the drive shaft 1 to move toward the side close to the static iron core 9 until the bottom of the large end 41 of the moving iron core 4 overlaps the upper surface of the top magnetic yoke 5, the air gap one 17 disappears, and the air gap two 18 becomes a minimum value, the electromagnetic coil stops being energized, and the moving iron core 4 and the drive shaft 1 can overcome the reaction force generated by the elastic connection and the contact system only under the action of the magnetic field generated by the permanent magnet 11, providing the closing holding force for the contact system connected to the drive shaft 1, and the closing process is completed;

[0051] When opening and closing the switch, the electromagnetic coil is energized to generate a magnetic field, and the direction of the magnetic field is opposite to the direction of the magnetic field of the two closed magnetic circuits generated by the permanent magnet 11, the side magnetic yoke 6, the top magnetic yoke 5, the air gap one 17, the moving iron core 4, the air gap two 18, the static iron core 9, and the inner magnetic yoke 12; during the current flow process, the electromagnetic coil can quickly demagnetize the permanent magnet 11 to reverse the overall magnetic field. At this time, the moving iron core 4 is subjected to a repulsive force under the action of the overall magnetic field. Under the action of the magnetic field repulsive force, the spring 10 repulsive force and the contact system reaction force, the moving iron core 4 drives the drive shaft 1 to move rapidly away from the static iron core 9 until the upper surface of the large end 41 of the moving iron core 4 overlaps with the inner surface of the cover plate 2. During this process, the air gap one 17 and the air gap two 18 are gradually increased, and the electromagnetic coil stops being energized. The moving iron core 4 and the drive shaft can overcome the attraction provided by the magnetic field generated by the permanent magnet 11 only under the action of the reaction force generated by the spring 11, maintain the open state, and the opening process is completed.

[0052] In some possible implementations, in order to effectively realize the elastic connection between the static iron core 9 and the moving iron core 4; a groove coaxial with the driving shaft 1 is provided on the static iron core 9, and a spring 10 is installed in the groove. The spring 10 is sleeved on the outside of the driving shaft 1 and one end of the spring 10 passes through the groove and abuts against the bottom of the moving iron core 4;

[0053] By providing the groove, radial limiting of the spring 10 can be effectively achieved.

[0054] In some possible implementations, the cover plate 2 and the top magnetic yoke 5 form a space for the moving iron core 4 to axially expand and contract along the drive shaft 1 ; through holes for the drive shaft 1 to pass through are respectively provided on the cover plate 2 and the magnetic shielding shell 14 .

[0055] In some possible embodiments, the electromagnetic coil includes a frame 7 which is sleeved on the outside of the core assembly and abuts against the lower surface of the top magnetic yoke 5 and the upper surface of the inner magnetic yoke 12, and a winding 8 which is sleeved on the outside of the frame 7, and a gap is formed between the frame 7 and the inner surface of the side magnetic yoke 6.

[0056] In some possible implementations, the outer diameter of the winding 8 is smaller than the distance between the two sets of side yokes 6 .

[0057] In some possible implementations, a bottom plate 13 made of non-magnetic material is installed in the magnetic shielding shell 14, and the permanent magnet 11, the side magnetic yoke 6, and the static iron core 9 are installed on the bottom plate 13; the side magnetic yoke 6 is provided with a limiter to prevent the corresponding permanent magnet 11 from shifting in position;

[0058] Specifically, the limiting member is a limiting screw.

[0059] In some possible implementations, the magnetic shielding shell 14 has a three-layer structure, including an inner layer 141 , a middle layer 142 , and an outer layer 143 . The bottom plate 13 is installed in the inner layer 141 . A magnetically conductive flat pad 15 is provided between two adjacent layers.

[0060] In some possible implementations, grooves for the lead wires of the electromagnetic coil to pass through are respectively provided on the inner layer 141 and the middle layer 142 , a mounting hole is provided on the outer layer 143 , and a lead wire mounting seat is provided on the outer layer.

[0061] Furthermore, the length of each side of the bottom of the inner layer 141 is greater than the length of each side corresponding to the bottom plate 13, and the top of each layer (inner layer 141, middle layer 142 and outer layer 143) is flush with the top of the top yoke 5 when the installation is complete. The length of each side is greater than the length of each side corresponding to the bottom plate 13, and the top of each layer of the shielding cover is flush with the top of the top yoke 5 when the installation is complete.

[0062] The cover plate 2 is provided with a limiting groove 21 that cooperates with the moving iron core 4, so as to effectively avoid overshoot when opening the gate; there is a gap between the outer side surface of the moving iron core 4 and the inner side surface of the cover plate 2, and a limiting screw is provided on the outer side surface of the moving core 4, and the limiting screw is located in the limiting groove. The limiting groove 21 has a U-shaped structure, and its opening is provided on the side close to the top magnetic yoke 5;

[0063] In order to effectively connect the moving iron core 4 with the driving shaft 1; the moving iron core 4 is provided with a pin hole fixedly connected to the driving shaft 1, and the moving iron core 4 is provided with a screw hole for limiting connection with the cover plate 2, and the two are connected and fixed by pins; of course, a shaft sleeve plus a countersunk screw or a special-shaped shaft plus a countersunk screw can also be used to fix the bottom end face of the moving iron core 4.

[0064] The magnetic shielding shell 14 fixes the bottom plate 13 in the magnetic shielding shell 14 by fixing screws, and the whole device is connected and fixed to the circuit breaker frame 7 by the fixing screws;

[0065] For the magnetic shielding shell 14 , a thicker single-layer shell may be used instead of a three-layer structure, and the magnetic shielding shell 14 may be directly fixed on the bottom plate 13 .

[0066] 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 permanent magnet mechanism for a DC magnetic field circuit breaker, characterized in that: It comprises a magnetic shielding shell with a square structure and a U-shaped installation cavity, a permanent magnetic holding component installed in the U-shaped installation cavity, an iron core component sleeved in the permanent magnetic holding component and forming an annular cavity with the permanent magnetic holding component, and an electromagnetic coil located in the annular cavity and sleeved on the outside of the iron core component; the permanent magnetic holding component cooperates with the iron core component to form a closed magnetic circuit; The iron core assembly comprises a driving shaft coaxially arranged with the electromagnetic coil, a static iron core and a moving iron core sleeved on the outside of the driving shaft; the static iron core is fixedly installed in the magnetic shielding shell and elastically connected to the moving iron core; both ends of the driving shaft pass through the magnetic shielding shell; When in the open state, an air gap 1 is formed between the moving iron core and the top of the top magnetic yoke; and an air gap 2 is formed between the moving iron core and the static iron core.

2. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 1, characterized in that: The permanent magnet holding assembly includes two groups of side yokes fixed in a magnetic shielding shell and symmetrically arranged, a top yoke installed on the top of the side yokes and sleeved on the outside of the iron core, two groups of permanent magnets installed on the inner sides of the side yokes and located below the electromagnetic coil, and an inner yoke sleeved on the outside of the static iron core and connected to the permanent magnet; the permanent magnet, side yokes, top yokes, air gap one, moving iron core, air gap two, static iron core, and inner yoke form a closed magnetic circuit.

3. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 2, characterized in that: The moving iron core is fixedly sleeved on the outside of the driving shaft and has a T-shaped cross-section, including a large end located above the top magnetic yoke and a small end coaxially connected to the large end and located in the magnetic shielding shell; the small end is elastically connected to the static iron core; When closing the circuit breaker, the moving iron core is attracted by the magnetic field generated by the electromagnetic coil and the magnetic field generated by the permanent magnet, and the moving iron core drives the driving shaft to move toward the side close to the static iron core until the bottom of the large end of the moving iron core overlaps the upper surface of the top magnetic yoke, providing closing holding force for the contact system connected to the driving shaft, and the closing process is completed.

4. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 2, characterized in that: A groove coaxial with the driving shaft is arranged on the static iron core, and a spring is installed in the groove. The spring is sleeved on the outside of the driving shaft and one end of the spring passes through the groove and abuts against the bottom of the moving iron core.

5. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 2, characterized in that: A cover plate is also provided above the top magnetic yoke; one end of the driving shaft passes through the cover plate; The cover plate and the top magnetic yoke form a space for the moving iron core to expand and contract along the axial direction of the driving shaft; The cover plate and the magnetic shielding shell are respectively provided with through holes for the driving shaft to pass through.

6. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 2, characterized in that: The electromagnetic coil comprises a frame which is sleeved on the outside of the core assembly and abuts against the lower surface of the top magnetic yoke and the upper surface of the inner magnetic yoke, and a winding sleeved on the outside of the frame; a gap is formed between the frame and the inner surface of the side magnetic yoke.

7. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 6, characterized in that: The outer diameter of the winding is smaller than the distance between the two sets of side yokes.

8. A permanent magnet mechanism for a DC magnetic field circuit breaker according to any one of claims 2 to 6, characterized in that: A bottom plate made of non-magnetic material is installed in the magnetic shielding shell, and the permanent magnet, side yoke and static iron core are installed on the bottom plate; a limiter is provided on the side yoke to prevent the corresponding permanent magnet from shifting.

9. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 8, characterized in that: The magnetic shielding shell has a three-layer structure, including an inner layer, a middle layer and an outer layer. The bottom plate is installed in the inner layer. A magnetic conductive flat pad is arranged between two adjacent layers.

10. A permanent magnet mechanism for a DC magnetic field circuit breaker according to claim 9, characterized in that: The inner layer and the middle layer are respectively provided with grooves for the lead wires of the electromagnetic coil to pass through, the outer layer is provided with a mounting hole, and the outer layer is provided with a lead wire mounting seat.

Images