A moving contact device of a circuit breaker and a circuit breaker

Abstract

The utility model discloses a movable contact device of circuit breaker, contain movable contact, movable contact support, movable contact spring, the both ends of movable contact set up contact part, the receiving part of force respectively, the both ends of movable contact support set up drive part, limiting portion respectively, movable contact spring includes first arm and second arm, limiting portion contains first limiting portion and second limiting portion, and the rotation range of movable contact is limited between first limiting portion and second limiting portion, and the receiving part of force is pressed by the pressure of first arm and makes movable contact be limited on first limiting portion, when movable contact receives the counterclockwise rotation of electric repulsion and occurs, and the receiving part of force overcomes the pressure of first arm and slides with it to change the pressure direction of first arm to the receiving part of force, makes movable contact be limited on second limiting portion and makes movable contact device keep repelling state, when circuit breaker takes place short circuit, and electric repulsion accelerates movable contact opening speed, improves breaking capacity, avoids the back fall of movable contact repelling and causes fusion welding.

Description

Technical Field

[0001] This utility model relates to the field of low-voltage electrical appliances, specifically to a moving contact device for a circuit breaker and a circuit breaker. Background Technology

[0002] With societal progress and increasingly active human production activities, various industries are flourishing. Especially in the current era of electrification, the demand for electricity is growing rapidly. The increased power capacity places increasingly higher demands on circuit breakers in power distribution lines, with smaller size, higher breaking capacity, and larger capacity being key development directions. One crucial factor affecting the breaking capacity of a circuit breaker is the opening speed of its moving contact device. A faster opening speed results in a shorter arc duration, better current limiting, and higher breaking capacity. Current technology uses contact springs to directly contact the moving contact support in circuit breakers. On the circuit breaker, during short-circuit breaking, an electric repulsive force is generated between the moving contact and the stationary contact, causing the moving contact to be quickly repelled. During this repulsion process, the contact connection between the moving and stationary contacts becomes an arc connection, and the current drops sharply, as does the electric repulsive force. The greater the distance the moving contact is repelled, the greater the deformation of the contact spring, and the greater the reaction force on the moving contact. The moving contact is very prone to falling back and making contact again, causing the molten metal bridge to solidify and the moving and stationary contacts to stick together, leading to the circuit breaker exploding. Also, the breaking capacity cannot be improved because the moving contact repulsion speed is too slow. Utility Model Content

[0003] Based on the above background, by setting a force receiving part at one end of the moving contact, the force of the moving contact spring is applied to the force receiving part. When the moving contact is repelled by the electric repulsion force, the force receiving part slides and changes position with the spring contact surface, so that the pressure direction generated by the spring on the force receiving part changes on both sides of the rotation center of the moving contact. With the cooperation of the first limiting part and the second limiting part on the moving contact bracket, the moving contact device can switch between and maintain the two positions of free state and repulsion state. It can keep the moving contact in the open state after being repelled by the electric repulsion force. Since the pressure direction of the spring changes continuously with the repulsion distance of the moving contact, as the repulsion distance increases, the lever arm of the moving contact decreases continuously, and the force required for the moving contact to repel also gradually decreases until it crosses the rotation center of the moving contact to form a reverse lever arm. It will not cause the moving contact to fall back due to the decrease in current and the attenuation of repulsion force after the arc is generated, which would lead to the problem of welding between the moving contact and the stationary contact. It can also make the repulsion speed of the moving contact faster and the repulsion distance larger, which greatly improves the short circuit breaking capacity of the circuit breaker and effectively overcomes the above problems.

[0004] The technical solution of this utility model is as follows: On one hand, this utility model provides a moving contact device for a circuit breaker, the moving contact device comprising at least a moving contact, a moving contact support, and a moving contact spring; the moving contact is strip-shaped, with a contact portion at one end and a force receiving portion at the other end, and a support portion near the force receiving portion, the support portion being a shaft or a hole; the moving contact support is strip-shaped, with a driving portion at one end and a limiting portion at the other end, a moving contact mounting portion near the limiting portion, and a second support portion between the two ends, the second support portion being a shaft or a hole; the moving contact spring is a torsion spring, the torsion spring being sleeved on the second support portion, and includes a first arm and a second arm, the first arm pressing against the... On the force receiving part, the second arm is fixedly mounted on the moving contact bracket; the moving contact is hinged to the moving contact bracket, and the limiting part includes a first limiting part and a second limiting part. The rotation range of the moving contact on the moving contact bracket is limited between the first limiting part and the second limiting part. When the force receiving part is subjected to the pressure of the first arm, the moving contact is limited to the first limiting part and the moving contact device is kept in a free state. When the moving contact is subjected to the electric repulsive force and rotates counterclockwise, the force receiving part overcomes the pressure of the first arm and slides with it, thereby changing the pressure direction of the first arm on the force receiving part, so that the moving contact is limited to the second limiting part and the moving contact device is kept in a repulsive state.

[0005] In this manner, the moving contact is rotatably mounted on the moving contact support. The range of motion of the moving contact is limited by the limiting part on the moving contact support. The moving contact is pressed to the free position by the moving contact spring. When an electric repulsive force is generated, the moving contact is repelled and rotates around the moving contact support to the repelled position. During the repulsion process, it overcomes the pressure of the moving contact spring to switch to the repelled position. During the repulsion rotation of the moving contact, the torque of the moving contact spring on the moving contact gradually decreases until it passes the center of rotation of the moving contact and changes to a reverse torque to keep the moving contact in the repelled state. This setting ensures that the repulsion process of the moving contact does not increase the deformation of the moving contact spring and the reaction force due to the increase of the repulsion distance. It cleverly utilizes the torque change between the moving contact spring and the moving contact, so that the repulsion of the moving contact does not increase the electric force required for the repulsion of the moving contact due to the increase of the deformation of the contact spring. This effectively improves the repulsion distance and speed of the moving contact and greatly improves the breaking capacity of the circuit breaker.

[0006] In some embodiments, the moving contact device further includes a metal shaft, the second support portion is a circular hole, the metal shaft passes through the circular hole, the metal shaft is fixed on the insulating housing, and the operating mechanism of the circuit breaker drives the driving portion to rotate the moving contact bracket, thereby driving the moving contact to rotate synchronously to achieve contact or disconnection with the stationary contact of the circuit breaker.

[0007] In the above embodiments, the moving contact bracket serves as the carrier of the moving contact and is fixed inside the insulating housing by a metal shaft. It can be operated to close or open the circuit through an operating mechanism. The moving contact is rotatably fixed to the moving contact mounting part, and the rotation range of the moving contact is limited by a limiting part. The moving contact can be confined within the limiting part of the moving contact bracket by a moving contact spring, so that the moving contact device is kept in a free state. When the operating mechanism drives the moving contact bracket, the moving contact can make electrical contact and separate from the stationary contact.

[0008] In some embodiments, the moving contact is a double-piece moving contact, and the support portion of the double-piece moving contact is a round hole, which is hinged to the moving contact mounting portion on the moving contact bracket by a rivet.

[0009] In the above embodiments, the moving contact is configured as a double piece to carry a higher current. When using a high rated current, it has better stability when adapting to the torsion spring form of the moving contact spring. The moving contact spring abuts against the moving contacts hinged on both sides of the moving contact support in the form of a double torsion arm, which can realize that the double moving contacts can be simultaneously pushed away and held.

[0010] In some embodiments, the force receiving portion includes a first receiving surface and a second receiving surface. When the moving contact device is in a free state, the first arm abuts against the first receiving surface, pressing the moving contact against the first limiting portion of the moving contact bracket. When the operating mechanism drives the moving contact device to close with the stationary contact, the contact portion exerts pressure on the stationary contact, and the first receiving surface overcomes the pressure of the first arm, causing the moving contact to separate from the first limiting portion. When the moving contact and the stationary contact are subjected to an electric repulsive force, the moving contact rotates counterclockwise around the moving contact bracket to overcome the pressure of the first arm, causing the first receiving surface to disengage from the first arm, thereby abutting against the first arm with the second receiving surface. The moving contact abuts against and remains in contact with the second limiting portion.

[0011] In the above embodiment, the force receiving part is provided with a first receiving surface and a second receiving surface. In the free state, the first receiving surface of the moving contact is driven by the pressure of the first arm of the moving contact spring. The moving contact abuts against the first limiting part of the moving contact bracket. When the circuit is closed, the moving contact contacts the stationary contact. The operating mechanism drives the moving contact bracket to continue rotating. The moving contact starts to rotate counterclockwise due to the resistance of the stationary contact to overcome the pressure of the first arm. The moving contact disengages from the first limiting part. Thus, the pressure of the moving contact spring is indirectly applied to the contact position between the moving contact and the stationary contact to generate contact pressure. When an electric repulsive force is generated between the moving contact and the stationary contact, the moving contact further overcomes the pressure of the moving contact spring and rotates counterclockwise. The abutting relationship between the first receiving surface and the first arm gradually changes to the abutting relationship between the second receiving surface and the first arm. During the process, the torque between the first arm and the moving contact gradually decreases and forms a reverse torque until the moving contact abuts against the second limiting part to form a stuck state, realizing rapid repulsion and repulsion retention.

[0012] In some embodiments, the moving contact is a single-piece moving contact, and the support portion and the mounting portion of the single-piece moving contact are round holes. The moving contact bracket and the single-piece moving contact are hinged by rivets passing through the two round holes.

[0013] In the above embodiments, when the moving contact is a single piece, it is mainly used in specifications with relatively small rated current. Specifications with relatively small rated current do not have high requirements for current carrying capacity. The moving contact can be in the form of a single piece, which simplifies the structure and reduces costs. By hinged to the moving contact bracket and setting a force receiving part on the moving contact, it is also possible to achieve rapid repulsion and retention.

[0014] In some embodiments, the moving contact support consists of at least two pieces and is clamped on both sides of the moving contact. The limiting portion is an arc-shaped oval hole arranged around the moving contact mounting portion. The limiting portion includes a first limiting portion and a second limiting portion. The upper end of the arc-shaped oval hole is the first limiting portion, and the lower end of the arc-shaped oval hole is the second limiting portion.

[0015] In the above embodiments, the moving contact support needs to be provided with at least two pieces clamping the two sides of the moving contact, which can effectively improve the stability of the moving contact during the movement process. In order to limit the range of motion of the moving contact on the moving contact support, an arc-shaped oval hole is provided on the moving contact support to limit the range of motion of the moving contact within the arc-shaped oval hole.

[0016] In some embodiments, the force receiving part is a round shaft riveted to the moving contact.

[0017] In some embodiments, the circular shaft is inserted into the limiting portion of the moving contact bracket to limit the range of motion of the moving contact.

[0018] In the above embodiment, the round shaft riveted to the moving contact serves as a force receiving part. The round shaft is inserted into the arc-shaped oblong hole on the moving contact bracket to restrict the range of motion of the moving contact. The force receiving part is subjected to the pressure of the first arm of the moving contact spring, which presses the round shaft above the arc-shaped oblong hole, keeping the moving contact device in a free state.

[0019] In some embodiments, when the moving contact device is in a free state, the first arm abuts against the force receiving part, pressing the force receiving part against the first limiting part; when the operating mechanism drives the moving contact device to close with the stationary contact, the contact part generates pressure on the stationary contact, and the force receiving part overcomes the pressure of the first arm to separate the force receiving part from the first limiting part; when the moving contact and the stationary contact are subjected to an electric repulsive force, the force receiving part further overcomes the pressure of the first arm, and the moving contact rotates counterclockwise around the moving contact support, so that the force receiving part abuts against the second limiting part and remains in a repulsive state.

[0020] In the above embodiment, the force receiving part is riveted to the moving contact with a round shaft. The round shaft can slide between the first limiting part and the second limiting part on the moving contact bracket. The pressure of the first arm of the moving contact spring is applied to the round shaft, which abuts against the first limiting part. When the moving contact is closed, the moving contact contacts the stationary contact and rotates counterclockwise under force. The round shaft disengages from the first limiting part. The pressure of the moving contact spring is applied to the contact position between the moving contact and the stationary contact, thereby generating contact pressure. When the moving contact is repelled by the electric repulsive force, the moving contact continues to rotate counterclockwise to overcome the pressure of the moving contact spring. Due to the change in the position of the round shaft, the torque of the pressure of the moving contact spring applied to the moving contact continuously decreases until it becomes a reverse torque, causing the moving contact and the round shaft to slide together to the second limiting part. The repulsive force required during the repulsion process of the moving contact gradually decreases and then becomes a reverse torque, making the repulsion faster and more sustainable.

[0021] On the other hand, this utility model provides a circuit breaker, including a moving contact device, a stationary contact, and an operating mechanism. The stationary contact is provided with an alloy contact that abuts against the contact portion. The alloy contact is planar or arc-shaped, and the contact portion is arc-shaped or spherical. The contact portion and the alloy contact are in point contact or line contact.

[0022] In the above embodiments, the contact surface between the moving contact and the stationary contact is set as a point contact or a line contact, so that when the current passes through the moving contact and the stationary contact, a current contraction effect is generated, thereby generating a Holm force to repel the moving contact and provide a strong force for the repulsion of the moving contact.

[0023] In some embodiments, when the circuit breaker is in the closed state, a section of the conductor on the stationary contact where the alloy contact is located forms a U-shape with the moving contact.

[0024] In the above embodiment, the conductor segment of the moving contact and the conductor segment of the stationary contact are arranged in an overlapping layout, so that the current flowing through them is U-shaped. Since the current directions are opposite, a Lorentz force is generated between the two conductor segments, causing the moving contact to repel away from the stationary contact, providing a strong force for the repulsion of the moving contact.

[0025] The beneficial effects of this utility model are as follows: When the moving contact device of this utility model is short-circuited, the moving contact is subjected to an electric repulsive force. During the repulsion process, the torque applied to the moving contact by the moving contact spring gradually decreases, so the repulsion force also gradually decreases, making the repulsion easier. It avoids the large reaction force caused by the large deformation of the spring due to the increase in the repulsion distance. It cleverly utilizes the change of torque and gradually forms a reverse torque to reduce the force required for repulsion and accelerate the repulsion speed, thus greatly improving the short-circuit breaking capacity of the circuit breaker.

[0026] When the moving contact device of this utility model is short-circuited, the moving contact is subjected to an electric repulsive force. When the repulsion is completed, the torque applied to the moving contact by the moving contact spring is gradually reduced until a reverse torque is formed. The moving contact automatically springs open and abuts against the second limiting part and maintains the repulsive state. The entire repulsion and holding process is rapid and smooth, and there is no phenomenon of contact sticking due to falling back. This greatly improves the short-circuit breaking capacity of the circuit breaker and improves the reliability of the circuit breaker. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the internal structure of the circuit breaker according to the first embodiment of this utility model.

[0029] Figure 2 This is a schematic diagram of the moving contact device according to the first embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the moving contact bracket of the first embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the moving contact of the first embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the moving contact device in the closed state according to the first embodiment of this utility model.

[0033] Figure 6 This is a structural diagram of the moving contact device in the first embodiment of the present invention during the repulsion process.

[0034] Figure 7 This is a schematic diagram of the structure of the moving contact device in the first embodiment of the present invention when it is fully repelled and held.

[0035] Figure 8 This is a schematic diagram of the internal structure of the circuit breaker according to the second embodiment of this utility model.

[0036] Figure 9 This is a schematic diagram of the moving contact device according to the second embodiment of the present invention.

[0037] Figure 10 This is a schematic diagram of the structure of the moving contact bracket according to the second embodiment of the present invention.

[0038] Figure 11 This is a schematic diagram of the moving contact device in the closed state according to the second embodiment of this utility model.

[0039] Figure 12 This is a schematic diagram of the moving contact device in the second embodiment of the present invention during the repulsion process.

[0040] Figure 13 This is a schematic diagram of the structure of the moving contact device in the second embodiment of the present invention when it is fully repelled and held.

[0041] Numbering Explanation: Moving contact device 10; moving contact 101; contact portion 1011; support portion 1012; force receiving portion 1013; first receiving surface 1013A; second receiving surface 1013B; moving contact bracket 102; limiting portion 1021; first limiting portion 1021A; second limiting portion 1021B; second support portion 1022; driven portion 1023; moving contact mounting portion 1024; moving contact spring 103; first arm 1031; second arm 1032; rivet 104; insulating shell 20; metal shaft 201; stationary contact 30; alloy contact 301; operating mechanism 40; fault current protection device 50. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of the embodiments of this utility model will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this utility model. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0043] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0044] First embodiment: like Figure 1As shown, this utility model discloses a moving contact device and a circuit breaker including the moving contact device, comprising an insulating housing 20 and internal components disposed within the insulating housing 20. The internal components include at least: a moving contact device 10, a stationary contact 30, an operating mechanism 40, a fault current protection device 50, and a metal shaft 201. The moving contact device 10 includes at least a moving contact 101, a moving contact support 102, and a moving contact spring 103. One end of the moving contact 101 is provided with a contact portion 1011, and the stationary contact 30 is provided with a contact portion 1011 that abuts against the contact portion 1011. The alloy contacts are planar or arc-shaped, and the contact portion is arc-shaped or spherical. The contact portion and the alloy contacts are in point contact or line contact. When the circuit breaker is in the alloy state, a section of conductor with the alloy contacts on the stationary contact is U-shaped with the moving contact. This arrangement overlaps the conductor section of the moving contact with the conductor section of the stationary contact, so that the current flowing through it is U-shaped. The two conductor sections generate a Lorentz force due to the opposite direction of the current, causing the moving contact to repel away from the stationary contact, providing a strong force for the repulsion of the moving contact.

[0045] The moving contact support 102 is rotatably mounted on the insulating housing 20 via a metal shaft 201. The moving contact 101 is rotatably mounted on the moving contact support 102. The moving contact support 102 is provided with a limiting part 1021, which limits the rotation range of the moving contact 101 on the moving contact support 102. The moving contact spring 103 abuts against the moving contact support 102 and the moving contact 101. An electrical current is generated between the moving contact 101 and the stationary contact 30. The moving contact 101 is repelled by the dynamic repulsive force and remains in the open state. The moving contact 101 is rotatably mounted on the moving contact support 102. The range of motion of the moving contact is limited by the limiting part 1021 on the moving contact support 102. The moving contact is restricted to the limiting part 1021 by the contact spring 103. When an electric repulsive force is generated, the moving contact 101 overcomes the pressure of the moving contact spring 103 and is repelled. It rotates around the moving contact support 102 to switch to the repelled position so as to maintain the open position after repulsion.

[0046] like Figure 2 and Figure 3As shown, the moving contact bracket 102 has a second support portion 1022 in the middle. The metal shaft 201 passes through the second support portion 1022 and is fixed at both ends to the insulating shell 20. The metal shaft 201 is fixed inside the insulating shell 20. The moving contact bracket is generally strip-shaped, with a driven portion 1023 at one end and a moving contact mounting portion 1024 and a limiting portion 1021 at the other end. The limiting portion 1021 includes a first limiting portion 1021A and a second limiting portion 1021B. The first limiting portion 1021A and the second limiting portion 1021B are respectively provided on both sides of the moving contact mounting portion 1024. The first limiting portion 1021A restricts the relative position of the moving contact 101 and the moving contact bracket 102 in the free state, and the second limiting portion 1021B restricts the relative position of the moving contact 101 and the moving contact bracket 102 after the moving contact 101 is pushed apart.

[0047] Specifically, in this embodiment, the second support portion 1022, the driven portion 1023, and the moving contact mounting portion 1024 are circular holes of different sizes, although they can also be of the same size. The driven portion 1023, the second support portion 1022, and the moving contact mounting portion 1024 are spaced apart along the length of the moving contact bracket 102. Two recesses are formed between the arc-shaped protrusion at the other end of the moving contact bracket 102 and the protrusions on both sides. The first limiting portion 1021A is a limiting surface on one of the recesses, and the second limiting portion 1021B is a limiting surface on the other recess. The first limiting portion 1021A is located on the side accessible by the moving contact 101 in the clockwise rotation direction, and the second limiting portion 1021B is located on the side accessible by the moving contact 101 in the counterclockwise rotation direction.

[0048] Please refer to Figure 2 and Figure 4 The moving contact spring 103 is a torsion spring, which includes a first arm 1031 and a second arm 1032. The moving contact spring 103 is sleeved on the metal shaft 201, and the second arm 1032 is fixedly mounted on the moving contact bracket 102. The first arm 1031 abuts against the moving contact 101. The moving contact 101 is a double-piece moving contact, which includes a moving contact rod and a contact portion 1011 disposed at one end of the moving contact rod. A force receiving portion 1013 is formed on the other end of the moving contact rod. A support portion 1012 is disposed on the moving contact rod. The support portion 1012 is disposed near the end of the force receiving portion 1013. The support portion 1012 is a hole, and a rivet 104 passes through the support portion 1012 and the moving contact mounting portion 1024 to rotatably connect the moving contact 101 to the moving contact bracket 102.

[0049] The force receiving part 1013 is composed of at least a first receiving surface 1013A and a second receiving surface 1013B. The first receiving surface 1013A and the second receiving surface 1013B have different inclination directions and form an approximately obtuse angle. When the moving contact device 10 is in a free state, the first arm 1031 of the moving contact spring 103 abuts against the first receiving surface 1013A, pressing the moving contact 101 against the first limiting part 1021A of the moving contact support 102. When the moving contact device 10 contacts the stationary contact 30 and generates pressure, the first receiving surface 1013A of the moving contact 101 overcomes the moving contact spring 103. The pressure of the first arm 1031 causes the moving contact 101 to separate from the first limiting part 1021A of the moving contact support 102, and transmits the force generated by the first arm 1031 to the contact part 1011 of the moving contact 101 and the stationary contact 30. When the moving contact 101 and the stationary contact 30 are subjected to electric repulsion, the moving contact 101 continues to rotate counterclockwise around the moving contact support 102 to overcome the pressure of the first arm 1031 of the moving contact spring 103, so that the first receiving surface 1013A gradually separates from the first arm 1031 of the moving contact spring 103, and the second receiving surface 1013B abuts against the first arm 1031 of the moving contact spring 103. The moving contact 101 abuts against and remains in contact with the second limiting part 1021B.

[0050] like Figure 5 As shown, the stationary contact 30 is provided with an alloy contact 301 that abuts against the contact portion 1011 of the moving contact 101. The alloy contact 301 is planar or arc-shaped, and the contact portion 1011 is arc-shaped or spherical. The contact portion 1011 and the alloy contact 301 are in point contact or line contact. In the point contact or line contact state, when a large current passes through, the current contraction will generate a Holm force. The Holm force acts on the moving contact, which is conducive to the rapid repulsion of the moving contact. The operating mechanism 4 When the driven part 1023 on the moving contact support 102 causes the moving contact device 10 to close with the stationary contact 30, the current path flowing through the stationary contact 30 and the moving contact 101 forms a U-shape. When a large current passes through the U-shaped current path, a Lorentz force can be generated between the moving contact 101 and the stationary contact 30, which is conducive to the rapid repulsion of the moving contact 101. Under the combined action of the Holm force and the Lorentz force, the moving contact 101 repulses even faster, which is beneficial for rapid disconnection and current limiting.

[0051] When the operating mechanism 40 drives the driven part 1023 on the moving contact support 102 to close the moving contact device 10 with the stationary contact 30, the contact part 1011 of the moving contact 101 abuts against the alloy contact 301 of the stationary contact 30. The moving contact 101 rotates counterclockwise around the moving contact support 102. The first receiving surface 1013A of the moving contact 101 overcomes the pressure of the first arm 1032 of the moving contact spring, causing the moving contact 101 to disengage from the first limiting surface 1021A of the moving contact support 102 to form a closed state. The first arm 1032 of the moving contact spring 103 provides pressure on the stationary contact 30 for the moving contact 101, thus achieving electrical contact.

[0052] like Figure 6 and Figure 7 As shown, when encountering a large short-circuit current, the moving contact 101 is rapidly repelled by the combined action of the Lorentz force and the Holm force. The moving contact 101 rotates counterclockwise around the moving contact support 102. During the rotation, the first receiving surface 1013A of the moving contact 101 overcomes the pressure of the first arm 1031 of the moving contact spring, causing the direction of the force exerted by the first arm 1031 of the moving contact spring on the first receiving surface 1013A of the moving contact 101 to change. As the repulsion distance increases, the direction of the force is directly aligned with the rotation center of the support 1012. The shorter the vertical distance, the shorter the vertical distance from the line of the force direction applied by the moving contact spring 103 to the force receiving part 1013 to the rotation center of the support part 1012, the smaller the force required to drive the moving contact 101 to rotate counterclockwise. The force required for the moving contact 101 to repel is a gradually decreasing process. When the moving contact 101 repels to a certain distance, the line of the force direction applied by the first arm 1031 of the moving contact spring to the force receiving part 1013 gradually approaches and passes the rotation center of the support part 1012. The first arm 1031 of the moving contact spring 103 gradually changes from abutting against the first receiving surface 1013A of the moving contact to abutting against the second receiving surface 1013B. The direction of the force exerted by the first arm 1031 of the moving contact spring 103 on the second receiving surface 1013B has passed the rotation center of the moving contact support 1012. The torque exerted by the first arm 1031 of the moving contact spring 103 on the moving contact 101 becomes a counterclockwise torque, causing the moving contact 101 to be subjected to Holm force, Lorentz force, and the force generated by the first arm 1031 of the moving contact spring 103. The combined pressure causes the moving contact 101 to accelerate its repulsion until it comes into contact with the second limiting surface 1021B of the moving contact support 102 and remains in a repulsive state. During the entire repulsion process, due to the change in the force direction between the force receiving part 1013 and the first arm 1031, the electric repulsion force required for the entire repulsion process gradually decreases. Furthermore, when the repulsion reaches a certain distance, it will accelerate and remain in a repulsive state, which greatly shortens the opening time of the moving contact 101 and plays a role in current limiting and improving short-circuit breaking capacity.

[0053] Specifically, refer to Figure 5 , Figure 5 This is a schematic diagram showing the moving contact 101 and the stationary contact 30 in the closed state. The vertical distance between the line containing the force F1 applied to the moving contact 101 by the first arm 1031 of the contact spring 103 and the rotation center of the support portion 1012 is the first force arm L1 applied by the contact spring to the moving contact. The moving contact is acted upon by force F1, and the vertical distance between the line containing the force F2 applied to the stationary contact by its contact portion 1011 and the rotation center of the support portion 1012 is the second force arm L2. (Referring to...) Figure 6 , Figure 6 The state is that the moving contact 101 is repelled a certain distance. Due to the counterclockwise rotation of the moving contact 101, the first lever arm L1 gradually decreases. With F1 remaining constant, F2 also decreases. Therefore, the repulsive force required to repel the moving contact gradually decreases. When it is repelled to a certain distance, L1 will be 0, and at this point, the force required to repel the moving contact is also 0. (Refer to...) Figure 7 , Figure 7 The moving contact 101 is fully open and abuts against the second limiting part 1021B and remains in the same position. At this moment, the first lever arm L1 is compared to Figure 5 and Figure 6 The first lever arm L1 has changed from large to small until it changed direction and became negative. The straight line where the force F1 is located has passed the rotation center of the support part 1012 and reached the other side. The torque applied by F1 to the moving contact has formed a reverse torque, causing the moving contact to rotate counterclockwise on its own and press the moving contact against the second limiting part 1021B and keep it in a repelled state.

[0054] Second embodiment: like Figure 8-13 As shown, the difference between this embodiment and the first embodiment is that the moving contact 101 is a single-piece moving contact, and there are three moving contact supports 102. All three moving contact supports 102 are plate-shaped, with two being long moving contact supports 102 and one being a short moving contact support 102. The two long moving contact supports 102 are located on both sides of the short moving contact support 102, thus forming a gap between the two long moving contact supports 102 with a thickness equivalent to that of the short moving contact support 102. The single-piece moving contact is arranged in the gap, that is, the two long moving contact supports 102 are arranged on both sides of the single-piece moving contact, and the one short moving contact support 102 is located at one end of the single-piece moving contact. The support portion 1012 on the single-piece moving contact is hinged to the moving contact mounting portion 1024 on the moving contact support 102 by rivets.

[0055] In the first embodiment, the limiting part 1021 is formed in two inclined surfaces at the other end of the moving contact bracket. The difference between this embodiment and the first embodiment is that the limiting part 1021 is an arc-shaped oval hole provided on the moving contact bracket. The arc-shaped oval hole is located between the second support part 1022 and the moving contact mounting part 1024. One end face of the arc-shaped oval hole is the first limiting part 1021A, and the other end face is the second limiting part 1021B. The force receiving part 1013 on the moving contact 101 is a round shaft riveted to the moving contact 101. The round shaft is inserted into the limiting part 1021 of the moving contact bracket 102 to limit the range of motion of the moving contact.

[0056] When the moving contact device 10 is in a free state, the first arm 1031 of the moving contact spring 103 abuts against the force receiving part 1013, pressing the moving contact 101 against the first limiting part 1021A of the moving contact support 102. When the moving contact device 10 contacts the stationary contact 30 and generates pressure, the force receiving part 1013 of the moving contact 101 overcomes the pressure of the first arm 1031 of the moving contact spring 103, causing the moving contact 101 to separate from the first limiting part 1021A of the moving contact support 102. Since the force receiving part 1013 is a round shaft, it will slide against the first arm 1031 of the moving contact spring 103 during the movement. When the moving contact 101 contacts the stationary contact... When subjected to an electric repulsive force, the moving contact 101 overcomes the pressure of the first arm 1031 and rotates counterclockwise around the moving contact support 102, causing the force receiving part 1013 to slide so that the moving contact 101 abuts against the second limiting part 1021B and remains in a repulsive state. The moving contact support 102 is a three-piece stacked structure. The moving contact 101 is clamped by the two outer pieces, and an additional moving contact support is added in the middle space of the clamping to maintain balance. The moving contact 101 is hinged by rivets. The use of a single moving contact structure can save the amount of moving contact copper material and greatly reduce material costs. It can be applied in specifications with low rated current and can also improve the breaking force.

[0057] This invention may be implemented in other specific forms without departing from its spirit and essential characteristics. The present embodiments are to be regarded in all respects as exemplary rather than limiting, and the scope of this invention is defined by the appended claims rather than the foregoing description, and all modifications falling within the meaning of the claims and their equivalents are thus included within the scope of this invention.

Claims

1. A moving contact device, the moving contact device comprising at least a moving contact, a moving contact support, and a moving contact spring; The moving contact is strip-shaped, with a contact portion at one end and a force receiving portion at the other end. A support portion is provided at the end near the force receiving portion, and the support portion is a shaft or a hole. The moving contact bracket is strip-shaped, with a driving part at one end and a limiting part at the other end. A moving contact mounting part is provided at the end near the limiting part, and a second support part is provided between the two ends. The second support part is a shaft or a hole. The moving contact spring is a torsion spring, which is sleeved on the second support part and includes a first arm and a second arm. The first arm presses against the force receiving part, and the second arm is fixedly mounted on the moving contact bracket. Its features are: The moving contact is hinged to the moving contact bracket. The limiting part includes a first limiting part and a second limiting part. The rotation range of the moving contact on the moving contact bracket is limited between the first limiting part and the second limiting part. When the force receiving part is subjected to the pressure of the first arm, the moving contact is limited to the first limiting part and the moving contact device is kept in a free state. When the moving contact is subjected to the electric repulsive force and rotates counterclockwise, the force receiving part overcomes the pressure of the first arm and slides with it, thereby changing the pressure direction of the first arm on the force receiving part, so that the moving contact is limited to the second limiting part and the moving contact device is kept in a repulsive state.

2. The moving contact device according to claim 1, characterized in that, It also includes a metal shaft, the second support part is a round hole, the metal shaft passes through the round hole, the metal shaft is fixed on the insulating shell, the circuit breaker's operating mechanism drives the driving part to rotate the moving contact bracket, thereby driving the moving contact to rotate synchronously to achieve contact or disconnection with the circuit breaker's stationary contact.

3. The moving contact device according to claim 1, characterized in that, The moving contact is a double-piece moving contact, and the support part of the double-piece moving contact is a round hole, which is hinged to the moving contact mounting part on the moving contact bracket by rivets.

4. The moving contact device according to claim 1, characterized in that, The force receiving part includes a first receiving surface and a second receiving surface. When the moving contact device is in a free state, the first arm abuts against the first receiving surface, pressing the moving contact against the first limiting part of the moving contact bracket. When the operating mechanism drives the moving contact device to close with the stationary contact, the contact part generates pressure on the stationary contact, and the first receiving surface overcomes the pressure of the first arm, causing the moving contact to separate from the first limiting part. When the moving contact and the stationary contact are subjected to an electric repulsive force, the moving contact rotates counterclockwise around the moving contact bracket to overcome the pressure of the first arm, causing the first receiving surface to separate from the first arm, so that the second receiving surface abuts against the first arm, and the moving contact abuts against and remains with the second limiting part.

5. The moving contact device according to claim 1, characterized in that, The moving contact is a single-piece moving contact. Both the support part and the mounting part of the single-piece moving contact are round holes. The moving contact bracket and the single-piece moving contact are hinged by rivets passing through the two round holes.

6. The moving contact device according to claim 5, characterized in that, The moving contact support consists of at least two pieces and is clamped on both sides of the moving contact. The limiting part is an arc-shaped oval hole arranged around the moving contact mounting part. The limiting part includes a first limiting part and a second limiting part. The upper end of the arc-shaped oval hole is the first limiting part, and the lower end of the arc-shaped oval hole is the second limiting part.

7. The moving contact device according to claim 6, characterized in that, The force receiving part is a round shaft riveted to the moving contact.

8. The moving contact device according to claim 7, characterized in that, The circular shaft is inserted into the limiting part of the moving contact bracket to limit the range of motion of the moving contact.

9. The moving contact device according to any one of claims 5 to 8, characterized in that, When the moving contact device is in a free state, the first arm abuts against the force receiving part, pressing the force receiving part against the first limiting part; when the operating mechanism drives the moving contact device to close with the stationary contact, the contact part generates pressure on the stationary contact, and the force receiving part overcomes the pressure of the first arm, causing the force receiving part to separate from the first limiting part; when the moving contact and the stationary contact are subjected to an electric repulsive force, the force receiving part further overcomes the pressure of the first arm, and the moving contact rotates counterclockwise around the moving contact support, causing the force receiving part to abut against the second limiting part and remain in a repulsive state.

10. A circuit breaker, characterized in that, Includes the moving contact device, stationary contact, and operating mechanism as described in any one of claims 1 to 9, wherein the stationary contact is provided with an alloy contact that abuts against the contact portion, the alloy contact being planar or arc-shaped, the contact portion being arc-shaped or spherical, and the contact portion and the alloy contact being in point contact or line contact.

11. The circuit breaker according to claim 10, characterized in that, When the circuit breaker is in the closed state, a section of conductor on the stationary contact with the alloy contact is U-shaped with the moving contact.

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