Multi-part moving shaft assembly for ultra high-turn actuator for use in

Abstract

A multi-part assembly for driving a moving conductor of a circuit interrupter to move away from a stationary conductor shortens the opening time of separable contacts by reducing the number of components that must travel to form an initial gap between the separable contacts during an initial phase of the opening stroke. The components that must travel in order to disconnect the separable contacts are included only in some parts but not all parts of the movable assembly. In one embodiment, a split switch shaft coupled with a moving conductor includes a head shaft coupled to a tail shaft with a sliding pin such that the head shaft can travel an initial distance while the tail shaft remains stationary, thereby forming an initial gap between contacts. In another embodiment, the moving conductor assembly is coupled to the hydraulic device such that the assembly can travel an initial distance at a higher speed prior to being damped by the hydraulic fluid.

Description

Technical Field

[0001] The concepts of the present disclosure generally relate to circuit breakers, and more particularly, to a shaft assembly used with a moving conductor assembly to disconnect separable contacts of a circuit breaker at a relatively high speed. Background Art

[0002] Circuit breakers (such as but not limited to circuit breakers) are commonly used to protect circuit systems from damage caused by overcurrent conditions (such as overload conditions, short circuits) or other fault conditions (such as arc faults or ground faults). Circuit breakers generally include mechanically separable electrical contacts that operate as mechanical switches. When the separable contacts are in a closed state and in contact with each other, current can flow through any circuit connected to the circuit breaker. When the separable contacts are in an open state and physically separated from each other, current flow through any circuit connected to the circuit breaker is blocked. The separable contacts can be manually operated by an operator's handle, remotely operated by an electrical signal, or automatically operated in response to a detected fault condition. Generally, such circuit breakers include: an actuator designed to quickly open or close the separable contacts; and a trip mechanism, such as a trip unit, which can sense multiple fault conditions and automatically trip the actuator to open the separable contacts when a fault condition is sensed.

[0003] In addition to mechanically separable contacts, hybrid circuit breakers also employ power electronic breakers. The electronic breaker is connected in parallel with the mechanical contacts and includes electronic devices configured to commutate current after a fault is detected. After the current is commutated from the mechanical switch to the electronic breaker, the mechanically separable contacts can be separated, thereby reducing the risk of arc discharge. To limit the let-through current during a fault condition, it is advantageous to commutate as much current as possible to the electronic branch as quickly as possible and quickly open the mechanically separable contacts.

[0004] Mechanically separable contacts generally include one stationary contact disposed at the end of a stationary electrode bar and one moving contact disposed at the end of a moving electrode bar, where the electrode bars are components of a larger moving conductor assembly. Due to the relatively large mass of the moving conductor assembly and the associated shaft assembly that must be driven to open to separate the separable contacts during a fault condition, the force required to quickly open the mechanically separable contacts can be large. Thomson coil actuators are known for their ability to open mechanically separable contacts at a very high speed and are commonly used in hybrid circuit breakers. However, because any time interval between the occurrence of a fault condition and the opening of the mechanically separable contacts results in at least some current flowing through the mechanically separable contacts, there is always a need for a moving conductor assembly and an associated switch shaft assembly with a lower mass than existing components to facilitate faster opening of the mechanical contacts.

[0005] Therefore, there is still room for improvement in the moving conductor assembly of the separable contact for quickly disconnecting a circuit breaker and the related switch shaft assembly. Summary of the Invention

[0006] These needs and other needs are met by a multi-part assembly that drives the moving conductor of the circuit breaker away from the stationary conductor. Manufacturing the drive assembly as a multi-part assembly rather than a one-piece assembly reduces the number of components that must travel during the initial stage of the opening stroke to form an initial gap between the separable contacts, thereby shortening the opening time of the separable contacts. In one embodiment, a multi-part split shaft assembly configured to be coupled to the moving conductor assembly includes a head shaft coupled to a tail shaft. The head shaft and the tail shaft are coupled together using a sliding pin, which allows the head shaft to travel an initial distance during the opening stroke while the tail shaft remains stationary. This forms an initial gap between the separable contacts while only the head shaft needs to travel this initial opening distance, rather than both the head shaft and the tail shaft. In other embodiments, the moving assembly includes a first part and a second part. During the opening stroke, only the first part needs to travel to form an initial gap between the separable contacts while the components in the second part remain stationary. This forms an initial gap between the separable contacts while only the first part of the moving assembly needs to travel this initial opening distance, rather than both the first part and the second part.

[0007] According to one aspect of the present disclosure concept, a split switch shaft is configured for use in a pole assembly of a circuit breaker. The pole assembly includes: a stationary conductor having separable stationary contacts; and a moving conductor assembly having separable moving contacts, wherein the moving conductor assembly is configured to travel in a disconnection direction from a closed state during a disconnection stroke to separate the separable moving contacts from the separable stationary contacts. The split switch shaft includes: a head shaft configured such that a proximal end of the head shaft is coupled to the moving conductor assembly; a sliding pin; a tail shaft; and a return spring. The head shaft includes a first pin receiving opening extending laterally through a distal end of the head shaft. The tail shaft includes: a proximal end coupled to the distal end of the head shaft; and a second pin receiving opening extending laterally through the proximal end of the tail shaft. The proximal end of the tail shaft includes a plurality of spring mounting flanges and a shaft coupling opening disposed between the spring mounting flanges. The return spring is mounted on the spring mounting flanges. The distal end of the head shaft is inserted into the proximal end of the tail shaft such that the first pin receiving opening and the second pin receiving opening are aligned. The sliding pin is inserted into the first pin receiving opening and the second pin receiving opening, and the return spring maintains a minimum clearance distance between a most distal surface of the head shaft and a distal surface of the shaft coupling opening. The second pin receiving opening is longer than the first pin receiving opening, and the head shaft is configured such that when the moving conductor assembly travels the minimum clearance distance during the disconnection stroke, the head shaft also travels the minimum clearance distance in the disconnection direction. The tail shaft is configured to remain stationary when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke.

[0008] According to another aspect of the present disclosure concept, a pole assembly for a circuit breaker includes: a stationary conductor having separable stationary contacts; a moving conductor assembly having separable moving contacts; a Thomson coil actuator; and a split switch shaft. The Thomson coil actuator is configured to move the moving conductor assembly from a closed state in a disconnection direction during a disconnection stroke to separate the separable moving contacts from the separable stationary contacts. The split switch shaft includes: a head shaft configured such that a proximal end of the head shaft is coupled to the moving conductor assembly; a sliding pin; a tail shaft; and a return spring. The head shaft includes a first pin receiving opening extending laterally through a distal end of the head shaft. The tail shaft includes: a proximal end coupled to the distal end of the head shaft; and a second pin receiving opening extending laterally through the proximal end of the tail shaft. The proximal end of the tail shaft includes a plurality of spring mounting flanges and a shaft coupling opening disposed between the spring mounting flanges. The return spring is mounted on the spring mounting flanges. The distal end of the head shaft is inserted into the proximal end of the tail shaft such that the first pin receiving opening and the second pin receiving opening are aligned. The sliding pin is inserted into the first pin receiving opening and the second pin receiving opening, and the return spring maintains a minimum clearance distance between a most distal surface of the head shaft and a distal surface of the shaft coupling opening. The second pin receiving opening is longer than the first pin receiving opening, and the head shaft is configured such that when the moving conductor assembly travels the minimum clearance distance during the disconnection stroke, the head shaft also travels the minimum clearance distance in the disconnection direction. The tail shaft is configured to remain stationary when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke.

[0009] According to another aspect of the present disclosure concept, a multi-part moving assembly is configured for use in a pole assembly of a circuit breaker. The pole assembly includes: a stationary conductor having separable stationary contacts; and a moving conductor assembly having separable moving contacts, wherein the moving conductor assembly is configured to move from a closed state in a disconnection direction during a disconnection stroke to separate the separable moving contacts from the separable stationary contacts. The multi-part moving assembly includes: a piston configured such that a proximal end of the piston is coupled to the moving conductor assembly; a hydraulic housing containing hydraulic fluid; a return spring coupled to a proximal surface of a distal end of the hydraulic housing; and a switch shaft having a proximal end coupled to the distal end of the hydraulic housing. The piston includes a connecting rod and a crown extending distally from a distal end of the connecting rod. The hydraulic fluid is supported on the proximal surface of the distal end of the hydraulic housing, and the return spring is configured such that in an uncompressed state, a proximal end of the return spring extends proximally beyond the hydraulic fluid. A distal end of the crown of the piston engages the proximal end of the return spring, and the return spring maintains a minimum clearance distance between a most distal surface of the crown of the piston and the proximal surface of the hydraulic fluid. The piston is configured to travel the minimum clearance distance in the disconnection direction when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke, and the hydraulic housing is configured to remain stationary when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke. Description of the Drawings

[0010] A full understanding of the present invention can be obtained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings, in which:

[0011] Figure 1 is a schematic view of a hybrid circuit breaker according to an exemplary embodiment of the present disclosure;

[0012] Figure 2 is a cross-sectional view of a pole assembly according to an exemplary embodiment of the present disclosure that can be used with a circuit breaker (such as Figure 1 the circuit breaker schematically depicted therein) and includes a portion of an improved multi-part split switch shaft for use with a moving conductor assembly, showing the separable contacts of the pole assembly in the closed state;

[0013] Figure 3 is of the pole assembly according to an exemplary embodiment of the present disclosure Figure 2 the same cross-sectional view of the pole assembly shown in, showing the pole assembly after the separable contacts have separated to an initial gap distance during the initial stage of the opening stroke;

[0014] Figure 4 is of the pole assembly according to an exemplary embodiment of the present disclosure Figure 3 the same cross-sectional view of the pole assembly shown in, showing the pole assembly after the separable contacts have further separated during the second stage of the opening stroke and the entire movable assembly coupled to the separable moving contact has been latched in the open position;

[0015] Figure 5 shows the same cross-sectional view of the pole assembly shown in according to an exemplary embodiment of the present disclosure Figure 4 wherein the pole assembly is shown in the initial stage of reclosing the separable contacts;

[0016] Figure 6 shows the same cross-sectional view of the pole assembly shown in according to an exemplary embodiment of the present disclosure Figures 2 to 5 a partial exploded isometric view of the multi-part split switch shaft shown in;

[0017] Figure 7A is a front view of a prior art one-piece switch shaft;

[0018] Figure 7B is Figures 2 to 6 a front view of the multi-part split switch shaft shown in, which is shown aligned with the prior art switch shaft shown in Figure 7A in order to compare the dimensions of the shaft shown in Figures 2 to 6 with the shaft shown in Figure 7Acompare the dimensions of the prior art switch shaft shown in; and

[0019] Figure 8 is a simplified representation of a multi-part movable component according to another exemplary embodiment of the present disclosure, which can be used to replace the multi-part split switch shaft in a pole component (such as Figures 2 to 5 the pole component shown in). Detailed Description

[0020] The directional phrases used herein (e.g., left, right, front, back, top, bottom and their derivatives) are related to the orientation of the elements shown in the drawings and do not limit the claims unless expressly recited in the claims.

[0021] As used herein, the statement that two or more parts or components are "coupled" means that these parts are joined together or operate together directly or indirectly (i.e., through one or more intermediate parts or components), as long as there is a connection. As used herein, "directly coupled" means that two elements are in direct contact with each other. As used herein, "fixedly coupled" or "fixed" means that two components are coupled to move as a unit while maintaining a constant orientation relative to each other.

[0022] As used herein, when ordinal terms such as "first" and "second" are used to modify a noun, such use is only intended to distinguish one item from another and does not necessarily require a sequential order unless otherwise stated.

[0023] As used herein, the term "quantity" refers to an integer of one or greater than one (i.e., a plurality).

[0024] As used herein, the term "processing unit" or "processor" refers to a programmable analog and / or digital device that can store, retrieve, and process data; a microprocessor; a microcontroller; a microcomputer; a central processing unit; or any suitable processing device or apparatus.

[0025] Figure 1 is a schematic diagram of a hybrid circuit breaker 1 (such as, but not limited to, a circuit breaker) according to an exemplary embodiment of the present disclosure. The circuit breaker 1 includes line conductors 2 configured to electrically connect a power source 3 to a load 4. The circuit breaker 1 is configured to trip open in the event of a fault condition (such as, but not limited to, an overcurrent condition) to interrupt the flow of current between the power source 3 and the load 4, thereby protecting the load 4, the circuitry associated with the load 4, and the power source 3.

[0026] The circuit breaker 1 further includes a hybrid switch assembly 6, an operating mechanism 8, and an electronic trip unit 10. Figure 1The hybrid switch assembly 6 therein is a simplified depiction of a hybrid switch, which is intended to demonstrate how current is commutated through the mechanically separable contacts 12 in the hybrid switch and is not intended to limit the different types of hybrid switch assemblies that can be included in the hybrid circuit breaker 1. The hybrid switch assembly 6 includes an electronic interruptor 14 and a set of mechanically separable contacts 12. The electronic trip unit 10 is configured to monitor the power flowing through the circuit breaker 1 via a current sensor 16 and / or other sensors and to detect a fault condition based on the power flowing through the circuit breaker 1.

[0027] Under normal operating conditions, the mechanical contacts 12 are in a closed state such that they are in contact with each other, enabling current to flow from the power source 3 through the line conductors 2 and the mechanical contacts 12 to the load 4. Additionally, the electronic interruptor 14 is de-energized under normal operating conditions such that current cannot flow through the electronic interruptor 14. In response to detecting a fault condition, the electronic trip unit 10 is configured to output a first signal to energize the electronic interruptor 14 and is configured to output a second signal to the operating mechanism 8 to initiate actuation of the operating mechanism 8 to open the mechanical contacts 12. Energizing the electronic interruptor 14 with the first signal enables the electronic interruptor 14 to commutate the fault current from the mechanical contacts 12 to the electronic interruptor 14. The transmission of the second signal from the trip unit 10 to the operating mechanism 8 is timed to ensure that the operating mechanism 8 does not open the mechanical contacts 12 until the current has been commutated to the electronic interruptor 14, in order to minimize the effects of let-through current and arcing.

[0028] Now referring Figures 2 to 5 , a cross-sectional view is shown of a portion of a pole assembly 20 according to an exemplary embodiment of the present disclosure concept, including an improved multi-part split switch shaft 100 for use with a moving conductor assembly. The pole assembly 20 can be used, for example but not limited to, in a circuit breaker, such as Figure 1 the hybrid circuit breaker 1 shown. The pole assembly 20 includes mechanically separable contacts and a Thomson coil assembly, which respectively correspond to Figure 1 the mechanically separable contacts 12 and a portion of the operating mechanism 8 depicted in Figure 6 . Additionally, Figures 2 to 5 an exploded view of the components of the split switch shaft 100 is shown to better highlight the details of the components and viewing in conjunction with Figure 6 any one of the figures in Figures 2 to 5 can assist in better understanding the details of Figure 6 . It should be noted that the line S-S drawn in Figures 2 to 5 represents the viewing plane of the pole assembly 20 in

[0029] As will be described in further detail below, Figure 2 , Figure 3 , Figure 4 and Figure 5Each of the figures shows the pole assembly 20 at a different stage of the opening stroke. Figure 2 The pole assembly 20 is shown at the beginning of the opening stroke, when the separable contacts 12 are in the closed state. Figure 3 The pole assembly 20 is shown after the moving conductor assembly has travelled an initial distance of "X" millimeters (mm) such that there is an initial gap between the separable contacts a distance of "X" mm. Figure 4 The pole assembly 20 is shown after the moving conductor assembly has traveled its maximum distance and opened the separable moving contacts to a maximum separation gap of a distance of "X+G" mm, wherein the split switch shaft 100 is latched by the latch assembly to maintain the separable moving contacts in their fully open position. Figure 5 The pole assembly 20 is shown after the split switch shaft 100 has begun to reset in preparation for reclosing the separable contacts.

[0030] First reference Figure 2 , the mechanical contacts of the pole assembly 20 are shown in a closed state. The pole assembly 20 includes a stationary conductor 21 and a moving conductor 23, the stationary conductor includes a separable stationary contact 22, and the moving conductor includes a separable moving contact 24. The separable stationary contact 22 and the separable moving contact 24 correspond to Figure 1 . The moving conductor 23 is part of a larger moving conductor assembly 25, which also includes a drive shaft 26 coupled to the moving conductor 23 via an isolating coupling 28. The pole assembly 20 also includes a Thomson coil device, which includes: a Thomson coil 30, which is fixed in place around the drive shaft 26; and a conductive plate 32, which is coupled to the drive shaft 26. The separation of the separable contacts 22, 24 during the disconnection stroke is achieved when the Thomson coil device drives the moving conductor assembly 25 to move in the direction indicated by the arrow 41. The coil 30 is configured to be connected to a power source (not shown in the drawings), and when a time-varying current is supplied to the coil 30, an opposite magnetic field is generated and induced in the coil 30 and the conductive plate 32, so that the conductive plate 32 is repelled by the coil 30 and drives the moving conductor assembly 25 to move in the direction indicated by the arrow 41.

[0031] The moving conductor assembly 25 is further coupled to the split switch shaft 100 of the present disclosure. Figure 2 An enlarged illustration marked “I” is shown in FIG. 1 to better illustrate the details of the split switch shaft 100 . Figure 2 A second enlarged illustration labeled "II" is also shown in order to better show the details of the latch assembly 150 included in the pole assembly 20; however, the latch assembly 150 will be described later in conjunction with the following Figure 4 and Figure 2 Further detailed discussion. Known switch shafts generally include a single integral body, as will be further detailed later below in conjunction with FIG. 7. In contrast,Figure 2 The improved switch shaft 100 shown in and enlarged in Illustration I includes a head shaft 102 and a tail shaft 104 joined together by a coupling pin 106. Specifically, the distal end 103 of the head shaft 102 is coupled to the proximal end 105 of the tail shaft 104.

[0032] Before first and before discussing the split switch shaft 100 of the present disclosure in further detail, it should be noted that with respect to any given component of the pole assembly 20, the term "proximal end" as used hereinafter refers to the end of the component that is closest to the separable contacts 22, 24 arranged, and the term "distal end" as used hereinafter refers to the end of the component that is arranged furthest from the separable contacts 22, 24. That is, the distal end of a given component is arranged opposite to the proximal end of the given component. In addition, the term "towards the proximal end" can be used to indicate the direction of movement towards the separable contacts 22, 24, and the term "towards the distal end" can be used to indicate the direction of movement away from the separable contacts 22, 24. In addition, both the "proximal end" direction and the "distal end" direction are "axial" directions, where the "axial" direction is indicated by Figure 2 the arrow 42 in. The travel of the moving conductor assembly 25 in the distal end direction can also be referred to as travel in the "open direction" because this travel will cause the separable contacts 22, 24 to open. Conversely, when the separable contacts 22, 24 are open and need to be re-closed, the travel of the moving conductor assembly 25 in the proximal end direction can also be referred to as travel in the "closed direction" 43 (numbered in Figure 5 ). Finally, the "lateral" direction refers to the direction arranged orthogonally to the axial direction, indicated by Figure 2 the arrow 44 in.

[0033] Continuing to refer to Figure 2 and the split switch shaft 100, the head shaft 102 and the tail shaft 104 are constructed as follows: the proximal end 107 of the head shaft 102 is configured to be coupled to the distal end of the drive shaft 26, and the proximal end 105 of the tail shaft 104 is configured to be coupled to the distal end 103 of the head shaft 102. The proximal end 105 of the tail shaft is formed with a shaft coupling opening 108 configured to receive the distal end 103 of the head shaft. The shaft coupling opening 108 is a cutout in the proximal end 104 of the tail shaft that extends in the distal end direction from the nearest side surface of the tail shaft 104. In addition, the distal end 103 of the head shaft is formed with a pin receiving opening 110, and the proximal end of the tail shaft 104 is formed with a pin receiving opening 112 that is laterally longer and axially wider than the pin receiving opening 110, where the pin receiving openings 110 and 112 extend in the lateral direction through the distal end 103 of the corresponding head shaft 102 and the proximal end 105 of the tail shaft 104, respectively. The distal end 103 of the head shaft and the proximal end 105 of the tail shaft are each configured such that when the distal end 103 of the head shaft is inserted into the shaft coupling opening 108 of the proximal end 104 of the tail shaft, the pin receiving opening 110 of the head shaft 102 is aligned with the pin receiving opening 112 of the tail shaft 104.

[0034] The split switch shaft 100 is configured such that when the separable contacts 22, 24 are in the closed state, there is a gap 500 (numbered in enlarged inset I in Figure 2 ) between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108. It should be understood that as the moving conductor assembly 25 moves in the direction indicated by arrow 41 during the opening stroke, the gap 500 decreases. When the separable contacts are in the closed state (as shown in Figure 2 ), the gap 500 is at its maximum length, and this maximum distance has a length X, which will be further discussed below in connection with Figure 3 .

[0035] Briefly referring to Figure 6 , it should be noted that the proximal end 105 of the tail shaft is formed with a plurality of spring mounting flanges 117 so that one end of the weak return spring 118 can be mounted on the proximal end 105 of the tail shaft. As a result of arranging the weak return spring 118 in this way, when no force acts on the head shaft 102 in the opening direction 41 to overcome the force of the weak return spring 118, a gap 500 of maximum length X is maintained between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108 (as shown in Figure 2 ). This is because both the distal end 103 of the head shaft and the spring support portion 119 of the head shaft 102 (positioned proximal to the distal end 103 of the head shaft) are configured to fit within the center of the return spring 118, while the spring stop structure 120 arranged proximal to the spring support portion 119 of the head shaft 102 is configured to prevent the return spring 118 from further advancing proximally towards the head shaft 102. As can be seen from Figure 6 , the spring stop structure 120 is wider than the spring support portion 119 and the weak return spring 118 in at least one dimension, thereby preventing the weak return spring from extending proximally beyond the spring stop structure 120.

[0036] Now referring to Figure 3 , which shows the pole assembly 20 after the moving conductor assembly 25 has traveled an initial gap distance "X" in the opening direction 41 during the initial stage of the opening stroke, where the initial gap distance "X" is equal to the length of the gap 500 shown in Figure 2 (the gap 500 in Figure 2 is between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108). This initial stroke of the moving conductor assembly 25 is represented by the letter "X" in Figure 3 , and this letter "X" is used to represent the gap between the separable contacts 22, 24. It should be noted that since the moving conductor assembly 25 has traveled this initial gap distance "X", the gap 500 that appears between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108 in Figure 2 is inFigure 3 is no longer present in, i.e., since the moving conductor assembly 25 has traveled the initial gap distance "X" in the disconnect direction and has caused the head shaft 102 to also travel the initial gap distance "X" in the disconnect direction, thus closing the gap 500, therefore, in Figure 3 the length of the gap 500 between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108 is zero distance.

[0037] Still referring to Figure 3 , now note that the pole assembly also includes a shaft support structure 130, such as a solenoid core, which is a part of the solenoid assembly 131 for slowing down the disconnect operation in a non-fault condition, for example but not limited to this. The shaft support structure 130 (e.g., solenoid core) remains fixed in place during the rapid disconnect operation in a fault condition, and this shaft support structure includes an axially extending central opening 132 such that the tail shaft 104 is received by the support structure central opening 132 and can move axially within the central opening 132 during the disconnect stroke and the closing stroke. The lateral width 132 of the central opening is just wide enough to allow the tail shaft 104 to move freely in the disconnect direction and the closing direction, but narrow enough to prevent the tail shaft from moving laterally. Additionally, as Figure 3 marked in the enlarged view I in

[0038] As Figure 3 shown in the enlarged view I of Figure 3 , after the moving conductor assembly 25 has disconnected the separable contacts to the initial gap of distance "X", there still remains a distance 510, which is the distance that the coupling pin 106 can move in the distal direction within the pin receiving opening 134 of the shaft support structure 130. It should be noted that Figure 4 the length of the gap 510 in Figure 3 is the distance G, which will be further discussed below in connection with Figure 3

[0039] Figure 4 Now referring to Figure 4, showing the pole assembly 20 after the moving conductor assembly 25 has traveled a further linear distance "G" in the disconnection direction 41 during the second stage of the disconnection stroke, where the distance "G" is equal to Figure 3 the linear length of the gap 510 shown in enlarged view I in Figure 3 (the gap 510 in Figure 4 is the gap between the distal edge of the coupling pin 106 and the distal end of the pin receiving opening 134 of the shaft support structure 130). This second distance traveled by the moving conductor assembly 25 is represented in Figure 3 by the sum "X + G", which is used to represent the gap between the separable contacts 22, 24. It should be noted that since the moving conductor assembly 25 has traveled a distance G after traveling a distance X, the gap 510 that appears between the coupling pin 106 and the distal end of the pin receiving opening 134 of the shaft support structure 130 in Figure 4 no longer exists in Figure 4 , that is, since the moving conductor assembly 25 has traveled a distance X in the disconnection direction and then traveled a distance G in the disconnection direction, in

[0040] still referring to Figure 4 , Figure 4 provides again in Figure 2 the enlarged illustration II first shown in Figure 2 to show details of the latch assembly 150 of the pole assembly 20 and the state change of the latch assembly 150 due to the moving conductor assembly 25 traveling a distance "X + G" from the Figure 2 and Figure 4 shown closed position. Generally, it should be noted that the latch assembly 150 is configured such that when the distal end of the tail shaft 104 travels far enough in the disconnection direction, the latch assembly latches the tail shaft 104 in place, thereby holding the separable contacts 22, 24 in the disconnected state. The latch assembly 150 includes a plurality of components that are configured to actuate sequentially with each other to fully latch the tail shaft 104 in the disconnected state, but only a few components are discussed herein. The latch assembly 150 is disposed at the distal end of the shaft support structure 130 and will be discussed with reference to both Figure 4 and Figure 2 . To prevent the drawing reference numerals in the drawings from being overly cluttered, there are more drawing reference numerals provided in the enlarged illustration II of Figure 3 than in the enlarged illustration II of

[0041] It should be noted that the distal end 141 of the tail shaft 104 is wider than the adjacent portion 142 of the tail shaft 104 disposed adjacent to the distal end 141 of the tail shaft. It should be noted that the tail shaft portion 142 extends distally from the distal side of the central opening 132 of the shaft support structure 130. The tail shaft 104 includes an inclined surface 143 that joins the tail shaft portion 142 to the distal end 141 of the tail shaft. The intersection of the inclined surface 143 and the distal end 141 of the tail shaft forms a stepped portion 144. The tail shaft stepped portion 144 is designed to engage the latch 151 of the latch assembly 150.

[0042] The latch assembly 150 includes a bracket 152 that is fixed in place within the pole assembly 20. The latch 151 is rotatably coupled to the bracket 152 via a pivot pin 153 such that the pivot pin 153 is fixedly held in place and the latch 151 is capable of rotating about the pivot pin 153. The latch 151 includes a side facing the inclined surface 143 of the tail shaft 144, and a closed state notch 154 and an open state notch 156 are formed in this side, wherein the open state notch 156 is axially arranged relative to the closed state notch 154. Figure 2 As can be seen, when the separable contacts 22, 24 are in the closed state, the closed state notch 154 of the latch 151 engages the tail shaft stepped portion 144. Figure 3 As can be seen, after the head moving conductor assembly 25 travels a distance X in the open direction and causes the head shaft 102 to also travel a distance X in the open direction to close the gap 500, the closed state notch 154 of the latch 151 still engages the tail shaft stepped portion 144 (the latch 151, the closed state notch 154 of the latch, and the tail shaft stepped portion 144 are not numbered in Figure 3 . Thus, although in Figure 3 , the moving conductor assembly 25 and the head shaft 102 have traveled a distance X to separate the separable contacts 22, 24 by an initial gap of length X, the tail shaft 104 is still disposed in its closed position, i.e., the position where the tail shaft 204 is disposed when the separable contacts 22, 24 are in the closed state as shown in Figure 2 .

[0043] As expected, the arrangement of the latch 151 changes only when the moving conductor assembly 25 travels a distance X + G (mentioned in Figure 4 ), which is expected because the tail shaft 104 is not driven to travel in the open direction 41 until the gap 500 in Figure 2 is closed by the head shaft 102. It should be understood that when the coupling pin 106 travels a distance G to intersect the distal end of the pin receiving opening 134 of the shaft support structure 130 (as shown in Figure 4 ), this causes the tail shaft 104 to also travel a distance G in the open direction 41.

[0044] Still referring to Figure 4The travel of the tail shaft 104 in the disconnection direction 41 as shown should be noted. The latch 151 and the tail shaft step 144 are configured such that the travel of the tail shaft 104 in the disconnection direction 41 from its initial closed position causes the closed state notch 154 of the latch 151 to disengage from the tail shaft step 144. After the closed state notch 154 of the latch disengages from the tail shaft step 144, when the tail shaft step 144 still travels in the disconnection direction 41, the latch 151 rotates (i.e., clockwise with respect to the view shown in the drawing), such that the open state notch 156 then engages the tail shaft step 144, as Figure 4 shown. At the same time, the outermost distal point of the distal end 141 of the tail shaft causes the reset lever 161 of the latch assembly 150 to rotate by pushing the reset shaft 163 of the reset lever 163. The reset lever 161 is rotatably coupled to another bracket 165 fixed in place. The engagement of the tail shaft step 144 with the open state notch 156 of the latch holds the tail shaft 104 in its open position until a reset operation is performed to drive the split switch shaft 100 and the moving conductor assembly 25 to move in the closing direction to re-close the separable contacts 22, 24.

[0045] Now referring to Figure 5 , when it is necessary to re-close the separable contacts 22, 24, the current supply to the Thomson coil 30 is cut off to deactivate the Thomson coil device. The latch assembly 150 is configured to hold the tail shaft 104 in its open position until the components of the latch assembly 150 are reset. Therefore, when the Thomson coil device is deactivated and no longer applies a force to the head shaft 102 in the disconnection direction 41, only the head shaft 102 moves in the closing direction 43 because the weak return spring 118 is configured to maintain a gap 500 of length X between the outermost distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108, as detailed earlier in this document in connection with Figure 6 . The deactivation of the Thomson coil 30 enables the weak return spring 118 to extend from its compressed state and push the head shaft 102 and the moving conductor assembly 25 to move a distance X in the closing direction, thereby reforming a gap 500 of length X between the outermost distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108, as shown in the enlarged inset I of Figure 2 .

[0046] Now referring to Figure 7A and Figure 7B , the split switch shaft 100 of the present disclosure will now be compared with the prior art single-piece switch shaft 50 to highlight the advantageous features of the split switch shaft 100. As Figure 7A shown, the prior art single-piece switch shaft 50 includes a single integral body. The length of the single-piece switch shaft 50 is "A", while the length of the split switch shaft 100 is "A + X", where "X" is due to the weak return spring 118 (as Figure 2As shown, a gap 500 is formed between the most distal surface 114 of the head shaft 102 and the distal surface 116 of the shaft coupling opening 108 when the return spring 118 is not compressed. The mass of the single-piece switch shaft 50 is "M". The mass of the split switch shaft 100 is also "M", where the mass of the head shaft 102 is 0.5M and the mass of the tail shaft 104 is 0.5M.

[0047] If the pole assembly uses the single-piece switch shaft 50 instead of the split switch shaft 100, and the same moving conductor assembly 25, Thomson coil device, and latch assembly 150 as shown in Figures 2 to 5 are used to separate the separable contacts 22, 24 to an acceptable gap in a fault condition, then the entire mass M of the single-piece switch shaft 50 needs to travel in the separating direction. In contrast, since the distance X is considered to be a sufficient distance between the separable contacts 22, 24, the split switch shaft assembly 100 only needs to move the head shaft 102 with a mass of 0.5M in a fault condition to separate the separable contacts to an acceptable gap. This means that the split switch shaft assembly 100 only needs to move half (0.5M) of the mass that the single-piece switch shaft 50 must move to form a sufficient gap between the separable contacts 22, 24, so that the split switch shaft 100 can separate the separable contacts 22, 24 at a higher speed and significantly shorter time than the single-piece switch shaft 50.

[0048] The split shaft design of the split switch shaft 100 enables the head shaft 102 to travel a distance of "X" mm at high speed and only engages with the tail shaft 104 after an acceptable gap is reached between the separable contacts 22, 24. The engagement of the tail shaft 104 with the head shaft 102 will increase the moving mass from 0.5M to 1.0M after a travel of "X" mm, which is used to reduce the momentum of all moving parts in the pole assembly 20, including both the split switch shaft 100 and the moving conductor assembly 25. It should be noted that the mass of the tail shaft 104 can be adjusted according to the damping requirements of a specific application. For example, if higher damping is required, the tail shaft 104 can be made heavier.

[0049] To separate the separable contacts 22, 24 to an acceptable distance and engage the latch assembly 150 to latch the moving conductor assembly 25 in the open state, the single-piece switch shaft 50 must travel a distance Z during the opening operation. For the split switch shaft 100, since the head shaft 102 traveling a distance X in the separating direction 41 ensures the full separation of the separable contacts 22, 24, after the head shaft 102 engages with the tail shaft 104, the tail shaft 104 only needs to travel a distance of "Z - X" in the separating direction 41 to engage the latch assembly 150, thereby latching the moving conductor assembly 25 in the open state.

[0050] Now refer to Figure 8, shows a multi - part movable assembly 200 for disconnecting separable contacts of a circuit breaker, according to other exemplary embodiments of the present disclosure concept. The multi - part movable assembly 200 is for use in a pole assembly including a plurality of components identical to those of the pole assembly shown in Figures 2 to 5 and uses the same reference numerals for components common to the pole assembly 20 in Figure 8 . Figure 8 The components of the pole assembly 20 shown include a drive shaft 26, a Thomson coil 30, a conductive plate 32, and a latch assembly 150. It should be noted that Figure 8 the drive shaft 26 shown can be coupled to the moving conductor 23 as part of a moving conductor assembly 25 as shown in Figures 2 to 5 , and the moving conductor assembly 25 can be arranged relative to the stationary conductor 21 as shown in Figures 2 to 5 . It should be noted that Figure 8 depicts the multi - part movable assembly 200 in a closed position, i.e., the position when the separable contacts 22, 24 are in a closed state.

[0051] In Figure 8 , the multi - part movable assembly 200 includes a piston 202, a hydraulic housing 204, and a switch shaft 206. The hydraulic housing 204 houses a hydraulic fluid 208 and a return spring 210 configured to be compressed and extended in the axial direction 42. The hydraulic fluid 208 is supported on the proximal surface of the distal end of the hydraulic housing 204, and the return spring 210 is positioned such that the distal end of the spring 210 engages the proximal surface of the distal end of the hydraulic housing 204 and the proximal end of the spring 210 engages the distal surface of the piston crown 214, so that at least a portion of the return spring 210 is always immersed in the hydraulic fluid 208.

[0052] The proximal end of the connecting rod 212 of the piston 202 is coupled to the distal end of the conductive plate 32. The amount of the hydraulic fluid 208 and the length of the return spring 210 are selected such that when the return spring 210 is in its uncompressed state, the length by which the return spring 210 extends beyond the proximal end of the hydraulic fluid 208 is equal to or greater than the distance that the separable moving contact 24 needs to travel during a successful disconnection operation in a fault condition. This length is hereinafter referred to as the clearance distance of the return spring 210. In an exemplary embodiment, the clearance distance of the return spring 210 is selected to be between 1.0 mm and 1.5 mm. This clearance distance is represented as the distance "X" in Figure 8 .

[0053] The proximal end of the switch shaft 206 is coupled to the distal end of the hydraulic housing 204, and the distal end of the switch shaft 206 engages the latch assembly 150. The switch shaft 206 can be a single - part switch shaft, such as Figure 7AThe single-piece switch shaft 50 as shown. When the Thomson coil 30 is activated to start the opening stroke, the moving conductor 23, the drive shaft 26, the conductive plate 32, and the piston 202 all travel in the opening direction 41 to compress the return spring 210. The hydraulic housing 204 is configured to move axially, and after the return spring 210 is fully compressed, the opening force of the moving conductor 23, the drive shaft 26, the conductive plate 32, and the piston 202 drives the hydraulic housing 202 and the switch shaft 206 to move in the opening direction 41, thereby actuating the latch assembly 150 to latch all the moving parts of the multi-piece movable assembly 200 in the open state.

[0054] It should be noted that when the Thomson coil 30 is activated, the moving conductor 23, the drive shaft 26, the conductive plate 32, and the piston 202 all initially travel at a high speed until the return spring 210 is compressed by a clearance distance of "X" mm. After the return spring 210 is compressed by the clearance distance of "X" mm, once the piston 202 is further pushed towards the distal end into the hydraulic fluid 208, the speed of the moving parts is damped. After the return spring 210 is fully compressed,

[0055] The multi-piece movable assembly 200 is similar to the split switch shaft 100 in that the design of the multi-piece movable assembly 200 enables the first part of the pole assembly (which includes the moving conductor 23, the drive shaft 26, the conductive plate 32, and the piston 202) to first travel at a high speed for a distance of "X" mm in order to form an initial clearance "X" between the separable contacts 22, 24 before engaging with the second part of the pole assembly (the hydraulic fluid 208, the hydraulic housing 204, and the switch shaft 206), thereby damping the high-speed movement of the first part before the latch assembly 150 latches all the moving parts in the open state. Similar to the split switch shaft 100, the multi-piece movable assembly 200 only requires the first part of the pole assembly to travel at a high speed, and after the first part engages with the second part, the second part of the pole assembly damps the movement of the first part, thereby reducing the mass of the components in the pole assembly that need to travel at a high speed to achieve the initial separation between the separable contacts 22, 24. It should be understood that constructing the pole assembly in this way enables the separable contacts 22, 24 to be separated to the initial clearance of "X" mm with a much smaller force compared to the force required when both the first part and the second part need to travel a distance of "X".

[0056] It should be noted that other embodiments can be obtained by implementing variations of the multi-part movable component 200. In one non-limiting example, the hydraulic system is replaced by a damping component which, if desired, can also dissipate energy. The system exhibits performance similar to that of the movable component 200 but with more energy dissipation, which is useful in situations where increased structural strength is required. In another non-limiting example, the hydraulic system is replaced by a solid momentum receiving component, where the distal side of the conductive plate 32 is coupled to a solid component capable of withstanding a high impact, and there is a gap between the component coupled to the conductive plate 32 and the momentum receiving component such that during the disengagement stroke, an impact occurs between the solid component coupled to the conductive plate 32 and the momentum receiving component. Some of the momentum is transferred from the solid component coupled to the conductive plate 32 to the momentum receiving component, and then the two sets of components move in the same direction and are subsequently latched.

[0057] While the specific embodiments of the present invention have been described in detail, those skilled in the art should understand that various modifications and alternatives to these details can be developed in accordance with the general teachings of this disclosure. Therefore, the specific arrangements of this disclosure are illustrative only and do not limit the scope of the inventive concept of this disclosure, which is determined by the full breadth of the appended claims and any and all equivalents thereof.

Claims

1. A split switch shaft for use in a pole assembly of a circuit breaker, the pole assembly comprising: An axial support structure having a central opening extending axially; A static conductor having separable static contacts; And a moving conductor assembly having separable moving contacts, the moving conductor assembly configured to travel in a disconnection direction from a closed state during a disconnection stroke to separate the separable moving contacts from the separable static contacts, the split switch shaft comprising: A head shaft configured such that a proximal end of the head shaft is coupled to the moving conductor assembly, the head shaft including: A first pin receiving opening extending laterally through a distal end of the head shaft; A sliding pin; A tail shaft, the tail shaft including: A proximal end coupled to the distal end of the head shaft, the proximal end of the tail shaft including: A plurality of spring mounting flanges; and A shaft coupling opening extending laterally between the spring mounting flanges; and A second pin receiving opening extending laterally through the proximal end of the tail shaft; and A return spring mounted on the spring mounting flanges, Wherein a distal end of the head shaft is inserted into the proximal end of the tail shaft such that the first pin receiving opening and the second pin receiving opening are aligned, Wherein the sliding pin is inserted into the first pin receiving opening and the second pin receiving opening, Wherein, in the absence of any compressive force acting on the return spring, the return spring maintains an initial gap distance between a most distal surface of the head shaft and a distal surface of the shaft coupling opening, Wherein the second pin receiving opening is longer laterally than the first pin receiving opening, Wherein the head shaft is configured such that when the moving conductor assembly travels the initial gap distance in the disconnection direction during the disconnection stroke, the head shaft also travels the initial gap distance in the disconnection direction, and Wherein the tail shaft is configured such that when the moving conductor assembly travels the initial gap distance in the disconnection direction from the closed state during the disconnection stroke, the tail shaft remains stationary.

2. The split switch shaft according to claim 1, Among them, The second pin receiving opening is wider axially than the first pin receiving opening and is configured such that when the moving conductor assembly is in the closed state, the sliding pin engages a proximal end of the second pin receiving opening.

3. The split switch shaft according to claim 2, Among them, The tail shaft is configured such that after the moving conductor assembly travels the initial gap distance during the disconnection stroke, the sliding pin is disposed at the initial gap distance from the proximal end of the second pin receiving opening.

4. The split switch shaft according to claim 3, Among them, A distal surface of the tail shaft and the head shaft are configured such that after the moving conductor assembly travels the initial gap distance during the disconnection stroke, the most distal surface of the head shaft engages the distal surface of the shaft coupling opening.

5. The split switch shaft according to claim 4, Among them, The second pin receiving opening is configured to prevent the tail shaft from traveling in the disconnection direction before the moving conductor assembly travels the initial gap distance in the disconnection direction from the closed state, and Wherein, the tail shaft is configured to be inserted into the central opening of the shaft support structure such that after the moving conductor assembly travels the initial clearance distance during the opening stroke, the switch shaft can travel in the opening direction to engage the latch assembly, thereby latching the moving conductor assembly in the open state.

6. A pole assembly for a circuit interrupter, the pole assembly comprising: A stationary conductor having separable stationary contacts; A moving conductor assembly having separable moving contacts; A Thomson coil actuator configured to cause the moving conductor assembly to travel in an opening direction from a closed state during an opening stroke to separate the separable moving contacts from the separable stationary contacts; A shaft support structure having an axially extending central opening; And A split switch shaft, the split switch shaft comprising: A head shaft configured such that a proximal end of the head shaft is coupled to the moving conductor assembly, the head shaft comprising: A first pin receiving opening extending laterally through a distal end of the head shaft; A sliding pin; A tail shaft, the tail shaft comprising: A proximal end coupled to the distal end of the head shaft, the proximal end of the tail shaft comprising: A plurality of spring mounting flanges; and A shaft coupling opening extending laterally between the spring mounting flanges; and A second pin receiving opening extending laterally through the proximal end of the tail shaft; and A return spring mounted on the spring mounting flanges, Wherein, the distal end of the head shaft is inserted into the proximal end of the tail shaft such that the first pin receiving opening and the second pin receiving opening are aligned, Wherein, the sliding pin is inserted into the first pin receiving opening and the second pin receiving opening, Wherein, in the absence of any compressive force acting on the return spring, the return spring maintains an initial clearance distance between a most distal surface of the head shaft and a distal surface of the shaft coupling opening, Wherein, the second pin receiving opening is longer laterally than the first pin receiving opening, Wherein, the head shaft is configured such that when the moving conductor assembly travels the initial clearance distance in the opening direction during the opening stroke, the head shaft also travels the initial clearance distance in the opening direction, and Wherein, the tail shaft is configured such that when the moving conductor assembly travels the initial clearance distance in the opening direction from the closed state during the opening stroke, the tail shaft remains stationary.

7. The pole assembly according to claim 6, Among them, The second pin receiving opening is wider axially than the first pin receiving opening and is configured such that when the moving conductor assembly is in the closed state, the sliding pin engages a proximal end of the second pin receiving opening.

8. The pole assembly according to claim 7, further comprising: A latch assembly configured to latch the moving conductor assembly in the open state when engaged by the tail shaft, Wherein, the shaft support structure includes a third pin receiving opening that is longer laterally than the second pin receiving opening, Wherein, the tail shaft is inserted into the central opening of the shaft support structure such that the first pin receiving opening, the second pin receiving opening, and the third pin receiving opening are aligned, Wherein, the third pin receiving opening is configured such that after the moving conductor assembly travels the initial clearance distance during the disconnection stroke, the sliding pin is disposed at the initial clearance distance from the proximal end of the second pin receiving opening and at a latching distance from the distal end of the third pin receiving opening.

9. The pole assembly according to claim 8, Among them, The head shaft and the tail shaft are configured such that after the moving conductor assembly travels the initial clearance distance during the disconnection stroke, the most distal surface of the head shaft engages the distal surface of the shaft coupling opening.

10. The pole assembly according to claim 9, Among them, The second pin receiving opening is configured to prevent the tail shaft from traveling in the disconnection direction before the moving conductor assembly travels the initial clearance distance in the disconnection direction from the closed state.

11. A multi-part moving component for use in a pole component of a circuit breaker, the pole component comprising: A static conductor having a separable static contact; And a moving conductor assembly having a separable moving contact, the moving conductor assembly being configured to travel in a disconnection direction from a closed state during a disconnection stroke to separate the separable moving contact from the separable static contact, the multi-part moving assembly comprising: A piston configured such that the proximal end of the piston is coupled to the moving conductor assembly, the piston comprising: A connecting rod; and A crown portion extending distally from the distal end of the connecting rod; A hydraulic housing containing hydraulic fluid; A return spring coupled to the proximal surface of the distal end of the hydraulic housing; and A switch shaft, the proximal end of the switch shaft being coupled to the distal end of the hydraulic housing, Wherein, the hydraulic fluid is supported on the proximal surface of the distal end of the hydraulic housing, Wherein, the return spring is configured such that in an uncompressed state, the proximal end of the return spring extends proximally beyond the hydraulic fluid, Wherein, the distal end of the crown portion of the piston engages the proximal end of the return spring; Wherein, the return spring maintains a minimum clearance distance between the most distal surface of the crown portion of the piston and the proximal surface of the hydraulic fluid, Wherein, the piston is configured such that when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke, the piston also travels the minimum clearance distance in the disconnection direction, and Wherein, the hydraulic housing is configured such that when the moving conductor assembly travels the minimum clearance distance from the closed state during the disconnection stroke, the hydraulic housing remains stationary.

12. The multi-part moving assembly according to claim 11, Among them, The volume of the hydraulic fluid is such that the distal surface of the crown portion of the piston does not contact the hydraulic fluid until after the piston travels the minimum clearance distance during the disconnection stroke.

13. The multi-part moving assembly according to claim 12, Among them, The piston is configured to continue to move in the disconnection direction after traveling the minimum clearance distance during the disconnection stroke, Wherein, the return spring is configured such that the piston moving in the disconnection direction beyond the minimum clearance distance causes the crown portion of the piston to compress the return spring and travel through the hydraulic fluid.

14. The multi-part moving assembly according to claim 13, Among them, The hydraulic housing is configured such that during the disconnection stroke, only after the crown of the piston has maximally compressed the return spring, does the hydraulic housing move in the disconnection direction.

15. The multi-part moving assembly according to claim 14, Among them, The multi-part moving assembly is configured such that during the disconnection stroke, after the crown of the piston has maximally compressed the return spring and the hydraulic housing moves in the disconnection direction, the distal end of the switch shaft engages a latch assembly to latch the moving conductor assembly in the disconnected state.

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