Push-pull transmission structure of direct-acting three-position switch

Abstract

This invention discloses a push-pull transmission structure for a direct-acting three-position switch. Each phase's moving contact is connected to a chain assembly driven by sprockets. The three-phase sprockets move synchronously along a common drive shaft mounted on a bearing seat. A bevel gear set drives the drive shaft, enabling the sprockets to rotate in both directions. This push-pull mechanism moves the moving contact between the closing contact, isolating contact, and grounding contact, achieving the three-position state of the switch. This invention utilizes a rigid chain push-pull structure to achieve the three-position switching of the switch. The sprockets driving the chain can complete the three-position switching of the contacts within a single turn. The mechanism can be designed simply, reducing costs and increasing efficiency. Furthermore, it facilitates the use of ceramic materials to quickly conduct heat from the moving contact to the switch housing, significantly improving the switch's heat dissipation efficiency.

Description

Technical Field

[0001] This invention relates to the field of power switchgear technology, specifically to a push-pull transmission structure for a direct-acting three-position switch. Background Technology

[0002] A three-position switch includes a disconnector and a grounding switch. The disconnector is the most widely used switching device in a power system, with a demand approximately three times that of a circuit breaker. When the disconnector is closed, it can carry both normal operating current and safe short-circuit fault current. When the disconnector is open, it has a clear isolation gap, isolating downstream power lines, transformers, reactors, and other electrical equipment or energized busbars. The grounding switch is a commonly used switching device in a power system. When the grounding switch is closed, it ensures reliable grounding of the feeder circuit, guaranteeing reliable line grounding and improving the safety of maintenance work. When the grounding switch is open, it has a grounding gap, meeting the electrical insulation requirements of a break-in switchgear. The common structure of direct-acting three-position switches on the market is that the disconnector and grounding switch share the same moving contact and opening contact. The moving contact is a round bar shape. The stationary contacts are divided into grounding contact, opening contact, and disconnecting contact, arranged coaxially in sequence, all of which are cylindrical structures. The switching state is switched by moving the moving contact among three stationary contacts through an operating mechanism.

[0003] Currently, most direct-acting three-position switches on the market use a screw drive structure for the reciprocating motion of the moving contact. For example, patent document CN114743823A discloses a three-position switch operating mechanism, including: a frame; a drive motor with a drive gear at the output end; a screw with a first gear meshing with the drive gear at one end; a nut slider threadedly connected to the screw, and a guide structure on the frame; a first sprocket rotatably mounted on the frame directly or via a first shaft; a second sprocket rotatably mounted on the frame directly or via a second shaft; a chain mounted on the first and second sprockets, and the chain is fixed to the nut slider to drive the first and second sprockets to rotate when the nut slider moves left and right; a first output structure on the first sprocket or the first shaft; and / or a second output structure on the second sprocket or the second shaft; and a protruding structure extending out of the frame for easy observation on the nut slider. The extended structure moves linearly left and right with the nut slider, corresponding to the linear movement of the moving contact of the three-position switch. This allows for direct visual judgment of the moving contact's position from outside the machine frame. Patent documents with publication numbers CN218004758U, CN216980428U, CN215988468U, CN213846057U, and CN203250679U also use a screw drive structure to drive the moving contact.

[0004] The three-position switch uses a lead screw drive structure for its moving contact, which is simple in structure. However, the lead screw usually needs to rotate dozens of times to achieve the long stroke of the moving contact, while the operation positioning and status indication of the mechanism usually need to be achieved within a single rotation. At this time, the transmission link of the mechanism needs to be equipped with a reducer structure, which is complex. In addition, the traditional lead screw structure is difficult to process using high thermal conductivity materials due to the excessive length of the lead screw. Therefore, existing heat dissipation structures increase the heat dissipation area of ​​the switch and rely on the thermal conductivity of 10. -2 The insulating gas, operating at W / (m·K) levels, conducts heat to the switch housing, resulting in poor heat dissipation efficiency. Therefore, heat dissipation has always been a challenge for high-current direct-acting three-position switches. Some industry players have made initial attempts to use chains and sprockets for power transmission. For example, patent document CN102543560A discloses a rigid power transmission device comprising a chain retainer, a sprocket, a chain, a three-position switch moving contact, and a housing. The chain retainer is U-shaped. The chain is mounted on the chain retainer. The sprocket cooperates with the chain; when the sprocket rotates, the chain moves along the chain retainer. The three-position switch moving contact is housed within the housing via a conductive spring. The lower end of the three-position switch moving contact is connected to one end of the sprocket. The upper end of the three-position switch moving contact is connected to a disconnector moving contact. The disconnector moving contact and the three-position switch moving contact... The chain connected to the lower end of the moving contact of the three-position switch is arranged on the same vertical line. The rigid power transmission device of the present invention drives the chain to move up and down in a straight line through the rotation of the sprocket, thereby controlling the up and down movement of the moving contact of the isolating switch, and thus controlling the opening / closing of the vacuum circuit breaker. However, since the chain in this solution is only a single chain, it becomes unstable after it goes out of the chain retainer. It can only drive one position in practice. If the chain cannot extend out, it cannot drive the next two positions. If it is necessary to drive to the last position, an overtravel spring must be added to the end of the chain to maintain the closed state of the circuit breaker. However, this solution does not include this feature. Therefore, this preliminary attempt has no practical value and cannot successfully solve the problem. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a push-pull transmission structure for a direct-acting three-position switch, thereby solving the problems of traditional lead screw transmission requiring a reducer, complex structure, and low heat dissipation efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A push-pull transmission structure for a direct-acting three-position switch includes a direct-acting position switch and a push-pull transmission mechanism. The direct-acting position switch includes a closing contact, a moving contact, an isolating contact, and a grounding contact. The moving contact moves linearly within the direct-acting position switch and contacts the closing contact, isolating contact, and grounding contact at different positions. The push-pull transmission mechanism includes a chain assembly, a sprocket, a bearing housing, a bevel gear assembly, a transmission shaft, a front plate of an air box, a bracket, a moving engagement, and a connecting screw. The bevel gear assembly includes a first bevel gear and a second bevel gear. One end of the chain assembly is fixed to the sprocket, and the other end is fixed to the moving contact of the direct-acting position switch via the connecting screw. The chain assembly is mounted on the sprocket and rotates under the drive of the sprocket, thus driving the moving contact to move linearly. When the moving contact moves from the grounding position to the closing position, the sprocket rotates less than one revolution. The sprocket is mounted and fixed on the transmission shaft and rotates under the drive of the transmission shaft. A first bevel gear is also fixedly mounted on the drive shaft and rotates under the drive of the first bevel gear. The drive shaft is installed in the bearing in the bearing housing. The bearing housing is mounted on the bracket. The bracket is mounted on the front plate of the air box. The second bevel gear is arranged vertically next to the first bevel gear and meshes with the first bevel gear. The second bevel gear is mounted on the dynamic fit. The dynamic fit drives the first bevel gear to rotate through the second bevel gear. The chain assembly includes a drive chain assembly and a driven chain assembly. The drive chain assembly and the driven chain assembly mesh with each other on the outer side in addition to meshing with their respective sprockets on the inner side. The drive chain assembly and the driven chain assembly are both composed of rigid push-pull chains, including an outer chain, inner chain plates, rollers, and pins. The rigid push-pull chain is alternately hinged between the outer chain and two inner chain plates. The hinge point is passed through and fixed by a pin with elastic end. The inner and outer inner chain plates are installed inside the chain plates of the outer chain and separated by rollers.

[0008] Preferably, the bearing housing includes a pair of opposing drive shaft bearing housings and a pair of driven shaft bearing housings, and the vertically arranged drive shaft bearing housings and driven shaft bearing housings are mounted on the front plate of the air box by a bracket.

[0009] Preferably, the transmission shaft includes a drive shaft and a driven shaft, with both ends of the drive shaft respectively fitted into bearings in the drive shaft bearing housing, and both ends of the driven shaft respectively fitted into bearings in the driven shaft bearing housing.

[0010] Preferably, the sprocket includes a drive sprocket and a driven sprocket. The drive sprocket of each phase is sleeved on the drive shaft and rotates synchronously with the drive shaft. A first bevel gear is installed on the drive shaft. The driven sprocket of each phase is sleeved on the driven shaft.

[0011] Preferably, the inner rollers of the drive chain group mesh with the drive sprocket, the inner rollers of the driven chain group mesh with the driven sprocket, and the outer chains of the drive chain group and the driven chain group mesh with each other.

[0012] Preferably, the outer chain is a specially designed U-shaped structure, with chain plates on both sides of the U-shape and trapezoidal teeth on the back side of the U-shape. The trapezoidal teeth fit together so that when the outer middle surfaces of the upper and lower outer chains are coplanar, the head and tail are pressed together and can only be bent on one side towards the opening. Two pin holes are opened on the chain plates on both sides.

[0013] Preferably, the inner chain plate is oval-shaped and also has two through holes.

[0014] Preferably, the end of the pin has a barbed structure with a cross groove, and the end passes through the pin hole of one chain plate of the outer chain, the pin hole of one inner chain plate, the roller, the pin hole of another inner chain plate, and the pin hole of another chain plate of the outer chain before self-locking.

[0015] Preferably, the outer chain, inner chain plate, roller, and pin are all made of PA66 or insulating high thermal conductivity ceramic, which is insulating and has high structural strength. Using high thermal conductivity ceramic can solve the temperature rise problem and has good thermal conductivity.

[0016] Compared to existing technologies, the advantages of this invention are as follows: It designs a rigid chain push-pull structure to achieve three-position switching of the switch, which is widely applicable to switches across the industry; the drive shaft and sprocket of the drive chain can complete the three-position switching of the contacts within a single revolution of no more than 360°, reducing the difficulty of mechanism design, reducing the number of mechanical parts, lowering the cost, and greatly improving design and production efficiency; simultaneously, in high-current applications with high heat dissipation requirements, when temperature rise needs to be addressed, the detachable chain structure can be easily made of high thermal conductivity ceramic materials, with thermal conductivity up to 500 times that of traditional transmission structure materials such as PA66, thereby quickly conducting the heat from the moving contact to the switch housing, significantly improving the switch's heat dissipation efficiency, reducing the volume of the heat dissipation structure, lowering costs, and effectively solving the heat dissipation problem of three-position switches under high current conditions greater than 2500A; furthermore, the connection between the transmission structure and the external mechanism of the gas box in this solution only requires one moving fit, while traditional structures require multiple, saving a corresponding number of moving fits, reducing costs, and reducing multiple leakage risk points. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the three-dimensional structure of this scheme;

[0018] Figure 2 This is a general schematic diagram of the operating mechanism connected at the rear in this scheme;

[0019] Figure 3 This is a schematic diagram of the chain and sprocket assembly for this solution;

[0020] Figure 4 This is a schematic diagram of the push-pull transmission structure in this scheme assembled inside the air box;

[0021] Figure 5 This is a schematic diagram of the push-pull transmission structure in this scheme.

[0022] Among them, 1-direct-acting station switch, 11-closing contact, 12-moving contact, 13-isolating contact, 14-grounding contact, 2-push-pull transmission mechanism, 21-chain assembly, 211-outer chain, 2111-chain plate, 2112-trapezoidal tooth, 212-inner chain plate, 213-roller, 214-pin, 218-drive chain assembly, 219-driven chain assembly, 22-sprocket, 221-drive 222-Driven sprocket, 23-Bearing housing, 231-Drive shaft bearing housing, 232-Driven shaft bearing housing, 24-Bevel gear set, 241-First bevel gear, 242-Second bevel gear, 25-Transmission shaft, 251-Drive shaft, 252-Driven shaft, 26-Air box front plate, 27-Bracket, 28-Dynamic fit, 29-Connecting screw, 3-Operating mechanism, 301-Operating handle. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] This embodiment provides a technical solution: a push-pull transmission structure for a direct-acting three-position switch of the present invention, comprising three direct-acting position switches 1 and a push-pull transmission mechanism 2. Each direct-acting position switch 1 includes a closing contact 11, a moving contact 12, an isolating contact 13, and a grounding contact 14. The moving contact 12 moves linearly within the direct-acting position switch 1 and contacts the closing contact 11, the isolating contact 13, and the grounding contact 14 at different positions. The push-pull transmission mechanism 2 includes two sets of chain groups 21 (main and slave), two sets of sprockets 22, two pairs of bearing seats 23, and a set of bevel gears 24. The system includes two drive shafts 25, a front air box plate 26, a bracket 27, a moving fit 28, and three connecting screws 29. A set of bevel gears 24 includes a first bevel gear 241 and a second bevel gear 242. One end of each of the two chain sets 21 is fixed to a sprocket 22, and the other end is fixed to each automatic contact 12 of each direct-acting station switch 1 via a connecting screw 29. The connecting screw 29 is a machined, irregularly shaped part, with one end connected to the chain and the other end being an externally threaded screw connecting to the moving contact. Each chain set 21 is mounted on its respective sprocket 22 and drives the sprocket 22. The sprocket 22 rotates downwards, then drives the moving contact 12 to move linearly. When the moving contact 12 moves from the grounding position to the closing position, the sprocket 22 rotates less than one revolution. Each chain set 21 includes three rigid push-pull chains corresponding to the three phases. The two chain sets 21 include a lower set of drive chain sets 218 and a lower set of driven chain sets 219. The drive chain sets 218 and driven chain sets 219 mesh with each other on the outer side in addition to meshing with their respective sprockets 22 on the inner side. Each set of sprockets 22 is mounted and fixed on the drive shaft 25 of its respective set and rotates under the drive of the drive shaft 25. Each set of sprockets 22 includes an upper set of driving sprockets 221 and a lower set of driven sprockets 222. The upper set of sprockets 22 includes three driving sprockets 221 corresponding to the three phases, and the lower set of sprockets 22 also includes three driven sprockets 222 corresponding to the three phases. The two transmission shafts 25 include one driving shaft 251 and one driven shaft 252. The driving sprockets 221 of each phase are sleeved on the driving shaft 251 and rotate synchronously with the driving shaft 251. The driven sprockets 222 of each phase are sleeved on the driven shaft 252 and can rotate freely. The driven sprockets 222 are driven by the driven chain group 219.Both ends of the drive shaft 251 are respectively fitted into bearings in the drive shaft bearing housing 231, and both ends of the driven shaft 252 are respectively fitted into bearings in the driven shaft bearing housing 232. A first bevel gear 241 is also mounted and fixed on the drive shaft 251 and rotates synchronously under the drive of the first bevel gear 241. The bearing housing 23 includes a pair of opposing drive shaft bearing housings 231 and a pair of driven shaft bearing housings 232. The vertically arranged drive shaft bearing housings 231 and driven shaft bearing housings 232 are mounted on the front plate 26 of the air box through a bracket 27. The second bevel gear 242 is vertically arranged. The first bevel gear 241 is located next to and meshes with the first bevel gear 241, rotating synchronously. The second bevel gear 242 is mounted on the moving fit 28, which is also mounted on the front plate 26 of the air box. It is positioned on both sides of the front plate 26 of the air box, separate from the bracket 27, and serves as a mechanism for transmission and rotation sealing. The moving fit 28 drives the first bevel gear 241 to rotate through the second bevel gear 242. The moving fit 28 is driven by the operating mechanism 3, which in turn drives the bevel gear set 24 to drive the transmission shaft 25. The operating mechanism 3 is also equipped with an operating handle 301, which can be used to manually rotate the mechanism to control the transmission mechanism.

[0025] Both the drive chain assembly 218 and the driven chain assembly 219 are composed of rigid push-pull chains. This embodiment is a preferred structure of the rigid push-pull chain, but it is not limited to this structure. The preferred structure includes an outer chain 211, an inner chain plate 212, a roller 213, and a pin 214. The rigid push-pull chain is alternately hinged between the outer chain 211 and two inner chain plates 212. The hinge point is passed through and fixed by a pin 214 with elastic end. The two inner chain plates 212 are installed inside the chain plate 2111 of the outer chain 211 and separated by rollers 213. The inner rollers 213 of the drive chain assembly 218 mesh with the drive sprocket 221. The inner rollers 213 of the driven chain assembly 219 mesh with the driven sprocket 222. The outer chains 211 of the drive chain assembly 218 and the driven chain assembly 219 mesh with each other. The outer chain 211 has a specially designed U-shaped structure. The two sides of the U-shape are shaped like chain plates 2111, and the back of the U-shape has trapezoidal teeth 2112 in the middle. The trapezoidal teeth 2112 fit together at the head and tail, so that when the outer middle surfaces of the two outer chains 211 are coplanar, the head and tail are tightly joined together, allowing bending only towards the open side. Two pin holes are opened on the chain plates 2111 on both sides. The inner chain plate 212 is oval-shaped and also has two pin holes. The pin 214 has a barbed structure at its end with a cross groove. The end passes through the pin hole of one chain plate 2111 of the outer chain 211, the pin hole of one inner chain plate 212, the roller 213, the pin hole of the other inner chain plate 212, and the pin hole of the other chain plate 2111 of the outer chain 211, and then self-locks.

[0026] In low-current, high-voltage applications, where heat dissipation requirements are less stringent, high-strength insulating materials such as PA66 are typically chosen. These materials can withstand the voltage to ground of the switch and meet the dielectric strength requirements. However, in high-current, high-voltage applications, the chain of the transmission structure can be made of high thermal conductivity ceramic materials. These high thermal conductivity ceramic materials refer to ceramic materials with a room temperature thermal conductivity greater than 20 W / (m·K) as specified in the national standard GB / T 39862-2021 "Test of Thermal Conductivity of High Thermal Conductivity Ceramics", such as aluminum nitride ceramics and alumina ceramics. This addresses the heat dissipation problem of high-current three-position switches. Some of these materials have thermal conductivity as high as 200 W / (m·K), which can significantly improve the heat dissipation efficiency of the switch.

[0027] The shape of the outer chain 211 restricts the bending of a single chain assembly 21 to one side. When the driving chain assembly 218 and the driven chain assembly 219 are engaged, they mutually restrict the bending direction of each other's chains, and the two become a rigid rod. The ends of the two chains are rigidly connected to the connecting screw 29. The connecting screw 29 is pre-screwed into the internal thread of the moving contact 12. The moving contact 12 is restricted by the positioning pin and cannot rotate, and the chain cannot be twisted, so the connecting screw 29 will not loosen. The end links of the chains are fixed to the sprocket 22, so the two chains remain engaged with the sprocket 22 when they disengage from each other. When the moving contact 12 is in the ground position, when the driving sprocket 221 rotates clockwise by a certain angle (149° in this embodiment), it drives the chain assembly 21 to the right, pushing the moving contact 12 to the open position. If it rotates counterclockwise by 149° at this time, the moving contact 12 is pulled back, and the switch returns to the ground position. If the moving contact 12 continues to rotate 149° clockwise, it will be pushed to the closed position by the chain. Then it can be pulled back by rotating 149° counterclockwise. This ensures that when the moving contact 12 moves from the grounded position to the closed position, the sprocket 22 rotates less than one revolution. In this embodiment, it is 298°, which is much less than 360°.

[0028] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A push-pull transmission structure for a direct-acting three-position switch, comprising a direct-acting position switch (1) and a push-pull transmission mechanism (2), wherein the direct-acting position switch (1) comprises a closing contact (11), a moving contact (12), an isolating contact (13), and a grounding contact (14), wherein the moving contact (12) moves linearly within the direct-acting position switch (1) and contacts the closing contact (11), the isolating contact (13), and the grounding contact (14) at different positions, characterized in that: The push-pull transmission mechanism (2) includes a chain assembly (21), a sprocket (22), a bearing seat (23), a bevel gear assembly (24), a drive shaft (25), a front plate of the air box (26), a bracket (27), a dynamic fit (28), and a connecting screw (29). The bevel gear assembly (24) includes a first bevel gear (241) and a second bevel gear (242). One end of the chain assembly (21) is fixed to the sprocket (22), and the other end is fixed to the moving contact (12) of the direct-acting station switch (1) via the connecting screw (29). The chain assembly (21) is mounted on the sprocket (22). The sprocket (22) rotates on the ground and drives the moving contact (12) to move linearly. When the moving contact (12) moves from the ground position to the closed position, the sprocket (22) rotates less than one revolution. The sprocket (22) is mounted and fixed on the transmission shaft (25) and rotates under the drive of the transmission shaft (25). The first bevel gear (241) is also mounted and fixed on the transmission shaft (25) and rotates under the drive of the first bevel gear (241). The transmission shaft (25) is installed in the bearing in the bearing seat (23). The bearing seat (23) is mounted on the bracket (27). On the air box front plate (26), the bracket (27) is mounted on the air box front plate (26). The second bevel gear (242) is arranged vertically next to the first bevel gear (241) and meshes with the first bevel gear (241). The second bevel gear (242) is mounted on the moving fit (28). The moving fit (28) drives the first bevel gear (241) to rotate through the second bevel gear (242). The chain assembly (21) includes a drive chain assembly (218) and a driven chain assembly (219). The drive chain assembly (218) and the driven chain assembly (219) are connected to their respective chains on the inner side. The wheels (22) mesh with each other on the outside and on the outside; the drive chain group (218) and the driven chain group (219) are both composed of rigid push-pull chains, including an outer chain (211), an inner chain plate (212), a roller (213), and a pin (214). The rigid push-pull chain is alternately hinged to the outer chain (211) and the two inner chain plates (212) at the front and rear. The hinge point is passed through and fixed by a pin (214) with elastic end. The two inner chain plates (212) are installed inside the chain plate (2111) of the outer chain (211) and separated by a roller (213).

2. The push-pull transmission structure of the direct-acting three-position switch according to claim 1, characterized in that: The bearing housing (23) includes a pair of drive shaft bearing housings (231) and a pair of driven shaft bearing housings (232) facing each other. The drive shaft bearing housings (231) and driven shaft bearing housings (232) arranged vertically are mounted on the front plate (26) of the air box by a bracket (27).

3. The push-pull transmission structure of the direct-acting three-position switch according to claim 2, characterized in that: The transmission shaft (25) includes a drive shaft (251) and a driven shaft (252). The two ends of the drive shaft (251) are respectively fitted into the bearings in the drive shaft bearing housing (231), and the two ends of the driven shaft (252) are respectively fitted into the bearings in the driven shaft bearing housing (232).

4. The push-pull transmission structure of the direct-acting three-position switch according to claim 3, characterized in that: The sprocket (22) includes a drive sprocket (221) and a driven sprocket (222). The drive sprocket (221) of each phase is sleeved on the drive shaft (251) and rotates synchronously with the drive shaft (251). A first bevel gear (241) is installed on the drive shaft (251). The driven sprocket (222) of each phase is sleeved on the driven shaft (252).

5. The push-pull transmission structure of the direct-acting three-position switch according to claim 4, characterized in that: The inner roller (213) of the drive chain assembly (218) meshes with the drive sprocket (221), the inner roller (213) of the driven chain assembly (219) meshes with the driven sprocket (222), and the outer chain (211) of the drive chain assembly (218) meshes with the driven chain assembly (219).

6. The push-pull transmission structure of the direct-acting three-position switch according to claim 5, characterized in that: The outer chain (211) is a specially made U-shaped structure. The two sides of the U-shape are chain plates (2111), and the back of the U-shape is a trapezoidal tooth (2112) in the middle. The trapezoidal teeth (2112) fit together at the head and tail, so that when the outer middle surfaces of the two outer chains (211) are coplanar, the head and tail are close together and can only be bent on one side towards the opening side. The chain plates (2111) on both sides have two through holes.

7. The push-pull transmission structure of the direct-acting three-position switch according to claim 5, characterized in that: The inner chain plate (212) is oval in shape and also has two through holes.

8. The push-pull transmission structure of the direct-acting three-position switch according to claim 5, characterized in that: The pin (214) has a barbed structure at the end with a cross groove. The end passes through the pin hole of one chain plate (2111) of the outer chain (211), the pin hole of one inner chain plate (212), the roller (213), the pin hole of another inner chain plate (212), and the pin hole of another chain plate (2111) of the outer chain (211) and then self-locks.

9. The push-pull transmission structure of the direct-acting three-position switch according to claim 5, characterized in that: The outer chain (211), inner chain plate (212), roller (213), and pin (214) are all made of PA66 or insulating high thermal conductivity ceramic.

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