An explosion-proof through-wall transfer switch

Abstract

This utility model employs an explosion-proof through-wall changeover switch, including a switch housing, a drive switch, a knob, a circuit board, a protective sleeve, and a bearing. A top extension end is formed on the switch housing facing the knob. The protective sleeve is fitted onto the top extension end, and the bearing is fitted onto the protective sleeve. The inner ring of the bearing is tightly fitted with the protective sleeve, and the outer ring of the bearing is tightly fitted with the inner surface of the knob. The end of the drive rod extends into the knob and forms a through-fit with the knob, thus transmitting force between the knob and the drive switch. This ensures that if the changeover switch is subjected to excessive external force or other accidents, even if damage occurs, only the knob portion, specifically the through-fit connection between the knob and the drive rod of the drive switch, will be damaged. In the event of damage, the knob will simply rotate on the switch housing along with the bearing, preventing the destructive force from being directly transmitted to the changeover switch and causing it to fail. This ensures the reliability of the changeover switch.

Description

Technical Field

[0001] This utility model relates to the field of changeover switch technology, and in particular to an explosion-proof through-wall changeover switch. Background Technology

[0002] Explosion-proof through-wall changeover switches are industrial devices designed specifically for flammable and explosive environments. They are mainly used to control the starting, stopping, speed changing, and reversing operations of motors, and have explosion-proof functions (through the combination of built-in explosion-proof elements and explosion-proof housing, they can effectively prevent explosion accidents and are suitable for dangerous environments such as underground coal mines).

[0003] Existing explosion-proof through-wall changeover switches typically operate by the operator rotating a knob. The rotation of the knob drives a central shaft directly connected to the knob, transmitting the control action to the control board. However, several problems have been identified in practical use: 1. Because the knob is directly connected to the central shaft, the shaft is susceptible to damage due to excessive force or other unforeseen circumstances, potentially causing the entire switch to malfunction. 2. Some existing switches, due to unreliable design, may generate sparks during switching, posing a safety hazard. Summary of the Invention

[0004] In view of the above shortcomings, this utility model provides an explosion-proof through-wall switch that can improve the reliability of the central shaft and prevent damage caused by external forces during use.

[0005] To achieve the above objectives, this utility model employs an explosion-proof through-wall changeover switch, comprising a switch housing, a drive switch having a drive rod and a switch body distributed within the switch housing, a knob distributed along the rod end direction of the drive rod, and a circuit board distributed along the electrical connection end direction of the drive switch. The changeover switch also includes a protective sleeve and a bearing having an inner ring layer and an outer ring layer. The switch housing extends towards the end where the knob is distributed, extending into the knob and forming a top side extension end. The protective sleeve is fitted onto the top side extension end, and the bearing is fitted onto the protective sleeve. The inner ring layer of the bearing fitted onto the protective sleeve is tightly fitted with the protective sleeve, and the outer ring layer of the bearing is tightly fitted with the inner surface of the knob. The rod end of the drive rod extends into the knob and forms a through-fit tightly fitted with the knob, thus transmitting force between the knob and the drive switch.

[0006] The present invention is further configured such that the changeover switch also includes an explosion-proof base, the drive rod includes a drive rod start end connected to the switch body, a drive rod end extending into the knob, and a drive rod connecting section distributed between the drive rod start end and the drive rod end, the outside of the switch housing also includes a bottom side extension end attached to the outside of the circumferential surface of the switch body, and a housing extension section distributed outside the drive rod connecting section, the bottom side extension end, the housing extension section and the top side extension end are distributed in a stepped manner; The explosion-proof base is sleeved on the housing extension section of the stepped switch housing, and one side of the explosion-proof base facing the bottom extension end abuts against the stepped surface of the bottom extension end, while the other side of the explosion-proof base faces the knob. A limiting member is engaged between the explosion-proof base and the knob, and the limiting member is screwed onto the housing extension section and contacts the other side of the explosion-proof base. The explosion-proof base forms an axial limit on the switch body through the stepped surface of the bottom extension end and the limiting member screwed onto the housing extension section. The bottom extension end on the outer side of the circumferential surface of the switch body extends away from the side of the housing extension section, and a potting area is formed inside the bottom extension end. The circuit board is distributed in the potting area and is potted for protection. An explosion-proof surface one is formed between the explosion-proof base and the outer edge of the housing extension section of the switch housing, and an explosion-proof surface two is formed between the inner side of the housing extension section and the drive rod connection section.

[0007] The present invention is further configured such that the changeover switch also includes a sealing ring one and a sealing ring two. A sealing ring groove is provided on the side of the housing extension relative to the adjacent limiting member. The sealing ring one is sleeved on the housing extension through the sealing ring groove, and the two sides of the sealing ring one sleeved on the sealing ring groove are bidirectionally squeezed between the limiting member and the groove wall of the sealing ring groove facing the limiting member. The starting end of the drive rod is a rod seat on the drive rod. The switch housing includes a through hole for the drive rod to be fitted through. The through hole is connected to the potting area. A sealing ring mounting groove is provided in the through hole on the side facing the potting area. The side wall of the rod seat is adapted to the hole wall of the sealing ring mounting groove. The sealing ring is sleeved on the connecting section of the drive rod. The drive rod is inserted into the through hole. As the bottom of the sealing ring mounting groove approaches the end face of the rod seat on the drive rod, the sealing ring is pressed between the end face of the rod seat and the bottom of the sealing ring mounting groove.

[0008] The present invention is further configured such that a bearing mounting cavity is provided on the knob at a position on the inner wall corresponding to the protective sleeve, and the bearing is tightly fitted and embedded in the knob through the bearing mounting cavity.

[0009] The present invention is further configured such that the top side of the knob includes a D-shaped notch, and the outer edge of the end of the drive rod is a D-shaped shaft structure adapted to the D-shaped notch. Through the insertion of the D-shaped shaft into the D-shaped notch, torque is transmitted between the knob and the drive rod.

[0010] The present invention is further configured such that the limiting member is a nut screwed onto the extension section of the housing, and a threaded surface adapted to the nut is formed on the extension section of the housing. The nut is screwed onto the threaded surface of the extension section of the housing and moves toward the explosion-proof base to limit the explosion-proof base on the changeover switch.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows: By designing the structure of the explosion-proof through-wall switch relative to the knob position, in addition to the knob, it also involves a protective sleeve fitted on the top extension end of the switch housing and a bearing fitted on the protective sleeve. When the knob is assembled on the switch housing, the knob part is assembled on the switch first acting on the bearing (i.e., the inner ring of the bearing is tightly fitted with the protective sleeve, and the outer ring of the bearing is tightly fitted with the inside of the knob). Simultaneously, the top extension end of the drive rod of the drive switch on the switch extends into the knob and is tightly fitted with the knob. Thus, when the knob is started or the gear is switched on the explosion-proof through-wall switch, the force between the knob and the drive switch can be transmitted through the position of the tight fit. Therefore, the preferred solution is to involve a D-shaped notch on the top side of the knob, and design the outer edge of the end of the drive rod as a D-shaped shaft structure. The insertion of the D-shaped shaft into the D-shaped notch ensures the reliability of torque transmission between the knob and the drive rod. Furthermore, in the event of excessive external force or other unexpected situations during use, the explosion-proof wall-penetrating changeover switch involved in this utility model will only be damaged at the knob part, specifically at the point where the knob and the drive rod of the drive switch are tightly fitted together, i.e., at the D-shaped notch on the top side of the knob. If the corresponding D-shaped notch is damaged, the knob will simply rotate around on the switch housing along with the bearing, without any corresponding destructive force being directly transmitted to the explosion-proof wall-penetrating changeover switch, thus preventing it from failing and ensuring its reliability. Attached Figure Description

[0012] Figure 1 This is a three-dimensional schematic diagram of the changeover switch according to an embodiment of this utility model; Figure 2 This is a top view schematic diagram of the changeover switch according to an embodiment of this utility model; Figure 3 yes Figure 2 AA sectional view; Figure 4 yes Figure 3 Enlarged schematic diagram of part A; Figure 5 yes Figure 3 Enlarged schematic diagram of part B; Figure 6 This is an exploded view of the changeover switch according to an embodiment of the present invention; Figure 7 This is a three-dimensional schematic diagram of the switch housing according to an embodiment of the present utility model; Figure 8 This is a cross-sectional schematic diagram of the switch housing according to an embodiment of the present utility model; Figure 9 This is a three-dimensional schematic diagram of the drive switch according to an embodiment of the present invention. Detailed Implementation

[0013] like Figure 1-9 As shown, a specific embodiment of this utility model is an explosion-proof through-wall changeover switch, including a switch housing 4, a drive switch 5 distributed within the switch housing 4 and having a drive rod 51 and a switch body 52, a knob 1 distributed in the rod end direction of the drive rod 51, and a circuit board 7 distributed in the electrical connection end direction of the drive switch 5. The changeover switch also includes a protective sleeve 9 and a bearing 6 having an inner ring layer and an outer ring layer. The switch housing 4 is extended relative to the end facing the knob 1, and extends into the knob 1 to form a top side extension end 41. The protective sleeve 9 is sleeved on the top side extension end 41. The bearing 6 is sleeved on the protective sleeve 9. The inner ring layer of the bearing 6 sleeved on the protective sleeve 9 is tightly fitted with the protective sleeve 9. The outer ring layer of the bearing 6 is tightly fitted with the inner surface of the knob 1. The rod end of the drive rod 51 extends into the knob 1 and forms a through-fit tightly fitted with the knob 1, thus constituting the force transmission between the knob 1 and the drive switch 5. The top side of the knob 1 includes a D-shaped notch 11, and the outer edge of the end of the drive rod 51 is a D-shaped shaft 514 structure that is adapted to the D-shaped notch 11. Through the insertion of the D-shaped shaft 514 into the D-shaped notch 11, torque is transmitted between the knob 1 and the drive rod 51.

[0014] By designing the structure of the explosion-proof through-wall switch relative to the knob 1, in addition to the knob 1, it also includes a protective sleeve 9 fitted on the top extension end 41 of the switch housing 4, and a bearing 6 fitted on the protective sleeve 9. This ensures that when the knob 1 is assembled onto the switch housing 4, the knob 1 part is first acted upon by the bearing 6 (i.e., the inner ring of the bearing 6 is tightly fitted with the protective sleeve 9, and the outer ring of the bearing 6 is tightly fitted with the inside of the knob 1). Simultaneously, the drive rod 51 of the drive switch 5 on the switch extends its top extension end 41... The rod extends into the knob 1 and is connected to the knob 1 in a through-type tight fit. This allows the force to be transmitted between the knob 1 and the drive switch 5 when the knob 1 is activated or the gear is switched by the explosion-proof through-wall switch. The preferred solution is to make a D-shaped notch 11 on the top side of the knob 1 and design the outer edge of the rod end of the drive rod 51 as a D-shaped shaft 514 structure. The insertion of the D-shaped shaft 514 into the D-shaped notch 11 ensures the reliability of torque transmission between the knob 1 and the drive rod 51. Furthermore, in the event of excessive external force or other unexpected situations during use, the explosion-proof wall-penetrating changeover switch involved in this utility model will only be damaged at the knob 1 part, that is, the position where the knob 1 and the drive rod 51 of the drive switch 5 are tightly fitted together, i.e., the D-shaped notch 11 position on the top side of the knob 1. After the corresponding D-shaped notch 11 position is damaged, the knob 1 will rotate on the switch housing 4 along with the bearing 6, and there will be no corresponding destructive force directly transmitted to the explosion-proof wall-penetrating changeover switch, causing the explosion-proof wall-penetrating changeover switch to fail, thereby ensuring the reliability of the explosion-proof wall-penetrating changeover switch.

[0015] like Figure 1 , 3 As shown in -9, the changeover switch also includes an explosion-proof base 3, and the drive rod 51 includes a drive rod start end 513 connected to the switch body 52, a drive rod end 511 extending into the knob 1, and a drive rod connecting section 512 distributed between the drive rod start end 513 and the drive rod end 511. The outside of the switch housing 4 also includes a bottom extension end 43 attached to the outside of the circumferential surface of the switch body 52, and a housing extension section 42 distributed outside the drive rod connecting section 512. The bottom extension end 43, the housing extension section 42, and the top extension end 41 are distributed in a stepped manner. The explosion-proof base 3 is sleeved on the housing extension section 42 of the stepped switch housing 4, and one side of the explosion-proof base 3 facing the bottom extension end 43 abuts against the stepped surface of the bottom extension end 43, while the other side of the explosion-proof base 3 faces the knob 1. A limiting member 2 is engaged between the explosion-proof base 3 and the knob 1. The limiting member 2 is screwed onto the housing extension section 42 and contacts the other side of the explosion-proof base 3. The explosion-proof base 3 is axially limited on the switch body 52 by the stepped surface of the bottom extension end 43 and the limiting member 2 screwed onto the housing extension section 42. The bottom extension end 43 of the switch body 52 extends outward from the side away from the housing extension section 42, and a potting area 100 is formed inside the bottom extension end 43. The circuit board 7 is distributed in the potting area 100 and is potted for protection. An explosion-proof surface 300 is formed between the explosion-proof base 3 and the outer edge of the housing extension section 42 of the switch housing 4, and an explosion-proof surface 200 is formed between the inner side of the housing extension section 42 and the drive rod connecting section 512. This allows the switch to be protected during use by the action of the explosion-proof base 3, i.e., the explosion-proof base 3 forms an upper explosion-proof surface 3 with the outer edge of the housing extension section 42. At the same time, an upper explosion-proof surface 200 is formed between the inner side of the housing extension section 42 and the drive rod connection section 512. Then, through the potting area 100 formed inside the bottom extension end 43 of the switch body 52, the inner potting area 100 is filled with potting material, so that the circuit board 7 of the changeover switch is potted. Thus, when the changeover switch is in use, the explosion-proof surface 300, the explosion-proof surface 200 and the potting area 100 work together to form an explosion-proof area for the switch components used on the changeover switch, thereby blocking the leakage of sparks during the use of the changeover switch.

[0016] like Figure 3-9 As shown, the changeover switch also includes a first sealing ring 10 and a second sealing ring 8. A sealing ring groove 47 is provided on the side of the housing extension 42 relative to the adjacent limiting member 2. The first sealing ring 10 is sleeved on the housing extension 42 through the sealing ring groove 47. The two sides of the first sealing ring 10 sleeved on the sealing ring groove 47 are bidirectionally squeezed between the limiting member 2 and the groove wall of the sealing ring groove 47 facing the limiting member 2. The starting end 513 of the drive rod is a rod seat on the drive rod 51. The switch housing 4 includes a through hole 45 for the drive rod 51 to be fitted through. The through hole 45 is connected to the potting area 100. A sealing ring mounting groove 451 is provided in the through hole 45 on the side facing the potting area 100. The side wall of the rod seat is adapted to the hole wall of the sealing ring mounting groove 451. The sealing ring 8 is sleeved on the drive rod connecting section 512. The drive rod 51 is inserted into the through hole 45. As the bottom of the sealing ring mounting groove 451 approaches the end face of the rod seat on the drive rod 51, the sealing ring 8 is pressed between the end face of the rod seat and the bottom of the sealing ring mounting groove 451. This design allows the changeover switch to achieve a combination of internal and external sealing through the cooperation of the sealing ring 1 and the sealing ring 8, ensuring that the changeover switch can prevent the intrusion of dust and liquid when used in explosion-proof environments.

[0017] like Figure 3-4 As shown, a bearing mounting cavity 400 is provided on the knob 1 at the position of the inner wall corresponding to the protective sleeve 9. Through the bearing mounting cavity 400, the bearing 6 is tightly embedded in the knob 1, which can realize that the bearing 6 added to the changeover switch can be reliably installed on the knob 1, thereby ensuring the reliability of the design and installation of this utility model.

[0018] like Figure 3-4 As shown in 6-8, the limiting member 2 is a nut screwed onto the housing extension 42. The housing extension 42 has a threaded surface 44 that matches the nut. The nut engages with the threaded surface 44 of the housing extension 42 and moves towards the explosion-proof base 3, thus forming a limiting design for the explosion-proof base 3 on the changeover switch. This design enables reliable installation and limiting of the limiting member 2 on the switch housing 4, while also ensuring reliable limiting of the explosion-proof base 3 on the changeover switch.

Claims

1. An explosion-proof through-wall changeover switch, comprising a switch housing, a drive switch having a drive rod and a switch body distributed within the switch housing, knobs distributed along the rod end direction of the drive rod, and a circuit board distributed along the electrical connection end direction of the drive switch, characterized in that: The selector switch also includes a protective sleeve and a bearing with an inner ring and an outer ring. The switch housing extends towards the end where the knob is located, and extends into the knob to form a top extension end. The protective sleeve is fitted onto the top extension end, and the bearing is fitted onto the protective sleeve. The inner ring of the bearing fitted onto the protective sleeve is tightly fitted with the protective sleeve, and the outer ring of the bearing is tightly fitted with the inner surface of the knob. The end of the drive rod extends into the knob and forms a through-type tight fit with the knob, thus transmitting force between the knob and the drive switch.

2. The flameproof through-the-wall transfer switch of claim 1, wherein: The changeover switch also includes an explosion-proof base. The drive rod includes a drive rod start end connected to the switch body, a drive rod end extending into the knob, and a drive rod connecting section distributed between the drive rod start end and the drive rod end. The outside of the switch housing also includes a bottom extension end attached to the outside of the circumferential surface of the switch body and a housing extension section distributed outside the drive rod connecting section. The bottom extension end, the housing extension section, and the top extension end are arranged in a stepped manner. The explosion-proof base is sleeved on the housing extension section of the stepped switch housing, and one side of the explosion-proof base facing the bottom extension end abuts against the stepped surface of the bottom extension end, while the other side of the explosion-proof base faces the knob. A limiting member is engaged between the explosion-proof base and the knob, and the limiting member is screwed onto the housing extension section and contacts the other side of the explosion-proof base. The explosion-proof base forms an axial limit on the switch body through the stepped surface of the bottom extension end and the limiting member screwed onto the housing extension section. The bottom extension end on the outer side of the circumferential surface of the switch body extends away from the side of the housing extension section, and a potting area is formed inside the bottom extension end. The circuit board is distributed in the potting area and is potted for protection. An explosion-proof surface one is formed between the explosion-proof base and the outer edge of the housing extension section of the switch housing, and an explosion-proof surface two is formed between the inner side of the housing extension section and the drive rod connection section.

3. The flameproof through-the-wall transfer switch of claim 2, wherein: The changeover switch also includes a sealing ring one and a sealing ring two. A sealing ring groove is provided on the side of the housing extension relative to the adjacent limiting member. The sealing ring one is sleeved on the housing extension through the sealing ring groove. The two sides of the sealing ring one sleeved on the sealing ring groove are bidirectionally squeezed between the limiting member and the groove wall of the sealing ring groove facing the limiting member. The starting end of the drive rod is a rod seat on the drive rod. The switch housing includes a through hole for the drive rod to be fitted through. The through hole is connected to the potting area. A sealing ring mounting groove is provided in the through hole on the side facing the potting area. The side wall of the rod seat is adapted to the hole wall of the sealing ring mounting groove. The sealing ring is sleeved on the connecting section of the drive rod. The drive rod is inserted into the through hole. As the bottom of the sealing ring mounting groove approaches the end face of the rod seat on the drive rod, the sealing ring is pressed between the end face of the rod seat and the bottom of the sealing ring mounting groove.

4. The flameproof through-the-wall transfer switch of claim 1, 2, or 3, wherein: The knob has a bearing mounting cavity at a position on the inner wall corresponding to the protective sleeve, through which the bearing is tightly fitted into the knob.

5. The flameproof through-the-wall transfer switch of claim 1, 2, or 3, wherein: The knob has a D-shaped notch on its top side, and the outer edge of the end of the drive rod is a D-shaped shaft structure that matches the D-shaped notch. Torque is transmitted between the knob and the drive rod through the insertion of the D-shaped shaft into the D-shaped notch.

6. The flameproof through-the-wall transfer switch of claim 2 or 3, wherein: The limiting component is a nut screwed onto the housing extension. The housing extension has a threaded surface adapted to the nut. The nut engages with the threaded surface of the housing extension and moves toward the explosion-proof base, thus limiting the explosion-proof base on the changeover switch.

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