Neutral point connecting structure of linear motor and insulation forming method

Abstract

The invention belongs to the technical field of linear motors, and particularly relates to a neutral point connecting structure of a linear motor and an insulation forming method. According to the technical scheme, the neutral point connecting structure of the linear motor comprises an insulation box and a neutral point connector, the neutral point connector tightly presses three cables and is installed in the insulation box, one side of the insulation box is provided with an upper U-shaped hole for one cable to penetrate out, and the other side of the insulation box is provided with a lower U-shaped hole for the other cable to penetrate out. The other side of the insulation box is provided with two lower U-shaped holes for the other two cables to pass through, and the insulation box is filled with room temperature curing glue. The invention provides a neutral point connecting structure of a linear motor and an insulation forming method. The neutral point connecting structure is simple to operate and high in insulation reliability.

Description

Technical Field

[0001] This invention belongs to the field of linear motor technology, and specifically relates to a neutral point connection structure and insulation forming method for a linear motor. Background Technology

[0002] Currently, linear motors all operate using frequency conversion, with the neutral point internally short-circuited. The neutral point can only be formed by connecting the modules on both sides of the air gap together via a cable. Current connection methods for the neutral point of linear motors include cable + short-circuit copper busbar, cable + Y-joint tee, cable + T-joint tee, and cable + parallel groove clamp. All these connection methods result in irregularly shaped joints, making insulation wrapping difficult. Furthermore, the irregular shape leads to incomplete insulation wrapping, leaving small gaps that can become weak points for later insulation discharge. Summary of the Invention

[0003] In order to solve the above-mentioned problems in the prior art, the purpose of this invention is to provide a neutral point connection structure and insulation forming method for a linear motor, which is simple to operate and has high insulation reliability.

[0004] The technical solution adopted in this invention is as follows: A neutral point connection structure for a linear motor includes an insulating box and a neutral point connector. The neutral point connector clamps three cables. The neutral point connector is installed inside the insulating box. One side of the insulating box has an upper U-shaped hole for one of the cables to pass through, and the other side of the insulating box has two lower U-shaped holes for the other two cables to pass through. The insulating box is filled with room temperature curing adhesive.

[0005] After stripping the insulation from the three cables leading from the long stator of the linear motor, insert them into the pre-drilled holes of the neutral point connector. Tighten the bolts, and the neutral point connector will clamp the cables, achieving equipotential bonding between the cables. After the neutral point connector is insulated according to specifications, it is installed into an insulation box, and glue is poured in and cured through the glue-filling hole on the insulation box.

[0006] The neutral point connector of this invention can accommodate three cables. After tightening the connector with screws, equipotential bonding between the three cables is achieved. The insulating box is a standard cuboid. After placing the neutral point connector into the insulating box, it is filled with room temperature curing adhesive to complete the insulation molding. This invention simplifies the connection of three cables via the neutral point connector and the insulation molding process by filling the insulating box with room temperature curing adhesive. Furthermore, the insulation molding difficulty of this invention is significantly reduced, resulting in better insulation wrapping, higher insulation reliability, and the ability to withstand higher operating voltages.

[0007] As a preferred embodiment of the present invention, the neutral point connector includes a cover plate and a pressure plate, which are connected by screws. The side of the cover plate facing the pressure plate and the side of the pressure plate facing the cover plate are each provided with three semi-circular holes. The semi-circular holes of the cover plate and the semi-circular holes of the pressure plate are combined to form a through hole, and the three cables are respectively pressed into the three through holes.

[0008] As a preferred embodiment of the present invention, the cable in the upper U-shaped hole is inserted into the through hole in the middle of the neutral point connector, and the cables in the two lower U-shaped holes are respectively inserted into the through holes on both sides of the neutral point connector.

[0009] As a preferred embodiment of the present invention, the distance between two adjacent through holes on the neutral point connector is greater than the outer diameter of the cable.

[0010] As a preferred embodiment of the present invention, the diameter of the through hole is smaller than the outer diameter of the cable core.

[0011] As a preferred embodiment of the present invention, the neutral point connector is wrapped with insulating material.

[0012] As a preferred embodiment of the present invention, the insulating box includes an insulating box body, an upper U-shaped hole and a lower U-shaped hole are respectively provided on both sides of the insulating box body, a sealing plate is inserted into the lower U-shaped hole, a cable through hole is provided on the sealing plate, and an insulating box cover is connected to the open side of the insulating box body.

[0013] As a preferred embodiment of the present invention, the insulating box includes a base plate, and an upper plate, a lower plate and two upright plates are respectively provided on the four sides of the base plate. The two upright plates are respectively connected to the two sides between the upper plate and the lower plate. An upper U-shaped hole is provided on the upper plate and two lower U-shaped holes are provided on the lower plate. The upper plate, the lower plate and the two upright plates are respectively connected to the insulating box cover.

[0014] As a preferred embodiment of the present invention, the sealing plate is composed of two symmetrical halves joined together.

[0015] A method for forming neutral point insulation in a linear motor includes the following steps: S1: After stripping the insulation material from the end of the neutral point connection cable, insert it into the neutral point connector and tighten the bolts on the neutral point connector to compact the cable core; S2: Use room temperature curing filler to fill the gaps between neutral point joints and the gaps between bolt heads and bolt holes. Curing at room temperature shall not be less than 24 hours. S3: Wrap mica foil and fiberglass tape alternately and semi-overlap on the surface of the neutral point joint, and brush room temperature curing epoxy adhesive while wrapping; S4: Place the neutral point connector into the insulating box, seal the lower U-shaped hole on the insulating box with a sealing plate, and then use polyimide film tape to stick the insulating box cover to the opening side of the insulating box. S5: Fill the insulation box with room temperature curing adhesive through the U-shaped hole at the top; S6: Apply two layers of low-resistance anti-corona paint to the surface of the insulating box and the neutral point connecting cable. After the first layer is applied and cured for 8 hours, apply the second layer of low-resistance anti-corona paint. The curing time at room temperature shall not be less than 24 hours.

[0016] The beneficial effects of this invention are as follows: The neutral point connector of this invention can accommodate three cables. After tightening the connector with screws, equipotential bonding between the three cables is achieved. The insulating box is a standard cuboid. After placing the neutral point connector into the insulating box, it is filled with room temperature curing adhesive to complete the insulation molding. This invention simplifies the connection of three cables via the neutral point connector and the insulation molding process by filling the insulating box with room temperature curing adhesive. Furthermore, the insulation molding difficulty of this invention is significantly reduced, resulting in better insulation wrapping, higher insulation reliability, and the ability to withstand higher operating voltages. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the neutral point connector. Figure 3 This is a structural diagram of the pressure plate; Figure 4 This is a structural schematic diagram of the cover plate; Figure 5 This is a schematic diagram of the insulating box. Figure 6 This is a structural schematic diagram of the insulating box; Figure 7 This is a schematic diagram of the sealing plate.

[0018] In the diagram: 1-Insulation box; 2-Neutral point connector; 3-Cable; 11-Insulation box body; 12-Sealing plate; 13-Insulation box cover; 21-Cover plate; 22-Pressure plate; 23-Through hole; 111-Bottom plate; 112-Upper plate; 113-Lower plate; 114-Vertical plate; 115-Upper U-shaped hole; 116-Lower U-shaped hole; 121-Cable through hole. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0021] like Figure 1 As shown, the neutral point connection structure of the linear motor in this embodiment includes an insulating box 1 and a neutral point connector 2. The neutral point connector 2 clamps three cables 3 respectively. The neutral point connector 2 is installed in the insulating box 1. One side of the insulating box 1 is provided with an upper U-shaped hole 115 for one of the cables 3 to pass through, and the other side of the insulating box 1 is provided with two lower U-shaped holes 116 for the other two cables 3 to pass through. The insulating box 1 is filled with room temperature curing adhesive.

[0022] After the insulation of the three cables 3 leading from the long stator of the linear motor is removed, they are inserted into the reserved holes of the neutral point connector 2. After tightening the bolts, the neutral point connector 2 clamps the cables 3, achieving equipotential bonding between the cables 3. After the neutral point connector 2 is wrapped with insulation according to specifications, it is installed into the insulation box 1, and glue is poured in and cured through the glue-filling hole on the insulation box 1.

[0023] The neutral point connector 2 of this invention can accommodate three cables 3. After tightening the neutral point connector 2 with screws, equipotential bonding between the three cables 3 is achieved. The insulating box 1 is a standard cuboid. After placing the neutral point connector 2 into the insulating box 1, it is filled with room temperature curing adhesive to achieve insulation molding. This invention simplifies the connection of the three cables 3 via the neutral point connector 2 and the insulation molding process by filling the insulating box 1 with room temperature curing adhesive. Furthermore, the insulation molding difficulty of this invention is significantly reduced, resulting in better insulation wrapping, higher insulation reliability, and the ability to withstand higher operating voltages.

[0024] Specifically, such as Figures 2-4 As shown, the neutral point connector 2 includes a cover plate 21 and a pressure plate 22, which are connected by screws. Three semi-circular holes are provided on both the side of the cover plate 21 facing the pressure plate 22 and the side of the pressure plate 22 facing the cover plate 21. The semi-circular holes of the cover plate 21 and the pressure plate 22 are combined to form a through hole 23, and three cables 3 are respectively pressed into the three through holes 23. The cable 3 in the upper U-shaped hole 115 is inserted into the middle through hole 23 of the neutral point connector 2, and the cables 3 in the two lower U-shaped holes 116 are respectively inserted into the through holes 23 on both sides of the neutral point connector 2.

[0025] The neutral point connector 2 consists of a cover plate 21, a pressure plate 22, and two hexagon socket head cap screws. The pressure plate 22 is a 20x50x100mm cuboid, galvanized after machining. The pressure plate 22 is made of Q235 carbon steel. Three sets of through semi-circular holes are machined on the side closest to the cover plate 21. The spacing between adjacent semi-circular holes along the length direction must be greater than the outer diameter of the cable 3 to avoid interference between adjacent cables 3 during installation. The diameter of the semi-circular holes must be slightly smaller than the outer diameter of the cable 3 core to ensure reliable clamping of the cable 3 core when the connector is tightened. Additionally, two sets of M12 through-bolt holes are machined along the thickness direction of the pressure plate 22 for bolt tightening.

[0026] The cover plate 21 of the neutral point connector 2 is a 25x50x100mm cuboid, and is galvanized after machining. The cover plate 21 is made of Q235 carbon steel. Three sets of through semi-circular holes are machined on the side near the pressure plate 22. The distance between adjacent semi-circular holes along the length direction must be greater than the outer diameter of the cable 3 to avoid interference between adjacent cables 3 during installation. The diameter of the semi-circular holes must be slightly smaller than the outer diameter of the cable 3 core to ensure that the cable 3 core is reliably clamped when the connector is tightened. Additionally, two sets of 14mm diameter through holes 23 are machined along the thickness direction of the cover plate 21 for bolt tightening. Furthermore, to ensure that the bolt head does not protrude from the outer surface of the cover plate 21 after installation, two sets of countersunk holes 15mm deep and 20mm in diameter are machined on the side of the cover plate 21 away from the cable 3 holes. The neutral point connector 2 uses standard hexagonal socket head cap screws with a strength grade of 8.8, and the bolts are galvanized.

[0027] Specifically, such as Figures 5-7 As shown, the insulating box 1 includes an insulating box body 11, an upper U-shaped hole 115 and a lower U-shaped hole 116 are respectively provided on both sides of the insulating box body 11, a sealing plate 12 is inserted into the lower U-shaped hole 116, a cable through hole 121 is provided on the sealing plate 12, and an insulating box cover 13 is connected to the open side of the insulating box body 11.

[0028] The insulating box 11 includes a base plate 111. The four sides of the base plate 111 are respectively provided with an upper plate 112, a lower plate 113 and two upright plates 114. The two upright plates 114 are respectively connected to the two sides between the upper plate 112 and the lower plate 113. An upper U-shaped hole 115 is provided on the upper plate 112 and two lower U-shaped holes 116 are provided on the lower plate 113. The upper plate 112, the lower plate 113 and the two upright plates 114 are respectively connected to the insulating box cover 13.

[0029] The sealing plate 12 is composed of two symmetrical halves joined together.

[0030] The insulating box 1 consists of an insulating box body 11, an insulating box cover 13, and a sealing plate 12. The insulating box body 11 is usually integrally cast from a polymer material. The insulating box body 11 is formed by splicing together one base plate 111, two vertical plates 114, one upper plate 112, and one lower plate 113. The base plate 111 of the insulating box body 11 is a 3x60x120 high-strength laminate 22DECJ0902. The vertical plate 114 is a 3x60x54 high-strength laminate 22DECJ0902. The upper plate 112 is a 3x60x120 high-strength laminate 22DECJ0902, and a 50mm wide upper U-shaped hole 115 is machined on the upper plate 112 for the introduction of the upper cable 3 and for potting. The lower panel 113 is a 3x60x120mm high-strength laminate 22DECJ0902. Two 25mm wide U-shaped holes 116 are machined on the lower panel 113 for the introduction of the lower cable 3. Two layers of 0.06x50mm polyimide film tape 6240 are used to bond the joints of adjacent panels.

[0031] The insulating box cover 13 is made of 3x60x120 high-strength laminated glass cloth; there are two sets of sealing plates 12. A cable through-hole 121 is machined on the sealing plate 12. The diameter of the cable through-hole 121 is 1-2mm larger than the outer diameter of the cable 3. After the sealing plate 12 is fully machined, along... Figure 7 The shown bifurcation lines divide each of the two lobes.

[0032] After the neutral point connector 2 is insulated, place the neutral point connector 2 inside the box, then attach the sealing plate 12 to the lower U-shaped hole 116 on the lower plate 113, then attach the insulating box cover 13 to the side of the insulating box 11 with polyimide film tape, and finally inject glue from the upper U-shaped hole 115 on the upper plate 112 to achieve the insulation function.

[0033] The linear motor neutral point insulation forming method of this embodiment includes the following steps: S1: After stripping 48mm of insulation from the neutral point connecting cable 3, insert it into the neutral point connector 2, ensuring that the insulation end face of the cable 3 is tightly against the neutral point connector 2, and then tighten the bolts to compact the core of the cable 3. S2: Use room temperature curing filler to fill the gaps between neutral point joints 2 and the gaps between bolt heads and countersunk holes of cover plate 21. Curing at room temperature shall not be less than 24 hours. S3: Wrap and semi-overlap mica foil and fiberglass tape alternately on the surface of neutral point joint 2, and brush room temperature curing epoxy adhesive while wrapping. The wrapping and semi-overlapping should be uniform, dense and wrinkle-free. S4: Place the neutral point connector 2 into the insulation box 1, seal the lower U-shaped hole 116 of the insulation box 1 with the sealing plate 12, and then use polyimide film tape to stick the insulation box cover 13 to the opening side of the insulation box body 11. S5: Fill the insulation box 1 with room temperature curing adhesive through the upper U-shaped hole 115, ensuring that the filling is smooth and dense; S6: Apply two layers of low-resistance anti-corona paint to the surfaces of insulation box 1 and neutral point connecting cable 3. After the first layer is applied and cured for 8 hours, apply the second layer of low-resistance anti-corona paint. The paint should be applied evenly and without omissions, and the room temperature curing time should not be less than 24 hours.

[0034] The present invention significantly reduces the difficulty of insulation forming. In the original design, the cable 3+ short-circuit copper busbar structure requires the use of DT-shaped copper terminals, connecting bolts, nuts, etc., to achieve equipotential bonding. Due to the presence of bolts and nuts, the surface height difference of the neutral point joint 2 is too large, making insulation wrapping difficult. The cable 3+T-shaped tee structure and the cable 3+Y-shaped tee structure are even more irregular in shape, resulting in poorer insulation wrapping density of the entire joint. The structure of the present invention is a standard cuboid, making insulation wrapping much easier to achieve.

[0035] The present invention has a higher insulation withstand voltage rating. The structural insulation molding difficulty of the present invention is significantly reduced, the insulation wrapping effect is better, the insulation reliability is higher, and it can withstand higher operating voltages.

[0036] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A neutral point connection structure for a linear motor, characterized in that: The device includes an insulating box (1) and a neutral point connector (2). The neutral point connector (2) presses the three cables (3) together. The neutral point connector (2) is installed inside the insulating box (1). One side of the insulating box (1) is provided with an upper U-shaped hole (115) for one of the cables (3) to pass through. The other side of the insulating box (1) is provided with two lower U-shaped holes (116) for the other two cables (3) to pass through. The insulating box (1) is filled with room temperature curing adhesive.

2. The neutral point connection structure of a linear motor according to claim 1, characterized in that: The neutral point connector (2) includes a cover plate (21) and a pressure plate (22). The cover plate (21) and the pressure plate (22) are connected by screws. The side of the cover plate (21) facing the pressure plate (22) and the side of the pressure plate (22) facing the cover plate (21) are provided with three semi-circular holes. The semi-circular holes of the cover plate (21) and the semi-circular holes of the pressure plate (22) are combined to form a through hole (23). The three cables (3) are pressed into the three through holes (23) respectively.

3. The neutral point connection structure of a linear motor according to claim 2, characterized in that: The cable (3) in the upper U-shaped hole (115) is inserted into the through hole (23) in the middle of the neutral point connector (2), and the cables (3) in the two lower U-shaped holes (116) are respectively inserted into the through holes (23) on both sides of the neutral point connector (2).

4. The neutral point connection structure of a linear motor according to claim 2, characterized in that: The distance between two adjacent through holes (23) on the neutral point connector (2) is greater than the outer diameter of the cable (3).

5. The neutral point connection structure of a linear motor according to claim 2, characterized in that: The diameter of the through hole (23) is smaller than the outer diameter of the cable core (3).

6. The neutral point connection structure of a linear motor according to claim 1, characterized in that: The neutral point connector (2) is wrapped with insulating material.

7. The neutral point connection structure of a linear motor according to claim 1, characterized in that: The insulating box (1) includes an insulating box body (11), an upper U-shaped hole (115) and a lower U-shaped hole (116) are respectively provided on both sides of the insulating box body (11), a sealing plate (12) is inserted into the lower U-shaped hole (116), a cable through hole (121) is provided on the sealing plate (12), and an insulating box cover (13) is connected to the opening side of the insulating box body (11).

8. The neutral point connection structure of a linear motor according to claim 7, characterized in that: The insulating box (11) includes a base plate (111). The four sides of the base plate (111) are respectively provided with an upper plate (112), a lower plate (113) and two upright plates (114). The two upright plates (114) are respectively connected to the two sides between the upper plate (112) and the lower plate (113). An upper U-shaped hole (115) is provided on the upper plate (112), and two lower U-shaped holes (116) are provided on the lower plate (113). The upper plate (112), the lower plate (113) and the two upright plates (114) are respectively connected to the insulating box cover (13).

9. The neutral point connection structure of a linear motor according to claim 7, characterized in that: The sealing plate (12) is composed of two symmetrical halves joined together.

10. A method for forming insulation at the neutral point of a linear motor, using the neutral point connection structure of a linear motor as described in claim 7, characterized in that: Includes the following steps: S1: After stripping the insulation material from the end of the neutral point connecting cable (3), insert it into the neutral point connector (2) and tighten the bolt on the neutral point connector (2) to compact the cable (3) core; S2: Use room temperature curing filler to fill the gap between the neutral point joints (2) and the gap between the bolt head and the bolt hole, and cure at room temperature for no less than 24 hours; S3: Wrap mica foil and fiberglass tape alternately and half-overlap on the surface of the neutral point joint (2), and brush room temperature curing epoxy adhesive while wrapping; S4: Place the neutral point connector (2) into the insulating box (11), seal the lower U-shaped hole (116) on the insulating box (11) with the sealing plate (12), and then use polyimide film tape to stick the insulating box cover (13) to the opening side of the insulating box (11). S5: Fill the insulation box (1) with room temperature curing adhesive through the upper U-shaped hole (115); S6: Apply two layers of low-resistance anti-corona paint to the surface of the insulating box (1) and the neutral point connecting cable (3). After the first layer is applied and cured for 8 hours, apply the second layer of low-resistance anti-corona paint. The room temperature curing time is not less than 24 hours.

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