Corona-resistant insulating mica paper for motor

Abstract

The corona-resistant insulating mica paper comprises a base body and a surface layer, the surface layer is formed on the surface of one side of the base body, and a composite functional layer is formed between the base body and the surface layer; the base body and the surface layer are mica paper layers; the composite functional layer comprises a corona-resistant reinforcing layer and a physical reinforcing layer, the corona-resistant reinforcing layer is an insulating film layer, the physical reinforcing layer is a composite structure layer of a uniaxial stretching polymer film and an insulating fiber layer, rhombic lattice holes are formed in the surface of the uniaxial stretching polymer film, the long diagonal lines of the rhombic lattice holes are parallel to the length direction of the base body, and the long diagonal lines of the rhombic lattice holes are parallel to the length direction of the base body. The width of the film belt between the rhombic lattice holes adjacent in position is 1 / 5-1 / 3 of the length of the short diagonal lines of the rhombic lattice holes; and the insulating fiber layer is formed by uniformly dispersing impregnated chopped insulating fibers on the surface of the uniaxial stretching polymer film. By improving the structure of the mica paper, the corona resistance, long-term stability and durability of the mica paper in electrical equipment such as a motor are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic materials, and particularly relates to a corona-resistant insulating mica paper for motors. Background Technique

[0002] Corona, as a common type of partial discharge phenomenon, often occurs around high-voltage wires and near the tips of charged bodies. Corona can consume electrical energy and have a negative impact on the normal operation of motors, such as causing unnecessary current leakage and power loss of the motor; generating significant noise and vibration during operation; reducing the insulation strength of the motor, accelerating the aging and damage of the motor insulation material, resulting in a reduction in the motor life and an increase in maintenance costs, and even potentially causing safety hazards such as electric shock and fire.

[0003] Currently, in order to reduce the impact of corona on motors, the measures that can be taken, in addition to adjusting the motor operating conditions, such as reducing voltage, reducing current, etc., and strengthening the maintenance and upkeep of the motor, are to select suitable insulating materials and coatings to improve the insulation performance of the motor. Mica paper, as a type of insulating material, is a secondary processed product of mica and has excellent electrical properties such as high electrical strength, low dielectric loss, high surface resistance, and high volume resistance. Although the utility model patent previously applied by the applicant: a corona-resistant mica paper (202321801596.6) has initially solved the insulation problem of mica paper in a corona environment, in actual applications, we still found that there are some areas for improvement, especially in terms of long-term stability and durability in high-voltage and high-current environments such as motors.

[0004] Therefore, in order to further improve the corona resistance of mica paper, it is necessary to improve the structure of the original corona-resistant insulating mica paper to meet the higher requirements of electrical equipment such as motors for insulating materials. Content of the Utility Model

[0005] The technical problem solved by the utility model is to provide a corona-resistant insulating mica paper for motors to solve the deficiencies in the above background technique.

[0006] The technical problem solved by the utility model is achieved by adopting the following technical solutions:

[0007] A corona-resistant insulating mica paper for motors includes a substrate and a surface layer. The surface layer is formed on one side surface of the substrate, and a composite functional layer is formed between the substrate and the surface layer;

[0008] Both the substrate and the surface layer are mica paper layers;

[0009] The composite functional layer includes a corona-resistant enhancement layer and a physical enhancement layer. The corona-resistant enhancement layer includes an insulating film layer, and the insulating film layer is attached to and formed on the side surface of the surface layer. The physical enhancement layer is a composite structural layer of a unidirectionally stretched polymer film and an insulating fiber layer. The unidirectionally stretched polymer film is a BOPP film, and diamond-shaped holes are formed on its surface. The long diagonal of the diamond-shaped holes is parallel to the length direction of the substrate, and the width of the film strip between adjacent diamond-shaped holes is 1 / 5 to 1 / 3 of the length of the short diagonal of the diamond-shaped holes. The insulating fiber layer is obtained by uniformly dispersing impregnated chopped insulating fibers on the surface of the unidirectionally stretched polymer film and then forming it.

[0010] As a further limitation, the thickness of the mica paper layer serving as the substrate is 1.5 to 2 times the thickness of the mica paper layer serving as the surface layer.

[0011] As a further limitation, the mica paper layer serving as the substrate is phlogopite paper or synthetic mica paper; while the mica paper layer serving as the surface layer is synthetic mica paper or sericite paper.

[0012] As a further limitation, a waterproof coating is coated on the surface of the surface layer, and the waterproof coating is a high-temperature resistant polymer waterproof coating.

[0013] As a further limitation, the insulating film layer of the corona-resistant enhancement layer is one of a polyimide film layer, a polytetrafluoroethylene film layer, or a polystyrene film layer.

[0014] As a further limitation, a corona-resistant coating is also formed on the surface of the insulating film layer of the corona-resistant enhancement layer, and the corona-resistant coating is a silicone rubber coating or a polytetrafluoroethylene coating.

[0015] As a further limitation, a graphene layer is also formed between the corona-resistant enhancement layer and the surface layer. One side surface of the graphene layer is nickel-plated, and the graphene layer is attached to the surface of the corona-resistant enhancement layer on the nickel-plated side surface.

[0016] As a further limitation, the ratio of the length of the long diagonal to the length of the short diagonal of the diamond-shaped holes on the unidirectionally stretched polymer film in the physical enhancement layer is 1:1 to 3:1.

[0017] As a further limitation, the impregnated chopped insulating fibers used in the insulating fiber layer are one or a combination of non-alkali glass fibers, ceramic fibers, aromatic polyamide fibers, aromatic polysulfone amide fibers, and oxadiazole fibers; the impregnated sizing used is epoxy resin sizing.

[0018] As a further limitation, a high-temperature resistant protective layer is formed at the position between the unidirectionally stretched polymer film and the insulating fiber layer in the physical enhancement layer, and the high-temperature resistant protective layer is nano high-temperature resistant inorganic powder uniformly dispersed at the interface position between the unidirectionally stretched polymer film and the insulating fiber layer;

[0019] The nano high-temperature resistant inorganic powder is alumina, aluminum nitride or silicon nitride.

[0020] Beneficial effects: The corona-resistant insulating mica paper for motors of the present utility model can maintain the physical and electrical properties of the mica paper itself. By setting a composite functional layer between the substrate and the surface layer, adding a high-temperature resistant protective layer between the composite functional layer and the substrate, adding a reinforcing fiber layer outside the surface layer and coating a waterproof coating, etc., the corona resistance, high-temperature resistance, mechanical strength and waterproof performance of the mica paper are further improved, enabling it to better meet the high requirements of electrical equipment such as motors for insulating materials, and improving the operating efficiency and safety of the motors. Description of the drawings

[0021] Figure 1 It is a schematic structural diagram of a preferred embodiment of the present utility model.

[0022] Figure 2 It is a schematic structural diagram of the unidirectional stretching polymer film in a preferred embodiment of the present utility model.

[0023] Among them: 1. Substrate; 2. Insulating fiber layer; 3. Unidirectional stretching polymer film; 4. Corona-resistant coating; 5. Insulating film layer; 6. Surface layer; 7. Waterproof coating. Specific embodiments

[0024] In order to make the technical means, creative features, achieved purposes and effects of the present utility model easy to understand, the present utility model will be further described below with reference to specific drawings.

[0025] See Figure 1 、 Figure 2 A preferred embodiment of a corona-resistant insulating mica paper for motors. In this embodiment, the corona-resistant insulating mica paper for motors mainly includes a substrate 1, a composite functional layer and a surface layer 6. The substrate 1, as the main structural support and basic insulating structure, is made of phlogopite paper or synthetic mica paper and has excellent electrical properties and mechanical strength; while the surface layer 6, as the surface protection layer, is made of synthetic mica paper or sericite paper to improve the surface wear resistance and corrosion resistance of the mica paper.

[0026] The thickness of the substrate 1 is designed to be 1.5 to 2 times the thickness of the surface layer 6 to ensure the stability and strength of the overall structure.

[0027] The composite functional layer is located between the substrate 1 and the surface layer 6 and is composed of a corona-resistant enhancement layer and a physical enhancement layer. The corona-resistant enhancement layer thereof includes an insulating film layer 5, and the insulating film layer 5 adopts one of a polyimide film layer, a polytetrafluoroethylene film layer or a polystyrene film layer. These materials have good insulation performance and corona resistance performance and can be used to enhance the insulation performance of mica paper in a corona environment. The insulating film layer 5 is attached to and formed on the side surface of the surface layer 6 to form a tight protective layer, effectively blocking the damage of corona to the mica paper mounting components; while the physical enhancement layer, as another important part of the composite functional layer, adopts a composite structural layer of a unidirectionally stretched polymer film 3 and an insulating fiber layer 2. The unidirectionally stretched polymer film 3 is a BOPP film, and its structural pattern is as Figure 2 shown. The surface of the unidirectionally stretched polymer film 3 is formed with diamond-shaped holes, and the long diagonal of the diamond-shaped holes is parallel to the length direction of the substrate 1. This structure enables the mica paper to produce a tensile enhancement effect when subjected to external forces, thereby improving the toughness of the mica paper and ensuring sufficient strength and stability of the mica paper. At the same time, the width of the film strip between adjacent diamond-shaped holes is 1 / 5 to 1 / 3 of the length of the short diagonal of the diamond-shaped holes. This design enables the film to maintain a certain strength in both the length and width directions and also has a certain air permeability, which is beneficial to the dissipation of heat inside the mica paper.

[0028] In order to further improve the corona resistance performance, a corona-resistant coating layer 4 is respectively formed on both side surfaces of the insulating film layer 5 in this embodiment. The corona-resistant coating layer 4 adopts a silicone rubber coating layer or a polytetrafluoroethylene coating layer. These coating materials not only have good corona resistance performance, can effectively resist corona discharge, and improve the long-term stability and durability of mica paper; but also have excellent high-temperature resistance performance and can maintain stable performance in a high-temperature environment, thereby further improving the corona resistance performance of mica paper.

[0029] In another embodiment, in order to enhance the physical properties of mica paper, a graphene layer can also be formed between the insulating film layer 5 of the corona-resistant enhancement layer and the surface layer 6. The graphene layer has excellent electrical conductivity and mechanical strength and can effectively improve the mechanical strength and electrical properties of mica paper. At the same time, the graphene layer is deliberately plated with nickel on one side surface. The nickel plating layer not only enhances the electrical conductivity of the graphene layer but also improves its adhesion performance with the insulating film layer 5, making the entire composite functional layer more stable.

[0030] In the physical enhancement layer of the composite functional layer in this embodiment, the interlayer positional relationship between the unidirectionally stretched polymer film 3 and the insulating fiber layer 2 can be interchanged without special requirements. The insulating fiber layer 2 in the physical enhancement layer is obtained by uniformly dispersing impregnated chopped insulating fibers on the surface of the unidirectionally stretched polymer film 3 and then integrally hot-pressing with mica paper. The impregnated chopped insulating fibers in the insulating fiber layer 2 are made of one or a combination of alkali-free glass fibers, ceramic fibers, aromatic polyamide fibers, aromatic polysulfonamide fibers, and oxadiazole fibers. These fiber materials have good electrical properties and mechanical strength, and can effectively improve the insulation performance and mechanical strength of mica paper. The impregnating adhesive is an epoxy resin adhesive, which has good adhesion and high-temperature resistance, and can ensure the firm bonding between the insulating fiber layer 2 and the unidirectionally stretched polymer film 3, further enhancing the mechanical strength and stability of mica paper.

[0031] To enhance the waterproof performance of mica paper, a waterproof coating 7 is also coated on the surface layer 6 of the mica paper in this embodiment. The waterproof coating 7 is a high-temperature resistant polymer waterproof coating. This coating material not only has good waterproof performance but also excellent high-temperature resistance, and can maintain stable performance in high-temperature environments, thereby ensuring the electrical performance and mechanical strength of mica paper in humid environments.

[0032] In another embodiment, to further improve the high-temperature resistance of mica paper, a high-temperature resistant protective layer is formed at the position between the unidirectionally stretched polymer film 3 and the insulating fiber layer 2 in the physical enhancement layer. The high-temperature resistant protective layer is nano high-temperature inorganic powder uniformly dispersed at the interface position between the unidirectionally stretched polymer film 3 and the insulating fiber layer 2, such as alumina, aluminum nitride, or silicon nitride. These nano powders have good high-temperature resistance and can maintain stable performance in high-temperature environments, thereby effectively improving the high-temperature resistance of mica paper.

[0033] In summary, the corona-resistant insulating mica paper for motors of the present utility model realizes a comprehensive improvement in the corona resistance, high-temperature resistance, mechanical strength, and waterproof performance of mica paper by adopting a multi-layer composite structure and combining various functional materials, enabling it to better meet the high requirements of electrical equipment such as motors for insulating materials, and improving the operating efficiency and safety of motors.

[0034] The above shows and describes the basic principles, main features, and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and all these changes and improvements fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A corona-resistant insulating mica paper for motors, characterized in that: It comprises a substrate and a surface layer, wherein the surface layer is formed on a single side surface of the substrate, and a composite functional layer is formed between the substrate and the surface layer; The substrate and the surface layer are both mica paper layers; The composite functional layer includes a corona-resistant reinforcement layer and a physical reinforcement layer. The corona-resistant reinforcement layer includes an insulating film layer, which is attached to and formed on the side surface of the surface layer. The physical reinforcement layer is a composite structural layer of a uniaxially stretched polymer film and an insulating fiber layer. The uniaxially stretched polymer film is a BOPP film, and diamond holes are formed on its surface. The long diagonal of the diamond holes is parallel to the length direction of the substrate, and the width of the film strip between adjacent diamond holes is 1 / 5 to 1 / 3 of the length of the short diagonal of the diamond holes. The insulating fiber layer is obtained by uniformly dispersing impregnated chopped insulating fibers on the surface of the uniaxially stretched polymer film.

2. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The thickness of the mica paper layer as the substrate is 1.5 to 2 times the thickness of the mica paper layer as the surface layer.

3. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The mica paper layer as the base is phlogopite paper or synthetic mica paper; and the mica paper layer as the surface layer is synthetic mica paper or sericite mica paper.

4. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The surface of the surface layer is coated with a waterproof coating, and the waterproof coating is a high-temperature resistant polymer waterproof coating.

5. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The insulating film layer of the corona-resistant enhancement layer is one of a polyimide film layer, a polytetrafluoroethylene film layer or a polystyrene film layer.

6. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: A layer of corona-resistant coating is also formed on the surface of the insulating film layer of the corona-resistant reinforcement layer. The corona-resistant coating is a silicone rubber coating or a polytetrafluoroethylene coating.

7. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: A graphene layer is formed between the corona-resistant enhancement layer and the surface layer. The single-side surface of the graphene layer is nickel-plated, and the graphene layer is attached to the surface of the corona-resistant enhancement layer on the nickel-plated side.

8. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The ratio of the length of the long diagonal line to the short diagonal line of the diamond-shaped holes on the uniaxially stretched polymer film in the physical reinforcement layer is 1:1 to 3:

1.

9. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The impregnated short-cut insulating fibers used in the insulating fiber layer are one or a combination of alkali-free glass fibers, ceramic fibers, aromatic polyamide fibers, aromatic polysulfoneamide fibers, and oxadiazole fibers; and the impregnated adhesive material used is epoxy resin adhesive.

10. The corona-resistant insulating mica paper for motors according to claim 1, characterized in that: The physical reinforcement layer is formed with a high temperature resistant protective layer between the uniaxially stretched polymer film and the insulating fiber layer, and the high temperature resistant protective layer is a nanometer high temperature resistant inorganic powder uniformly dispersed at the interface between the uniaxially stretched polymer film and the insulating fiber layer; The nanometer high temperature resistant inorganic powder is aluminum oxide, aluminum nitride or silicon nitride.

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