Shaft current blocking insulation structure for motor

Abstract

The invention provides a shaft current blocking insulation structure for a motor, which is characterized by comprising an insulation film, the thickness of the insulation film is not less than 0.5 mm, two ends of the insulation film are connected to form a closed structure, an outer metal wrapping layer wraps the outer side of the insulation film, an inner metal wrapping layer wraps the inner side of the insulation film, and the outer metal wrapping layer wraps the inner metal wrapping layer. The outer side of the outer metal wrapping layer is matched with the inner side of the base in shape and size, and the inner side of the inner metal wrapping layer is matched with the outer side of the bearing seat in shape and size. The problems of poor insulation effect and unqualified ground insulation of the variable frequency motor shaft in the prior art are solved, the original structure and support effect are not changed, and the insulation function is added.

Description

Technical Field

[0001] The present invention relates to the technical field of motor manufacturing, and specifically to an insulation structure for blocking shaft current in a motor. Background Art

[0002] Due to the power supply conditions during operation, variable-frequency motors inevitably generate shaft voltage inside the motor. Once an electrical circuit is formed, it will damage the bearings and affect the normal operation of the motor. Therefore, an insulating layer needs to be added to block this electrical circuit. The original insulation measures include using insulated bearings; or covering the end covers and bearing sleeves with non-woven tape materials and insulating the periphery of the fasteners; or adopting an integral insulation structure. However, the cost of the original insulated bearings is too high, the non-woven tape structure is relatively cumbersome to operate and has low reliability; the integral insulation has insufficient flexibility due to the need for complex mold pressing and cannot adapt to multiple models. Summary of the Invention

[0003] The present invention provides an insulation structure for blocking shaft current in a motor to solve the technical defects of the above-mentioned prior art.

[0004] To solve the above technical problems, the technical solution of the present invention is an insulation structure for blocking shaft current in a motor, which is characterized by including an insulating film. The thickness of the insulating film is not less than 0.5 mm. Both ends of the insulating film are connected to form a closed structure. An outer metal wrapping layer is wrapped outside the insulating film, and an inner metal wrapping layer is wrapped inside the insulating film. The outer shape and size of the outer metal wrapping layer match those of the inner side of the machine base, and the outer shape and size of the inner metal wrapping layer match those of the outer side of the bearing seat.

[0005] Specifically, the insulation structure is matched with a variable-frequency motor.

[0006] Specifically, the outer metal wrapping layer and the inner metal wrapping layer are integrally annular.

[0007] Specifically, when the insulation structure is assembled, when the insulating film is wrapped outside the inner metal wrapping layer, the outer metal wrapping layer needs to be heated, and then the inner side of the outer metal wrapping layer is heat-sleeved on the insulating film.

[0008] Specifically, after the outer metal wrapping layer and the inner metal wrapping layer wrap the insulating film, an epoxy-based adhesive is sealed at the joint, and all indicators need to meet the requirements specified in GB / T 4612 of the national standard.

[0009] Specifically, the epoxy-based adhesive is a thermally conductive insulating epoxy adhesive.

[0010] Specifically, the outer metal wrapping layer and the inner metal wrapping layer are made of cast iron.

[0011] Specifically, the insulating film is made of polyimide.

[0012] Due to structures such as the insulating film, the beneficial effects of the present invention are as follows:

[0013] 1. It solves the problems of poor original insulation effect and unqualified insulation between the shaft of the variable-frequency motor and the ground. Without changing the original structure and supporting function, it adds an insulation function, and does not increase the weight and particularly complex processes, improving the reliability of the product.

[0014] 1. This insulation structure can be directly fabricated on the metal body without special processing equipment and processes, and can flexibly adapt to various requirements. The material and processing costs are also relatively low. After assembly, no machining operations are required. This improves the reliability of the motor, reduces the manufacturing cost, and the structure is simpler, more reasonable, easier to implement, and avoids quality problems.

[0015] 2. The entire structure is in a combined form, and the manufacturing dimensions of each component can be adjusted according to the specific installation requirements of different models. Each component can be mass-produced, assembled into the final form elsewhere, and then enter the work station for the overall assembly of the generator, which is suitable for variable-frequency motor orders with multiple varieties and small batches. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application and do not limit the present application.

[0017] Figure 1 2D schematic diagram of the upper half of an insulation structure for blocking shaft current in a motor according to the present invention

[0018] Figure 2 Schematic diagram of the position of the upper half of an insulation structure for blocking shaft current in a motor according to the present invention, the machine base, and the bearing seat

[0019] Figure 3 3D schematic diagram of the upper half of an insulation structure for blocking shaft current in a motor according to the present invention

[0020] Wherein, 1. Outer metal wrapping layer, 2. Inner metal wrapping layer, 3. Epoxy adhesive, 4. Insulating film, 5. Machine base, 6. Bearing seat DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0022] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art to which the present application pertains.

[0023] As Figures 1 to 3 shown, the technical solution of the present invention is an insulating structure for blocking shaft current in a motor, which is characterized by including an insulating film 4. The thickness of the insulating film 4 is not less than 0.5 mm. Both ends of the insulating film 4 are connected to form a closed structure. An outer metal wrapping layer 1 is wrapped outside the insulating film 4, and an inner metal wrapping layer 2 is wrapped inside the insulating film 4. The outer shape and size of the outer metal wrapping layer 1 match those of the inner side of the machine base 5, and the outer shape and size of the inner metal wrapping layer 2 match those of the outer side of the bearing seat 6. The insulating film 4 is the key of the present invention. Not only is the electrical circuit blocked through it, but considering the insulation effect and necessary mechanical strength, the thickness of the insulating layer after wrapping is not less than 0.5 mm. The outer metal wrapping layer 1 provides protection for the insulating film 4 on the one hand and forms a stable structure by connecting with the machine base 5 on the other hand. The inner metal wrapping layer 2 provides protection for the insulating film 4 on the one hand and forms a stable structure by connecting with the bearing seat 6 on the other hand. Finally, the present invention is connected between the machine base 5 and the bearing seat 6, which not only improves the overall stability of the equipment, but also blocks the electrical circuit, avoids damage to the bearing, and avoids affecting the normal operation of the motor.

[0024] Specifically, the insulating structure is matched with a variable-frequency motor. Insulation measures for a variable-frequency motor are necessary, while they will increase the cost for a general motor.

[0025] Specifically, the outer metal wrapping layer 1 and the inner metal wrapping layer 2 are integrally annular, and the annular shape is adapted to most machine bases 5 and bearing seats 6, improving the versatility.

[0026] Specifically, when the insulating structure is assembled, when the insulating film 4 is wrapped outside the inner metal wrapping layer 2, the outer metal wrapping layer 1 needs to be heated, and then the inner side of the outer metal wrapping layer 1 is thermally sleeved on the insulating film 4, improving the installation reliability.

[0027] Specifically, after the outer metal wrapping layer 1 and the inner metal wrapping layer 2 wrap the insulating film, an epoxy adhesive 3 is sealed at the joint, and all indicators need to meet the requirements specified in GB / T 4612 of the national standard. The outer metal wrapping layer 1 and the inner metal wrapping layer 2 are combined to form a closed ring, and both are sealed with the epoxy adhesive 3, which improves the safety of the insulating film.

[0028] Specifically, the epoxy adhesive 3 is a thermally conductive insulating epoxy adhesive, which further improves the insulation performance, and at the same time transfers heat to play a heat dissipation function.

[0029] Specifically, the outer metal wrapping layer 1 and the inner metal wrapping layer 2 are made of cast iron. Cast iron has high compressive strength, excellent vibration damping performance, low cost, mature casting process, is suitable for mass production, is wear-resistant and corrosion-resistant, and the surface can be spray-treated to extend the service life.

[0030] Specifically, the insulating film 4 is made of polyimide. Polyimide is heat-resistant, suitable for high-speed / high-power motors, has high insulation strength to effectively block shaft current, has high mechanical strength, is resistant to stretching and wear, and is suitable for bearing seats and machine base installations with high tightening force.

[0031] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present invention, rather than to limit the present invention. As long as it is within the scope of the essential spirit of the present invention, changes and modifications to the above-described embodiments will fall within the scope of the claims of the present invention.

Claims

1. An insulation structure for blocking shaft current of an electric motor, characterized in that It includes an insulating film (4) with a thickness of not less than 0.5 mm. Both ends of the insulating film (4) are connected to form a closed structure. An outer metal wrapping layer (1) is wrapped around the outside of the insulating film (4), and an inner metal wrapping layer (2) is wrapped around the inside of the insulating film (4). The outer shape and size of the outer metal wrapping layer (1) match those of the inner side of the machine base (5), and the outer shape and size of the inner metal wrapping layer (2) match those of the outer side of the bearing housing (6).

2. The insulating structure for blocking shaft current of an electric machine according to claim 1, wherein The insulating structure is matched with a variable-frequency motor.

3. An insulation structure for blocking shaft current of an electric motor according to claim 1, characterized in that The outer metal wrapping layer (1) and the inner metal wrapping layer (2) are integrally annular.

4. An insulation structure for blocking shaft current of an electric motor according to claim 1, characterized in that When the insulating structure is assembled, when the insulating film (4) is wrapped around the outside of the inner metal wrapping layer (2), the outer metal wrapping layer (1) needs to be heated, and then the inner side of the outer metal wrapping layer (1) is shrink-fitted onto the insulating film.

5. The insulating structure for blocking shaft current of an electric machine according to claim 1, characterized in that After the outer metal wrapping layer (1) and the inner metal wrapping layer (2) wrap the insulating film (4), an epoxy adhesive (3) is sealed at the joint, and all indicators need to meet the requirements specified in GB / T 4612 of the national standard.

6. An insulation structure for blocking shaft current of an electric machine according to claim 5, characterized in that The epoxy adhesive (3) is a thermally conductive insulating epoxy adhesive.

7. An insulation structure for blocking shaft current of an electric machine according to claim 1, characterized in that The outer metal wrapping layer (1) and the inner metal wrapping layer (2) are made of cast iron.

8. The insulation structure for blocking shaft current of any of the motors according to claims 1 to 7, characterized in that The insulating film (4) is made of polyimide.

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