A composite bar rotor suitable for closed rotor slot induction motor

Abstract

The present invention discloses a composite material bar rotor suitable for a closed rotor slot induction motor, comprising a rotor core, inner layer bars, and outer layer bars. The rotor core is provided with closed slots, and the inner and outer layer bars are radially arranged within the closed slots. The inner layer bars are closer to the axis of the rotor core relative to the outer layer bars, i.e., the bars closer to the air gap are the outer layer bars. The outer and inner layer bars are made of different conductive and magnetic materials. The rotor proposed by the present invention has high magnetic permeability in the upper layer bars of the rotor core, thereby reducing the magnetic bridge saturation effect that occurs during motor rotation. The rotor also optimizes the sinusoidality of the motor's air gap magnetic flux density and reduces air gap magnetic flux harmonics. Consequently, the motor's radial electromagnetic force harmonics are reduced, and vibration caused by the radial electromagnetic force is reduced. The overall electromagnetic vibration and noise of the motor are reduced. The present invention has a simple structure, significant noise reduction effects, and wide versatility.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a composite material guide bar rotor suitable for a closed rotor slot induction motor. Background Art

[0002] Currently, aluminum and copper bars are commonly used in induction motor rotors. Due to environmental factors, some motors use closed rotor slots. Motor vibration and noise impact production and daily life, with electromagnetic vibration and noise being the primary sources. Furthermore, the magnetic bridge saturation that occurs during operation in closed-slot induction motors increases air gap magnetic flux harmonics, increasing motor vibration and noise. Summary of the Invention

[0003] The purpose of the present invention is to propose a composite material conductive bar rotor suitable for a closed rotor slot induction motor, which can effectively reduce the magnetic bridge saturation effect of the closed slot, thereby reducing the air gap magnetic flux harmonics of the motor, further reducing the radial electromagnetic force harmonics of the motor, and reducing the electromagnetic vibration and noise of the motor.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A composite material bar rotor suitable for a closed rotor slot induction motor comprises a rotor core, inner layer bars, and outer layer bars, wherein: the rotor core is provided with closed slots, the inner layer bars and outer layer bars are arranged in the closed slots along the radial direction of the rotor core, the inner layer bars are closer to the axis of the rotor core relative to the outer layer bars, that is, closer to the air gap, and the outer layer bars and the inner layer bars are made of different conductive and magnetic materials.

[0006] As a further optimization solution of the present invention, all closed slots of the rotor core are filled with inner layer conductor bars and outer layer conductor bars.

[0007] As a further optimization scheme of the present invention, the magnetic permeability of the outer layer of conductive bars is higher than that of the inner layer of conductive bars, and the magnetic circuit can pass through the outer layer of conductive bars, thereby reducing the saturation degree of the rotor core near the air gap, reducing the leakage flux of the motor, and improving the operating reliability of the motor.

[0008] As a further optimization scheme of the present invention, the outer layer conductive bar material is cobalt material, and the magnetic permeability of cobalt material is greater than that of aluminum material and copper material. The magnetic circuit can pass through the outer layer conductive bar, reducing the saturation degree of the rotor core near the air gap. The inner layer conductive bar material is aluminum material or copper material. Aluminum material and copper material have low cost and magnetic permeability less than that of cobalt material, which reduces the leakage flux of the motor and improves the operating reliability of the motor.

[0009] As a further optimization solution of the present invention, the thickness of the outer layer of conductive bars is less than that of the inner layer of conductive bars, which effectively reduces the saturation effect of the motor and improves the motor performance.

[0010] As a further optimization solution of the present invention, the outer layer conductive bars and the inner layer conductive bars are bonded or welded into a whole by using metal glue, and the outer layer conductive bars and the inner layer conductive bars cannot move relative to each other after becoming a whole.

[0011] As a further optimization scheme of the present invention, it also includes an end ring, which is arranged at the end of the rotor core and is welded to the outer conductor bar and the inner conductor bar, so that the end ring, the outer conductor bar and the inner conductor bar are integrated into a whole, forming a rotor circuit, generating an induced current, and allowing the motor to operate normally.

[0012] As a further optimization solution of the present invention, the material of the connecting end ring is the same as that of the inner layer guide bar, thereby improving the operating reliability of the motor.

[0013] The beneficial effects of the present invention are embodied in:

[0014] The present invention proposes a composite material conductive bar rotor suitable for a closed rotor slot induction motor. The upper conductive bars of the rotor core have high magnetic permeability, which reduces the magnetic bridge saturation effect that occurs during the rotation of the motor; at the same time, the sinusoidality of the motor's air gap magnetic density is optimized and the air gap magnetic density harmonics are reduced; thereby, the radial electromagnetic force harmonics of the motor are reduced, and the vibration caused by the radial electromagnetic force is reduced; the overall electromagnetic vibration and noise of the motor are reduced; the present invention has a simple structure, a significant noise reduction effect, and wide versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings in the specification, which constitute a part of this application, are used to provide further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute improper limitations on this application.

[0016] Figure 1 Schematic diagram of the cross-sectional structure of the composite material guide bar rotor;

[0017] Figure 2 for Figure 1 A magnified view of the local area A;

[0018] Figure 3 Schematic diagram of the composite bar rotor guide bar and end ring structure;

[0019] Figure 4 Schematic diagram of the cross-sectional structure of the aluminum bar rotor;

[0020] Figure 5 This is a comparison chart of the noise sound pressure level of the composite bar rotor motor and the aluminum bar rotor motor.

[0021] Numbers in the figure: 1 rotor core, 2 outer conductor bars, 3 inner conductor bars, 2 / 3 outer conductor bars and inner conductor bars, 4 rotor outer diameter, 5 magnetic bridge area, 6 end ring, 7 aluminum conductor bars, A local area. DETAILED DESCRIPTION

[0022] The present application is described in further detail below in conjunction with the accompanying drawings. It is necessary to point out that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technicians in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0023] like Figure 1 As shown, the present invention provides a composite bar rotor. The rotor cross-section shows a rotor core 1, outer bars 2, and inner bars 3. The rotor core 1 is provided with radially closed slots. The outer bars 2 and inner bars 3 are radially arranged within the closed slots, with the inner bars 3 positioned close to the axis of the rotor core 1. The outer bars 2 are made of cobalt, while the inner bars 3 are made of aluminum. The magnetic permeability of the outer bars 2 is greater than that of the inner bars 3. The outer bars 2 and inner bars 3 are welded together to form a single unit. Once integrated, the outer bars 2 and inner bars 3 cannot move relative to each other. Local area A encompasses the rotor core 1, the outer bars 2, and the inner bars 3.

[0024] like Figure 2 As shown, the area between the rotor outer diameter 4 and the outer conductor bar 2 is the magnetic bridge region 5; the thickness of the outer conductor bar 2 is a; the combined thickness of the inner conductor bar 3 and the outer conductor bar 2 is b; and the rotor composite conductor bar satisfies the following: a / b = 0.17. When a closed-slot motor rotates, the magnetic flux density in the magnetic bridge region 5 increases, often leading to saturation in the magnetic bridge region 5. By using the composite conductor bar of the present invention, the high magnetic permeability of the outer conductor bar 2 reduces saturation in the magnetic bridge region 5, thereby reducing air gap magnetic flux harmonics, lowering the motor's electromagnetic vibration and noise, and effectively reducing the overall vibration and noise of the motor.

[0025] like Figure 3 As shown, it also includes an end ring 6, which is arranged at the end of the rotor core 1. The end ring 6 is welded to the outer conductor bar and the inner conductor bar 2 / 3. The material of the end ring 6 is the same as that of the inner conductor bar 3, and the material of the end ring 6 is aluminum.

[0026] like Figure 4 FIG. 1 is a structural diagram of a rotor in the prior art, in which aluminum bars 7 are placed in the closed slots of the rotor core.

[0027] like Figure 5As shown in the figure, from the curves of the noise sound pressure level variation with frequency of the 6-pole closed rotor slot induction motor with 72 stator slots and 58 rotor slots, when it has an aluminum bar rotor and a composite bar rotor, it can be seen that: the maximum noise sound pressure level of the aluminum bar rotor motor is 117.6dB; the maximum noise sound pressure level of the composite bar rotor motor is 106.2dB; the composite bar rotor motor has a reduced saturation effect, which reduces the air gap magnetic flux harmonics and radial force harmonics of the motor, effectively reducing the motor noise.

[0028] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A composite bar rotor suitable for a closed rotor slot induction motor, characterized by: It includes rotor core, inner conductor bars and outer conductor bars, among which: A closed slot is opened on the rotor core, and the inner and outer conductive bars are arranged in the closed slot along the radial direction of the rotor core. The inner conductive bars are closer to the axis of the rotor core than the outer conductive bars. The outer and inner conductive bars are made of different conductive and magnetic materials; the magnetic permeability of the outer conductive bars is higher than that of the inner conductive bars. The outer conductor bars are made of cobalt and the inner conductor bars are made of aluminum or copper. The thickness of the outer conductor bar is smaller than that of the inner conductor bar.

2. The composite bar rotor for a closed rotor slot induction motor according to claim 1, characterized in that: The outer layer conductor bars and the inner layer conductor bars are fixed by metal adhesive bonding or welding.

3. The composite bar rotor for a closed rotor slot induction motor according to claim 1, characterized in that: It also includes an end ring, which is arranged at the end of the rotor core and is welded to the outer layer conductor bar and the inner layer conductor bar.

4. The composite bar rotor for a closed rotor slot induction motor according to claim 3, characterized in that: The material of the end ring is the same as that of the inner conductor bar.

Images