High-speed asynchronous motor full-rotor hot isostatic pressing welding structure

Abstract

A high-speed asynchronous motor full-rotor hot isostatic pressing welding structure disclosed by the present invention comprises a motor shell, a rotor axis, a rotor copper bar, a rotor end ring and a rotor mouse cage are arranged in the motor shell, the rotor mouse cage is sleeved with a rotor retaining ring, a stator is fixedly installed on the inner wall of the motor shell, and the stator is fixedly installed on the inner wall of the motor shell. And the axis of the rotor rotates in the inner ring of the stator. According to the high-speed asynchronous motor full-rotor hot isostatic pressing welding structure, the rotor axis, the copper bars and the end rings are welded into an integrated structure through the high-temperature and high-pressure hot isostatic pressing technology, the manufacturing cost is saved through hot isostatic pressing welding, the rotor operation stability can be enhanced, and the rotor integrated structure installation position can be improved. Therefore, the rotor core finally achieves the functions of structural strength and reliability of the rotor core at a high rotating speed, effectively improves the safety quality and imbalance of the motor rotor during operation, and reduces the manufacturing and processing cost of the bipolar motor.

Description

Technical Field

[0001] The invention relates to the technical field of hot isostatic pressing of a full rotor of an electric motor, in particular to a hot isostatic pressing welding structure of a full rotor of a high-speed asynchronous motor. Background Art

[0002] At present, with the rapid development of domestic and foreign industries, the demand for asynchronous motors in all walks of life has increased significantly, and the requirements for high-speed motors have become increasingly higher. Some industries that use high-speed motors with variable frequency speed regulation functions and industries that require high-speed two-pole motors also put forward higher requirements for the operating performance and safety and reliability of two-pole motors. The rotor form of high-speed two-pole motors is mainly determined by working conditions. For heavy-load starting and machinery that requires soft characteristics, winding rotors should be selected. In general, squirrel cage asynchronous motors should be preferred. Squirrel cage asynchronous motors have a simple structure, low cost, and are easy to use and maintain. According to the different shapes of the rotor copper bars, squirrel cage motors are divided into single cages, dual cages, deep groove cages, and special-shaped cage bars.

[0003] The rotor of the two-pole motor adopts a rotor cage winding to weld the rotor copper bar and the rotor connecting ring together. The creep-resistant copper alloy rotor copper bar and the rotor end ring are used in the cage structure, and the cage winding is subjected to thermal analysis, structural analysis and creep analysis to ensure its service life. When welding the rotor cage winding of the asynchronous motor, the traditional induction brazing method can be used. This brazing method allows each end of the rotor to be brazed separately and obtains a joint with both rigid electromagnetic and mechanical properties. At present, the rotor cage structure in the traditional high-speed two-pole motor adopts hard copper busbar as the rotor copper bar, and the rotor connecting ring is processed by copper forgings. An annular groove slightly wider than the rotor copper bar is processed on the rotor connecting ring, and the rotor copper bar is extended into the groove for welding. The rotor core laminations of the traditional asynchronous motor are mounted on the rotating shaft by shrink sleeve. In order to prevent the rotor core laminations from axially moving, the axial position of the rotor core patch is limited by the processing of the pillow block and ring key on the rotating shaft. And the rotor ring key of the traditional asynchronous motor is installed in the groove on the rotating shaft and spot welded with the shaft. The rotor of a high-speed motor is a high-speed rotating component, which has very high requirements on the safety of the components. It is necessary to perform high-cycle fatigue analysis and fracture mechanics analysis on the shaft. In order to improve the safety of rotating parts, while ensuring that the two-pole motor can reduce the generation of vibration under the high-speed operation of 6000r / min, and under the premise of meeting the safety and stiffness requirements of the shaft, the rotor copper bar is welded to the rotor axis at the appropriate position of the rotor shaft section. This not only saves the need to install rotor punchings on the rotor and improves the stability of the motor operation, but also enhances the stability of the welding between the motor rotor and the end ring, ensuring that the motor rotor end ring does not run away when the motor rotates. Summary of the invention

[0004] The purpose of the present invention is to provide a full rotor hot isostatic pressing welding structure of a high-speed asynchronous motor in view of the deficiencies of the prior art, so as to solve the problems raised in the background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a full-rotor hot isostatic pressing welding structure of a high-speed asynchronous motor, comprising a motor housing, wherein a rotor shaft, rotor copper bars, rotor end rings and a rotor cage are arranged inside the motor housing, a rotor guard ring is mounted on the rotor cage, a stator is fixedly mounted on the inner wall of the motor housing, the rotor shaft rotates inside the inner ring of the stator, the rotor copper bars are laid on the outer surface of the rotor core, and the rotor core and the rotor shaft are integrally formed.

[0006] As a preferred technical solution of the present invention, a rotor slot is provided on the outer surface of the rotor axis, and a rotor cage is provided in the rotor slot provided on the rotor axis.

[0007] As a preferred technical solution of the present invention, the rotor cage is a rotor copper bar and a rotor end ring assembled into one by hot isostatic pressing.

[0008] As a preferred technical solution of the present invention, the rotor shaft, rotor copper bars and rotor end rings are integrally formed by hot isostatic pressing.

[0009] As a preferred technical solution of the present invention, the rotor cage is a copper or aluminum rotor coil cast in a cage-shaped slot on the rotor core, and the coil is a closed loop not connected to other parts.

[0010] As a preferred technical solution of the present invention, the rotor core, rotor copper bars, rotor end rings, rotor cage and rotor shaft can form a rotor.

[0011] As a preferred technical solution of the present invention, the rotor core 1 is formed by stacking silicon steel sheets, and the rotor guard ring is made of metal material and installed around the rotor.

[0012] Compared with the prior art, the present invention provides a high-speed asynchronous motor full rotor hot isostatic pressing welding structure, which has the following beneficial effects:

[0013] 1. The high-speed asynchronous motor has a full rotor hot isostatic pressing welding structure. The high-speed two-pole asynchronous motor rotor axis structure is designed on the shaft. Combined with the 6000 rpm speed, the first-order critical speed and the second-order critical speed requirements, and the high-speed two-pole motor dynamic balance standard, the rotor axis length and the rotor slot type are calculated. Under the premise of meeting the safety and rigidity requirements of the shaft, the rotor copper bar is hot isostatically pressed and welded on the rotor axis. The rotor axis, copper bar and end ring are welded into an integrated structure through high-temperature and high-pressure hot isostatic pressing technology. Hot isostatic pressing welding not only saves manufacturing costs, but also enhances the rotor operation stability.

[0014] 2. The hot isostatic pressing welding structure of the full rotor of the high-speed asynchronous motor solves the problem of rotor end ring running or cracking at the first critical speed and high-speed operation of 6000r / min of the high-speed two-pole motor, ensuring the stiffness of the rotor shaft of the asynchronous motor. By optimizing the length of the rotor axis and the position of the rotor copper bar on the shaft, the design has better rotational vibration reduction, and finally determines the installation position of the rotor integrated structure, so that the rotor core can finally achieve the function of rotor core structural strength and reliability at high speed;

[0015] 3. The hot isostatic pressing welding structure of the full rotor of the high-speed asynchronous motor solves the problem of running away during the operation of the high-speed two-pole motor, ensures the reliability of the motor operation and the functionality of the service life. By optimizing the selection of the rotor axis position and length of the high-speed two-pole motor in the scheme, the design has better functionality and reliability, and finally determines the material and width of the rotor copper bar, so that the rotor can finally achieve the function of the rotor core structure strength and reliability at high speed, and effectively improve the safety quality and imbalance of the motor rotor during operation, and reduce the manufacturing and processing costs of the two-pole motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the rotor shaft structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the axial cross-section structure of the present invention;

[0018] Figure 3 It is a schematic diagram of the structure of the integrated rotor cage of the present invention;

[0019] Figure 4 This is a schematic diagram of the rotor structure of the motor with a guard ring according to the present invention.

[0020] Figure numerals: 1. rotor core; 2. rotor copper bars; 3. rotor end rings; 4. rotor cage; 5. rotor guard ring; 6. rotor axis. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] See also Figure 1-Figure 4In this embodiment: the full rotor hot isostatic pressing welding structure of the high-speed asynchronous motor includes a motor housing, the interior of the motor housing is provided with a rotor shaft 6, a rotor copper bar 2, a rotor end ring 3 and a rotor cage 4, the rotor cage 4 is provided with a rotor guard ring 5, the inner wall of the motor housing is fixedly mounted with a stator, the rotor shaft 6 is located in the inner ring of the stator and rotates, the rotor copper bar 2 is laid on the outer surface of the rotor core 1, it and the rotor core 1 on the rotor constitute the rotor circuit in the motor, the rotor core 1 and the rotor shaft 6 are integrally formed, which can ensure the stable operation and working efficiency of the rotor.

[0023] In this embodiment, rotor slots are provided on the outer surface of the rotor shaft 6, and a rotor cage 4 is provided in the rotor slots provided on the rotor shaft 6. The rotor cage 4 is assembled into one piece by hot isostatic pressing of the rotor copper bars 2 and the rotor end rings 3, so that sufficient contact area can be ensured while minimizing the cost increase. The two have the same thermal expansion coefficient and fatigue cycle. The rotor shaft 6 is formed into one piece by hot isostatic pressing with the rotor copper bars 2 and the rotor end rings 3. Hot isostatic pressing welding can save manufacturing costs and enhance the rotor operation stability to improve the operation reliability. The rotor cage 4 is a copper or aluminum rotor coil cast in a cage-shaped slot on the rotor core 1. The coil is a closed loop not connected to other parts. The rotor core 1, the rotor copper bars 2, the rotor end rings 3, the rotor cage 4, and the rotor shaft 6 can form a rotor. The rotor core 1 is formed by stacking silicon steel sheets. The rotor guard ring 5 is made of metal material and is installed around the rotor.

[0024] The working principle and use process of the present invention: The high-speed asynchronous motor full rotor hot isostatic pressing welding structure is designed and manufactured to be a high-speed two-pole high-speed asynchronous motor full rotor hot isostatic pressing welding structure. The rotor core 1 designed according to the size of the two-pole motor and the rotor core 1 required by the design specification is shown in the structure. Figure 1 As shown, the rotor shaft 6 structure of the high-speed two-pole asynchronous motor is designed on the shaft, and the length of the rotor shaft 6 and the rotor slot type are calculated by combining the 6000 rpm speed, the first-order critical speed and the second-order critical speed requirements, and the high-speed two-pole motor dynamic balance standard. On the premise of meeting the safety and rigidity requirements of the shaft, the rotor copper bar 2 is hot isostatically pressed and welded to the rotor shaft 6. The rotor shaft 6, the rotor copper bar 2 and the rotor end ring 3 are welded into an integrated structure through high-temperature and high-pressure hot isostatic pressing technology. Hot isostatic pressing welding not only saves manufacturing costs, but also enhances the stability of rotor operation.

[0025] By means of high temperature and high pressure hot isostatic pressing technology, the rotor shaft 6, the rotor copper bar 2 and the rotor end ring 3 are welded into an integrated structure, which can not only ensure the dynamic balance stability of the shaft, but also will not affect the first-order critical speed and the second-order critical speed of the two-pole motor, and will not cause runaway when the motor rotates at high speed. In the design of the rotor core 1 structure, it is necessary to consider the selection of the rotor shaft material to meet the requirements of the motor rotor stiffness. In addition, in the design of the shaft structure, it is also necessary to consider high-cycle fatigue analysis and shaft fracture mechanics analysis. Fracture mechanics analysis is brittle fracture analysis and shaft safety analysis. The purpose of fatigue analysis is to ensure that fatigue cracks will not occur under normal working loads during the service life of the shaft. Fracture mechanics analysis is divided into two parts. The more stringent restriction in fracture mechanics analysis is that the hypothetical crack is smaller than the requirements of the flaw detection standard and will not expand under normal working loads. The other part is that the hypothetical crack will not expand rapidly under extreme working conditions such as earthquakes and overspeed. The load value of the motor under earthquake and overspeed loads is more than twice the load under normal working conditions, and the fracture toughness of the shaft material is equivalent to 20 times the ultimate stress intensity factor of fatigue crack expansion. Therefore, the fracture mechanics analysis under normal working load is more stringent than that under extreme working conditions. Through high temperature and high pressure hot isostatic pressing technology, the rotor shaft 6, rotor copper bar 2 and rotor end ring 3 are welded into an integrated structure for the above analysis. The analysis structure shows that the integrated structure can fully meet the fatigue and stress analysis requirements. In addition, it is concluded in the analysis that the linear speed of the rotating shaft is relatively large at 6000r / min. Through high temperature and high pressure hot isostatic pressing technology, the rotor shaft 6, rotor copper bar 2 and rotor end ring 3 are welded into an integrated structure, so that the fatigue and stress analysis results of the shaft are more optimized, effectively solving the technical difficulties of the high-speed two-pole motor rotor during operation and the cracking of the end ring welding part, and increasing the safety and reliability of the rotor core 1 during motor operation.

[0026] The invention discloses a high-speed asynchronous motor full rotor hot isostatic pressing welding structure, wherein a rotor slot is processed at a suitable position on the rotating shaft, and the rotor, the rotor copper bar 2, and the rotor end ring 3 are assembled into an integrated rotor cage 4 structure by hot isostatic pressing to improve the operating reliability. Figure 1 shown.

[0027] The present invention solves the problem of the rotor end ring 3 running away or cracking at the first-order critical speed and the high-speed operation of 6000r / min of the high-speed two-pole motor, ensures the rigidity of the rotor shaft of the asynchronous motor, and optimizes the length of the rotor shaft core 6 and the selection of the position of the rotor copper bar 2 on the shaft to design a better rotational vibration reduction match, and finally determines the installation position of the rotor integrated structure, so that the rotor core 1 finally realizes the function of the structural strength and reliability of the rotor core 1 at high speed, such as Figure 3 Schematic diagram of the welding of the integrated rotor cage 4 structure.

[0028] According to the structure and installation requirements of the rotor core 1, the structure of the high-speed two-pole motor rotor shaft core 6 is designed in detail. Figure 1 Considering the high hardness of the rotor shaft material, the design pressure, the primary stress under the operating conditions and the reaction of the circumferential force formed by the rotation, the integrated rotor cage 4 structure welding schematic diagram is designed as follows Figure 3 As shown, its stress meets the requirements of allowable film stress and the functional requirements of the motor core.

[0029] according to Figure 3 According to the designed high-strength two-pole integrated rotor cage 4 structural welding diagram dimensions and design specification requirements, stress analysis calculations and stress cloud map calculations are used to select two-pole motor rotor electromagnetic property structural materials that meet the design specifications and use requirements, and complete the design of the rotor shaft 6 structural position and dimensions. When the rotor shaft 6 structure is hot isostatically pressed into one piece with the rotor copper bars 2 and the rotor end rings 3, the rotor shaft 6, the rotor copper bars 2 and the rotor end rings 3 are welded together under high temperature and high pressure conditions. This can ensure sufficient contact area while minimizing the cost increase, and the two have the same thermal expansion coefficient and fatigue cycle. Because the motor rotor of a high-speed two-pole motor is in a high-speed rotation state under operating conditions, the rotor pays special attention to the safety of the mating parts. Whether the mating parts are safe is the key to whether the motor will run away during operation. Figure 4 As shown, in the actual manufacturing process of the motor, through multiple comparative practical studies, it is finally concluded that manufacturing the rotor into an integrated structure can increase the rotor's moment of inertia, improve the imbalance problem of the two-pole motor in the manufacturing process, effectively improve the safety quality of the rotor's rotating parts, and ultimately achieve the structural functional design of the rotor core 1 assembly.

[0030] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A full rotor hot isostatic pressing welding structure of a high-speed asynchronous motor, including a motor housing, characterized in that: The motor housing is provided with a rotor shaft (6), rotor copper bars (2), rotor end rings (3) and a rotor cage (4); a rotor guard ring (5) is mounted on the rotor cage (4); a stator is fixedly mounted on the inner wall of the motor housing; the rotor shaft (6) rotates in the inner ring of the stator; the rotor copper bars (2) are laid on the outer surface of the rotor core (1); and the rotor core (1) and the rotor shaft (6) are integrally formed.

2. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1 is characterized in that: The outer surface of the rotor shaft (6) is provided with a rotor slot, and a rotor cage (4) is arranged in the rotor slot provided on the rotor shaft (6).

3. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1 is characterized in that: The rotor cage (4) is a rotor copper bar (2) and a rotor end ring (3) assembled into one piece by hot isostatic pressing.

4. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1, characterized in that: The rotor shaft (6), the rotor copper bars (2) and the rotor end rings (3) are integrally formed by hot isostatic pressing.

5. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1, characterized in that: The rotor cage (4) is a copper or aluminum rotor coil cast in a cage-shaped slot on the rotor core (1). The coil is a closed loop not connected to other parts.

6. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1, characterized in that: The rotor iron core (1), the rotor copper bars (2), the rotor end rings (3), the rotor cage (4), and the rotor shaft (6) can form a rotor.

7. The high-speed asynchronous motor full rotor hot isostatic pressing welding structure according to claim 1, characterized in that: The rotor core 1 is formed by stacking silicon steel sheets, and the rotor guard ring (5) is made of metal material and is installed around the rotor.

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