CN212381088U - Stepped conical surface welding structure for end part of copper bar of asynchronous motor rotor - Google Patents

Abstract

The utility model relates to an asynchronous motor rotor copper bar tip ladder conical surface welded structure, 1 both ends of electric motor rotor copper bar all weld rotor end links 2 and constitute asynchronous motor rotor squirrel cage bar structure 3, and 1 both ends of rotor copper bar all have step 4, radially have first conical surface 5 along electric motor rotor copper bar 1, and 5 lower parts of first conical surface are second conical surface 6, rotor copper bar step 4 and first conical surface 5, second conical surface 6 and rotor end links 2 welded fastening. The utility model discloses an optimized scheme's rotor copper bar terminal surface processing step degree of depth and the tapered selection of two continuous conical surfaces of rotor copper bar tip, the design has better pliability and lower stress amplitude and fatigue usage rate, and the radial degree of depth of final definite rotor copper bar step and the tapering of the conical surface realize its function. And the rotor copper bar finally realizes the function of strengthening the structural strength and reliability of the rotor rat cage bar at high rotating speed.

Description

Stepped conical surface welding structure for end part of copper bar of asynchronous motor rotor

Technical Field

The utility model relates to an asynchronous motor rotor copper bar tip ladder conical surface welded structure.

Background

At present, with the rapid development of domestic and foreign industries, the demand of various industries on asynchronous motors is remarkably increased, and the requirements on the asynchronous motors are higher and higher. Some industries applying the variable frequency speed regulation function of the asynchronous motor and industries needing the high-rotating-speed asynchronous motor also provide higher requirements on the running performance and the safety and reliability of the asynchronous motor. The rotor form of the asynchronous motor is mainly determined according to working conditions, and for machines requiring soft characteristics for heavy-load starting and mechanical characteristics, a winding type rotor is selected. Generally, a squirrel cage type asynchronous motor should be preferred. The squirrel-cage asynchronous motor has simple structure, low cost and convenient use and maintenance. The squirrel-cage motor is divided into a unit cage, a double-unit cage, a deep groove cage, cage bars with special shapes and the like according to the different shapes of the rotor copper bars.

According to the specification requirement and the performance calculation of the motor, the unit cage structure is generally used for small and medium-sized asynchronous motors. When designing the rotor cage bar structure, firstly, the mechanical and mechanical properties of the rotor copper bar and the rotor end ring should be considered separately. When the rotor copper bar is designed, the creep fatigue life of the copper bar is calculated, and the primary stress of the rotor copper bar is considered. Because the secondary stress of the copper bars is self-limiting in the calculation of the rotor copper bars and is released when creep occurs. The locations where stress concentration is most likely to occur for the rotor copper bars are the locations of the connections to the rotor end rings and the locations of the steps machined in the rotor copper bars. And when the creep fatigue life of the rotor copper bar is calculated, carrying out linear analysis on the bending stress at the position where the copper bar is most likely to generate high stress, calculating the corresponding fatigue life according to the operating temperature and the stress data of the rotor copper bar and the rotor end ring, and finally obtaining the fatigue life cycle and the creep rate. And finally, the highest stress area of the rotor copper bar is located at the brazing position of the rotor copper bar and the rotor end ring and the contact position of the copper bar and the groove bottom. Therefore, the end parts of the rotor copper bars are designed, the end parts of the rotor copper bars are processed at the welding joint of the rotor copper bars and the rotor end ring, the welding quality and reliability between the rotor copper bars and the rotor end ring can be greatly improved, and the method has very important practical significance.

The invention content is as follows:

the utility model aims at providing an asynchronous motor rotor copper bar tip ladder conical surface welded structure, this rotor copper bar tip ladder conical surface welded structure can guarantee welded reliability and welding strength between the two of rotor copper bar and rotor end links, can effectually reduce the stress concentration of rotor copper bar and rotor end links junction again. The technical scheme of the utility model is that: the utility model provides an asynchronous motor rotor copper bar tip ladder conical surface welded structure, 1 both ends of motor rotor copper bar all weld rotor end ring 2 and constitute asynchronous motor rotor squirrel cage bar structure 3, and 1 both ends of rotor copper bar all have step 4, have first conical surface 5 along 1 radial of motor rotor copper bar, and 5 lower parts of first conical surface are second conical surface 6, and rotor copper bar step 4 and first conical surface 5, second conical surface 6 and rotor end ring 2 welded fastening.

The utility model has the advantages that:

the utility model discloses mainly design and make an asynchronous motor rotor copper bar tip ladder conical surface welded structure. The structure of the rotor copper bar designed according to the asynchronous motor is shown in figures 1 and 3. The rotor copper bars and the rotor end rings form a rotor squirrel cage bar structure of the asynchronous motor, which is shown in figure 2 and is a rotating part in the motor. Therefore, the safety of the rotor cage bars influences the operational reliability of the motor.

The rotor copper bar and the rotor end ring form a rotor squirrel cage bar of the asynchronous motor through intermediate frequency welding, the rotor copper bar is processed before the rotor copper bar and the rotor end ring are welded, the end part of the rotor copper bar can conveniently go deep into a groove of the rotor end ring through processing one step, two step-shaped tapers are continuously processed at the end part of the rotor copper bar, full contact between welding materials and a welding part is facilitated in the welding process, the welding reliability is ensured, the stress concentration at the joint of the rotor copper bar and the rotor end ring is reduced, the running integrity and functionality are ensured, and the requirement of service life is met. By considering the design specification requirement and the stress amplitude and the fatigue utilization rate of the rotor copper bars, the depth of the processing steps at the end parts of the rotor copper bars and the processing taper of the conical surfaces at the end parts of the rotor copper bars are finally determined, and the technical problems of strengthening the welding reliability of the rotor copper bars and the rotor end rings and improving the stress concentration at the connection parts of the rotor copper bars and the rotor end rings are finally solved.

Drawings

FIG. 1 is a schematic view of the end face processing of a rotor copper bar

FIG. 2 schematic diagram of rotor squirrel cage bar structure

FIG. 3 is a perspective view of FIG. 1

Detailed Description

As shown in figure 1, the stepped conical surface welding structure for the end part of the copper bar of the asynchronous motor rotor is characterized in that a rotor end ring 2 is welded at both ends of a copper bar 1 of the motor rotor to form a squirrel cage bar structure 3 of the asynchronous motor rotor, as shown in figure 2, steps 4 are arranged at both ends of the copper bar 1 of the rotor, as shown in figure 3, a first conical surface 5 is arranged along the radial direction of the copper bar 1 of the motor rotor, the lower part of the first conical surface 5 is a second conical surface 6, and the steps 4 of the copper bar of the rotor are fixedly welded with the first conical surface 5 and the second conical surface.

According to the structure of the rotor squirrel cage bars and the welding requirement, a processing structure of the end parts of the rotor copper bars is designed in detail as shown in figure 1. Considering the stress amplitude analysis and fatigue life analysis of the rotor copper bar and the rotor end ring, the high hardness of the materials of the rotor copper bar and the rotor end ring, the primary stress of the rotor copper bar and the rotor end ring under the design and operation conditions and the reaction of the circumferential force formed by rotation are combined, the high-stress area on the rotor copper bar is designed, and the stress of the high-stress area meets the requirement of allowable film stress and the functional requirement of the motor squirrel cage bar structure.

According to the requirements of the rotor copper bar size and the design specification designed in the figure 1, the rotor copper bar material meeting the design specification and the use requirement is selected by utilizing stress analysis calculation and stress cloud picture calculation, and the design of the whole length and the cross-sectional area of the rotor copper bar is completed. In the structural design of the end part of the rotor copper bar, a step is processed at the end part of the rotor copper bar, and two conical surfaces are continuously processed at the welding contact surface of the end part of the rotor copper bar and a rotor end ring. Finally determining the depth of the step at the end part of the rotor copper bar by considering the electric density value and the stress amplitude value on the sectional area of the rotor copper bar and the fatigue utilization rate, and processing a fillet at the step to reduce stress concentration. In the manufacture of a plurality of asynchronous motors, through continuous experience and repeated verification, two conical surfaces are continuously processed at the welding position of the end face of a rotor copper bar and a rotor end ring, the welding effect and quality of the rotor copper bar and the rotor end ring are greatly improved, finally, the stress amplitude of the contact surface of the rotor copper bar and the rotor end ring is calculated through analysis and calculation, and the improvement of the welding quality has great practical significance on the stress concentration distribution condition and the fatigue life cycle of the connection position of the rotor copper bar and the rotor end ring.

Claims (1)

1. The utility model provides an asynchronous motor rotor copper bar tip ladder conical surface welded structure which characterized by: rotor end ring (2) all welds at electric motor rotor copper bar (1) both ends and constitutes asynchronous motor rotor squirrel cage bar structure (3), and rotor copper bar (1) both ends all have step (4), radially have first conical surface (5) along electric motor rotor copper bar (1), and first conical surface (5) lower part is second conical surface (6), and rotor copper bar step (4) and first conical surface (5), second conical surface (6) and rotor end ring (2) welded fastening.

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