Hollow cage bar rotor structure of miniature medium-frequency asynchronous motor

Abstract

The hollow cage bar rotor structure comprises a central shaft which is arranged along the left-right direction, an iron core is coaxially arranged on the central shaft, the iron core comprises a left end ring, a lamination assembly and a right end ring which are sequentially arranged from left to right, and the inner circle of the lamination assembly is fixedly connected with the central shaft. A plurality of hollow cage bars which are parallel to the central shaft are arranged among the left end ring, the lamination assembly and the right end ring; and the hollow cage bars are uniformly arranged along the circumferential direction of the central shaft. According to the utility model, the conventional solid cage bar is mainly improved into the hollow cage bar, the material and the wall thickness of the cage bar are changed, and different torque characteristics can be generated for motors with the same power to adapt to different working conditions, so that large starting torque and higher power factor can be realized.

Description

TECHNICAL FIELD

[0001] The utility model belongs to asynchronous motor technical field, concretely relates to a hollow cage bar rotor structure of micro middle frequency asynchronous motor. BACKGROUND

[0002] The micro asynchronous motor generally adopts 400HZ middle frequency power supply, and the rotating speed can reach 20000RPM, and the cylindrical cage bar design is usually adopted, and the diameter is usually less than 6mm. The outer diameter of the rotor is less than 30mm, and the micro motor is difficult to adopt the cast aluminum structure, and T2 red copper bar is usually adopted as the cage bar, and the end ring adopts the same material as the cage bar. After welding, the rotor is processed to the appropriate size by using the lathe and grinding machine. Then, the rotor is completed after checking the dynamic balance.

[0003] The middle frequency micro asynchronous motor is a high-speed motor. The high-speed motor is characterized by high speed and low torque. Therefore, in extreme conditions, such as low temperature and viscous grease, the starting torque is relatively large. When the high-speed motor starts, the high-frequency oscillation torque may occur, and it may be difficult to start. In order to increase the starting torque, the number of turns of the coil is usually reduced or the cage bar is replaced with a large resistance material. However, reducing the number of turns of the coil can greatly reduce the power factor of the motor. It is not easy to match the appropriate material by replacing the cage bar material. Therefore, it is urgent to improve the rotor structure of the existing high-speed motor. CONTENT OF THE UTILITY MODEL

[0004] In order to solve the above technical problems in the prior art, the utility model provides a hollow cage bar rotor structure of micro middle frequency asynchronous motor with larger starting torque without reducing the power factor of the motor.

[0005] In order to solve the above technical problems, the utility model adopts the following technical scheme: the hollow cage bar rotor structure of micro middle frequency asynchronous motor, the center shaft is provided along the left-right direction, the iron core is coaxially installed on the center shaft, the iron core includes left end ring, lamination assembly and right end ring which are sequentially arranged from left to right, the inner circle of the lamination assembly is fixedly connected with the center shaft, a plurality of hollow cage bars parallel to the center shaft are arranged between the left end ring, the lamination assembly and the right end ring, and the hollow cage bars are uniformly arranged along the circumferential direction of the center shaft.

[0006] The left end ring and the right end ring are the same structure and left-right symmetrical, a plurality of left-right through perforations are uniformly arranged on the left end ring, the lamination assembly and the right end ring along the circumferential direction, the hollow cage bars are inserted into the perforations, the left and right ends of the hollow cage bars are flush with the left end face of the left end ring and the right end face of the right end ring respectively, the left half of the perforation of the left end ring and the right half of the perforation of the right end ring are left large right small conical holes, and the outer circles of the left and right ends of the hollow cage bars are fixedly connected with the left end ring and the right end ring as a whole by welding in the conical holes.

[0007] The left end ring inner circle is sleeved on the positioning shaft shoulder and is in clearance fit with the positioning shaft shoulder outer circle, and the right end ring inner circle is sleeved on the shaft sleeve and is in clearance fit with the shaft sleeve outer circle.

[0008] By using the hollow cage bar (metal tube), different wall thickness copper tubes or hollow cage bars of other materials are matched according to the working conditions required by users, and the advantages are that the stator and rotor of the micro middle frequency asynchronous motor are unchanged at the same power speed, only different materials are provided as the cage bar material, the mechanical characteristics of the motor can be changed by only changing the wall thickness and material of the hollow cage bar, thereby meeting the requirements of different working conditions.

[0009] During installation, the lamination assembly is first installed on the hollow shaft from right to left, then the shaft sleeve is installed, the left end ring is installed outside the positioning shaft shoulder, then the right end ring is installed outside the shaft sleeve, the perforations on the left end ring, the lamination assembly and the right end ring are in left-right correspondence and penetration, then the hollow cage bar is inserted into the perforations, and finally the left and right ends of the hollow cage bar are welded to the left end ring and the right end ring respectively.

[0010] In summary, the hollow cage bar is improved from the existing solid cage bar, and the cage bar material and wall thickness are changed, different torque characteristics can be generated for the same power motor, different working conditions are adapted, and large starting torque and high power factor can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a structural schematic view of the utility model;

[0012] Figure 2 is a plane structural schematic view of the left end ring and the right end ring;

[0013] Figure 3 is Figure 2 C-C sectional view;

[0014] Figure 4 is an axial sectional view of the hollow cage bar. DETAILED DESCRIPTION

[0015] The embodiments of the utility model will be further described in detail below in combination with the drawings and examples.

[0016] As Figures 1-4 The utility model discloses a hollow cage bar rotor structure of micro - intermediate frequency asynchronous motor, including the center shaft 1 who sets up along left and right directions, the coaxial installation of center shaft 1 has the iron core, and the iron core includes left end ring 2, lamination assembly 3 and right end ring 4 who sets up in proper order from left to right, and the inner circle of lamination assembly 3 is fixedly connected with center shaft 1, and the left end ring 2, lamination assembly 3 and right end ring 4 are equipped with several hollow cage bars 5 parallel to center shaft 1, and the hollow cage bar 5 is evenly arranged along the circumferential direction of center shaft 1.

[0017] The left end ring 2 and right end ring 4 are same in structure and left-right symmetrical, and the left end ring 2, lamination assembly 3 and right end ring 4 are evenly provided with a plurality of left-right through perforations 6 along the circumferential direction, the hollow cage bar 5 is inserted in the perforation 6, and the left and right ends of the hollow cage bar 5 are flush with the left end surface of the left end ring 2 and the right end surface of the right end ring 4 respectively, the left half of the perforation 6 of the left end ring 2 and the right half of the perforation 6 of the right end ring 4 are all left large right small conical holes 7, and the outer circles of the left and right ends of the hollow cage bar 5 are fixedly connected with the left end ring 2 and the right end ring 4 as a whole in the conical hole 7 by welding.

[0018] The center shaft 1 is integrally provided with a positioning shaft shoulder 8 on the left side, the inner circle of the left end ring 2 is sleeved on the positioning shaft shoulder 8 and is in clearance fit with the outer circle of the positioning shaft shoulder 8, and the center shaft 1 is threadedly connected with a shaft sleeve 9 on the right side, and the inner circle of the right end ring 4 is sleeved on the shaft sleeve 9 and is in clearance fit with the outer circle of the shaft sleeve 9.

[0019] The utility model discloses a hollow cage bar 5 (metal pipe), according to the working condition of user demand, matches the hollow cage bar 5 of different wall thickness of copper pipe or other material, and the advantage is that the hollow cage bar 5 wall thickness and material can change the mechanical characteristic of motor only by providing different material as the cage bar material, only changing the hollow cage bar 5 wall thickness and material can change the mechanical characteristic of motor, thereby adapting the demand of different working conditions.

[0020] During installation, first, the lamination assembly 3 is installed on the hollow shaft from right to left, then the shaft sleeve 9 is installed, then the left end ring 2 is installed outside the positioning shaft shoulder 8, then the right end ring 4 is installed outside the shaft sleeve 9, the perforations 6 on the left end ring 2, lamination assembly 3 and right end ring 4 are left-right corresponding and through, then the hollow cage bar 5 is inserted into the perforation 6, and finally the left and right ends of the hollow cage bar 5 are welded with the left end ring 2 and the right end ring 4.

[0021] The utility model discloses through test, the iron core outside diameter of design Phi 69mm is installed to the asynchronous motor of work rotational speed 11800rpm, adopts Phi 3.5mm, wall thickness 1mm cage strip, and starting torque increases from 25mNm to 55mNm, and power factor is basically invariable, has solved the problem of low temperature with load starting difficulty, has completely reached the customer demand.

[0022] The above examples illustrate the basic principles and characteristics of the present application, but the above only illustrates the preferred embodiments of the present application, and is not limited by the described embodiments. Those skilled in the art can make many forms of deformation and improvement without departing from the purpose of the present application and the scope of the claims, which are all within the scope of protection of the present application. Therefore, the utility model patent and the protection scope should be subject to the appended claims.

Claims

1. A micro intermediate frequency asynchronous motor hollow cage bar rotor structure, comprising a center shaft arranged in the left and right directions, characterized in that: The iron core is coaxially mounted on the center shaft and comprises, from left to right, a left end ring, a lamination assembly and a right end ring. The inner circle of the lamination assembly is fixedly connected with the center shaft. A plurality of hollow cage bars parallel to the center shaft are arranged between the left end ring, the lamination assembly and the right end ring.

2. The micro-IF asynchronous motor hollow-cored cage-bar rotor structure according to claim 1, characterized in that: The left end ring and the right end ring are identical and left-right symmetrical. A plurality of left-right through perforations are uniformly arranged on the left end ring, the lamination assembly and the right end ring along the circumferential direction. The hollow cage bars are inserted into the perforations. The left and right ends of the hollow cage bars are flush with the left end face of the left end ring and the right end face of the right end ring. The left half of the perforation of the left end ring and the right half of the perforation of the right end ring are left-large-right-small conical holes. The outer circles of the left and right ends of the hollow cage bars are fixedly connected with the left end ring and the right end ring by welding in the conical holes.

3. The micro-IF asynchronous motor hollow-cored cage-bar rotor structure according to claim 1 or 2, characterized in that: A positioning shoulder is integrally arranged on the left side of the center shaft. The inner circle of the left end ring is sleeved on the positioning shoulder and gap-fitted with the outer circle of the positioning shoulder. A shaft sleeve is threadedly connected with the right side of the center shaft. The inner circle of the right end ring is sleeved on the shaft sleeve and gap-fitted with the outer circle of the shaft sleeve.

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