A device for detecting permanent magnet motor rotor magnetic steel using magnetorheological fluid

Abstract

The present invention discloses a device for detecting permanent magnet motor rotor magnet steel by using magnetorheological fluid, comprising a ring sleeve mounted on the outer side of the permanent magnet motor rotor magnet steel, and evenly arranged detection units are arranged inside the ring sleeve; the detection unit comprises a magnetic isolation wall, a balloon is arranged inside the magnetic isolation wall, and the magnetorheological fluid is arranged inside the balloon; a pressure sensor is arranged on the top of the balloon, a pressure head is arranged above the pressure sensor, and the upper end of the pressure head abuts against the inner side of the balloon; a locking ring is arranged outside the balloon. The advantages of the present invention are: the balloon and the pressure head apply pressure to the balloon filled with magnetorheological fluid, and because the magnetic field at the defect position is different from the magnetic field at the normal position, the pressure of the detection unit at the defect position is different from the pressure at the normal position; and the computer can detect the position and type of the defect through the change value of the pressure combined with the position information of the rotor.

Description

Technical Field

[0001] The invention relates to the field of machinery, in particular to a motor manufacturing technology, and more particularly to a motor rotor detection device. Background Art

[0002] The rotor of a permanent magnet synchronous motor has fixed magnetic poles, and the installation and detection of the fixed magnetic poles are directly related to the performance of the motor. There are not many detection methods for non-planar permanent magnetic materials in the prior art. For example, Chinese patent application No. 201710888019.8 discloses a material profile defect detection method with both arc-shaped and straight-line edges, an optical detection method, specifically a detection method designed to detect surface corner defects of arc-shaped magnetic materials. The straight edge part and the arc-shaped edge part are separated, and corresponding profile defect detection methods are given respectively, which solves the problem of surface profile defect detection of materials with arc-shaped edges. This method is an automatic optical detection method for detecting surface corner defects of arc-shaped magnetic materials that is simple to operate, fast, and effective, and can meet actual detection requirements. This method requires relatively precise instruments and complex calculations, and is not suitable for the actual production of motor rotors. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a device for detecting the permanent magnet motor rotor magnet using magnetorheological fluid, comprising a ring sleeve mounted on the outside of the permanent magnet motor rotor magnet, and evenly arranged detection units are arranged on the inside of the ring sleeve; the detection unit comprises a magnetic isolation wall, a balloon is arranged inside the magnetic isolation wall, and the magnetorheological fluid is arranged inside the balloon; a pressure sensor is arranged on the top of the balloon, a pressure head is arranged above the pressure sensor, and the upper end of the pressure head abuts against the inner side of the balloon; a locking ring is arranged on the outside of the balloon.

[0004] The pressure sensor is connected to the signal conversion module; the pressure sensor is a thin film type.

[0005] The detection units are neatly arranged along the axial direction and the circumferential direction of the inner side of the ring sleeve.

[0006] From the radial perspective of the annulus, the magnetic separation wall is rectangular and the balloon is also rectangular accordingly.

[0007] The signal conversion module is connected to the host computer.

[0008] There are multiple locking rings arranged along the axial direction of the airbag.

[0009] The pressure head comprises a plate-shaped pressing piece, on which a columnar handle is fixed, and the end of the columnar handle is hemispherical; the pressing piece abuts against the pressure sensor, and the end of the columnar handle abuts against the airbag.

[0010] The magnetic isolation walls of each detection unit are symmetrically arranged.

[0011] The advantages of the present invention are: the magnetorheological fluid exhibits the characteristics of a non-Newtonian fluid under the action of an external magnetic field, and changes from a free-flowing liquid to a semi-solid or even a solid within milliseconds, showing a strong controllable rheological characteristic. The outer surface of the rotor is arranged into a plurality of transverse and longitudinal detection units, and each detection unit is provided with a magnetic isolation wall to avoid mutual interference and the influence of the rotor magnetic field at adjacent positions. An external air bag and a pressure head are used to apply pressure to a balloon filled with the magnetorheological fluid. Since the magnetic field at the defect position is different from the magnetic field at the normal position, the pressure of the detection unit at the defect position is different from the pressure at the normal position. The computer can detect the position and type of the defect through the change value of the pressure combined with the position information of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the appearance of the present invention;

[0013] Figure 2 for Figure 1 A top view of

[0014] Figure 3 for Figure 2 A magnified view of part A;

[0015] Figure 4 This is a schematic diagram of the arrangement of the detection unit outside the ring sleeve. DETAILED DESCRIPTION

[0016] The present invention is described in detail below in conjunction with the accompanying drawings. As shown in the figure, the present invention includes a ring sleeve 2 sleeved on the outside of the permanent magnet motor rotor magnetic steel 1, and the material of the ring sleeve can be nylon or other elastic materials; uniformly arranged detection units are arranged on the inside of the ring sleeve; the detection unit includes a magnetic isolation wall 4, and the magnetic isolation wall is arranged along the radial normal of the ring sleeve, that is, the extension line of the magnetic isolation wall passes through the axis P of the ring sleeve; a balloon 5 is arranged in the magnetic isolation wall, and the magnetorheological fluid is arranged in the balloon 5; a pressure sensor 7 is arranged on the top of the balloon 5, and a pressure head 6 is arranged above the pressure sensor 7, and the upper end of the pressure head 6 abuts against the inner side of the airbag 3; a locking ring 8 is arranged on the outside of the airbag.

[0017] The pressure sensor is connected to the signal conversion module;

[0018] Preferably, the pressure sensor is of thin film type.

[0019] The signal conversion module is connected to the host computer; in order to facilitate positioning on the computer (host computer), the detection units are neatly arranged along the axial and circumferential directions of the inner side of the ring sleeve; this facilitates comparison with the pre-input rotor shape and size.

[0020] like Figure 4 As shown, from the radial perspective of the annulus, the magnetic separation wall is rectangular and the balloon is also rectangular accordingly.

[0021] In order to ensure uniform force application of the airbag, there are multiple locking rings arranged along the axial direction of the airbag.

[0022] Preferably, the pressure head 6 comprises a plate-shaped pressing piece 61, on which a columnar handle 62 is fixed, and the end of the columnar handle is hemispherical 63; the pressing piece abuts against the pressure sensor, and the end of the columnar handle abuts against the airbag. The magnetic isolation wall of each detection unit is symmetrically arranged.

[0023] The principle of the present invention is: put the ring on the outer circle of the rotor, then buckle the locking ring, inflate the airbag, and the inflation of the airbag pushes the pressure head to press down the airbag; since the magnetic field of the rotor position corresponding to each detection unit is different, the degree of hardening of the magnetorheological fluid is different, and the pressure sensor converts the pressure into an electrical signal after receiving the pressure and transmits it to the signal conversion module, and finally inputs it into the host computer; the host computer judges the magnetic field state of the rotor according to the change of the pressure value at each position and compares it with the preset standard magnetic field.

[0024] The magnetorheological fluid of the present invention can be a commercial product, such as the product of Shenzhen Asec Lubricating Materials Co., Ltd.; the pressure sensor can be a product of Shenzhen Bofengsheng Electronics Co., Ltd.

Claims

1. A device for detecting permanent magnet motor rotor magnetic steel using magnetorheological fluid, characterized in that: It comprises a ring sleeve which is sleeved on the outer side of the permanent magnet motor rotor magnetic steel, and the inner side of the ring sleeve is provided with uniformly arranged detection units; the detection unit comprises a magnetic isolation wall which is arranged along the radial normal of the ring sleeve; a balloon is arranged inside the magnetic isolation wall, and a magnetorheological fluid is arranged inside the balloon; a pressure sensor is arranged on the top of the balloon, a pressure head is arranged above the pressure sensor, and the upper end of the pressure head abuts against the inner side of the balloon; a locking ring is arranged on the outer side of the balloon; The pressure sensor is connected to the signal conversion module; the pressure sensor is a thin film type; The detection units are neatly arranged along the axial direction and the circumferential direction of the inner side of the ring sleeve; From the radial perspective of the annulus, the magnetic separation wall is rectangular, and the balloon is also rectangular accordingly; The signal conversion module is connected to the host computer; There are multiple locking rings, which are arranged along the axial direction of the airbag; The pressure head includes a plate-shaped pressing piece, on which a columnar handle is fixed, and the end of the columnar handle is hemispherical; the pressing piece abuts against the pressure sensor, and the end of the columnar handle abuts against the airbag; The magnetic isolation walls of each detection unit are symmetrically arranged.

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