Inspection device for rotor vanes
By using a magnetic field-induced current detection device and a conductive fork to determine the integrity of the guide strip, the problems of low detection efficiency and missed detection in the existing technology are solved, and efficient and accurate guide strip detection is achieved.
Patent Information
- Application Number
- CN202521393141.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-07-04
AI Technical Summary
In the existing technology, the detection efficiency of rotor guide bars is low and they are easy to miss, especially when the broken bars are in the rotor slots, which is difficult to detect and affects the operating quality of the motor.
An inspection device for rotor guide bars is used, including a magnetic field generator and a conductive fork. The integrity of the guide bar is detected by inducing current through the magnetic field. The vibration response of the iron sheet is used to determine whether the guide bar is broken, and the breakage point is determined by moving the fork.
It enables efficient and accurate detection of breakage and breakage points of guide strips, improving detection efficiency, preventing missed detections, and ensuring inspection quality.
Smart Images
Figure CN224682176U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an inspection device for the rotor guide bar of an electric motor. Background Technology
[0002] See Figure 1 The rotor of the electric motor includes an iron core, a shaft 3, an end ring 5, and guide bars 9. The guide bars are embedded in the slots of the iron core, and both ends of the guide bars are connected to the end rings. The guide bars and the end rings are formed as a whole by casting aluminum. If the quality of the cast aluminum is poor, the guide bars will break, which is called broken bars. Broken bars will cause the motor to run abnormally. In order to ensure quality, the rotor needs to be inspected. Usually, the guide bars are inspected by visual inspection. However, visual fatigue is easy to occur, and the inspection efficiency is not high. In addition, if the broken bar occurs in the rotor slot, it is not easy to detect, allowing defective rotors to flow into the next process. Utility Model Content
[0003] To ensure inspection quality and improve inspection efficiency, this utility model proposes an inspection device for rotor guide bars.
[0004] The technical solution of this utility model is a test device for rotor guide bars, which includes a base 1, and V-shaped irons 2 on both sides of the base for supporting the rotor shaft 3. The test device for rotor guide bars also includes a magnetic field generator, a rectangular iron sheet 6, and a conductive fork 8. The magnetic field generator includes a U-shaped iron core 11, on which a coil 10 is sleeved. The coil is connected to an external AC power supply. The distance between the two arms of the iron core is greater than the thickness of the rotor guide bar 9. One end of the iron sheet 6 is connected to the fork through a spring 7. The bottom of the iron sheet and the fork are on the same plane.
[0005] In use, place the iron core 11 on the rotor, with the guide bar positioned between the two arms of the iron core. Place the fork and the iron plate on the guide bar. If the guide bar is normal, the iron plate will vibrate; if the guide bar is broken, the iron plate will not vibrate. To determine the break point, move the fork. During the movement, the iron plate will vibrate. The position between the two teeth of the fork at this point is the break point.
[0006] The beneficial effects of this invention are that the device is easy to use, can accurately detect broken guide strips and breakage points, can prevent missed detections, ensure inspection quality, and improve inspection efficiency. Attached Figure Description
[0007] Figure 1 This is a schematic diagram of the structure of this utility model.
[0008] Figure 2 for Figure 1 Top view.
[0009] Figure 3 for Figure 1A-direction view.
[0010] Figure 4 for Figure 1 The enlarged view from direction B shows that the fork handle is not drawn.
[0011] Figure 5 for Figure 1 A magnified view of section C.
[0012] Attached diagram symbols: 1-base, 2-V-shaped iron, 3-rotating shaft, 4-vertical rod, 5-end ring, 6-iron sheet, 7-spring, 8-fork, 9-guide bar, 10-coil, 11-iron core, 12-clamp, 13-connecting rod, 14-sleeve, 15-break point, 16-magnetic lines. Detailed Implementation
[0013] A testing device for rotor guide bars includes a base 1, with V-shaped irons 2 vertically mounted on both sides of the base to support the rotor shaft 3. The device further includes a magnetic field generator, a rectangular iron sheet 6, and a conductive fork 8. The magnetic field generator includes a U-shaped iron core 11 with a coil 10 fitted on it. The coil is connected to an external AC power source. The distance between the two arms of the U-shaped iron core is greater than the thickness of the rotor guide bar 9. One end of the iron sheet 6 is connected to the fork via a spring 7. The bottom of the iron sheet and the fork are on the same plane, and the fork is made of metal.
[0014] The external AC power source can be mains power or power source after voltage reduction by a transformer.
[0015] The spring is made of steel wire with a diameter of about 0.05 mm, and the diameter of the wound wire is about 5 mm. The length is 10 to 20 mm, preferably 15 mm. This makes the connection between the iron plate and the fork approximately a flexible connection, reducing the constraint when the iron plate vibrates, maximizing the vibration amplitude of the iron plate, and making it easy to observe.
[0016] In use, place the U-shaped iron core on the rotor, with the guide bar positioned between the two arms of the U-shaped iron core. Hold the fork handle and place the fork and iron plate on the guide bar. If the guide bar is normal, the iron plate will vibrate radially; if the guide bar is broken, the iron plate will not vibrate. To determine the break point, move the fork. During the movement, if the fork straddles both sides of the break point, the iron plate will vibrate. The position between the two teeth of the fork at this time is the break point 15 (e.g., ...). Figure 5 (As shown). The purpose of identifying the fracture point is to repair it by welding.
[0017] The smaller the spacing between the teeth of the fork 8, the more accurate the location of the break point can be determined. The spacing between the teeth of the fork 8 is 3 to 8 millimeters, preferably 5 millimeters.
[0018] The principle is that when the coil is connected to an AC power source, the U-shaped iron core generates an AC magnetic field, and the magnetic field lines 16 are as follows: Figure 3 As shown, the current enters the rotor core and surrounds the guide bar, generating an induced current in the guide bar. This induced current generates an induced magnetic field, causing the iron sheet to vibrate radially within the induced magnetic field. If the guide bar breaks, no induced current is generated in that guide bar, and the iron sheet will not vibrate.
[0019] To further improve testing efficiency, a vertical rod 4 is vertically connected to one side of the base, and a sleeve 14 is fitted onto the vertical rod. The sleeve is fixed to the vertical rod with screws. A clamp 12 is provided on the iron core 11, and the clamp has a U-shaped notch. The iron core is fixed in the notch, with the arm end of the iron core protruding from the notch. The sleeve and the clamp are connected by a connecting rod 13. By adjusting the position and rotation angle of the sleeve on the vertical rod, the iron core can be positioned above and close to the rotor, with the current guide bar on the rotor located between the two arms of the iron core. After testing one current bar, the shaft is rotated to position the next current guide bar between the two arms of the iron core for inspection. In this way, it is not necessary to hold the iron core 11 during the inspection process.
[0020] When the break point of the guide bar is located at the lower part of the iron core 11, that is, the break point is covered by the iron core, the fork cannot enter the lower part of the iron core 11 and cannot accurately measure the location of the break point. Therefore, a vertical rod 4 is also vertically connected to the other side of the base. The sleeve 14 can be moved onto the vertical rod, and the corresponding connecting rod 13, clamp 12 and iron core 11 also move. In this way, the fork can detect the location of the break point. In addition, it can also be adapted to the operator's operating habits, such as some people are used to holding the fork handle with their right hand and others are used to holding the fork handle with their left hand.
Claims
1. An inspection device for rotor guide bars, comprising a base (1), on both sides of which V-shaped irons (2) are vertically mounted to support the rotor shaft (3), characterized in that, The inspection device for the rotor guide bar also includes a magnetic field generator, a rectangular iron sheet (6), and a conductive fork (8). The magnetic field generator includes a U-shaped iron core (11), on which a coil (10) is fitted. The coil is connected to an external AC power supply. The distance between the two arms of the iron core is greater than the thickness of the rotor guide bar (9). One end of the iron sheet (6) is connected to the fork through a spring (7). The bottom of the iron sheet and the fork are on the same plane.
2. The inspection device for rotor guide bars according to claim 1, characterized in that, The spring is made of steel wire with a diameter of about 0.05 mm, and the diameter of the wound wire is 5 mm and the length is 15 mm.
3. The inspection device for rotor guide bars according to claim 1 or 2, characterized in that, The spacing between the teeth of the fork (8) is 5 mm.
4. The inspection device for rotor guide bars according to claim 3, characterized in that, A vertical rod (4) is vertically connected to one side of the base. A sleeve (14) is fitted on the vertical rod and fixed to the vertical rod by screws. A clamp (12) is provided on the iron core (11). The clamp has a U-shaped notch and the iron core is fixed in the notch. The sleeve and the clamp are connected by a connecting rod (13). The iron core is located above the rotor and close to the rotor. The guide strip on the rotor is located between the two arms of the iron core.
5. The inspection device for rotor guide bars according to claim 4, characterized in that, A vertical rod (4) is also vertically connected to the other side of the base.