A polishing tool for a crane motor slip ring

Abstract

The utility model relates to motor technical field, namely a crane motor slip ring polishing tool, be applied to each drive mechanism motor of bridge crane. It includes epoxy resin stick, fixed one inverted abrasive wheel at one end of epoxy resin stick, inverted abrasive wheel is a semicircle abrasive wheel, and a section of tabular connecting section is processed out at both ends of semicircle abrasive wheel, tabular connecting section is fixed with epoxy resin stick through the banding of insulating material, and the one end of epoxy resin stick is processed with flat bottom recess, and tabular connecting section is overlapped with flat bottom recess. Portable on site, the operation mode of simple implementation maintenance is simple, and the production is simple, and the cost is low, and the connection is reliable, and the installation is convenient, and the use is safe.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically a tool for grinding slip rings of electric motors for cranes, which is applied to the electric motors of various drive mechanisms of bridge cranes. Background Technology

[0002] In existing technology, the three-phase wound-rotor asynchronous motors used in metallurgical cranes include carbon brushes for conductive contact with slip rings, facilitating speed control via circuitry. Slip ring connecting plates are used to securely connect to the internal rotor windings of the motor. Three-phase slip rings (collector rings) are used to achieve conductive contact with the carbon brushes during rotation. Over long-term use, due to external environment, usage frequency, and improper maintenance, the surface of the motor rotor slip rings may become corroded, resulting in a rough surface. This leads to poor contact between the internal carbon brushes and the slip rings, causing arcing and open circuits in the rotor. The hazards are as follows: 1. Affecting the motor's speed control function, resulting in slow equipment operation. 2. Affecting the output torque, resulting in weak motor power. 3. Accelerated wear and replacement of the motor rotor carbon brushes, increasing labor intensity and carbon brush usage costs. If negligent inspections fail to address the problem promptly, the fault can escalate, directly damaging the carbon brush holder and the motor. 4. Prolonged and frequent use can lead to open circuits due to poor contact between the motor rotor carbon brushes and slip rings. This can cause abnormally high current in the other two phases, resulting in overheating, excessive heat, and even smoke from the motor, ultimately leading to serious equipment accidents such as motor burnout. 5. Current grinding tools, due to defects in their contact surface design, while using similar principles, often result in thin or worn-out slip rings, or even arcing and breakdown due to electrolytic corrosion during reuse, causing complete motor damage. These defects cause inconvenience and contribute to wasted costs. In the past, when the rotor slip ring of a motor was damaged, it was necessary to send it to a professional institution for machining to maintain the smoothness of the slip ring surface and make it better in contact with the carbon brush. However, when such faults occurred on-site while the equipment was running online, the motor was often disassembled and repaired offline, which required a lot of manpower for emergency repairs. At the same time, it would inevitably cause a long period of hot shutdown of the production line, affecting the efficiency of the production line. Even if the motor was sent for repair, it would still incur certain maintenance costs. If the motor burned out, whether it was purchasing a new motor or overhauling it, these were all considerable economic expenses. Utility Model Content

[0003] The purpose of this invention is to provide a tool for grinding slip rings of crane motors, addressing the aforementioned shortcomings. It can quickly resolve faults online in a short time, allowing the motor to continue normal online operation after processing.

[0004] The technical solution of this utility model is: a grinding tool for a motor slip ring of a crane, comprising an epoxy resin rod, a cast grinding wheel fixed at one end of the epoxy resin rod, the cast grinding wheel being a semi-circular grinding wheel, and a plate-shaped connecting section processed at both ends of the semi-circular grinding wheel; the plate-shaped connecting section is bound and fixed to the epoxy resin rod by an insulating material tape; a flat-bottomed recess is processed at one end of the epoxy resin rod for the plate-shaped connecting section to overlap with the flat-bottomed recess.

[0005] The insulating material tape is either nylon cable ties or PVC tape.

[0006] The advantages of this utility model are: 1. This tool is lightweight and portable on-site, and the operation method for maintenance is simple. 2. Due to its simple manufacturing and low cost, the grinding wheel can be made from worn and scrapped wheel pieces, which is convenient for planning and implementation. 3. The grinding wheel and epoxy resin rod are fixed by insulated binding, which is reliable, easy to install, and safe to use. 4. The treated slip ring has a good surface finish, and the motor does not need to be offline for operation. It can be treated online and then reused, saving time, manpower, and costs, making it easier to promote and use, and more practical.

[0007] The embodiments of this utility model will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0008] Figure 1 This is a simplified structural diagram of the present invention.

[0009] The parts in the diagram are named as follows: 1. Epoxy resin rod, 2. Casting grinding wheel, 3. Plate-shaped connecting section, 4. Insulating material strip, 5. Flat bottom recess. Detailed Implementation

[0010] See Figure 1 A grinding tool for motor slip rings in cranes includes an epoxy resin rod 1, a handle end for the epoxy resin rod 1, F-class insulation, 5-10KV / mm, suitable for use with motors, transformers, etc. One end of the epoxy resin rod 1 has a flat-bottomed recess 5 for overlapping with a plate-shaped connecting section 3. A custom-made grinding wheel 2 is fixed to one end of the epoxy resin rod 1. The custom-made grinding wheel is created by using a flat chisel or saw to make a shape and size that matches the installation position for easy installation. Specifically, the custom-made grinding wheel is a semi-circular grinding wheel, with a plate-shaped connecting section 3 machined at both ends. The plate-shaped connecting section 3 is bound and fixed to the epoxy resin rod 1 with insulating material tape 4, such as nylon cable ties or PVC tape.

[0011] The parts in the diagram are named as follows: 1. Epoxy resin rod, 2. Casting grinding wheel, 3. Plate-shaped connecting section, 4. Insulating material strip, 5. Flat bottom recess.

[0012] Instructions for use: When the slip ring of the motor rotor fails due to surface electrolytic corrosion, hold the tool by the handle and push it into the slip ring of the motor rotor. At the same time, align the surface of the grinding wheel 2 with the surface of the slip ring (slip ring) (ensuring a tight fit). Then, another person starts the motor. After starting, the motor will gradually accelerate according to the controller speed, generally controlled at around 300 rpm. During the grinding process, the maintenance personnel hold the grinding rod to grind. Once the surface electrolytic corrosion pits of the slip ring are ground off and the surface is smooth, the grinding is complete. After grinding, the motor can continue to operate online as a normal motor without further processing.

[0013] Function and application conditions of this tool: 1. This tool is designed to address motor malfunctions caused by pitting and unevenness in the rotor slip rings (slip rings) due to electro-erosion. It is specifically designed for use under live operation (energized operation) of motors, utilizing the rotational friction of the motor to polish the electro-eroded pits on the rotor slip ring surface, making it smooth and ensuring good contact between the motor rotor carbon brushes and the slip ring. 2. Because it is an energized operation with a circuit voltage of 380V, this tool uses epoxy resin rods with a withstand voltage insulation class of F, suitable for low-voltage electrical control equipment below 500V. It is applied to 380V powered bridge cranes, primarily dealing with YZR and JZR series metallurgical crane three-phase wound-rotor asynchronous motors with rated power between 1.5KW and 110KW. Besides the above applications, it can also be used in other types of motor equipment with rotor slip rings operating under similar electrical control conditions.

[0014] Composition of this tool: 1. The tool handle is made of national standard epoxy resin rod 1. Due to the special environment (electrical) of the part it is used in, its safety requirements are high. Its application scenarios are mostly in various working conditions and small substations within enterprises, where it is a commonly used tool for voltage testing. Its surface coating has the characteristics of being an insulating medium that resists corrosion and moisture, and has high strength, ensuring operational safety. 2. Different installation and fixing methods and usage effects. This tool uses a grinding block that is cast to form two ends for fixing with insulating material, which meets on-site requirements and differs from other fixing methods. Compared to some methods that use metal screws for fixing, this method is extremely unsafe in an electric environment and is also harmful to the part being repaired (motor slip ring). Because the entire tool body is fixed with insulating material and there are no metal objects, the slip ring surface will not be damaged during processing. The grinding wheel of this tool is a grinding block that is manually cast on-site, and its fixing method uses PVC or electrical insulating material, unlike other metal fixing methods. The disadvantages of metal fixing are: during grinding, the grinding block also wears down. With metal-fixed grinding blocks, after a certain wear level, the slip ring surface will rub against the metal fixing pins, screws, etc. Especially when the motor rotates, the metal directly contacts and rubs against the slip ring body, easily causing scratches, breakage, and severe grooves on the motor slip ring body, and even damaging the motor. Furthermore, if metal fixing is used, it must be fixed to an insulator inside the grinding block, which limits the grinding block's frictional thickness and, to some extent, increases the frequency of grinding block replacement, causing some inconvenience for later tool use. This tool has no internal metal components, maximizing the thickness worn down by the grinding wheel, resulting in a longer tool life. There are no internal metal fixings, so the motor slip ring surface will not be damaged. 3. The slip ring grinding contact form is different. The grinding wheel 2 is a raised type with a raised center. The raised part makes line contact with the slip ring body. In actual application, the contact area is small. It is mainly used to grind irregular electro-erosion pits and edge oxidation surfaces on the motor surface. The grinding effect meets the normal use requirements of the motor. This method greatly protects the slip ring of the motor, minimizes the wear and loss (copper or iron) on the surface of the slip ring conductive layer, and is conducive to the long-term use of the motor and extends the service life of the motor.

[0015] The above description is merely a specific embodiment of this utility model, and the various examples do not constitute a limitation on the substantive content of this utility model.

Claims

1. A grinding tool for a slip ring of a crane motor, characterized in that... The device includes an epoxy resin rod (1), a cast grinding wheel (2) fixed at one end of the epoxy resin rod (1), the cast grinding wheel being a semi-circular grinding wheel, and a plate-shaped connecting section (3) processed at both ends of the semi-circular grinding wheel; the plate-shaped connecting section (3) is bound and fixed to the epoxy resin rod (1) by an insulating material tape (4); a flat-bottomed recess (5) is processed at one end of the epoxy resin rod (1) for the plate-shaped connecting section (3) to overlap with the flat-bottomed recess (5).

2. A crane motor slip ring grinding tool according to claim 1, characterized in that... The insulating material tape (4) is nylon cable ties or PVC tape.

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