The driving parts of high-speed centrifuges and ultra-high-speed centrifuges are high-speed motors. For high-rise motors, the general method of repairing ordinary motors can not be repaired. After repairing, it may not be able to be used for a long time. According to the domestic and foreign practical experience, introduce the maintenance method of the high speed motor with the speed of 2O000RPM and the general low speed motor.
1. Determine if the armature needs to be disassembled
Observe whether there is spark between the carbon brush and the commutator when the motor is running, the degree of sparking, (I) is no spark. It means that the carbon brush and the commutator are normal, no need to repair; (2) only 2~4 A very small spark. At this time, carefully observe that the surface of the commutator is flat. In most cases, it is not necessary to repair; (3) In addition to r, there are 4 very small sparks with F, and 1 to 3 large sparks, To disassemble the armature, just use a sandpaper to grind the carbon brush commutator; (4) If there are 4 large sparks, you need to use a sandpaper to grind the commutator, or even carefully add the commutator to the car. Remove the carbon brush and the armature. Of course, after a giant commutator is processed, it is necessary to change the carbon brush to brush the carbon brush.
2. Method of disassembling high speed motor
Because the vibration will damage the carbon brush when the end cap and the armature are removed, the carbon brush should first be removed from the carbon brush. It is also fixed that the angle between the two carbon and the slanting device is not necessarily the same. In order to ensure that the left and right carbon brushes are not reversed during installation, the left and right carbon brushes must be marked before the carbon brushes are removed. Remember not to damage the contact surface of the carbon and commutator.
At one end of the high-speed motor, there is usually a heat-dissipating wind. At the other end, there may be a magnet or a speed-measuring ring for measuring the speed. When disassembling the fan blade and the magnet or the speed-measuring ring, be careful not to drop the fan. The speed measuring magnet is broken. Secondly, it should be proud of the fan bushing or between the magnetic steel bushing and the shaft, so that it can be installed according to the original marked position after the repair is completed. Because the dynamic balance test of the high-speed motor is carried with a fan blade or a speed measuring ring (speed measuring magnetic) Steel), so assembly must be assembled according to the symbol when disassembling. This is a trivial matter in general motor repair. I can deal with the overall situation in the repair of high-speed motors. Because once the speed measuring ring or the fan chip is damaged, or the segment is assembled by the mark, even if other parts are repaired very well, after assembly, the unbalanced vibration of the whole machine may be caused at high speed.
When disassembling a high-speed motor, you can't use a hammer or a punch. If you want to use a hard pull, you should use a puller. When using a puller, pay attention to it: pull it* directly on the *eye. In the case of Rama* and *eye Pad A protective pad whose purpose is to protect the *eyes on the armature shaft from damage.
Fix the end caps on both ends of the eMule. Before disassembling, mark the seven lower end caps so that they can be installed as they are after repair. The bearing on the armature of the r arm should be carefully cleaned. Clean the gasoline in the house when cleaning. After the gasoline is dry, fill the bearing chamber with 7014 (or 7018) bearing grease. (The bearings of the high-speed motor cannot be used with ordinary butter or disulfide. Molybdenum). Put it in a clean place for use; if the surface of the commutator is flat and has a purple luster, this is the oxide layer that protects the surface of the commutator. Use a soft brush to remove the powder from the surface.
3, the repair of the commutator
(1) The commutator is basically flat, except that there are very small scratches or sparks. For the second case, the port 1 is ground by hand sanding with water sandpaper without disassembling the armature. The order of grinding is: firstly, according to the outer arc of the commutator, machine a wooden tool, cut several different thickness of water sandpaper into strips as wide as the commutator, and remove the carbon brush (please note) Make a mark on the handle of the removed carbon brush and the carbon brush groove to ensure that the right and wrong are not changed when installing.) Use a wooden tool wrapped with sandpaper to stick the commutator, and use the other hand to press the direction of the motor. Lightly rotating the shaft commutator. Use the order of the thickness of the sandpaper first and then coarse and fine. When a piece of sandpaper is too thick to be used, change the finer sandpaper until the fine sandpaper (or metallographic sandpaper) is used.
(2) The surface of the commutator is obviously uneven (hand touchable) or the spark of the motor is running as in the fourth case. At this time, the armature needs to be disassembled, and the machine tool for commutator turning machine should be a precision lathe. The specific process is: the speed is 1600r/rain, the cutting amount is 0.03mm, and the knife is 0.1 to 0.05mm. Knife.
4, the armature wear-in
Install the armature and carbon brush in reverse order of disassembly, and gently move the commutator by hand to manually wear the carbon brush. Firstly grind the commutator according to the method of (1). Then run it on again. The running-in process is as follows: firstly run at 5000RPM without load for 10h, and find that there is a large spark in the running-in process, you need to stop running-in. Check whether the assembly is proper. If there is no spark, the second stage can use 10000RPH, and the platform can be used for 4h. After all normal, it can enter the third stage. The third stage has a load of 2500RPM. If it is loaded with a high-speed centrifuge, the indication of the tachometer of the centrifuge can be used as a standard. However, it must be used with a high-speed centrifugal head to make a light load. High-speed centrifuges do load-running, you must understand the gear ratio. When you set the ultra-high-end centrifuge with a speed of 80000r/rain or more, you can use a small rotating head with a high speed, which makes the load lighter because of the ultra-high speed. The speed change ratio of the centrifuge is 4.2:1, so when the tachometer indicates 10000rrain, the actual speed of the motor is about 2500r/rain. In the whole no-load, load-loading process, the fourth situation occurs. A small spark or more than two large sparks can not continue, in addition to carefully check whether the installation is qualified, but also return to the last running-in process mushroom new running-in until qualified.
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