In medical tests, centrifuges are commonly used to separate serum, plasma, precipitated proteins, or instruments for urine sediment testing. The centrifuge can be used to rapidly precipitate suspended particles in the mixture to separate various components of different specific gravity. In the inspection work, due to the relatively concentrated time of frequent opening and stopping of the centrifuge, the motor and the machine are worn and consumed greatly. If the maintenance work cannot be done regularly and on time, it is easy to cause the failure of the stop or the slow speed, which directly affects the inspection. The normal operation of the work. Therefore, it is very important to be able to grasp the methods of promptly and quickly eliminating various types of malfunctions of the centrifuge and ensure that the centrifuge is always in good working condition.
Troubleshooting: The centrifuge does not rotate or the speed is slow.
Analysis of the cause: After the centrifuge is energized, slowly increase the speed control knob clockwise to increase the speed of the motor until the required speed is run. When the centrifuge has a failure to stop or rotate slowly, the first part of the power supply must be eliminated. If the power cord is disconnected, the plug or socket is not in good contact, the bearing is damaged, or the stator or rotor coil is short-circuited or broken, and burned, etc., the main reason is that the brush is open, that is, the commutator on the rotor does not match the brush. , caused by poor contact.
Because the motors used on centrifuges are generally series motors. It consists of two parts, the stator and the rotor. The stator is a concentrated fixed magnetic pole composed of a core and a field coil. The rotor is composed of a core and a rotor coil and a commutator. The function of the brush is to connect the stator coil to the key components of the rotor coil via the commutator. The circuit working principle of the series-excited motor is that the current flows from the power source through the stator field coil, the brush, and the commutator into the rotor coil, and then the brush and the stator field coil return to the power source to form a loop. The field coil and the rotor coil are connected in series by a commutator. The currents in the line are equal, so only if the series circuit is unobstructed, the motor can work normally at the required speed.
It can be seen that the working condition of the brush directly affects the normal operation of the motor. However, due to the contact between the brush and the commutator, wear, consumption or spring failure, the brush open circuit and the commutator are easily disengaged. Is causing the centrifuge to stop or the speed is slow.
main reason.
Inspection steps: First clean the brush box and check the brush wear. When the length of the brush is less than 10mm, the brush of the same specification should be replaced. To replace the brush: Unscrew the brush cover and remove the old brush. If the spring on the old brush is intact, remove it and reattach it to the new one. If the spring fails or is damaged, replace the spring at the same time, then put it back into the box as it is, and let the brush fall freely inside the box, tighten it properly, and then tighten the lid. Remove the turntable, adjust the motor speed to Zui, let the motor run at no load, then the speed will be very high, and the end face of the brush will match the outer edge of the commutator in a few minutes. At this time, the machine can be shut down, the motor is disassembled, the oxide on the surface of the commutator is removed with fine sandpaper, and the carbon powder particles on the commutator are removed by a brush or a dry cloth. After zui, you can restore the machine.
Another simple method is: Find a cylinder that is larger than the commutator, and apply a layer of fine sandpaper with the sand surface facing outward, and grind the end face of the brush into a curved surface that matches the outer edge of the commutator. Then install it again. In order to ensure the normal operation of the centrifuge, preventive maintenance work should be done carefully. The wear of the commutator and the brush should be checked regularly (half year or year). Eliminate toner contamination on the surface of the commutator in a timely manner and prolong the service life of the brush. For damaged devices, such as brushes, springs, etc., be replaced in time to ensure that the centrifuge is in good working condition.
Pvc Coated Gloves With Chips,Black White Chips Pvc Gloves,Anti-Slip Chips Pvc Gloves,Dots Pvc Coated Gloves
SHANDONG SHUNXING LABOUR PROTECTIVE CO.,LTD , https://www.sdsxlb.com