Generally, the centrifuges equipped in the laboratory are divided into high-speed centrifuges and low-speed centrifuges. As the core working part of the centrifuges, the rotor body often encounters the problem of rotating imbalance. Let's follow Xiangzhi centrifuges to understand the common factors that cause the unbalanced operation of the centrifuges.
The first is the high-speed centrifuge. The high-speed centrifuge adopts the variable frequency motor, with the speed higher than 10000 rpm. The second is the low-speed centrifuge adopts the brushless motor, with the maintenance free speed generally lower than 10000 rpm. The premise of normal and high-speed operation of centrifuge is to ensure that the rotor body rotates in balance in the centrifugal cavity. At present, there are several reasons for the unbalanced rotation of the rotor body:
1. The working sample is not weighed as required (in principle, the weight difference of each sample shall be less than 1G), and the weight difference exceeds the allowable range of the machine, which will cause vector displacement of the center of gravity of the rotor body, deviate from the central axis, and cause unbalanced vibration.
2. When the centrifuged sample is not placed symmetrically in the center, causing severe vibration, leading to deflection of the transmission shaft, causing irreversible balance damage, contact the manufacturer for after-sales replacement of the corresponding parts.
3. The chemical structure and weight of some materials in the rotor body of the high-speed centrifuge are changed by the chemical corrosion of the rotor body caused by the residual separation samples in the centrifugal cavity of the rotor body or the spillage of the corrosive substances. This weight difference is often ignored, but it does exist universally. Therefore, it is necessary for operators to develop good use habits, operate in strict accordance with the use instructions, and do not use in violation of regulations. After use, it is necessary to clean up the stains in time, keep the centrifugal cavity clean and dry, and avoid corrosion damage to the machine.
4. The centrifuge is not placed horizontally or the support foot is unbalanced due to displacement during operation. At this time, the machine should be stopped from the newly placed machine to the horizontal position before use.