Balancing process and method of dynamic balancing machine; The process of rotor balancing, also known as balancing test, involves measuring the unbalance of an unbalanced rotor and correcting it to eliminate its imbalance. It is an important process in rotor machining.
1. The choice of the front of the school
The operation of eliminating the imbalance of the rotor and putting it in a balanced state is called balance correction. Balance correction is carried out on a plane perpendicular to the rotor axis, which is called the correction plane. The method of correcting balance within one calibration plane is called single-sided balance or static balance, and the method of correcting within two or more calibration planes is called double-sided balance or multi sided balance or dynamic balance. For rotors with large initial unbalance and excessive vibration during rotation, single side balancing should be performed before dynamic balancing verification to eliminate static unbalance. Sometimes, due to improper selection of the front face position (i.e. the center of gravity is not within the selected front face), correcting static balance can actually increase the even imbalance. Therefore, the front of the school chooses to be carried out in the plane where the center of gravity is located to reduce even imbalance. If the plane where the center of gravity is located does not allow for weight removal, it should generally be carried out on two planes located on both sides of the plane where the center of gravity is located. For rigid rotors, there are generally static and even imbalances. To achieve balance, the imbalance can be corrected within two randomly selected correction planes perpendicular to the axis, known as double-sided balance. The correction method is generally carried out by adding weight (such as using a balance block) or removing weight (such as punching holes). The position of the correction plane is generally determined by the structure of the rotor. To reduce the time and effort spent in balancing operations, efforts should be made to reduce the amount of correction. Therefore, under possible conditions, the distance and correction radius between the two calibration faces should be increased as much as possible to achieve a good balance effect.
2. Verification method
The imbalance of the rotor is caused by the non coincidence of its central principal axis of inertia with the rotational axis, and balance correction is to change the mass distribution of the rotor, so that its central principal axis of inertia coincides with the rotational axis to achieve balance. The commonly used correction methods include adjusting the correction weight, adding weight or removing weight, etc.
Weighting can be achieved through screw connection, riveting, and welding, which can achieve better balance and higher balance accuracy for the rotor, and is convenient and safe. Heavy removal often involves drilling, grinding, chiseling, milling, and other methods. Grinding is used to remove weight from the rotor and impeller of the pump, or weight is added to the coupling. The choice of calibration method depends on the rotor structure and process requirements, as well as the geometric shape of the calibration face. Generally, when designing a rotor, the position of adding or removing weight should be taken into consideration.
3. Correction error
1. The choice of the front of the school
The operation of eliminating the imbalance of the rotor and putting it in a balanced state is called balance correction. Balance correction is carried out on a plane perpendicular to the rotor axis, which is called the correction plane. The method of correcting balance within one calibration plane is called single-sided balance or static balance, and the method of correcting within two or more calibration planes is called double-sided balance or multi sided balance or dynamic balance. For rotors with large initial unbalance and excessive vibration during rotation, single side balancing should be performed before dynamic balancing verification to eliminate static unbalance. Sometimes, due to improper selection of the front face position (i.e. the center of gravity is not within the selected front face), correcting static balance can actually increase the even imbalance. Therefore, the front of the school chooses to be carried out in the plane where the center of gravity is located to reduce even imbalance. If the plane where the center of gravity is located does not allow for weight removal, it should generally be carried out on two planes located on both sides of the plane where the center of gravity is located. For rigid rotors, there are generally static and even imbalances. To achieve balance, the imbalance can be corrected within two randomly selected correction planes perpendicular to the axis, known as double-sided balance. The correction method is generally carried out by adding weight (such as using a balance block) or removing weight (such as punching holes). The position of the correction plane is generally determined by the structure of the rotor. To reduce the time and effort spent in balancing operations, efforts should be made to reduce the amount of correction. Therefore, under possible conditions, the distance and correction radius between the two calibration faces should be increased as much as possible to achieve a good balance effect.
2. Verification method
The imbalance of the rotor is caused by the non coincidence of its central principal axis of inertia with the rotational axis, and balance correction is to change the mass distribution of the rotor, so that its central principal axis of inertia coincides with the rotational axis to achieve balance. The commonly used correction methods include adjusting the correction weight, adding weight or removing weight, etc.
Weighting can be achieved through screw connection, riveting, and welding, which can achieve better balance and higher balance accuracy for the rotor, and is convenient and safe. Heavy removal often involves drilling, grinding, chiseling, milling, and other methods. Grinding is used to remove weight from the rotor and impeller of the pump, or weight is added to the coupling. The choice of calibration method depends on the rotor structure and process requirements, as well as the geometric shape of the calibration face. Generally, when designing a rotor, the position of adding or removing weight should be taken into consideration.
3. Correction error
During the balancing process, in addition to the measurement error of the balancing machine, there are also errors caused by inaccurate balance correction (including the size and position of the correction amount), which are called calibration errors. It can be divided into correction angle error, correction amplitude error, correction radius error, and correction plane position error. In practical calibration, most of the four types of errors mentioned above are comprehensive and should be considered comprehensively when analyzing. In addition, the ratio between the initial imbalance and the remaining imbalance, as well as the impact of the imbalance reduction rate of the dynamic balancing machine, should also be considered.
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