The hazards caused by rotor imbalance are in many aspects. When the rotor rotates, the unbalanced centrifugal force will be generated due to the imbalance, which will cause the rotor to deflect and deform and generate internal stress. Such deformation and internal stress will cause rotor fatigue and even rotor fracture. This force will be transmitted to the base through the bearing, so that the machine equipment generates vibration and noise, accelerates the wear of the bearing and the sealing parts, reduces the working accuracy and efficiency of the machine, shortens the service life of the machine, and sometimes even causes loose mating and component fracture, resulting in major accidents and huge economic losses. Practice shows that more than 30% of the faults in the motor with excessive vibration are caused by the unbalanced mass of the rotor itself. Rotating parts and components after dynamic balance correction can eliminate and slow down the mechanical vibration, extend the service life of the machine parts and reduce the noise.
Unbalance is an absolute value, while the rotating speed only converts the imbalance into dynamic load. The balancing machine converts the dynamic load into electrical signal through the sensor, and finally returns to the imbalance through the amplifier filter. The rotating speed shall be selected according to the balancing machine equipment, and the rotor is fixed with frequency and other factors. Based on the dynamic balance theory, the unbalance of the rotor has no relationship with the rotating speed.
Unbalance factors of rotor of universal joint dynamic balancer:
1. The rotor structure of the universal joint dynamic balancer is asymmetric. The most typical example is the crankshaft. The asymmetry of the crankshaft structure is determined by its working characteristics. Therefore, the crankshaft must be counterweighted in the design. Before leaving the factory, each crankshaft must be subjected to the balance test. The remaining imbalance can only be put into use if it meets the requirements.
2. Defects of raw materials or workblank cause imbalance of rotor due to material defects, which is a common phenomenon in mechanical engineering. For example, the density of raw materials is uneven, the workblank has pores, sand holes and loose structure, and the uneven weld joint will cause imbalance of rotor.
3. Processing or assembly error of rotor of universal joint dynamic balancing machine.
If there is an error in the machining or assembly process of the rotor, it will also change the mass distribution of the rotor, thus destroying the balance state of the rotor. For example, different shafts of rotor and journal axis, different tightening degree of coupling screw or winding deformation caused by welding will cause imbalance of rotor. The sum of all unbalance vectors distributed on the rotor can be considered as a vector concentrated on the "key point". Dynamic balance is a technology to determine the position and size of the key point of the unbalanced rotor, and then remove or add a counterweight of the same size at the corresponding position.
Factors affecting the calibrated u-joint balance:
1. Unbalance caused by manufacturing tolerance specified in design specification of main parts of universal coupling.
2. Unbalance caused by eccentricity of the centering surface between the cardan joint and the shaft.
3. Clearance between mating parts in a cardan joint.
4. Unbalance caused by uneven or asymmetric distribution of accessories in the universal joint.
5. Unbalance caused by uneven material or wear of parts of universal joint
Unbalance is an absolute value, while the rotating speed only converts the imbalance into dynamic load. The balancing machine converts the dynamic load into electrical signal through the sensor, and finally returns to the imbalance through the amplifier filter. The rotating speed shall be selected according to the balancing machine equipment, and the rotor is fixed with frequency and other factors. Based on the dynamic balance theory, the unbalance of the rotor has no relationship with the rotating speed.
Unbalance factors of rotor of universal joint dynamic balancer:
1. The rotor structure of the universal joint dynamic balancer is asymmetric. The most typical example is the crankshaft. The asymmetry of the crankshaft structure is determined by its working characteristics. Therefore, the crankshaft must be counterweighted in the design. Before leaving the factory, each crankshaft must be subjected to the balance test. The remaining imbalance can only be put into use if it meets the requirements.
2. Defects of raw materials or workblank cause imbalance of rotor due to material defects, which is a common phenomenon in mechanical engineering. For example, the density of raw materials is uneven, the workblank has pores, sand holes and loose structure, and the uneven weld joint will cause imbalance of rotor.
3. Processing or assembly error of rotor of universal joint dynamic balancing machine.
If there is an error in the machining or assembly process of the rotor, it will also change the mass distribution of the rotor, thus destroying the balance state of the rotor. For example, different shafts of rotor and journal axis, different tightening degree of coupling screw or winding deformation caused by welding will cause imbalance of rotor. The sum of all unbalance vectors distributed on the rotor can be considered as a vector concentrated on the "key point". Dynamic balance is a technology to determine the position and size of the key point of the unbalanced rotor, and then remove or add a counterweight of the same size at the corresponding position.
Factors affecting the calibrated u-joint balance:
1. Unbalance caused by manufacturing tolerance specified in design specification of main parts of universal coupling.
2. Unbalance caused by eccentricity of the centering surface between the cardan joint and the shaft.
3. Clearance between mating parts in a cardan joint.
4. Unbalance caused by uneven or asymmetric distribution of accessories in the universal joint.
5. Unbalance caused by uneven material or wear of parts of universal joint
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