The importance of servo motors for laser cutting machines
Servo motors are an important component of laser cutting machines, and their quality determines the stability of the equipment, especially the deformation of the processing contour.
How does the servo motor affect the operation of the laser cutting machine?
For fiber laser cutting machines, whether it is flat cutting or pipeline cutting, the key to the equipment processing according to the established pattern is the dynamic responsiveness and mutual cooperation of each axis involved in the processing. If the overall response of each axis is too slow during the machining process, or if one axis has a small deviation and the other axis has a large deviation, the problem of machining contour deformation will occur. There are many reasons for this inconsistency in deviation, including mechanical, external forces, servo response, control systems, or a combination of multiple factors. Therefore, the key to solving such problems lies in the good dynamic response and coordination of each axis, enabling it to strictly follow the established goals for processing actions. As an intermediate executing mechanism to undertake mechanical and control systems, servo motors can compensate, optimize, and coordinate the actions of various systems to a certain extent, thus achieving better control objectives.
Factors affecting the normal operation of servo motors:
1. Mechanical factors
Mechanical problems are quite common, mainly reflected in design, transmission, installation, materials, mechanical wear, and other aspects.
2. Mechanical resonance
The significant impact of mechanical resonance on the servo system is that it cannot continue to improve the responsiveness of the servo motor, resulting in the overall operation of the equipment in a relatively low response state. This type of problem is more common in synchronous belt transmission machinery, and in addition, this situation can sometimes occur with long-distance ball screws. The main reason is that the synchronous belt has low stiffness, low resonance frequency, large inertia of long-distance screw rods, and more deformation, especially when the motor capacity is selected, it is prone to vibration. At the same time, the assembly process and material quality can also affect mechanical resonance.
3. Mechanical shaking
The essence of mechanical vibration is also a natural frequency issue of machinery, which usually occurs more in single ended fixed suspension structures, especially during the acceleration and deceleration stages. Low frequency jitter appears as large waves in the processed parts, while high frequency jitter appears as serrations.
4. Mechanical internal stress, external force and other factors
Due to differences in mechanical materials and installation, the mechanical internal stress and static friction force of each transmission shaft on the equipment may be inconsistent. If the internal stress or static friction force of one of the two axes involved in track insertion control in the equipment is large, the servo torque will be consumed to a certain extent, leading to deformation of the machining contour. Usually, we can observe the internal stress of the transmission shaft through the waveform curve generated by the feedback of the servo driver.
The external force on the shaft is also similar. In general plate cutting machines, each axis is not in contact with the workpiece, and external forces may be limited. However, in some pipeline cutting machines, the conveying shaft will participate in the insertion during cutting, while the other shaft is usually non-contact. At this point, due to the influence of the fixture, the pipeline will generate a reverse force on the conveying shaft, causing inconsistent forces between the two axes involved in insertion control, and the cutting effect will definitely be affected.
5. CNC system factors
In some cases, the debugging effect of the servo is not significant. At this point, it may be necessary to intervene in the adjustment of the control system. When processing with a laser cutting machine, the linear speed is usually relatively constant, and the linear speed is the same as the curve speed. This is not a major problem in linear motion, but in curves, especially in the machining of small arcs, contour deformation may be caused by excessive acceleration.
