“Optimization of Spindle Gear Noise Control in the Noise Treatment Method of CNC Machine Tool Spindle”
During the operation of CNC machine tools, the problem of spindle gear noise often plagues operators and maintenance personnel. In order to effectively reduce the noise of the spindle gear and improve the machining accuracy and stability of the machine tool, we need to deeply optimize the control method of spindle gear noise.
I. Causes of spindle gear noise in CNC machine tools
The generation of gear noise is the result of the combined action of multiple factors. On one hand, the influence of tooth profile error and pitch will cause elastic deformation of the gear teeth when loaded, leading to instantaneous collision and impact when the gears mesh. On the other hand, errors in the processing process and poor long-term operating conditions can also cause tooth profile errors, which in turn generate noise. In addition, changes in the center distance of meshing gears will cause changes in the pressure angle. If the center distance changes periodically, the noise will also increase periodically. Improper use of lubricating oil, such as insufficient lubrication or excessive disturbance noise of the oil, will also have an impact on noise.
The generation of gear noise is the result of the combined action of multiple factors. On one hand, the influence of tooth profile error and pitch will cause elastic deformation of the gear teeth when loaded, leading to instantaneous collision and impact when the gears mesh. On the other hand, errors in the processing process and poor long-term operating conditions can also cause tooth profile errors, which in turn generate noise. In addition, changes in the center distance of meshing gears will cause changes in the pressure angle. If the center distance changes periodically, the noise will also increase periodically. Improper use of lubricating oil, such as insufficient lubrication or excessive disturbance noise of the oil, will also have an impact on noise.
II. Specific methods for optimizing spindle gear noise control
Topping chamfering
Principle and purpose: Topping chamfering is to correct the bending deformation of teeth and compensate for gear errors, reduce the meshing impact caused by the concave and convex tooth tops when the gears mesh, and thus reduce noise. The chamfering amount depends on the pitch error, the bending deformation amount of the gear after loading, and the bending direction.
Chamfering strategy: First, perform chamfering on those pairs of gears with high meshing frequency in defective machine tools, and adopt different chamfering amounts according to different modules (3, 4, and 5 millimeters). During the chamfering process, strictly control the chamfering amount and determine the appropriate chamfering amount through multiple tests to avoid excessive chamfering amount that damages the useful working tooth profile or insufficient chamfering amount that fails to play the role of chamfering. When performing tooth profile chamfering, only the tooth top or only the tooth root can be repaired according to the specific situation of the gear. When the effect of repairing only the tooth top or the tooth root is not good, then consider repairing the tooth top and the tooth root together. The radial and axial values of the chamfering amount can be allocated to one gear or two gears according to the situation.
Control tooth profile error
Error source analysis: Tooth profile errors are mainly generated during the processing process, and secondly caused by poor long-term operating conditions. Gears with concave tooth profiles will be subjected to two impacts in one meshing, resulting in large noise, and the more concave the tooth profile, the greater the noise.
Optimization measures: Reshape the gear teeth to make them moderately convex to reduce noise. Through fine processing and adjustment of gears, minimize tooth profile errors as much as possible and improve the accuracy and meshing quality of gears.
Control the change of the center distance of meshing gears
Noise generation mechanism: The change of the actual center distance of meshing gears will lead to the change of the pressure angle. If the center distance changes periodically, the pressure angle will also change periodically, thus making the noise increase periodically.
Control method: The outer diameter of the gear, the deformation of the transmission shaft, and the fit between the transmission shaft, gear and bearing should all be controlled in an ideal state. During installation and debugging, operate strictly in accordance with the design requirements to ensure that the center distance of the meshing gears remains stable. Through accurate processing and assembly, try to eliminate the noise caused by the change of the center distance of meshing.
Optimize the use of lubricating oil
Function of lubricating oil: While lubricating and cooling, lubricating oil also plays a certain damping role. The noise decreases with the increase of oil volume and viscosity. Maintaining a certain oil film thickness on the tooth surface can avoid direct contact between meshing tooth surfaces, weaken vibration energy and reduce noise.
Optimization strategy: Choosing oil with high viscosity is beneficial for reducing noise, but pay attention to controlling the disturbance noise of the oil caused by splash lubrication. Rearrange each oil pipe so that the lubricating oil splashes into each pair of gears as ideally as possible to control the noise generated due to insufficient lubrication. At the same time, adopting the oil supply method on the meshing side can not only play a cooling role but also form an oil film on the tooth surface before entering the meshing area. If the splashed oil can be controlled to enter the meshing area in a small amount, the noise reduction effect will be better.
Topping chamfering
Principle and purpose: Topping chamfering is to correct the bending deformation of teeth and compensate for gear errors, reduce the meshing impact caused by the concave and convex tooth tops when the gears mesh, and thus reduce noise. The chamfering amount depends on the pitch error, the bending deformation amount of the gear after loading, and the bending direction.
Chamfering strategy: First, perform chamfering on those pairs of gears with high meshing frequency in defective machine tools, and adopt different chamfering amounts according to different modules (3, 4, and 5 millimeters). During the chamfering process, strictly control the chamfering amount and determine the appropriate chamfering amount through multiple tests to avoid excessive chamfering amount that damages the useful working tooth profile or insufficient chamfering amount that fails to play the role of chamfering. When performing tooth profile chamfering, only the tooth top or only the tooth root can be repaired according to the specific situation of the gear. When the effect of repairing only the tooth top or the tooth root is not good, then consider repairing the tooth top and the tooth root together. The radial and axial values of the chamfering amount can be allocated to one gear or two gears according to the situation.
Control tooth profile error
Error source analysis: Tooth profile errors are mainly generated during the processing process, and secondly caused by poor long-term operating conditions. Gears with concave tooth profiles will be subjected to two impacts in one meshing, resulting in large noise, and the more concave the tooth profile, the greater the noise.
Optimization measures: Reshape the gear teeth to make them moderately convex to reduce noise. Through fine processing and adjustment of gears, minimize tooth profile errors as much as possible and improve the accuracy and meshing quality of gears.
Control the change of the center distance of meshing gears
Noise generation mechanism: The change of the actual center distance of meshing gears will lead to the change of the pressure angle. If the center distance changes periodically, the pressure angle will also change periodically, thus making the noise increase periodically.
Control method: The outer diameter of the gear, the deformation of the transmission shaft, and the fit between the transmission shaft, gear and bearing should all be controlled in an ideal state. During installation and debugging, operate strictly in accordance with the design requirements to ensure that the center distance of the meshing gears remains stable. Through accurate processing and assembly, try to eliminate the noise caused by the change of the center distance of meshing.
Optimize the use of lubricating oil
Function of lubricating oil: While lubricating and cooling, lubricating oil also plays a certain damping role. The noise decreases with the increase of oil volume and viscosity. Maintaining a certain oil film thickness on the tooth surface can avoid direct contact between meshing tooth surfaces, weaken vibration energy and reduce noise.
Optimization strategy: Choosing oil with high viscosity is beneficial for reducing noise, but pay attention to controlling the disturbance noise of the oil caused by splash lubrication. Rearrange each oil pipe so that the lubricating oil splashes into each pair of gears as ideally as possible to control the noise generated due to insufficient lubrication. At the same time, adopting the oil supply method on the meshing side can not only play a cooling role but also form an oil film on the tooth surface before entering the meshing area. If the splashed oil can be controlled to enter the meshing area in a small amount, the noise reduction effect will be better.
III. Precautions for implementing optimization measures
Accurate measurement and analysis: Before performing tooth top chamfering, controlling tooth profile errors and adjusting the center distance of meshing gears, it is necessary to accurately measure and analyze the gears to determine the specific situation and influencing factors of errors so as to formulate targeted optimization schemes.
Professional technology and equipment: Optimizing spindle gear noise control requires professional technical and equipment support. Operators should have rich experience and professional knowledge and be able to skillfully use measuring tools and processing equipment to ensure the accurate implementation of optimization measures.
Regular maintenance and inspection: In order to maintain the good operating state of the spindle gear and reduce noise, it is necessary to regularly maintain and inspect the machine tool. Timely detect and deal with problems such as gear wear and deformation, and ensure sufficient supply and reasonable use of lubricating oil.
Continuous improvement and innovation: With the continuous development and progress of technology, we should continuously pay attention to new noise reduction methods and technologies, continuously improve and innovate spindle gear noise control measures, and improve the performance and quality of machine tools.
Accurate measurement and analysis: Before performing tooth top chamfering, controlling tooth profile errors and adjusting the center distance of meshing gears, it is necessary to accurately measure and analyze the gears to determine the specific situation and influencing factors of errors so as to formulate targeted optimization schemes.
Professional technology and equipment: Optimizing spindle gear noise control requires professional technical and equipment support. Operators should have rich experience and professional knowledge and be able to skillfully use measuring tools and processing equipment to ensure the accurate implementation of optimization measures.
Regular maintenance and inspection: In order to maintain the good operating state of the spindle gear and reduce noise, it is necessary to regularly maintain and inspect the machine tool. Timely detect and deal with problems such as gear wear and deformation, and ensure sufficient supply and reasonable use of lubricating oil.
Continuous improvement and innovation: With the continuous development and progress of technology, we should continuously pay attention to new noise reduction methods and technologies, continuously improve and innovate spindle gear noise control measures, and improve the performance and quality of machine tools.
In conclusion, through the optimization of the noise control method of the CNC machine tool spindle gear, the noise of the spindle gear can be effectively reduced and the machining accuracy and stability of the machine tool can be improved. In the process of implementing optimization measures, various factors need to be comprehensively considered and scientific and reasonable methods need to be adopted to ensure the realization of optimization effects. At the same time, we should continuously explore and innovate to provide more effective technical support for the development of CNC machine tools.