Control carving spindle noise troubleshooting

1、Gear noise control

Due to the generation of gear noise is caused by multiple factors, some of which are gear design parameters determined by the characteristics of the spindle motion system gear noise for faulty milling machine, without changing the original design on the basis of the original gear repair and improvement to reduce noise.

(1) The top of the tooth repair edge. Due to the tooth shape error and the impact of tooth distance, in Dongguan Shenzhen CNC milling machine gear teeth bearing elastic deformation, resulting in gear meshing instantaneous top impact and impact. Therefore, in order to reduce the gear in the mesh due to the top of the tooth concave and convex caused by the mesh impact, can be carried out on the top of the tooth trimming edge. The purpose of top flanging is to correct the bending deformation of the teeth and compensate for the gear error, thereby reducing gear noise. The amount of edge trimming depends on the pitch error and the amount of bending deformation of the gear after loading, as well as the direction of bending. In trimming the edge must pay attention to trimming the control of the amount of edge, and take the method of repeated tests, so as not to trim the amount of edge is too large and destroy the effective work of the tooth profile, or trimming the amount of edge is too small can not play the role of trimming the edge of the teeth when trimming the edge, can be based on the specific circumstances of these pairs of gears only to fix the top or only to fix the root of the gear, only in the separate repair of the top or repair of the root of the teeth can not reach a good result, the top of the teeth and root before the common repair of the edge of the amount of radial and axial value of trimming can be Allocated to a gear, can also be allocated to two gears according to the situation.

(2) Control of tooth shape error. Tooth shape error is caused by a variety of factors, observation of faulty milling machine gears in the transmission system, found that the tooth shape error is mainly in the processing process, followed by a long period of time due to poor operating conditions. Tooth shape error is more common in the noise that occurs when gears mesh. In general, the larger the tooth shape error, the greater the noise. For the concave tooth shape, the gear teeth are impacted twice in one mesh, the noise is very large, and the more concave the tooth shape, the greater the noise. Therefore, the gear tooth modification, so that it is appropriate in the convex shape, in order to achieve the purpose of reducing noise.

(3) Control the meshing gear center distance change. Changes in the actual center distance of the meshing gear will cause changes in the pressure angle, if the center distance of the meshing gear appears to be a cyclical change, then it will also make the pressure angle cyclical changes, the noise will also increase periodically. The analysis of the meshing center distance shows that when the center distance is large, the noise effect is not obvious, while the center distance is small, the noise increases significantly in the control of the center distance of the meshing gears, the outer diameter of the gears, the deformation of the drive shaft, the drive shaft with the gears and bearings should be controlled in an ideal state. This can be eliminated as far as possible due to changes in the meshing center distance noise.

(4) CNC engraving and milling machine company pay attention to the role of lubricating oil on the control of noise. Lubricating oil in the lubrication and cooling at the same time, but also play a certain damping effect, the noise with the increase in the amount of oil and viscosity and become smaller. The main drive system of the faulty milling machine uses splash lubrication, and splash lubrication will increase the oil disturbance noise. The actual Jen gear lubrication requires very little oil, and its main purpose is to form a pressure oil film for lubrication. Experiments have proved that gear lubrication to meshing side to oil **. In this way, both play a cooling effect, but also in the meshing area before entering the formation of an oil film on the tooth surface. If you can control the splash of oil into the mesh area in small quantities, the noise reduction effect is better. Accordingly, the oil pipe rearrangement, so that the lubricant according to the ideal state splash into each pair of gears, in order to control the noise due to unfavorable lubrication.

2, bearing noise control

(1) control the quality of the inner and outer rings. Failure of Guangdong Dongguan CNC milling machine in the main drive system, all bearings are the inner ring rotation, the outer ring is fixed. At this time, the inner ring, such as radial deflection will cause rotation imbalance, resulting in vibration noise. If the outer ring of the bearing, with hole shape and position tolerance are not good, there will be radial swing, which will destroy the concentricity of the bearing parts. In addition to controlling the geometric deviation of the inner and outer rings of the bearing, it should also control the corrugation degree of the inner and outer ring raceways, reduce the surface roughness, and strictly control the surface knocking and scratching of the raceways in the assembly process, otherwise it is impossible to reduce the vibration noise of the bearing. Observed that the degree of corrugation of the raceway for the dense wave or sparse wave, the rolling body in the rolling contact point is obviously different, resulting in a large difference in the frequency of vibration.

(2) control bearing and hole and shaft fit accuracy. The main transmission system of the faulty milling machine, the bearing with the shaft and hole should ensure that the bearing has the necessary radial clearance. Therefore, the selection of initial clearance in the bearing is important for controlling the noise of the bearing. Excessive radial clearance will lead to an increase in the noise of the low-frequency part, while a smaller radial clearance will cause an increase in the noise of the high-frequency part. General clearance control at 0.01mm **. The form of fit of the outer ring in the bore affects the propagation of noise. A tighter fit will improve the sound transmission, thus increasing the noise. In addition, the form tolerance and surface roughness of the mating parts should be in accordance with the requirements of the selected bearing accuracy level. If the bearing is very tightly mounted on an inaccurately machined shaft, CNC milling machine then the shaft error will be transmitted to the inner ring raceway of the bearing and manifest itself in the form of a higher degree of corrugation, and the noise will increase.