CNC Router Representative

CNC Router In many CNC milling machines, because of the spindle's variable speed system still uses a number of transmission shafts, gears and bearings, CNC Router so in the work will inevitably produce vibration noise, friction noise and impact noise. The speed of the main transmission system of NC Milling machine is controlled by computer, so it is more continuous and representative than the noise produced by ordinary machine.

A numerical control milling machine, in the initial use of the noise is larger, and the noise source mainly from the main transmission system, with the use of time to extend the noise more and more, with the sound level meter in the spindle 2000r Min speed, the measured noise is $number. 2dB.

The mechanical system is subjected to any external excitation force, CNC Router and the system will vibrate because of the response to the excitation force. This vibrational energy is transmitted throughout the system, and when it is propagated to the radiant surface, the energy is converted into a pressure wave, which is radiated through the air. Therefore, the three steps of excitation response, CNC Router internal transmission and sound radiation are the forming process of vibration noise, friction noise and impact noise.

When the main drive system of NC Milling machine is made of soil, it is due to the excitation response of gears, bearings and other parts, and the noise is transmitted and radiated in the system, CNC Router and because of the abnormal condition, the excitation force is increased so that the noise increases.

(1) Gear noise analysis. The main drive system of the NC milling machine is mainly driven by gears to accomplish the speed change and transmission, so the meshing transmission of gears is one of the main noise sources.

In the main drive system of the machine tool, CNC Router the noise generated by the gears in operation is:

Shan gears in the meshing, the teeth and teeth between the continuous impact of the gear in the meshing frequency caused by forced vibration and bring impact noise.

Due to the effect of external exciting force, the Shan of gears produces the instantaneous free vibration of the natural frequency and brings noise.

Shan due to the eccentricity of the gear and the shaft and the bearing, the rotational unbalance inertia force is caused, which produces the low-frequency vibration consistent with the rotational speed. With the rotation of the axis, each turn sends a resonance noise.

The Shan caused by the friction between the teeth and the teeth causes the self-excited vibration of the gear and brings the friction noise. If the tooth surface is convex and uneven, CNC Router it can cause rapid periodic impact noise.

(2) Bearing noise analysis. The spindle speed control system of the NC milling machine has a total of 38 rolling bearings. The assembly, preload, concentricity, lubrication condition of bearing and axle neck and supporting hole, the load on the bearing, the radial clearance and so on, have great influence on the noise. And the bearing itself of the manufacturing deviation, to a large extent, determine the bearing noise. CNC Router The most easily deformed parts of rolling bearings are the inner and outer rings. Under the influence of external factors and their own precision, the inner and outer rings may produce swing vibration, axial vibration, radial vibration, CNC Router radial vibration and axial bending vibration of the bearing ring itself.

As with gears, the higher the rotational speed of the bearing, CNC Router the greater the rotary base frequency, the noise also increases the bearing rolling body inner and outer ring respective precision if not high, will become the main factor which affects the bearing noise, CNC Router the inner and outer ring of the rolling body or bearing is many, the higher harmonics of these frequencies are displayed on the spectrum, the higher the noise is caused.