Do you know the cause analysis and elimination method of the fan bearing failure?

1. Analysis of the reasons for the failure of the fan bearing:

The two sides of the vane are fixedly matched with the bearing seat bearing with an adapter sleeve. After re-testing, the high temperature of the free end bearing and the high vibration value occurred. The upper cover of the bearing turn was removed, and the fan was manually rotated at a slow speed. It was found that the bearing roller at a specific position of the rotating shaft also rolled in the non-load area. This confirms that the bearing running clearance variation is high and that the mounting clearance may be insufficient. According to the measurement, the internal clearance of the bearing is only 0.04mm, and the eccentricity of the rotating uranium is 0.08mm; due to the large span of the left and right bearings, it is difficult to avoid the deflection of the rotating shaft or the error of the bearing installation angle. Therefore, the large fan adopts automatic centering. Adjusted spherical roller bearings. However, when the internal clearance of the fan bearing is insufficient, the rolling parts inside the bearing are limited by the movement space, and their automatic centering function will be affected, and the vibration value will increase instead. The internal clearance of the fan bearing decreases with the increase of the fitting tightness, and a lubricating curved film cannot be formed. When the running clearance of the bearing decreases to zero due to the temperature rise, if the heat generated by the bearing operation is still greater than the heat dissipation, the bearing temperature That is, it will climb quickly. At this time, if it is not stopped immediately, the bearing will eventually burn out. The tight fit between the inner ring of the bearing and the shaft is the reason for the abnormally high temperature of the bearing in this example.

2. Exclusion method:

When processing, remove the adapter sleeve, re-adjust the tightness of the shaft and the inner ring, and take 0.10mm for the clearance after replacing the bearing. After re-installation, restart the fan, the bearing vibration value and operating temperature return to normal.

Too small internal clearance of fan bearing or poor design and manufacturing precision of parts are the main reasons for the high operating temperature of fan bearing. In order to facilitate the installation, repair and maintenance of fan equipment, the tapered hole of the adapter sleeve bearing is generally used in the design. However, the housing bearing matched with the inner ring is also prone to problems due to negligence in the installation procedure, especially the adjustment of the proper clearance. The internal clearance of the bearing is too small. The operating temperature rises rapidly: the fit between the tapered hole of the inner ring of the bearing and the adapter sleeve is too loose, and the bearing is easily damaged in a short time due to the loose fitting surface.

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