Reasons and treatment methods of abnormal noise of tower crane slewing bearing
You should often see tower cranes on construction sites, right? It operates flexibly and has a large carrying capacity, which has made great contributions to improving the construction progress and ensuring the quality of the project. The slewing bearing is one of the commonly used bearings of many construction machinery, and it is found in tower cranes. Many friends who are engaged in the operation of tower cranes will report the problem of abnormal noise in the slewing bearing. Next, the editor of Hengguan will summarize the reasons and treatment methods for abnormal noise of tower crane slewing bearing.
1. Reasons for abnormal noise of tower crane slewing bearing
1. The machining accuracy of the bearing gear is not enough
The precision of the slewing bearing gear determines the stability, accuracy and uniformity of the load distribution of the slewing bearing transmission. The higher the gear precision, the denser the contact spots on the meshing tooth surface. The normal level should be between 7 and 11. If the precision is not enough, it is easy to cause abnormal noise.
2. The internal machining accuracy of the bearing is not enough
The inner steel ball and raceway of the slewing bearing have low machining accuracy or quality defects, which can easily cause the collision between the rolling body and the spacer, which affects the stability of the bearing operation and also causes excessive noise.
3. Bearing gear wear
Due to the powerful work of the tower crane, after the slewing bearing gear is under load for a long time, small pieces of metal or strip-shaped metal iron filings will fall off near the pitch line of the tooth surface, forming pitting or gnawing teeth until the tooth shape is damaged. The abnormal noise and impact increase when the tower crane rotates.
4. Insufficient bearing lubrication
The lack of grease in the slewing bearing or the deterioration of the grease will cause the friction between the rolling element and the raceway to increase, the rotational resistance to increase, and the rotation to be inflexible, resulting in abnormal noise.
2. Processing method
1. Choose a slewing bearing with reliable quality
To avoid the problem of abnormal sound of slewing bearing, the premise is to control the procurement. Ensure that the bearing material quality is reliable, and the gear and internal machining accuracy is up to standard, making it more flexible in operation and longer in service life.
2. Supplement or replace grease in time
According to the bearing instructions or relevant operating specifications, add grease in time. For special working environments such as dust, high temperature difference, and high humidity, the lubrication cycle should be shortened. As a result, the friction between the gears can be reduced, the wear speed of the gear ring gear can be slowed down, and the frictional noise of operation can be reduced.
3. Fastening bolts
The connection bolts between the slewing bearing and the upper and lower supports are loose or the pre-tightening force cannot meet the requirements, which will cause the rear axial clearance to increase, the rolling elements rotate under a large overturning moment, and the raceway edge is subject to large contact stress, resulting in rolling. The edge of the road is damaged, causing abnormal noise. Therefore, it is necessary to fasten the bolts in time to make them reach the specified pre-tightening force.