Emergency repair of the auger sprocket of ABG511 paver

During the process of laying cement concrete pavement in Yili, Xinjiang, the ABG511 paver made abnormal noises from the chain box of the auger. The abnormal noise was found to be caused by the chain on the right side. After adjusting the tightness of this chain, the noise decreased. However, after using it for about ten hours, the noise increased again and eventually led to the chain breaking. Upon inspection, it was found that there were obvious impact scratches on the chain links. From this, it was concluded that the chain breakage was caused by being stuck and subjected to impact.

So, when inspecting the driving and driven sprockets, the driving sprocket is inspected first. Remove the cover plate at the top of the chain box and take out the broken chain. When the right side of the auger motor is turned, it is found that the driving sprocket can rotate freely, indicating that the power source of the driving sprocket is normal. After cleaning the driving sprocket and inspecting it, it was found that the chain teeth were slightly worn, but there were no obvious defects. When the right side of the auger shaft was rotated again, it was found that the driven sprocket also rotated normally. This indicates that there is no fault with the bearing inside the driven sprocket. Upon further inspection, it was found that the driven sprocket had been severely worn, with its upper chain teeth tilting in the same direction of rotation and taking on an eagle-nose shape. Obviously, this is the reason why the chain got stuck.

The reasons for its wear and tear are as follows: The machine has been in use for more than 6,000 hours. The driven sprocket is located at the bottom of the chain box. The particles produced by wear inside the chain box and the dust particles entering the box from the outside deposit at the bottom of the chain box. When these particles mix with oil stains, they surround the driven sprocket, accelerating the wear.

The emergency repair method we adopted was to first weld the worn parts on the sprocket with electric welding, then wrap the chain around the welded sprocket, identify each chain tooth that did not fit well with the chain, and then use a hand grinding wheel to grind them until the chain could rotate flexibly on the sprocket. Finally, polish the chain teeth with fine sandpaper and reinstall them. The test run indicated that the fault had been eliminated. It could still be used normally after the construction was completed more than 40 days later.