A Brief Discussion on Adjusting the Deviation of Conveyor Belts in Construction Machinery

Conveyor belts are widely used in on-site mixing equipment, ranging from a few meters in length to tens of meters in length. The AMP2000 type asphalt concrete mixing equipment for stabilized soil used by our company, whether it is the belt conveyor or the aggregate belt conveyor, always has varying degrees of deviation when the conveyor belt is working. This not only causes material leakage, abnormal wear, reduced production capacity and inaccurate gradation, More importantly, it affects the normal operation of the entire set of equipment, thereby influencing the construction work along the entire line.

To solve the problem of conveyor belt deviation, it is first necessary to understand the causes of the belt deviation. The fundamental reasons for the belt deviation are that the resultant force of the external force acting on the belt in the width direction of the belt is not zero or the tensile stress perpendicular to the width direction of the belt is uneven. From the perspective of the operation of conveyors, the pattern of belt deviation is "running tight rather than loose", "running high rather than low", and "running behind rather than ahead". The so-called "run tight, not loose" means that when the tightness on both sides of the tape is different, the tape will lean towards the tighter side. "Run high, not low" means that if the heights on both sides of the tape are different, the tape will lean towards the higher side. "Running backward but not forward" means that if the idler support is not installed on a cross-section perpendicular to the running direction of the belt, but one end is forward and the other end is backward, the belt will deviate towards the backward end.

After understanding the reasons for the deviation of the tape, the operator can eliminate the fault.

The phenomenon of tape deviation and its correction methods are generally as follows:

(1) It veers to the same side both under no-load and heavy-load conditions. It is indicated that the tightness on both sides of the tape is inconsistent. According to the rule of "running tight but not loose", the lead screw or counterweight of the tensioning mechanism should be adjusted.

(2) If the tape deviates left and right and does not fix its direction, it indicates that the tape is too loose. The lead screw of the tensioning mechanism should be adjusted to tighten the tape.

(3) When the belt is unloaded, it always deviates to one side. The idler support on the deviated side should be moved forward along the running direction of the belt by a certain distance, but it should not exceed 2cm, or the idler support on the other side should be appropriately raised.

(4) If the tape does not deviate when unloaded but always deviates in one direction when fully loaded, it indicates that there is an eccentric load. At this point, efforts should be made to ensure that the belt is evenly loaded. The position of the receiving hopper can be adjusted or the position of the conveyor can be adjusted.

(5) If the belt deviates at the roller, it indicates that the installation position of the roller is not good. The levelness and parallelism of the roller should be adjusted.

(6) If the roller or idler deviates due to the adhesion of materials in some areas, the adhered materials should be removed first to observe whether the deviation phenomenon has been eliminated. If it is effective, it indicates that the adhesion of materials has caused the diameter at that location to be too large, resulting in an increase in the tensile force of the belt adhesive.

(7) Severe wear at the edge of the tape or non-parallel seams of the tape can also cause the tape to deviate. At this point, the tape should be adjusted in time.

In addition, the belt can be returned to its normal position by installing limit idlers and deviation adjustment idlers. Limit idlers, as the name suggests, are installed on both sides of the belt to force the belt to return to its original position. The self-aligning idlers are two sets of self-aligning idlers installed on the conveyor, which can automatically correct the deviation of the belt. When the belt deviates and rubs against the small roller on one side, it causes the support on that side to move forward in the direction of the belt's movement. At this point, the belt will move to the other side until it returns to its normal position.

It should be noted that when adjusting the deviation of the tape, one should not be in a hurry for quick results. Instead, adjustments should be made gradually. During fine-tuning, one should observe carefully until satisfied.