Mining Dump Truck Maintenance: Repair and Clearance Adjustment of the Intermediate Axle Main Shaft Assembly

Mining Dump Truck Maintenance: Repair and Clearance Adjustment of the Intermediate Axle Main Shaft Assembly

The condition was serious, and the intermediate axle main shaft was immediately replaced for the user, restoring the vehicle to service.

　　Afterwards, the service personnel disassembled and inspected the replaced intermediate axle main shaft and found that the fault occurred mainly at the meshing area between the combination gear and the differential planetary bevel gear. The tooth breakage between the planetary bevel gear and the bevel gear in the combination gear was relatively serious, while the helical gear in the combination gear and other main shaft assembly components were only lightly damaged.

　　According to statistics from the after-sales service department, among the repair requests in October, 6 such faults occurred in Shanxi and central Inner Mongolia, accounting for about 3.3% of the failure rate that month.

　　Service personnel analyzed this type of fault and found that, apart from a small number of cases caused by relatively serious wear of the thrust washer (Part 15), most were caused by loosening of the lock plate (Part 10) under the slotted nut (Part 9), resulting in excessive meshing clearance between the combination gear and the planetary bevel gear. Therefore, to avoid recurrence of such faults, two points must be noted: first, before tightening the slotted nut, the gear meshing clearance must be measured and adjusted; second, when tightening the slotted nut, in addition to locking the slotted nut with the lock plate, the differential cross shaft must also be locked at the same time. Only in this way can the lock plate truly perform its anti-loosening function.

　　The specific method for adjusting the clearance is as follows: first measure the distance from the splined end face of the main shaft (Part 7) to the end face of the cross shaft. This distance can basically be regarded as the meshing clearance between the combination gear and the planetary bevel gear. The meshing clearance should be kept within the range of 0.2-0.4 mm; if it exceeds this range, it can be adjusted by replacing the thrust washer with one of a different thickness.

　　In addition, service personnel and users should be reminded that daily maintenance and servicing of mining vehicles is very important. When using mining vehicles, whether before departure each day or after finishing work, attention should always be paid to the operating condition of the vehicle. If any abnormal noise is heard, stop the vehicle immediately and have the company's professional mining vehicle service personnel inspect it and eliminate the fault. Only in this way can the problem be solved in the early stage of fault occurrence, avoiding further damage to more components and expansion of the fault caused by continued use after a fault occurs. Ultimately, this approach of early detection, early diagnosis, and early elimination ensures the service life of the vehicle and thus wins customer satisfaction.