Troubleshooting of forklift gear shifting fault:
Cpcd5aiiz forklift has strong impact and abnormal noise when it is in gear. Because the vehicle is equipped with hydraulic shift fixed shaft variable speed reducer or loose differential.
When the transmission shaft of the main reducer rotates its input shaft by hand, it is found that there is a free rotation clearance of nearly 30 degrees, so it is determined that the meshing clearance of the main reducer is too large. Remove the main reducer and measure that its clearance is 0.65mm (standard value is 0.30-0.50mm). Adjust the position of the bevel gear so that the meshing clearance between the bevel gear and the driving bevel gear is 0.35mm. After reassembly and test run, there is still gear impact and abnormal noise in gear, which is only slightly less than the original, but the fault remains.
To do this, remove the drive shaft again and leave the transmission in a no-load state. During the test, it is found that there is still obvious vibration when the engine is engaged and pushed in different gears, and there is still obvious vibration when the engine is engaged and pushed in different gears. Check whether the support fixing bolts of the transmission are loose. Judging from this phenomenon, the fault should be inside the transmission. Disassemble, clean and test the transmission, and find that the tapered roller bearings of the driving and driven shafts of the reverse and forward clutches are loose. Adjust the bearing to the proper clearance by increasing or decreasing shims and reassemble the test machine. The phenomenon of gear impact and abnormal noise is weakened, but the fault still exists.
After such careful inspection, the root cause of the failure has not been found. Is there any defect in the design or manufacture of this type of forklift? Therefore, the forklift produced by the factory of the same model was found for the road test of gear, push and lift gears. The results showed that there was slight gear impact, but the severity was different. Therefore, the focus of fault cause finding should be on the hydraulic control part of the transmission. Consult the transmission control schematic diagram and parts Atlas of the machine, and know that the piston return of the clutch is realized by the preload of the spring. Therefore, at the moment of shifting, the main clutch may have excessive pressure control oil flow, so it can quickly overcome the spring preload and make the friction between the driving plate and the driven plate engage too fast to produce gear impact. In order to verify this assumption, it is necessary to reform its hydraulic control pipeline. An adjustable flow valve is connected in series between the directional valve and each clutch piston to control its flow so that it can achieve the purpose of stable engagement.
