Troubleshooting of Shift Punch of Forklift
Summary:Troubleshooting for shifting punch of forklift: The forklift has strong impact and abnormal noise when shifting. Most cases may be caused by the loose...
Troubleshooting for shifting punch of forklift: The forklift has strong impact and abnormal noise when shifting. Most cases may be caused by the loose hydraulic shift fixed shaft variable reducer or differential.
Turn the input shaft of the main reducer drive shaft by hand. If free running clearance is found, it is determined that the gear clearance of the main reducer is too large. Remove the main reducer and measure its clearance distance (standard value is 0.30-0.50mm). Adjust the position of the bevel gear so that the clearance between it and the driving bevel gear is within the range of the standard clearance. After reassembly, test the machine. If there is still gear impact and abnormal noise when gear is engaged, and the degree is only slightly less than the original, but the fault is still the same.At this time, the transmission shaft can be removed again to make the transmission in the no-load state. Start the engine and repeat the tests of gear shifting, pushing and raising and lowering. If it is found that the abnormal noise generated at the moment of gear shifting still exists, and the transmission has obvious vibration. Check whether the support fixing bolts of the transmission are loose. If the bolts are fastened, it can be judged that the fault should be inside the transmission. Disassemble, clean and inspect the transmission, and check whether the tapered roller bearings of the driving and driven shafts of the reverse and forward clutches are loose. In case of looseness, the bearing can be adjusted to the appropriate clearance by adding or removing shims, and the machine can be re assembled after adjustment. Although the phenomena of gear impact and abnormal noise have been reduced, the fault still exists.Therefore, the fault cause should be found in the hydraulic control part of the transmission. Because the return of the piston of the clutch is achieved by the preload of the spring. Therefore, at the moment of gear shifting, the pressure control oil flow of the main clutch may be too large, so the spring preload can be quickly overcome, making the friction between the driving plate and the driven plate too fast to produce gear impact. In order to completely solve this problem, the hydraulic control pipeline needs to be modified to a certain extent. An adjustable flow valve is connected in series between the reversing valve and each clutch piston to control its flow, so that it can achieve the goal of stable engagement.