News
Home > News

Drive Shaft and Its Maintenance

Pulished on Jan. 09, 2021


In order to ensure the normal operation of the Drive Shaft and prolong its service life, pay attention to:


1. It is strictly forbidden for a car to start at a high gear.


2. Never lift the clutch pedal sharply.


3. It is strictly forbidden to overload and speed vehicles.


4. The working condition of the drive shaft should be checked frequently.


5. Always check the tightness of the transmission shaft hanger, whether the supporting rubber is damaged, whether each connection part of the transmission shaft is loose, and whether the transmission shaft is deformed.


6. In order to ensure the dynamic balance of the drive shaft, you should always pay attention to whether the balance pads are unsoldered. The new drive shaft assembly is provided as a complete set. When installing the new drive shaft, pay attention to the assembly mark of the telescopic sleeve and ensure that the flange fork is in a plane. When repairing and disassembling the drive shaft, the assembly mark should be printed on the telescopic sleeve and the flange shaft in order to keep the original assembly relationship unchanged during reassembly.


7. Grease should be frequently added to the universal Joint Cross Bearing. In summer, No. 3 lithium grease should be injected, and No. 2 lithium grease in winter.


Drive Shaft

Drive Shaft


malfunction repair


Wear problem


The damage, wear, deformation and loss of dynamic balance of the drive shaft components will cause abnormal noise and vibration when the car is driving, and will cause damage to related components in severe cases. When the car is running, it makes a "Gerdon" sound when it starts or accelerates rapidly, and it clearly shows the feeling of loose parts. If it is not the loosening of the drive axle transmission gear, it is obviously that the transmission shaft is loose. The loose parts are nothing more than universal joint cross bearings or steel bowl and flange fork, the spline shaft and spline sleeve of the telescopic sleeve. Generally speaking, the cross shaft diameter and the bearing openness should not exceed 0.13mm, and the meshing gap between the telescopic spline shaft and the spline sleeve should not exceed 0.3mm. Exceeding the service limit should be repaired or replaced.


If the chassis makes a "humming" sound while the car is running, and the higher the running speed, the louder the sound. This is generally due to the wear and tear of the universal joint cross shaft and the bearing, the middle bearing of the transmission shaft, the damage of the intermediate rubber support or the loose hanger, or the fixed position of the hanger.


Solution:


1) Traditional method


Domestically, repair welding, bushing, pitting and other methods are generally used for the wear of transmission shafts. However, when the shaft is made of 45# steel (quenched and tempered), if only surfacing welding is used, internal welding will occur. Stress, under heavy load or high-speed operation, cracks or even fractures may appear at the shaft shoulder. If stress relief annealing is used, it is difficult to operate, and the processing cycle is long, and the maintenance cost is high; when the shaft material is HT200 , The use of cast iron welding is not ideal. Some companies with higher maintenance technology will use brush plating, laser welding, micro-arc welding and even cold welding, etc. These maintenance technologies often require higher requirements and high costs.


2) The latest maintenance method


For the above repair technology, it is not common in European, American, Japanese and Korean companies. Developed countries generally use polymer composite technology and nanotechnology. Polymer technology can effectively improve maintenance efficiency and reduce maintenance costs and maintenance intensity. , Among them, the most widely used technology system is Mega Wah. Compared with traditional technology, polymer composite materials not only have the strength and hardness required by metal, but also have the retreat (variable relationship) that metal does not have. Through "mold repair", "part correspondence", "mechanical processing", etc. The technology can ensure the size matching of the repaired part and the mating parts to the greatest extent; at the same time, the composite material itself has the comprehensive advantages of compression resistance, bending resistance, and elongation rate, which can effectively absorb the impact of external forces and greatly resolve and offset the bearing The radial impact force on the shaft avoids the possibility of the gap, and also avoids the secondary wear of the equipment due to the increase of the gap.


Balance problem


Symptom diagnosis: When a 6×4 car is under heavy load, especially during driving bumps, it occasionally makes a knocking sound. Pay attention to check whether the balance shaft of the middle and rear axle is displaced and interferes with the transmission shaft. If the noise increases with the increase of the vehicle speed during the operation of the car, and is accompanied by jitter, this is generally caused by the loss of balance of the transmission shaft. This vibration is most noticeable in the cab. The unbalance of the dynamic balance of the drive shaft should be less than 100 g.cm.


A serious failure of the dynamic balance of the drive shaft will cause damage to related components. The most common are the clutch shell cracks and the fatigue damage of the middle rubber support.


Solution:


Tighten the front wheel of the car with mats, use a jack to lift the middle and rear drive axles on one side of the car; start the engine, put on high gear, and observe the vibration of the drive shaft. During the inspection, notice that when the speed drops, if the shimmy increases significantly, it indicates that the drive shaft is bent or the flange is skewed.


The bending of the transmission shaft is the bending of the shaft tube, most of which are caused by the overload of the car. Due to overloading and overhanging of coal-carrying vehicles, the drive shafts are bent and broken. If some trucks and trailers transport more than 60 tons of coal, the drive shaft is seriously damaged due to overload and overhang. Although the intermediate support of the transmission shaft was strengthened and the strength of the flange fork was strengthened, the failure of fracture and damage still occurred.


After replacing the drive shaft components and straightening, check the balance, and the unbalance should meet the standard requirements. The technical condition of the universal joint fork and the transmission shaft hanger should also be checked in detail. If the installation fails to meet the requirements, the cross shaft and roller damage will cause looseness and vibration, and the transmission shaft will also lose balance.


The company also provides Gear Shafts, please feel free to contact us if necessary


Previous: None

Next: Analysis and Maintenance of Gear Shaft Damage