Nowadays, there are more and more four-wheel drive tractors, and the proportion of two wheel drive tractors is decreasing. According to statistics, four-wheel drive tractors account for about 89%, while two wheel drive tractors only account for about 11%. With the increasing number of four-wheel drive tractors, there are also more and more problems that arise during use, including improper operation and maintenance. Here we will talk about common fault analysis in the use of the front axle of four-wheel drive tractors.
1. During the plowing process, the user locked the front drive shaft. There are many reasons that can cause gear tooth jumping. After gear tooth punching occurs, it is necessary to first understand whether the on-site work is overloaded and whether there is a significant impact load. When overloaded or subjected to excessive impact loads, it is easy to cause tooth jumping. Check if there are any problems with the assembly of the gears. If obvious improper assembly or excessive clearance is found, assemble the gears according to the correct assembly requirements and adjust the clearance. Analyze the damaged gears to see if there are any issues with the material and heat treatment. If there is a problem with the material or heat treatment of the gear, it should be replaced with a qualified gear.
2. During the plowing process, the front drive of the four-wheel drive tractor makes abnormal noise and feels frustrated and stuck. On site inspection found that the central transmission bevel gear of the front drive axle has teeth, and the central transmission bevel gears have been replaced and used normally. When assembling the large and small bevel gears of the central drive of the front drive axle, the contact marks and side clearances of the large and small bevel gears should be adjusted. The meshing imprint of the central and large bevel gears should be located at the small end in the middle position of the tooth surface, and the side clearance of the large and small bevel gears should be maintained within the range of 0.16 mm to 0.32 mm. The side clearance and meshing imprint should be adjusted by adjusting the shims on the large and small bevel gears.
3. When the user of a four-wheel drive tractor plows the land, there is no front wheel drive. On site inspection found that all the fixing bolts of the central transmission bevel gear of the front drive axle were broken, and the new central transmission assembly was functioning normally. There are many reasons for the fracture of all fixed bolts of the central bevel gear, one of which is the possibility of overload and significant impact load during operation. When the overload or impact load is too large, the bolt may break; Secondly, there may be quality issues with the bolts themselves, such as insufficient strength; The third issue is that the tightening torque does not meet the requirements, with excessive or insufficient torque.
4. When the user plows the land, there is an abnormal sound from the front drive axle. On site inspection found that the bearings on the small bevel gear shaft of the front drive axle were scattered, and the new central transmission assembly was functioning normally. The bearing detachment on the central transmission small gear shaft of the front drive axle is generally caused by the following reasons: firstly, improper installation, excessive interference, etc., which leads to bearing tilting and reduced bearing clearance, and the load on the bearing cage will increase, causing the bearing to scatter during use. Therefore, bearing installation is very important, and installation personnel must install the bearing in place according to the requirements of the bearing installation process; The second issue is poor lubrication of the bearings, which can increase their service life and reduce noise. If the lubrication is poor due to insufficient lubricating oil, the interior of the cage will be in a dry wear state, leading to cracking and scattering of the cage; The third issue is the poor cleanliness of the lubricating oil, which increases the friction force between the retainer and the outer and inner rings of the bearing, leading to bearing detachment.