Truck front wheel bearings are installed between the truck front axle assembly and tire rim, consisting of inner bearing, outer bearing, cage, oil reservoir, wheel hub, brake caliper, oil seal, etc. The wheel hub is connected to the front wheel assembly through the inner and outer bearing, and the wheel rotates rigidly around the rolling bearing during operation.
When the truck is running, the hydraulic steering system works to drive the steering cylinder to move, so that the front wheel assembly moves, because the tire, rim, steering cross tie bar and front wheel assembly are connected, so the tire and steering cross tie bar move with it, in this process, the front wheel assembly plays the role of “joint rod In this process, the front wheel assembly plays the role of “linkage”.
The loading quality of the truck is designed to be 260 t. Due to the heavy production task and the limitation of the operator’s skills, the overloading phenomenon of the truck occurs frequently, resulting in the increase of the load bearing of the front wheel and the pressure of the front wheel bearing, so the front wheel bearing is very easy to cause damage.
When the truck is running at high speed, the operator will increase the frequency of braking or braking use more urgent, so that the truck weight and load due to the role of the impact will be mostly concentrated in the front axle, the front axle withstand the impact force mainly on the front wheel bearings of the truck, the role of such a large impact will certainly aggravate the damage to the front wheel bearings of the truck, thus greatly reducing the service life of the front wheel bearings of the truck.
In the open pit mine, heavy truck operators adopt the form of 4 shifts and 3 reversing operations, so the phenomenon of continuous operation occurs more often. When one shift is over, the truck will be handed over to the next shift operator without fault, which will lead to incomplete heat dissipation of the truck, and the temperature of the front wheel bearing will rise after a long time in a high temperature state, so that the lubrication performance of grease will be reduced, which will aggravate the wear of the front wheel bearing of the truck.
bearing structure design is based on the use of performance target values to determine, such as load capacity, life, accuracy, reliability, vibration, wear, friction torque, etc.. Sometimes, due to the limited level of the designer, the bearing manufacturing process is poor, the clearance fit is unreasonable, and even deviates from the target value, which can easily cause the early failure of the bearing.
In terms of the quality of the bearing material itself, the existence of cracks, spots and burrs on the bearing surface, these defects are the main cause of bearing damage4.
Truck production operation task is heavy, due to the working environment temperature difference, the viscosity of the grease also changes, so that the grease does not have high temperature and high pressure resistance, a long time will make the viscosity of the grease reduce and become diluted, which will lead to a large loss of grease, reduce the grease in the bearing, seriously affect the lubrication efficiency of the bearing, and eventually will increase the wear and tear of the bearing, resulting in bearing damage.
After fixing the bearing, the clearance between the bearing and the pressure plate should be measured, but sometimes in the process of measurement, personnel ignore the accuracy of the vernier calipers, vernier calipers are not zeroed, so that the measured clearance increases, affecting the service life of the bearing, the bearing will be damaged.
When the bearing and platen are put on, the fixed bolts of the platen should be tightened, sometimes the maintenance personnel do not tighten the fixed bolts according to the standard torque, so that there is still a certain gap between the platen and the bearing; the truck will make the platen loose for a long time, thus causing the bearing to be damaged.
The inner wear bearing sleeve is a kind of bearing sleeve to prevent the main pin from rubbing with the front elevation angle, if the inner wear bearing sleeve is not properly installed, the main pin is easy to swing, so that the inner wear bearing sleeve is subject to wear and tear, increasing the bearing flicker, thus affecting the bearing life.
Truck accident prevention includes not only big mechanical failures, like cracked structural parts of the truck, damaged front wheel bearings, etc., but also some zero failures that usually occur. Fault prevention can effectively reduce the probability of truck failure, but also prevent the deterioration of truck performance.
3. Improve the front wheel bearing operating environment of the truck
4. Regular maintenance of truck front wheel bearings
5. Select qualified truck front wheel bearings
6. The viscosity of grease should be suitable to avoid the viscosity change due to temperature change.
7.Improve the skills of maintenance personnel
