5 Tons Wheel Loader Axle Reliability Improvement Based On Statistical Analysis

Located at the end of transmission system, drive axle of wheel loader is the composed of all transmission mechanisms between drive shaft and driving wheel. The main function of drive axle is to transmit the torque from the drive shaft to the driving wheel, and to make the wheel loader backward or forward. It can bear the weight of machine and ensure accessibility and safety in the complex environment.The machine must be stopped and repaired once the failure occurs for the drive axle. Apart from the lost for the machine, the indirect loose caused by machine halt, such as delaying the construction period, scraping the construction material is very huge. So it is very urgent to improve its quality.Through the introduction of axle of 5 tons Wheel loader, the brake caliper’s assembly structure and key points are understood and the location with frequent breakdown is illustrated. The main driver is very important so the installation and debugging method are also introduced. More detailed introduction is given to the brake caliper due to the safety of brake caliper and machine. The influence of temperature is also introduced as temperature is a very important factor to affect the failure rate.Through the statistical analysis of axle and Weibull methods, we know when the reliability is 90% of the axle its rated life is 291 days. There are diverse failure types for drive axle. To calculate the normal distribution of data according to the statistical data of the standard deviation.Find out the relationship between standard deviation and fault rate find out the main faults and secondary faults. Analysis the typical fault such as brake failure to find the fault reason, and analysis the fault reason by starting from the test methods and means of control to enhance the reliability of the typical parts.When doing this DMAIC six sigma management tools will be used, which includes definition, Measure, analysis and improvement, control, each stage consisting of a series of tools support method to achieve the goal of this phase. Drive axle has many faults; it has important significance to improve brake caliper which as security of irreplaceable parts. Aimed at the fault rate of brake, define the current fault level, set the improvement goal and ideal target, Ensure the improvement from procurement, quality inspection, production and manufacturing, process control and so on each link of the system. Take improving the reliability of the brake as a case, the processing quality of the piston diameter of brake caliper reliability has the greatest influence on the reliability of the brake, Through the piston machining process capability analysis and improvement, that when the diameter of the piston fit the normal distribution CPK reached 1.42, brake caliper fault rate reduced to 0.109% from 0.263%; at this time the rectangular sealing ring fault rate reduced to 9% from 40%; which improves the reliability of the brake caliper and greatly reduce the failure rate.When the former process measurement data of key parts is in a certain range, the reliability of parts can be controlled within a certain range to meet the expectation of target. By continuous monitoring of the control stage, it is found that after design improvement braking pliers failure rate significantly has decreased, the quality improvement has obtained the remarkable effect. Other failure parts system improvements were made in this way, after a series of quality improvement, also achieved good results. Which reduce the failure rate, improve the reliability, save social resources.