The failure characteristics of construction machinery and equipment are diverse, and have different characteristics according to different use stages.
(1) Failure characteristics in the early stages of construction machinery use. In the early stage of use of construction machinery (equivalent to the running-in period), its failure is from high to low (declining curve). The initial failure rate is related to the quality of manufacturing or maintenance and the use in the running-in period. High and can be used and maintained correctly. Then, the initial failure rate is low. Otherwise, the early failure rate will be high. The early failures were mostly loose or loose coupling bolts; loose or loose pipe joints: residual metal shavings or foundry sand easily blocked oil passages or caught mechanical parts during relative motion friction (such as actuator cylinders in hydraulic systems) As a result of oil leakage, the adjusted clearance or pressure changes, making the machine parts unable to perform the prescribed capacity, and some joints leak water, oil, and air due to the tight bolts.
(2) Failure characteristics of engineering machinery during normal use. After the closing period of the construction machinery, it enters the normal use phase. Construction machinery running in this stage, as long as it is maintained and used properly according to regulations, generally no failure will occur. Even if a failure occurs, it is also a random failure (this kind of failure is hidden and difficult to find during maintenance or inspection), so the failure rate Very low, the curve rises slightly. If the construction machinery fails during the normal use period, it is mostly accidental or caused by improper use and maintenance.
(3) The failure characteristics of engineering machinery near the overhaul period. When the use of construction machinery is approaching the overhaul period, the losses of various components increase. The technical situation deteriorates. The fault at this stage is characterized by a high failure rate. It is common, most of which are caused by excessive wear and aging of parts, and there are more blockages, leaks, and bad phenomena in the oil circuit.
(4) Failure characteristics of construction machinery in different seasons. The failure rate of multi-station hydraulic press construction machinery is related to the season. When using machinery at low temperatures in winter, the failure rate is higher than in summer. For example, fuel supply is often poorly atomized in winter due to low temperatures. The fuel is easy to solidify, the oil circuit is blocked and it is not easy to start. Or the engine is stalled when the engine is running. Poor lubricating oil fluidity accelerates the wear of the parts. The battery leakage causes the engine to be difficult to start, the brakes are not reliable, and the liquid transmission is abnormal.