Stages and characteristics of engineering machinery failure

The fault characteristics of construction machinery and equipment are diverse and have different characteristics according to different stages of use.

(1) Fault characteristics of the initial stage of construction machinery use. In the initial stage of use (equivalent to the running-in period), the failure of the construction machinery is from high to low (down curve). The initial failure rate is related to the quality of the manufacturing or maintenance and the use of the running-in period. If the quality of construction machinery or repair High and can be used and maintained correctly. Then, the initial failure rate is low. Otherwise the early failure rate will be high. In the early stage, the coupling bolts are loose or loose; the pipe joints are loose or loose: residual metal chips or foundry sand are easy to block the oil passage or are clamped in the relative motion friction to pull the parts (such as the actuator cylinder in the hydraulic system) The oil leakage is caused, and the adjusted clearance or pressure changes, so that the machine can not perform the specified ability, and some joints leak water, oil leakage, gas leakage, etc. due to the bolts are not tight.

(2) Fault characteristics of the construction machinery during normal use. After the completion period of the construction machinery, it will enter the normal use stage. The construction machinery runs in this stage. As long as it is maintained and used correctly according to the regulations, there is generally no failure. Even if the failure occurs, it is a random failure (this kind of failure is concealed and difficult to find during maintenance or inspection), so the failure rate Very low, the curve is gently rising slightly. If the construction machinery fails during the normal use period, it is mostly accidental or caused by improper use and maintenance.

(3) The use of engineering machinery is close to the fault characteristics of the overhaul period. When the construction machinery is used close to the overhaul period, the loss of each component increases and the technical condition deteriorates. The fault characteristics at this stage are high failure rate. It is common, and most of them are caused by excessive wear and aging of parts, and there are many plugging, leaking and bad phenomena in the oil circuit.

(4) Fault characteristics of construction machinery in different seasons. The failure rate of construction machinery is related to the season. When the machine is used at low temperatures in winter, the failure rate is higher than in summer. For example, in the winter, the fuel supply system is often poorly atomized due to low temperature. The fuel is easy to solidify and the oil circuit is blocked and not easy to start. Or the engine is turned off when the engine is running. The lubricating oil has poor fluidity and accelerates the wear of the machine. The battery leakage causes the engine to be difficult to start, the brake is unreliable, and the liquid transmission is abnormal.