How to extend the service life of excavators?

1. Ensure normal working load

The magnitude and nature of the working load of construction machinery have a significant impact on the wear and tear process of the machinery. Generally speaking, the wear of parts increases proportionally with the increase of load. When the load on a part exceeds the average design load, its wear will intensify. In addition, under the same other conditions, stable loads have less wear, fewer malfunctions and a shorter service life than dynamic loads. Tests show that when an engine operates under unstable loads, the wear of its cylinders will increase by twice compared to when it operates under stable loads. Engines operating under normal loads have a lower failure rate and a longer lifespan. On the contrary, an engine that is overloaded has a significantly higher failure rate and its lifespan will also be shorter than the design indicators.

The phenomenon where the surface of a metal is damaged due to chemical or electrochemical reactions with the surrounding medium is called corrosion. This corrosive effect not only affects the normal operation of mechanical surface equipment, but also corrodes the internal components of the machinery. Rainwater, chemical substances in the air, etc. can enter the interior of mechanical parts through external channels, gaps, etc., corroding the interior of mechanical parts, accelerating mechanical wear and increasing mechanical failures. Because this corrosive effect is sometimes invisible and intangible, it is easily overlooked by people, and thus its harmfulness is even greater. During operation, management and operation personnel should take effective measures based on the local weather conditions and air pollution situation at that time to reduce the impact of chemical corrosion on the machinery. The key is to prevent the invasion of rainwater and chemical components in the air into the machinery and minimize operations in the rain as much as possible.

2. Reduce various corrosive effects

The phenomenon where the surface of a metal is damaged due to chemical or electrochemical reactions with the surrounding medium is called corrosion. This corrosive effect not only affects the normal operation of mechanical surface equipment, but also corrodes the internal components of the machinery. Rainwater, chemical substances in the air, etc. can enter the interior of mechanical parts through external channels, gaps, etc., corroding the interior of mechanical parts, accelerating mechanical wear and increasing mechanical failures. Because this corrosive effect is sometimes invisible and intangible, it is easily overlooked by people, and thus its harmfulness is even greater. During operation, management and operation personnel should take effective measures based on the local weather conditions and air pollution situation at that time to reduce the impact of chemical corrosion on the machinery. The key is to prevent the invasion of rainwater and chemical components in the air into the machinery and minimize operations in the rain as much as possible.

3. Reduce the influence of mechanical impurities

Mechanical impurities generally refer to non-metallic substances such as dust and soil, as well as some metal shavings and wear products produced by construction machinery itself during its operation. Once these impurities enter the interior of the machinery and reach the mating surfaces, their harm is significant. Not only do they impede the relative motion and accelerate the wear of parts, but they also scratch the mating surfaces, damage the lubricating oil film, and cause the temperature of the parts to rise and the lubricating oil to deteriorate.

It has been measured that when the mechanical impurities in the lubrication increase to 0.15%, the wear rate of the first piston ring of the engine will be 2.5 times greater than the normal value. When impurity particles enter the rolling shaft, its service life will be reduced by 80% to 90%. Therefore, for construction machinery operating in harsh and complex environments, it is necessary to use high-quality and well-matched components, lubricating oil and grease to block the source of harmful impurities. Second, it is necessary to do a good job in mechanical protection at the work site to ensure that the corresponding mechanisms can operate normally and prevent various impurities from entering the interior of the machinery. For malfunctioning machinery, it is advisable to have it repaired at a regular repair site as much as possible. When conducting on-site repairs, protective measures should also be taken to prevent the parts to be replaced from being contaminated by dust and other impurities before entering the machinery.

4. Reduce the influence of temperature

In work, each component has its own normal temperature range. For instance, the temperature of general cooling water is 80-90℃, and that of hydraulic oil in hydraulic transmission systems is 30-60℃. If the temperature is lower or higher than this range, it will accelerate the wear of parts, cause the deterioration of lubricating oil, and result in changes in material properties, etc.

Tests show that the main transmission gears and bearings of various construction machinery wear out 10 to 12 times more when operating in lubricating oil at -5℃ than when operating in lubricating oil at 3℃. However, when the temperature is too high, it will accelerate the deterioration of the lubricating oil. For instance, when the oil temperature exceeds 55-60℃, for every 5℃ increase in oil temperature, the oxidation rate of the oil will double. For this reason, during the operation of construction machinery, it is necessary to prevent overloading at low temperatures, ensure the normal operation during the low-speed preheating stage, and wait until the machinery reaches the specified temperature before driving or working. Do not neglect its important role just because no problems occur at that time. Second, it is necessary to prevent the machinery from operating at high temperatures. During the operation of the machinery, the values on various thermometers should be frequently checked. If any problems are found, the machine should be stopped immediately for inspection and any faults should be promptly eliminated. For cases where the cause cannot be identified for the time being, the machinery must not be allowed to operate while faulty without any treatment. In daily work, it is necessary to pay attention to checking the working condition of the cooling system. For water-cooled machinery, it is necessary to inspect and add cooling water before each day's operation. For air-cooled machinery, it is also necessary to regularly clean the dust on the air-cooling system to ensure the unobstructed flow of the heat dissipation air ducts.