Excavator final drive motor use and maintenance
To achieve reasonable use of the hydraulic system, you must also pay attention to the following matters.
1) The hydraulic fluid in the fuel tank should always maintain a normal level. When the capacity of the pipeline and the hydraulic cylinder is large, a sufficient amount of oil should be initially placed. After the startup, the liquid will fall due to the oil entering the pipeline and the hydraulic cylinder, and even the filter will be exposed to the liquid surface. The oil must be replenished again. Leakage can also occur during use, so a level gauge should be placed on the fuel tank to allow frequent observation and replenishment of the fluid.
2) Final drive motor should be kept clean at all times. Check that the oil is cleaned frequently with the oil level.
3) The requirements for oil change are as follows.
1 The replacement of new oil or additional oil must comply with the oil grade used in this system, and should be tested and meet the specified specifications.
2 When changing the oil, all the old oil inside the tank must be discharged and the flushing is passed.
3 After the new oil is filtered, it is injected into the fuel tank. The filtration accuracy should not be lower than the filtration accuracy of the system.
4 Before the new oil is added to the fuel tank, the main oil return pipe flowing into the fuel tank should be taken apart and the oil should be connected with a temporary oil drum. The hydraulic pump motor is jogged so that the new oil "pushes" (displaces) the old oil in the pipeline. If the final drive parts, the steering valve of the hydraulic cylinder is manipulated, and the old oil in the cylinder can be replaced.
5 When adding oil, pay attention to the cleaning of the oil drum mouth, the fuel tank mouth and the oil filter inlet and outlet pipes.
6 The oil volume of the fuel tank should be kept within the specified liquid level after the system (pipes and components) is filled with oil.
7 The period of replacement of hydraulic oil (liquid) varies greatly depending on the type of oil (liquid), working environment and operating conditions. In general, in continuous operation, where high temperature, high humidity, and dust are present, it is necessary to shorten the oil change cycle. The replacement cycle given in Table 3 can be used for reference when storing oil before oil change. The replacement time of oil (liquid) should be based on the data detected during use. If one of the sampled oils (liquid) reaches the oil (liquid) The oil change indicator should be replaced in time to ensure the hydraulic system is working properly.
4) The oil temperature should be appropriate. The oil temperature of the fuel tank should not exceed 60 °C, and the general hydraulic machinery works well in the range of 35~55 °C. From a maintenance point of view, the oil temperature should also be absolutely avoided. If the oil temperature rises abnormally, it should be checked. The common reasons are as follows:
1 The viscosity of the oil is too high;
2 subject to external influences (such as oil pressure devices for opening and closing the door);
3 The circuit design is not good, for example, the efficiency is too low, the capacity of the components used is too small, and the flow rate is too high;
4 The fuel tank has a small capacity and slow heat dissipation (generally, the fuel tank capacity is more than three times the oil discharge per minute of the oil pump);
5 The performance of the valve is not good, such as the possibility of vibration, it may cause abnormal heat;
6 The oil quality deteriorates and the resistance increases;
7 The performance of the cooler is not good, such as insufficient water and scale in the pipe.
5) The air in the circuit should be completely removed. After entering the air in the circuit, because the volume and pressure of the gas are inversely proportional, the movement of the hydraulic cylinder is also affected as the load changes (for example, the cutting force of the machine tool changes frequently, but the feed speed needs to be kept stable, so In particular, air should be avoided.) In addition, air is an important cause of oil deterioration and heat generation, so special attention should be paid to the following items:
1 In order to prevent air from being brought back into the oil return pipe, the return pipe must be inserted below the oil level;
2 After the inlet filter is clogged, the suction resistance is greatly increased, and the air dissolved in the oil is separated, resulting in so-called cavitation;
3 At all places below the atmospheric pressure, such as the suction pipe and the pump shaft sealing part, care should be taken not to leak air;
4 The liquid level of the fuel tank should be as large as possible, and the suction side and the oil return side should be separated by a partition to achieve the purpose of eliminating bubbles;
5 The highest part of the pipeline and hydraulic cylinder must have a venting hole, and the air should be discharged when starting.
6) Pay attention to the following when using the hydraulic device installed outdoors:
1 The outdoor temperature changes more severely with the seasons, so use oil with a large viscosity index whenever possible;
2 Due to temperature changes, the water vapor in the fuel tank will condense into water droplets, and should be inspected once a week in the winter, and should be removed immediately after discovery;
3 Outdoors Because dirt easily enters the oil, it is necessary to change the oil frequently.
7) When starting the final drives for the first time, pay attention to the following:
1 Fill the pump with working medium;
2 Check if the direction of rotation is correct;
3 Whether the entrance and exit are reversed;
4 try to turn by hand;
5 Check if there is air leakage on the suction side;
6 Start and run at the specified speed.
8) When starting the travel motor at low temperature, pay attention to the following:
1 When starting the hydraulic pump in a cold zone or in winter, it should be opened and stopped, reciprocated several times to raise the oil temperature, and the hydraulic device is operated flexibly before entering the official operation;
2 Use a heater to heat the fuel tank in a short time. Although the oil temperature can be raised, the pump and other devices are still cold. Only the oil is hot, which is easy to cause malfunction. It should be noted.
9) Other notes:
1 When the hydraulic pump starts and stops, the relief valve should be unloaded;
2 The set pressure of the relief valve shall not exceed the maximum pressure of the hydraulic system;
3 should try to keep the voltage of the solenoid valve stable, otherwise it may cause the coil to overheat;
4 Vulnerable parts, such as seals, should always have spare parts for timely replacement. https://www.spfinaldrives.com/