CAT excavator hydraulic system heat failure analysis
Published:2013年04月17日 Source:未知 Click:次
1 excavator hydraulic system heat phenomena hazards:
Heating of the hydraulic system, a direct impact on the normal operation of the excavator, fever phenomenon harm, the following main points:
(1) so that the mechanical thermal deformation, when the type of hydraulic spool valve member, the valve body material, the thermal expansion coefficient is not the same between the valve body, the valve body due to thermal expansion valve stuck phenomenon appears to cause operation failure, the impact of hydraulic transmission accuracy of the system, resulting in deterioration of the quality of parts work.
(2) after the working fluid temperature rises, the viscosity of the hydraulic oil is reduced, the increase in leakage, the pump volumetric efficiency and overall system efficiency will be significantly reduced, the operation is not flexible.
(3) Since the viscosity of the oil is reduced, so that the lubricating properties of the working fluid is reduced, accelerated wear of the hydraulic components, accelerated wear failure of the element, to shorten the life of the components.
(4) hydraulic systems and components seal deterioration at high temperatures, elastic degeneration ability to reduce the sealing performance degradation, or even seal failure, the increase in leakage;
(5) increased oxidative deterioration of oil, and precipitation asphalt substances precipitation clogging damping holes and crannies valve port, the hydraulic component failure or death card can not move, the metal pipe elongation and bending Code, or even rupture. According to information on when the oil temperature exceeds 55 degrees Celsius temperature rise by 9 degrees Celsius, the life of the oil is reduced by half.
(6) so that the oil-air separation pressure reduction, the oil was dissolved air to escape, resulting in cavitation, resulting in a hydraulic system performance degradation.
Hydraulic system heat causes of fever can be divided into two categories: one is caused by fever because of the design; mainly caused by the irrational system design, such as matching between components is unreasonable, piping channel is too small, elbow, small bending radius, Fuel tank capacity is not enough to cause such problems should be fully considered during the design phase, otherwise it will cause the excavator hydraulic system deficiencies, after the product is made difficult to overcome another type of hydraulic component failure or improper use reasons, resulting in fever.Therefore, the heat of the hydraulic system from hydraulic component failure or improper use of reason.
Its exclusion caused by the heating of the hydraulic system of excavator reason:
(1) to improve the lubrication conditions of the excavator moving member, in order to reduce friction loss, and help to reduce the workload, reduce fever.
(2) climate and operating environment temperature is high, resulting in temperature rise. Continuous work in the hot summer, coupled with poor cooling effect or improper cooling, cause the machine to heat greater than the amount of heat the oil temperature is too high; engine water temperature heat sink temperature is high, so that the temperature rise.
(3) should always check the hydraulic oil level: To observe the oil level of the hydraulic oil in the tank at any time, and always maintain the hydraulic oil level height within the range of normal oil level, in order to ensure the cooling effect of the fuel tank, Caterpillar excavators leveldetection method: the arm perpendicular to the ground, bucket hands back and observe the hydraulic oil tank level sight glass tube, cold oil, hydraulic oil level between off the assembly line and neutral, hot oil, the oil level should be between the center line and on-line. When the hydraulic oil level in the tank below the minimum level to oiling to the tank.
Heating of the hydraulic system, a direct impact on the normal operation of the excavator, fever phenomenon harm, the following main points:
(1) so that the mechanical thermal deformation, when the type of hydraulic spool valve member, the valve body material, the thermal expansion coefficient is not the same between the valve body, the valve body due to thermal expansion valve stuck phenomenon appears to cause operation failure, the impact of hydraulic transmission accuracy of the system, resulting in deterioration of the quality of parts work.
(2) after the working fluid temperature rises, the viscosity of the hydraulic oil is reduced, the increase in leakage, the pump volumetric efficiency and overall system efficiency will be significantly reduced, the operation is not flexible.
(3) Since the viscosity of the oil is reduced, so that the lubricating properties of the working fluid is reduced, accelerated wear of the hydraulic components, accelerated wear failure of the element, to shorten the life of the components.
(4) hydraulic systems and components seal deterioration at high temperatures, elastic degeneration ability to reduce the sealing performance degradation, or even seal failure, the increase in leakage;
(5) increased oxidative deterioration of oil, and precipitation asphalt substances precipitation clogging damping holes and crannies valve port, the hydraulic component failure or death card can not move, the metal pipe elongation and bending Code, or even rupture. According to information on when the oil temperature exceeds 55 degrees Celsius temperature rise by 9 degrees Celsius, the life of the oil is reduced by half.
(6) so that the oil-air separation pressure reduction, the oil was dissolved air to escape, resulting in cavitation, resulting in a hydraulic system performance degradation.
Hydraulic system heat causes of fever can be divided into two categories: one is caused by fever because of the design; mainly caused by the irrational system design, such as matching between components is unreasonable, piping channel is too small, elbow, small bending radius, Fuel tank capacity is not enough to cause such problems should be fully considered during the design phase, otherwise it will cause the excavator hydraulic system deficiencies, after the product is made difficult to overcome another type of hydraulic component failure or improper use reasons, resulting in fever.Therefore, the heat of the hydraulic system from hydraulic component failure or improper use of reason.
Its exclusion caused by the heating of the hydraulic system of excavator reason:
(1) to improve the lubrication conditions of the excavator moving member, in order to reduce friction loss, and help to reduce the workload, reduce fever.
(2) climate and operating environment temperature is high, resulting in temperature rise. Continuous work in the hot summer, coupled with poor cooling effect or improper cooling, cause the machine to heat greater than the amount of heat the oil temperature is too high; engine water temperature heat sink temperature is high, so that the temperature rise.
(3) should always check the hydraulic oil level: To observe the oil level of the hydraulic oil in the tank at any time, and always maintain the hydraulic oil level height within the range of normal oil level, in order to ensure the cooling effect of the fuel tank, Caterpillar excavators leveldetection method: the arm perpendicular to the ground, bucket hands back and observe the hydraulic oil tank level sight glass tube, cold oil, hydraulic oil level between off the assembly line and neutral, hot oil, the oil level should be between the center line and on-line. When the hydraulic oil level in the tank below the minimum level to oiling to the tank.