Hydraulic equipment system There are some honeycomb holes in the inner wall of the cylinder of the hydraulic cylinder , the surface of the piston or the piston rod, which are all caused by cavitation. Cavitation will cause the mating surface of the cylinder barrel and piston rod to become rough, internal leakage will occur in the hydraulic cylinder, and the working speed will decrease. When cavitation and other forms of corrosion work together, it will accelerate the corrosion rate of the main parts of the hydraulic cylinder, which will seriously affect the normal use of construction machinery.
1. Factors affecting cavitation
When the surface of the hydraulic cylinder part moves relative to the hydraulic oil, the gas dissolved in the hydraulic oil easily precipitates and forms air bubbles. These bubbles flow into the high-pressure area and rupture. The instantaneous high-temperature and high-pressure microjet and impact force repeatedly act on the surface of the hydraulic cylinder part, which causes cavitation on the part surface. The conditions of cavitation in hydraulic cylinders are related to the hydraulic system structure, hydraulic cylinder parts materials, hydraulic oil quality, manufacturing and maintenance, etc.
(1) Hydraulic system structure
If the passages of the pipelines, control valves and other components of the hydraulic system are too narrow and there are too many elbows, the temperature of the hydraulic oil will increase, the impact force will increase, and air bubbles will easily be generated in the hydraulic oil, which will cause cavitation of the hydraulic cylinder.
(2) Hydraulic cylinder parts material
If the material used to make the hydraulic cylinder has better strength, toughness and corrosion resistance, its cavitation resistance is better; otherwise cavitation is likely to occur. In addition, the uniformity of the material structure has a greater impact on cavitation. The more uneven the material structure, the more likely it is to cause cavitation in areas with weak strength and low corrosion resistance.
Control elements (ie, various hydraulic valves) control and regulate the pressure, flow, and direction of the liquid in the hydraulic system. According to different control functions, hydraulic valves can be divided into pressure control valves, flow control valves and directional control valves. Pressure control valves are further divided into flow control valves (relief valves), pressure reducing valves, sequence valves, pressure relays, etc .; flow control valves include throttle valves, regulating valves, diverter manifolds, etc .; directional control valves include check valves, Hydraulically controlled check valve, shuttle valve, directional valve, etc. According to different control methods, hydraulic valves can be divided into on-off control valves, fixed value control valves and proportional control valves.
Auxiliary components include oil tank, oil filter tank, oil filter, oil pipe and pipe joint , seal ring, quick-change joint, high pressure ball valve, hose assembly, pressure gauge joint, pressure gauge, oil level oil thermometer, oil pipe and pipe joint , Seals, quick-change joints, high-pressure ball valves, hose assemblies, pressure measuring joints, pressure gauges, oil level oil thermometers, etc. Hydraulic oil is the working medium that transfers energy in the hydraulic system. There are various types of mineral oil, emulsion and synthetic hydraulic oil. Hydraulic equipment system