The overflow leakage of parts in mechanical hydraulic power transmission system is mainly divided into two types: the internal part overflow leakage and the internal overflow leakage of main engine parts.
The overflow leakage of internal components mainly occurs in the hydraulic cylinders such as the drive hydraulic valve, hydraulic pump, hydraulic motor, etc., which is manifested by the direct discharge of a large amount of oil from the high-pressure cavity outside the hydraulic pump; External leakage mainly occurs in the external transmission parts of the hydraulic oil transmission device driven by oil pipelines, hydraulic valves, hydraulic cylinders, hydraulic pumps, etc., and a large amount of oil leaks to the shell and surface of relevant parts. No matter what type of safety leakage risk, it will directly affect the mechanical hydraulic power transmission system, causing huge safety hazards.
Reasons for leakage of hydraulic control system
Hydraulic system design
Due to the unreasonable structural design of the hydraulic system itself, many large hydraulic presses have oil leakage problems in the past oil supply system.
The main reasons are:
(1) The rated capacity of the oil tank is generally about 3~5 times of the rated capacity flow of the oil pump, but the rated capacity of some oil tanks does not meet the design specifications, resulting in slow heat removal of the oil tank.
(2) The rated volume of power components commonly used in hydraulic control system is too small and the flow is too large.
(3) The structure design of the transmission system is unreasonable, resulting in low transmission power and too many residual power components and transmission circuits.
(4) In normal non-hydraulic operation, the hydraulic power transmission system lacks useful oil unloading treatment methods. The hydraulic control system pressure is too high, the pump pressure is too high, the oil loss is large, and the pump oil is heated quickly.
Cleanliness of oil
Generally speaking, the hydraulic oil in the hydraulic system contains a lot of chemical impurities. Excessive impurities in the hydraulic oil may directly lead to the overall leakage of the system.
The factors affecting the cleanliness of hydraulic oil are mainly divided into:
(1) During the installation and use of the equipment, the hydraulic parts were not cleaned in time, resulting in the plastic iron chips, metal coatings and other chemical impurities stuck on the hydraulic parts directly falling into the hydraulic oil, causing serious pollution to the entire hydraulic oil.
(2) When epoxy resin, asphalt, carbon residue and other compounds are directly mixed with these hydraulic oils, the peroxide in the hydraulic oil may be degraded, which may also be directly related to the overall cleanliness of the hydraulic oil. These impurities in the hydraulic oil material will increase the damage roughness of the surface holes of the horizontal rolling system of the entire hydraulic transmission components. If the hole is directly blocked by these impurities, the entire valve core of the hydraulic valve will be blocked, which will damage the entire hydraulic valve core, and the transmission device of the hydraulic components will have oil leakage.
Source: Zhengxi hydraulic press
