Hydraulic system How to prevent air from entering? To prevent air from entering the four pillars hydraulic press The following points should be paid attention to when using and protecting the hydraulic system:
(1) Check the oil level in the oil tank frequently to keep enough oil.
(2) During operation, the oil will be consumed, and new oil of the same specification must be added in time.
(3) Even at very low oil level, the oil suction pipe 1:3 and oil return pipe orifice should be kept below the oil level.
(4) Use seals with good functions, and replace invalid sealing devices in a timely manner, and tighten the screws at the pipe discussion and joint surfaces.
(5) In use, the pressure everywhere in the system is prevented from being lower than atmospheric pressure or forming partial vacuum.
(6) Air entering into the hydraulic system of four column hydraulic press is unavoidable. In order to break the air, some oil cylinders are equipped with exhaust valves on their upper parts. Before the machine is started, turn over the exhaust valve to make the oil cylinder move back and forth several times within the limit of a very large distance to break the air in the system.
(7) After changing the oil in the oil tank, the actuator should be turned on for several cycles to break the air in the system.
Where do the vibration and noise in the hydraulic system come from? The vibration and noise of the machine system are mainly caused by the machine transmission system driving the hydraulic pump, and the following aspects are important:
1: Unbalanced counter rotating bodies: In actual use, most motors drive hydraulic pumps through couplings. It is often difficult to make these counter rotating bodies complete in dynamic average short and long. If the unbalanced force is too large, it will produce a large winding vibration of the rotating shaft and generate noise when reversing.
2: Improper installation: the hydraulic system often causes vibration and noise due to problems in installation. Such as poor support of the system pipeline and defects of the foundation, or the difference between the hydraulic pump and the motor shaft, as well as loose coupling, these will cause greater vibration and noise.
3: Cavitation sign of the hydraulic pump: when the hydraulic pump is working, if the resistance of the hydraulic oil suction pipe is too large, at this time, the hydraulic oil has no time to fill the oil suction chamber of the pump, causing partial vacuum in the oil suction chamber, forming negative pressure. If the pressure just reaches the air separation pressure of the oil, the air dissolved in the oil will be separated in large quantities, forming free bubbles. With the running of the pump, the oil with bubbles turns into the high-pressure area. At this time, the bubbles shrink, break and dissipate due to the high pressure, forming a very high part of high-frequency pressure blow.
