Views: 267 Author: Site Editor Publish Time: 2020-11-17 Origin: Site
The hydrostatic drive systems system pressure of agricultural machinery will greatly affect the working performance of the hydraulic system of agricultural machinery. The working pressure abnormality of the hydraulic system is often manifested as the failure of the pressure regulating valve when the pressure is adjusted, the system pressure cannot be established, and the pressure is unstable.
(1) The hydraulic transmission system pump and motor have been used for too long. The internal wear, large leakage and low volumetric efficiency will lead to insufficient output flow of the hydraulic pump and low system pressure.
(2) The engine speed is too low and the power is insufficient, resulting in insufficient system flow and low hydraulic system pressure.
(3) The directional control of the hydraulic pump is installed in the wrong position, so the pump does not work and the system has no pressure.
If the pressure does not rise or fall during the working process of the agricultural machinery, it is likely that the reversing valve has failed, resulting in continuous unloading of the system or continuous high pressure.
Blockage of the orifice of the overflow valve, burrs on the main valve core, and dirt in the gap between the valve core and the valve hole may cause the main valve core to be stuck in the fully open position.
The hydraulic mechanical transmission oil output by the hydraulic pump is directly returned to the tank through the overflow valve. That is, the short connection between the pressure oil circuit and the return oil circuit will cause the system to be pressureless.
If the above-mentioned burrs or dirt jam the main valve core in the closed position, the system pressure may continue to be high and cannot drop.
When the spool of the relief valve or the reversing valve is stuck, the spool action is not flexible. At this time, the system components are prone to work instability, and the pressure is unstable when the system pressure is detected.
For systems with check valves, if the direction of the check valve is reversed, the pressure may not rise. Leaks inside and outside the system can also cause the system pressure to not rise, such as serious leakage between the valve core and the valve body hole.
(1) Assemble the hydraulic pump in strict accordance with the correct assembly method, and check whether the wiring of its control device is correct.
(2) Increase the height of the hydraulic oil tank relative to the hydraulic pump. Appropriately increasing the diameter of the oil suction pipe, replacing the oil filter element, and dredging the pipeline can solve the problem of pump oil suction and empty suction and avoid low system pressure. In addition, use the hydraulic oil with suitable viscosity to avoid difficulty in pumping oil due to excessive oil viscosity when the machine is at a lower ambient temperature.
(3) Treatment method for hydraulic control valve: Check whether the unloading or directional valve's on or off state is correct. Clean the spool and unblock the orifice. Check if the direction of the check valve is correct. Replace clean oil, etc.
(4) Submerge the oil return pipe in the oil tank below the liquid level, and strengthen the seal at the joint of the oil suction pipe, which can effectively prevent air from entering the system and avoid system pressure instability.
The hydraulic system is widely applied in the agricultural machinery, and the system pressure is of great important when working. Welcome to visite JAZZY to get more information of hydraulic quick release coupling, hydraulic ball valve and other hydraulic components!
