For the concrete mixer, the hydraulic system is very important, loading, unloading, mixing tank rotation are inseparable from the hydraulic system, many concrete mixers will encounter insufficient pressure of the hydraulic system, which in the end is why?
There are four reasons for the insufficient pressure of hydraulic system of concrete mixer
1. Whether the hydraulic pump can output hydraulic oil, if there is no hydraulic oil output, it may be that the steering of the pump is not right, the parts are seriously worn or damaged: the resistance of the oil suction pipe is too large (the oil filter is blocked, the oil viscosity is too high, etc.) or the air leaks. If it is a new hydraulic pump, it may be that the pump body has casting defects, such as sand holes, shrinkage holes, etc., which make the oil suction chamber and the oil pressure chamber connected, lose the oil pressure capacity, and the input power is insufficient, so that the oil delivery pressure of the pump can not meet the requirements, and the pump shaft is twisted and can not output oil. If there is oil output from the hydraulic oil pump, check each oil return pipe to see which part is leaking. If the return pipe of the relief valve leaks oil, the setting pressure may be low. At this time, tighten the pressure regulating spring of the relief valve. If the pressure does not change, the main valve core of the relief valve or the cone valve of the pilot part may be stuck in the open position due to dirt or corrosion; or the spring may be broken and lose its function; or the damping hole may be blocked by dirt, and the oil output from the pump will immediately flow to the oil tank through the relief valve. Troubleshooting: disassemble the relief valve, clean it, check or replace the spring, and restore its working performance.
two Whether the overflow valve of concrete mixer works normally, if not, it may be that a valve in the pressure oil circuit is stuck by dirt or other reasons and is in the oil return position, resulting in a short circuit between the pressure oil circuit and the overflow valve circuit, or it may be that the pipe joint is loose, or some valves in the pressure oil circuit leak seriously, or the seals of the hydraulic cylinder and hydraulic motor are damaged, resulting in serious leakage . Discharge method: disassemble the relevant valve for cleaning, check the size of the sealing gap or various sealing devices, and replace the sealing device if it is damaged.
3. If the output flow of the hydraulic pump decreases significantly with the increase of the pressure, and the pressure does not reach the specified value, it is due to the increase of the clearance after the wear of the hydraulic pump. The elimination method: by measuring the volumetric efficiency of the hydraulic pump, it can be determined whether the pump can continue to be used, and the parts with serious wear should be repaired or replaced.
4. If the hydraulic system of the whole concrete mixer can establish normal pressure, and there is no pressure in some pipelines or hydraulic cylinders, the pipeline, small hole or throttle valve, directional valve and other parts may be blocked. At this time, check the pressure one by one and find out the cause before removing.