Excavators often make some noise during use. For excavators, the noise of hydraulic components of excavators is a very common typical problem. But also because the noise category is not easy to distinguish, it has caused some obstacles for everyone to find the root cause of the fault. This article will explain the causes of pilot pump noise, overflow valve noise and hydraulic cylinder noise for reference only.
1. Pilot pump noise
The noise emitted by the pilot pump is sharp, with pulse vibration. Referring to the sound frequency of the tractor, the sound will rise and fall with the number of engine revolutions. The noise is mainly generated in the pump and the pump pressure regulating valve for the following reasons.
1) After the pilot pump sucks the hydraulic oil mixed with air, the double gears in the pump squeeze the oil with each other, so that the air is separated and broken from the hydraulic oil, resulting in noise.
2) The pressure regulating valve of the pilot pump needs to be opened frequently at ordinary times. The long-term reciprocating action will cause wear between the valve core and valve seat, resulting in clearance. At this time, the pressure and flow of hydraulic oil will be unstable and produce noise.
2. Noise of overflow valve
The noise of overflow valve is usually "ci", which is very sharp and harsh, and the sound is from high to low.
1) The noise of the overflow valve usually occurs at the limit position of the oil cylinder. It is emitted when the handle is "suffocated" and is generated by the valve core of the overflow valve.
2) In case of failure, you can first measure whether the pressure is normal. If the pressure is lost after adjustment and the pressure value fluctuates slightly, it indicates that the valve core has leakage and the overflow valve needs to be replaced.
3. Hydraulic cylinder noise
The noise emitted by the hydraulic cylinder is like deflation. The sound of "ci" lasts for a short time, about 1-2 seconds. There are usually two reasons.
1) A small amount of air is mixed into the hydraulic oil. When the hydraulic oil enters the oil cylinder, it will separate out and burst again under the action of high pressure, resulting in noise. It usually occurs after the hydraulic oil is replaced and the main pump and motor are replaced. When replacing hydraulic components and hydraulic oil daily, be sure to exhaust in time, and release the pressure of hydraulic oil tank regularly during normal work.
2) If the sealing ring of the cylinder head of the oil cylinder is too tight or the cylinder rod is bent, there will be a sharp mechanical friction sound when the cylinder rod moves, and there will be obvious scratches on the coating on the surface of the cylinder rod. In case of this fault, replace the factory sealing parts or replace the cylinder rod of the oil cylinder in time.
