One of the reasons for the high noise of the heater chiller is void soak of the hydraulic pump. When the air enters the oil, it will form cavitation in the high-pressure area and spread in the form of pressure wave, which will cause the oil to vibrate and make the system produce cavitation noise. The oil filter and oil inlet pipe of the hydraulic pump are blocked and the oil viscosity is too high, which will cause the vacuum at the oil inlet to be too high, so that air can penetrate into it. The shaft end oil seals of the hydraulic pump and the pilot pump are damaged or cannot be sealed, which will also cause air to enter. Also, do not use the oil level of the oil tank below the lowest line, otherwise the oil inlet pipe will be void soak.
In addition to the above reasons, excessive wear of internal parts of the heater chiller is also the cause of large noise. For example, the servo valve spool of the hydraulic pump and the piston controlling the flow will also cause pulsation of the piston during the working process due to local wear or strain, resulting in fluctuations in the output flow and pressure production force of the hydraulic pump, which will produce large vibration and noise at the pump outlet. In addition, the valve plate of the hydraulic pump is also one of the components that are very easy to cause noise. During the operation of the heater chiller, the valve plate is worn or stains are deposited at the opening of the unloading groove, which will cause the unloading groove to become shorter, thus changing the unloading position. The phenomenon of trapped oil will also occur, resulting in higher noise. Even the valve plate that has been repaired by our flat grinding will still have the phenomenon that the unloading groove will become shorter. If we can not properly lengthen it in time, it will still produce greater noise.
