Thread Content
A mixer truck is a type of construction machinery commonly seen in our daily lives. Its hydraulic system is relatively simple, generally falling into two main categories: open systems and closed systems. The simple structure of the hydraulic system also implies that the maintenance of the hydraulic pump in a mixer truck is straightforward; it is sufficient to carry out the maintenance work based on the different types of hydraulic systems. The open hydraulic system of mixer trucks has a simple structure, good heat dissipation performance, and is easy to maintain. Although the speed can also be adjusted using the engine’s throttle, it is energy-intensive and not economical. The disadvantage of open systems is that they require large fuel tanks, resulting in a bulky structure ； Air easily gets mixed into hydraulic oil, causing vibration and noise; as a result, its service life is short, and such systems are gradually being phased out nowadays. The closed hydraulic system of the mixer truck features a positive-displacement variable-speed pump with manual servo control. In addition to the main circuit necessary for performing the tasks, this hydraulic system also includes an auxiliary pump (gear pump) that is mounted coaxially with the main pump and integrated into it, as well as an auxiliary low-pressure oil filling and suction circuit formed by this pump, along with cooling and return oil pipelines. The auxiliary pump feeds oil to the low-pressure area of the main circuit via two check valves ； Along the way, it is connected to the servo hydraulic cylinder that adjusts the tilt angle of the main pump’s swash plate, thus forming the hydraulic circuit of the pump’s servo-variable mechanism ； Another path leads through the shuttle valve and low-pressure relief valve in the integrated valve block to the housing of the main pump and the fixed-displacement plunger hydraulic motor (referred to as the motor); from there, the oil returns to the tank via the return oil lines and cooler, thereby providing effective lubrication and cooling protection for the main pump and motor during operation. The closed hydraulic system of a mixer truck is characterized by a compact system design, a small fuel tank volume, and stable operation. As long as the cooling system functions properly, the mixer truck can operate stably for extended periods of time. When it is necessary to repair the hydraulic pump of a mixer truck, we only need to have a thorough understanding of the truck’s hydraulic system. If one does not have much knowledge of hydraulics or feels that their understanding is insufficient, and the hydraulic system of the mixer truck develops a fault, it is possible to seek out professional hydraulic pump repair companies (such as Shenzhen Autos) to carry out repairs on the hydraulic pump of the mixer truck. Hire professionals to handle professional tasks, ensuring the smooth progress of the project.