Tips for correct preheating of small and medium pump trucks

To ensure the normal operation of small and medium concrete pump trucks, we must pay attention to maintenance. What are the tips for correct preheating of small pump trucks? We have sorted it out for you, mainly in the following aspects:

1. The principle of the main oil pump gradually increasing the displacement

During the idling process of the hydraulic pump, components such as bearings and oil distribution plates will inevitably generate heat due to movement friction. This heat is gradually transferred to the surrounding hydraulic oil, which will gradually increase the temperature and viscosity of the hydraulic oil. After a period of time, the swash plate of the hydraulic pump can be adjusted to have a relatively small angle change, so that the hydraulic oil flows, so that the higher temperature hydraulic oil is delivered to the hydraulic circuit. The oil in the hydraulic motor and pipeline gradually heats up due to convection and conduction. Until then the hydraulic oil of the entire pumping system reaches the working temperature, and the preheating work ends smoothly.

2. The operation method of the main oil pump gradually increasing the displacement

Due to the difference between the open system and the closed system, there are two operating methods for gradually increasing the displacement of the main oil pump.

(1) For the concrete pump truck of the open system, the pumping displacement is gradually increased from the “zero” position, then the reversing valve starts to work, the hydraulic oil after the reversing valve flows back to the tank, and the entire pumping hydraulic system The oil temperature gradually rises. The displacement must be increased step by step, and at each displacement level must be maintained for at least 2-3 minutes, until the normal pumping displacement is reached. The whole process takes about 15-20 minutes.

(2) For small pump trucks with closed systems, start the pumping action in a very low displacement state. Keep it for 5-8 minutes, then it can be directly set to normal pumping displacement.