Pump Truck Hydraulic System Handout

The basic concept of the hydraulic system:

1. Hydraulic oil pressure:

The air we live in is at atmospheric pressure, and its value is about 1 bar. (1 bar = 0.1 MPa) atmospheric pressure retains the air on which we depend.

Submarines dive into the water, and they also bear the water pressure at the same time as the atmospheric pressure, so it is impossible to dive into the boat with unlimited depth.

In the hydraulic system, the hydraulic pressure causes the actuator to generate a corresponding force, thereby achieving the corresponding purpose. On the pump truck, in order to transport concrete from the ground to a certain height, a certain hydraulic oil pressure must be provided for the main cylinder on the pump truck.

Hydraulic oil flow:

In daily life, when we hit the water faucet at different angles, the amount of water flowing out in a certain period of time will be different, which means that the larger the angle, the greater the water flow.

In the hydraulic system, the flow of hydraulic oil determines the speed of the system. For example, on a pump truck, we increase the displacement to increase the number of hydraulic pump spare parts, so that the more concrete is pumped in a given time.

Hydraulic system power mechanism:

The power mechanism of the hydraulic system is what we usually call a "hydraulic pump", which generates hydraulic oil pressure and hydraulic oil flow for the hydraulic system to work.

Hydraulic system actuator:

Hydraulic system actuators include cylinders and motors. On the pump truck or tractor spare pump, we divide the cylinders into main cylinders, swing valve cylinders, boom cylinders and outrigger cylinders according to the purpose of each actuator. The motors are divided into stirring motors, air cooler motors, water pump motors and reducer motors.

Hydraulic system control mechanism:

The hydraulic system control mechanism is mainly various control valves. On the pump truck, there are pressure control valves, directional control valves and flow control valves. Pressure control valves such as main relief valves, stacked relief valves, directional control valves such as main four-way valves, swing cylinder four-way valves, flow control valves such as boom multi-way valves.