The water tank truck is mainly driven the gearbox by the engine. The gearbox is installed PTO (power takeoff) device. When pulling the PTO operation switch back, the power takeoff gear shall be placed in the meshing position to drive the water tank pump through the transmission shaft. The water tank pump shall generate power to spray the liquid inside the tank out through the pipe network. When the power takeoff switch moves forward, the water pump shall stop working.
The normal working of PTO device also cannot leave the solenoid valve which is the industrial equipment controlled by electromagnetism. It is used to adjust the direction, flow, velocity and other parameters of the medium in the industrial control system. Solenoid valve is used to control through the electromagnetic effect, and the main mode of control is by the relay. In this way, the solenoid valve can be matched with different circuits to achieve the desired control, and the accuracy and flexibility of control can be guaranteed.
Whether the water tank truck can work normally or not firstly depends on the PTO device. Once the water tank truck cannot work normally, firstly, check whether the transmission shaft between the PTO device and pump is in normal rotation. If there is no rotation, it can be sure that there is something wrong with the PTO device and solenoid valve. Secondly, Check the solenoid valve to determine whether there is damage due to the short circuit of electromagnetic valve. If it is, change a new solenoid valve. If the above two conditions are excluded, then it must dismantle the PTO device in the transmission of water tank truck to check whether there is friction and damage of the bearing, or whether there is damage of transmission gears and air leaking in air chamber.