How the oil arm works: 

1. Balance principle of oil transport arm. 

The no-load state of the oil transport arm should keep the balance between the inner arm and the outer arm, and the inner arm and outer arm should have the tendency to return to the non-working state. The balanced counterweight structure can meet this requirement. 

The oil transport arm has two balance weight blocks: the main (inner arm counterweight) and the secondary (outer arm counterweight), which can realize static balance. 

The principle of main counterweight balance is that the gravity moment produced by the weight of the upper end of the inner arm, the upper rope wheel and the outer arm is balanced with the gravity moment produced by the main counterweight, the lower rope wheel and the auxiliary counterweight of the lower end of the inner arm, taking the rotating joint in the middle of the inner arm as the rotating shaft, the upper end of the inner arm, the upper rope wheel and the outer arm. 

Adjusting the weight of the main counterweight at the lower end of the inner arm can ensure that the inner arm is balanced and has a tendency to return when the inner arm is not in the working state. 

The balance principle of the auxiliary counterweight is realized through the upper and lower rope wheel mechanism. The weight of the outer arm drives the upper rope wheel to have the torque to be resold in one direction, and the secondary counterweight drives the lower rope wheel to have the torque balance to rotate in the opposite direction. 

Adjusting the angle between the counterweight and the inner arm (retractable wire rope) or adjusting the position of the counterweight on the beam (lifting counterweight) can ensure that the outer arm is balanced and has a tendency to return when the outer arm is not working. 

2. Working principle of hydraulic system. 

Each hydraulic arm has three sets of cylinder drive systems, in which the fuel tank, oil pump and relief valve are common. 

The hydraulic oil is inhaled into the oil pump through the oil filter on the fuel tank, pressurized by the oil pump and entered into the three-position four-way reversing valve through the throttle valve. The direction of the cylinder in and out of the oil can be changed by controlling the reversing valve, so that the piston rod in the cylinder can be driven to reciprocate. 

If the inner arm drives the cylinder, it drives the inner arm of the oil transport arm to swing back and forth; if the outer arm drives the cylinder, it drives the outer arm to swing up and down; if it is a horizontal rotary cylinder, it drives the inner and outer arms to do horizontal rotary movement. 

The relief valve can adjust the working pressure of the hydraulic system, and the throttle valve can adjust the speed of cylinder piston rod movement. 

Due to the limitation of the piston movement stroke of the cylinder, the hydraulic delivery arm is equipped with a limit alarm system to prevent the cylinder from being damaged beyond the allowable working range. 

To learn more about the crane pipe, pay attention to the crane tube manufacturer Lianyungang huade Petrochemical Co., Ltd.