Oil pumping unit dynamic balance timely automatic regulating device and control method thereof

When the pumping unit is actually working, because the work done by the upstroke is to lift the weight of the sucker rod, the liquid volume at the front of the pump piston, and the fluid volume in all tubes behind the piston, the load is heavy, while the work done by the downstroke The purpose of lifting the weight of the crank and the balance weight is to convert the weight into potential energy, and the load is small. Another example is the change of underground liquid and gas volume. Sometimes the pump pumps all the liquid volume, sometimes it is gas, sometimes it is oil-gas mixture, and One factor is that the underground pressure will also change in stages, because the pumped medium will not be completely the same in a certain period of time, and the pressure will be different, so the load on the pumping unit on the ground will also show a relatively large stage This means that the current consumed by the up and down strokes of the pumping unit is not equal during operation. If it is not adjusted in time, it will appear. In order to maintain this dynamic unbalanced operation of the pumping unit, the pumping unit motor needs to overcome the dynamic The unbalanced part of the resistance will cause the motor to run overloaded, causing the torque factor to be too large, the torque peak value on the crank is too large, the torque fluctuation is too large, and the power consumption of the motor will also increase accordingly, destroying the uniform rotation and causing oil pumping All transmission parts of the machine are subject to a large impact, which causes uneven force on the internal gears of the reduction box, resulting in pushing teeth, belt slipping and burning, linking parts of the transmission connecting rod such as crank pins are loose and fall off, and tail shaft and middle shaft bearings are damaged.

[0003] For the above problems, the prior art has not been able to solve this problem well:

[0004] 1. Prior art 1, see attached figure 1 , the pumping unit fixedly installs a balance counterweight 11' on the crank 12' of the pumping unit, but in this way, because the position of the balance counterweight is fixed when the pumping unit is in operation, the up and down strokes The function is the same. When the crank is rotating, it cannot move relative to the crank. That is to say, the counterweight cannot be adjusted in time during operation. When the difference between the upper and lower stroke currents is too large, it can only be adjusted manually. Inaccurate, in actual work, after the pumping unit is balanced for a period of time (days or weeks), there will be an unbalanced state, so it is very difficult to maintain the ideal balance of the pumping unit.

[0005] 2. Prior art 2, see attached figure 2 , a position or mass-adjustable counterweight device 11 "is arranged at the middle or tail of the pumping unit beam 3 ", but this means is because the position of the beam is very high from the ground and the length of the beam is very long, so that no matter the counterweight The installation of the device or the maintenance and detection of the counterweight device are very inconvenient, and it is difficult to ensure the long-term reliable operation of the pumping unit in the harsh natural environment

Although this technology improves the dynamic balance of the pumping unit relative to the counterweight of the fixed weight, the shortcoming of this prior art is: because the hydraulic balance device 1 "' is directly connected between the beam and the pumping unit base , due to the inertia of the beam, the work of the piston rod is very unstable, and the controllability of the adjustment is still poor