Analysis on the causes of abnormal noise in connecting rod of beam pumping unit

Causes and solutions to crank pin abnormal noise

Cause Analysis

The most common abnormal sound in beam pumping units is the abnormal noise at the crank pin, and it mostly occurs in newly installed pumping units. Usually used in engineering are double donkey head pumping units and curved beam pumping units. In newly put into production curved beam pumping units, crank pin abnormal noise often occurs. Most of the newly put into production pumping units are produced and installed by third-party units, so there may be missing crank pin nuts during the installation process. Tightening conditions may cause abnormal noise during actual application and operation of the pumping unit. The abnormal noise of the double-head type oil pumping unit usually occurs after the oil pumping unit has been used for a period of time. The main reason for the abnormal sound is that the rear donkey head and the double-donkey-head type oil pumping unit should be softly connected with a steel wire. In the actual application process, the force of the head-type pumping unit is more uniform than that of the curved beam pumping unit, and the impact force received during the direction conversion link is relatively small.

solution strategy

If the curved beam pumping unit is in a newly installed state, then the machine needs to be inspected in detail before use to see if the crank pin nut is tightened. If it is not tightened, the nut needs to be disassembled, and then the crank pin must be tightened. , Normally, the nut needs to be screwed in about 270°, and then the nut is installed to start the motor, which can effectively solve the abnormal sound in the crank pin of the curved beam pumping unit. If there is still abnormal noise in the crank pin of the curved beam pumping unit after treatment, it may be due to the existence of a roller key in the crank pin, or the bushing inside the crank pin is damaged. In this case, the crank pin needs to be repaired. Replacement can effectively solve the abnormal noise problem.

Reasons and solutions for abnormal noise of beam pin and tail shaft

Cause Analysis

The main reason for the abnormal noise of the beam pin is that the pumping unit is unbalanced or the lubricating oil is insufficient. During the direction conversion process, the force on the small end of the connecting rod suddenly increases, resulting in abnormal noise. The abnormal noise usually occurs at the donkey head. position, also usually occurs at the transition between downstroke and upstroke. If there is abnormal noise in the tail shaft of the beam pumping unit, it is usually accompanied by abnormal noise in the beam pin. There are two main reasons for this situation. The first case is that the pumping unit has serious problems during operation. The second case of imbalance is that the tail shaft seat bolts are not tightened, causing a sound when the pumping unit changes direction. If the beam pumping unit makes abnormal noise during operation, it must be resolved in time to avoid adverse effects on the exploration and production of the oil field.

solution strategy

During the inspection of the beam range hood, it is necessary to strengthen the inspection of all connecting parts and check whether the bolts are tightened. If there is any failure to tighten, a wrench should be used to solve it in time. It is also necessary to add an appropriate amount of lubricating oil to the positions that need lubrication in the beam pumping unit, and then turn on the pumping unit. If the abnormal noise disappears, it means that there are no other reasons for the abnormal noise of the tail shaft and the beam cancellation shaft. If there is still abnormal noise after the pumping unit is turned on, it may be caused by an imbalance during the application of the pumping unit. At this time, the current method can be used to detect the balance of the pumping unit, and then based on According to the test results, the balance of the pumping unit can be appropriately increased, decreased, and adjusted. Through these methods, the problem of abnormal noise of the tail shaft and the abnormal noise of the beam pin in the beam pumping unit can be effectively solved.

Causes and solutions to reducer abnormal noise

Cause Analysis

• Gear teeth beating. During the actual operation of the pumping unit, the gear parts of the three major shafts are the most important parts of the reducer, which can effectively reduce the speed. During the actual operation and rotation of the gear, the inter-tooth meshing effect can enable the oil pumping unit to achieve continuous motion. During gear interaction and contact, contact and friction inevitably occur. During the on-site construction of beam pumping units, gear surface wear, gear tooth breakage, gear contact fatigue, etc. may occur. Therefore, gear toothing may cause abnormal noise during operation of the pumping unit.
• Reducer serial shaft. During the operation of the reducer, most of the transmission parts need to rely on shaft parts for movement, and during the movement, they need to be loaded through bearings. The beam-type pumping unit is subjected to relatively large forces during actual operation, which may cause the shaft to deviate from its inherent position, resulting in stringing of shafts. Most gear designs of currently used pumping units are mainly based on multi-channel load distribution, and the herringbone tooth structure is the main structure in the tooth shape. The output shaft of this structural design requires clear positioning of the centerline direction through the bearing. On the output shaft, there is no restriction on the use of the bearing along the centerline. Therefore, the reducer string shaft may cause abnormal noise during operation of the pumping unit.
• Bearing damage. The reasonable application of bearings in reducers can carry the load of mechanical rotating devices and can effectively reduce the friction caused by contact during movement. After long-term operation of the output shaft, the stress condition changes, which will increase the degree of bearing damage during the alternating process. Various degrees of damage to the bearings can be detected with the naked eye. Therefore, damage to the reducer bearing may cause abnormal noise in the oil pumping unit.
• The pumping unit is seriously unbalanced. If the pumping unit is unbalanced during operation, it may cause the pumping unit to make abnormal noises. This situation usually occurs when the pumping unit changes direction and a “knocking” sound can be heard in the pumping unit. When the well pumping operation is just started, there may be abnormal noise from the reducer. After working for a period of time, the abnormal noise will disappear. The main reason for this situation is that the underground load is large. When the pumping unit first enters, it may cause The pumping unit is unbalanced. If the pumping unit continues to extract liquid from the well, there may be insufficient underground liquid supply, which reduces the underground load and gradually returns the pumping unit to a balanced state, thereby solving the problem of abnormal noise in the reducer.

solution strategy

For analysis and inspection of gear toothing, bearing damage, string shaft, etc., the reducer needs to be opened for inspection and confirmation, and targeted maintenance work should be carried out based on the results. For intermittent pumping wells, the pumping start and shutdown time needs to be reasonably adjusted. If it is worn If the situation is not serious, you can add mechanical oil regularly. During the actual filling process, the oil level should be about 10cm above the middle tooth. At the same time, the oil return tank should be kept clear. If there is serious wear and tear, the gears need to be replaced in time. If the amount of shaft deflection is too large, it indicates that the gears are worn. If there is an excessive gap between the two gears, the reduction box needs to be replaced to avoid serious impacts and ensure that the pumping unit can maintain a balanced and stable state. Avoid causing larger losses.