What to do if the gear pump of the excavator makes abnormal noise or vibration?

The excavator itself will make a lot of mechanical noise during construction, and when the machine fails, there will also be abnormal noise. Many machine owners will confuse the two sounds because they lack certain experience in fault observation, which also makes troubleshooting difficult. Cause some trouble. Recently, a Kobelco machine owner encountered trouble. During the construction process, he could clearly hear loud noises from the gear pump, and he could feel vibrations in the cab. Let’s take a look at the entire troubleshooting process.

Failure cause analysis:
There are many reasons for the gear pump’s loud noise and vibration, so after the maintenance technician arrived at the scene, he first listed the various reasons in detail and investigated them one by one in order from simple to difficult.

1. The mixture of debris, impurities, etc. in the oil causes wear and strain on precision gear parts. This is also the most common source of abnormal noise. This situation is relatively easy to deal with. Replace the oil and filter element, and thoroughly clean the precision parts in the gear pump. If the wear is quite serious, the repair value is not great, and the faster way is to replace it with a new one.

2. The internal parts of the gear pump are damaged, resulting in abnormal vibration and sound, such as tooth shape errors, poor contact, or rough contact surfaces. During use, mechanical wear and damage will occur, and abnormal noise will occur. At the same time, the bearing’s needle roller cage is damaged, the long and short shaft journals and needle rollers are worn, etc., which can cause the bearing to rotate poorly and produce mechanical noise. At this time, the gear pump needs to be dismantled and repaired, and the needle roller bearing needs to be replaced.

3. The gear assembly clearance is small, and there are burrs and other factors that have not been polished thoroughly before assembly. The joint surface will be strained during high-speed operation. Over time, internal leakage will seriously cause gear strain. For the above situation, the most effective way is to repair it. Of course, you need some maintenance experience to dismantle the gear pump for grinding and repair, remove the burrs on the gear teeth (cannot chamfer); the end surfaces of the front and rear end caps after plane grinding The depth of the upper unloading groove will vary, and the width should be increased appropriately.

Summarize
The above-mentioned faults also serve as a reminder to all machine owners that excavators require three-thirds of daily maintenance and seven-minutes of maintenance, and the remaining 90 require more attention. This is not just talk. In particular, some abnormal sounds are easily confused with the roar of the machinery itself, which requires everyone to pay full attention to it. After all, no one wants to delay the construction time and waste unnecessary maintenance funds.

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