In the industry, we often hear many users complain about the quality of domestic piston pumps, such as new pumps installed on the noise, no pressure, leakage of shaft seals and easy to damage and so on. This has even led to some forums and group chats in the so-called "foreign affairs", that 20MPa above the hydraulic system of domestic pumps are completely unable to cope with, you must use imported pumps. However, is this really the case? Here, combined with our daily maintenance service in the process of the actual case, mainly on the source of abnormal noise for some in-depth analysis.

Many customers do not know whether the pump leakage chamber is filled with oil before operation. In fact, the lack of oil will lead to the pump cavity of the air through the gap into the pump to participate in the circulation of oil, thus generating noise, and may cause cavitation damage parts and friction early abnormal wear. Each piston pump manufacturer's samples or manuals will be clearly mentioned on the oil pump installation of oil filling requirements, such as Rexroth on the relevant concise tips, and we in the samples and installation instructions on the detailed description of the initial use of the pump or long-term storage of the pump after the operation should be filled with clean working fluid before starting, otherwise it is not allowed to start, and start to check the pump steering is accurate. Such a clear prompt, but so far there are still a large number of users in the use of domestic pumps did not do "filling oil" this basic requirement.

Secondly, you also need to understand the concentricity of the oil pump installation. From the host customer site or user photos, many host customers have no concept of concentricity, oil pump bracket mounting holes or even directly with gas cutting processing, coupling visible obvious skew, there is an axial top dead situation, these will lead to the commissioning of the new pump abnormal noise or abnormal damage to the pump.

Then, pay attention to the bubble or tumbling condition of the oil in the tank. Some host tank is too small, and no internal partition or partition and pipe layout is unreasonable, resulting in the host cylinder movement, the tank, such as tumbling, the oil is full of bubbles, because the tank is too small, the oil mixed with bubbles did not precipitate the time and space, and soon sucked into the cycle of the pump, which will inevitably lead to the whole system noise increases.

In summary, as long as the solution to the bubble, concentricity issues and the oil pump before the start of the oil filled with oil, the general noise problem can basically be solved. However, why these basic oil filling, ensure concentricity, avoid air bubbles and other requirements many users can not do it? In addition to ignorance and fearlessness, there is also a mentality that improper use of imported pumps need to be bad users to bear the loss of their own, while the domestic pumps can be changed for free anyway, so the use of imported pumps carefully, the domestic pumps are not taken seriously. Although this situation seems to be a loyal user of domestic pumps, but the use of non-standardized pump damage rate is high, seriously affecting the reputation of the domestic pumps, but also restricts the development of domestic pumps, how to communicate with such users and promote its improvement, the task is arduous and the road is long.

Finally, and then introduce the general requirements for the installation and use of hydraulic pumps:

1, all pumps, valves, cylinders, etc. back to the tank of the pipeline should be below the liquid level, the tank should be set up in the partition, the oil inlet area and the return area is separated, in order to reduce the inlet and return to the interference between the oil, to avoid the wash out of the bubbles and impurities caused by the noise or damage to the oil pump;

2, the oil pump inlet seams should be as little as possible, the hose should be fixed at each end of the use of two clamps side by side, clamp openings staggered 90 ° installation, to reduce the potential risk of air leakage, the inlet screen should be checked regularly to avoid clogging caused by the oil pump suction insufficient to cause damage;

3, the leakage of oil pump pipe joints should avoid sudden change in diameter to a small size, and should be connected directly back to the tank, avoiding and other pipeline merger, to ensure smooth oil return, reduce the possibility of oil leakage of the oil seal at the end of the shaft, but also reduce the noise of the oil pump, and to avoid abnormal wear and tear of the sliding shoe or fall off;

4, oil pump installation concentricity, oil cleanliness and other considerations can refer to the oil pump manual or hydraulic design manual and other information.