Price of constant flow overflow pump

Diamond cone 300 series gear pump

hydraulic gear pumpIt is a hydraulic component that provides pressurized fluid for hydraulic transmission and is a type of pump. Its function is to convert the mechanical energy of power machines (such as electric motors and internal combustion engines) into the pressure energy of liquids. The output flow rate that can be adjusted according to needs is called a variable pump, and the flow rate that cannot be adjusted by a gear pump is called a quantitative pump. There are three commonly used pumps in hydraulic systems: gear pumps, vane pumps, and plunger pumps. Gear pump: Small in size, simple in structure, not strict in oil cleanliness requirements, and relatively cheap in price; But the pump shaft is subjected to unbalanced force, severe wear, and significant leakage. Vane pumps: divided into double acting vane pumps and single acting vane pumps. This type of pump has uniform flow rate, smooth operation, low noise, higher working pressure and volumetric efficiency than gear pumps, and a more complex structure than gear pumps. Piston pump: high volumetric efficiency, small leakage, can work under high pressure, mostly used in high-power hydraulic systems; But the structure is complex, the requirements for materials and processing accuracy are high, the price is expensive, and the cleanliness of the oil is high. Piston pumps are generally used when gear pumps and vane pumps cannot meet the requirements. There are also some other forms of hydraulic gear pumps, such as screw pumps, but their applications are not as common as the above three.

Gear pump is used as an oil discharge pump in a vacuum oil filter to remove the purified oil from the vacuum separation tank and overcome the suction force of the vacuum when removing the oil from the vacuum tank. The noise generated by gear pumps is the main source of noise in vacuum oil filters. Analyzing the causes of noise generated by gear pumps and controlling their noise will help improve the quality of vacuum oil filters.

The main reasons for the noise generated by gear pumps are as follows: (1) The phenomenon of trapped oil causes pressure shock or cavitation, resulting in noise; (2) Due to manufacturing errors in gears, when they mesh and operate, the teeth may be subjected to sudden loading impacts, causing vibration and noise; (3) The pulsation of flow causes pressure pulsation and produces noise; (4) Noise caused by poor bearing accuracy or poor installation, as well as noise excited by friction between the side plate and the gear side.

The main reasons are (1) and (2), especially the phenomenon of trapped oil, which has the greatest impact on noise. In order to ensure smooth operation during gear meshing, the overlap coefficient must be greater than 1. Therefore, there will be two pairs of gear teeth meshing at the same time during a period of time, creating a trapped oil volume between these two pairs of gears that cannot discharge or absorb oil. The variation pattern of trapped oil volume. When the trapped oil volume changes from large to small (with a variation of Ah), the internal pressure rises, causing shock and vibration; When the trapped oil volume increases from small to large (with a change of AF2), the internal pressure decreases to form a vacuum, causing cavitation. This is the so-called trapped oil phenomenon.

In order to solve the noise caused by trapped oil, an effective measure is to process unloading grooves on the side plate. The principle is that when the trapped oil volume decreases from large to small, the unloading grooves are used to connect it with the pressure chamber and discharge the oil; When the trapped oil volume increases from small to large, the unloading groove is used to connect it with the oil suction chamber, thereby absorbing and breaking the oil, thus avoiding the phenomenon of trapped oil.

Analysis and Countermeasures of Noise Faults in a Gear Pump: For a formed gear pump, its unloading groove has been machined, and its gear tooth accuracy, bearing accuracy, and installation accuracy have been determined. Gear pumps sometimes still produce loud noise, especially when used as exhaust pumps in vacuum oil filters. Because when draining the oil from the vacuum tank, it is necessary to overcome the suction force of the vacuum, which makes it more difficult for the gear pump to drain the oil. If not handled properly, it is likely to produce significant noise. When the gear pump in the vacuum oil filter produces significant noise, the following reasons can be identified and countermeasures taken: (1) Local blockage of the oil suction pipeline or filter in front of the gear pump. At this moment, it can be seen from the oil pipe that there is very little oil being sucked in. Insufficient oil suction can cause dry grinding and cavitation, making loud noise. At this moment, the blockage point should be identified, dirt should be removed, and oil suction should be smooth.

(2) The oil suction pipe in front of the gear pump sucks in air. At this point, bubbles can be seen from the suction pipe, and bubbles can also be seen from the discharged oil. The gear pump will produce cavitation noise after inhaling air. The key areas to be identified are various valves in front of the pump, the inlet flange sealing ring of the pump, and the self tightening skeleton oil seal of the pump. After searching, they should be quickly eliminated.

(3) The flow area of the oil inlet filter is too small. If modern cutting tools are excluded from the substrate of high-speed steel cutting tools. The use of physical vapor deposition (PVD) method to coat a thin layer of wear-resistant material can significantly improve the performance of high-speed steel cutting tools. Coating materials such as TiN and TiC are used. But after using TiN coating, the surface of the tool appears golden yellow. Thick coated high-speed steel cutting tools appeared in the international market around 1980.