At present, there is no accurate definition of the service life of micro gear pump, and there is a big gap between the national standard and the actual service life, so the specific service life mainly depends on the working conditions, and the general service life is about one and a half years.
First, the factors affecting the life of hydraulic gear pump
1, equipment application
When the input journal of the hydraulic oil pump is connected with the motor shaft, the coaxiality error should not exceed 0. 1 mm, and it should be remembered that no connection is allowed. Appropriate hydraulic oil should be selected according to the operating instructions of the pump, and a filter should be added at the inlet of the pump, and the hydraulic oil should be filtered and replaced regularly according to the working environment of the hydraulic system.
2, bearing planning and selection
The service life of hydraulic gear pump should be considered in the use planning, and the failure of hydraulic gear pump is mostly due to bearing damage. At present, the better bearing material is SF composite. This material is a smooth material with steel plate as the matrix, sintered copper mesh as the intermediate layer and plastic (filled with tetrafluoroethylene and modified polyoxymethylene) as the conflict surface. This material has high mechanical strength, low friction coefficient, low noise, good wear resistance, good corrosion resistance, good thermal conductivity, small volume and low cost, and can be used under stable working conditions with little or no oil, with a wide working temperature range. Practice has proved that the application of SF bearing greatly prolongs the service life of gear pump.
3. Technical reasons
In order to ensure the reasonable clearance between the front cover and the back cover of the hydraulic gear pump, the processing and installation of the hydraulic gear pump are very important. The straightness difference between the two end faces of the gear and the axis of the hole should not exceed 0.0 1mm, and after being mounted on the shaft, its axial direction should be in a floating state. In order to ensure the correct positioning of the two shafts after installation, the error of the intermediate distance should not exceed 0.03mm when processing the front and rear bearing holes. In addition, the cracking of the shaft end of the input shaft is also a common phenomenon, so it is necessary to master the heat treatment process of the shaft, which can make it have certain strength and hardness, and have high impact resistance to avoid cracking.
4. Reasonable selection of data and components
In order to ensure the reasonable clearance of hydraulic gear pump in operation, the wear resistance of related materials is an important performance index. It is very important to choose reasonable materials and suitable heat treatment process. Oil leakage of oil seal is also a common cause of failure. Select oil seal with good raw materials, and pay attention to the firm cooperation between oil seal and bushing during processing and installation. The oil seal and the inner hole of the pump shaft should have sufficient tension to prevent oil leakage.
5, the end gap problem
Hydraulic gear pump often fails due to volume efficiency and pressure reduction in operation. The leakage of gear face accounts for 75% ~ 80% of the total leakage. Therefore, a reasonable end clearance is very important.
Second, how to make the gear pump last longer?
1. For the self-priming gear pump, the oil in the hydraulic oil tank should not be lower than the lower limit of the oil mark, and a sufficient amount of hydraulic oil should be maintained. The higher the cleanliness of hydraulic oil, the longer the service life of hydraulic pump.
2, after a period of time, the plane will appear concave phenomenon, before using the platform grinding, should first measure the original size and plane hardness. Measure the grinding amount after grinding, and if it is within 0. 18, it will not hinder the use of the cooler; If it is greater than 0.2 mm, nitriding should be adopted to maintain the original nitrided layer thickness.
3. When the plane is scraped out of the groove by the gear ball head, it can be repaired by laser cladding alloy powder. No matter which repair method is adopted, the original dimensional accuracy, hardness and surface roughness must be restored.
4. When the scratch on the surface of the cylinder valve port is shallow, grind and repair the spherical valve port friction pair; When the groove on the distribution surface of the cylinder block is deep, the groove should be filled with "surface engineering technology" before grinding, and blind grinding is not allowed to prevent the copper layer from thinning or leaking out of the steel base. The friction pair with plane distribution can be ground on a relatively high platform.
5. Bearing is the most important part of hydraulic gear pump. If there is clearance in the bearing, the normal clearance of the three pairs of friction pairs in the hydraulic pump cannot be guaranteed, and at the same time, the oil film thickness of the hydrostatic bearing of each friction pair will be destroyed, which will reduce the efficiency of the gear pump and affect the operation of the hydraulic system. If scratches or discoloration are found on the surface of the drum, it must be replaced.
6. Inspection and repair of three pairs of friction pairs: According to the replacement standard of gear pump parts, when various clearances of parts are out of tolerance, the gear rod and cylinder hole can be repaired in the following ways: if the cylinder body is inlaid with copper sleeve, it can be repaired by replacing the copper sleeve. First, trim the diameter of a group of gear rods to a uniform size, and then polish the outer diameter with sandpaper above 1000#.
Expand small knowledge
Knowledge point 1. Advantages of micro gear oil pump
1, long motor life: stronger sealing, details showing quality, long service life and high efficiency;
2. All-copper coil: 800# cold-rolled silicon steel sheet with low temperature rise, high efficiency, sufficient power and long service life;
3. Stainless steel shaft: the processing and molding run stably, and the surface is treated with moisture and rust prevention;
4. Ball bearing: heavy load bearing, simple structure, convenient use and good dustproof performance;
5, custom alloy seal: 304 stainless steel spring, high strength, small seal, small resistance, sand prevention;
6. High-quality gear: High-temperature quenching improves the hardness and strength of the alloy and is durable.
Knowledge point 2. Where is the screw pump mainly used?
1, Screw pump is widely used for conveying water, wet sludge and flocculant liquid medicine in sewage treatment plants because of its large conveying variable, strong self-priming ability, reversibility and the ability to convey liquid containing solid particles.
2. Because of its structure and working characteristics, the screw pump can transport medium with high solid content, with uniform flow and stable pressure, especially at low speed. Because of its good variable adjustability, it can be used for many purposes and conveying media with different viscosities.
3. The installation position of the screw pump can be tilted at will, which is suitable for conveying sensitive items and items easily damaged by centrifugal force.
Knowledge point three. Working characteristics of screw pump
Screw pump mainly has the following characteristics: simple structure, safe and reliable use, convenient use and maintenance, continuous and uniform liquid discharge, stable pressure, low noise and vibration, and self-priming ability, but screw processing is more troublesome.
Knowledge point 4. What is three screw pump?
Screw pump is a rotary positive displacement pump, which can be divided into single screw pump, double screw pump, three screw pump and multi-screw pump according to the number of screws. Three screw pump is a screw pump with three screws, which includes a driving screw inserted in the pump barrel, two driven screws engaged with it and three mutually engaged screws. They form a sealed cavity in the pump barrel according to their respective leads, resulting in the seal between the suction port and the discharge port.
Knowledge point 5. What are the uses of peristaltic pump?
Any use scenario of peristaltic pump is to treat fluid (any liquid or solid-liquid mixture with fluidity), and the main function of peristaltic pump is to transport. The conveying accuracy of peristaltic pump can reach up to 0.5%, which can meet the needs of quantitative conveying and quantitative distribution.
From the product function, the main uses of peristaltic pump are: quantitative or metered transportation, quantitative or metered distribution. Therefore, peristaltic pump can be used to meet the application requirements in all application scenarios with quantitative transportation and distribution requirements.
Peristaltic pump has excellent performance and reliability, so it is widely used to meet the application requirements of various processes, including experimental research, analytical instruments and industrial production. Therefore, peristaltic pumps have many uses and uses, mainly in the following fields:
1. Analytical instruments: chromatograph, atomic fluorescence photometer.
2. Medical industry: medical equipment and diagnostic reagents.
3. biopharmaceuticals: coating machine, granulator, fermentor, used for purification, fluid transportation, distribution and filling, and high-precision liquid preparation.
4. Laboratory and research equipment.
5. Food and beverage: beverage machine, yogurt machine, vending machine, intelligent milk tea machine, condiment distribution and addition, beer industry.