RENOVATION OF NECKS OF SLIDING BEARINGS OF CENTRAL PUMP SHAFTS FOR IRRIGATION

Abstract

The article considers the problems of improving the quality of machines involved in the technological cycle of irrigation. Analysis of the equipment involved in various methods of introducing water into the soil showed that the most important and responsible for ensuring quality irrigation are pumping units. Among the large number of pumps used mainly for irrigation, it should be noted centrifugal pumps, which create high pressure due to centrifugal force and have high performance properties. Despite the high performance and durability of centrifugal pumps, it should be noted that they usually work in harsh environments (humidity, steam, the presence of traces of acid or alkali in the air, etc.), which significantly increases the wear of their surfaces. The irreversible process of such operation is the main cause of wear of parts, changes in their geometric dimensions and condition. After the period of running in the surfaces of parts, a long time of installed wear, there is a period of catastrophic wear – a sharp deterioration in performance separately. It is substantiated that increase of reliability, increase of service life of working bodies of the centrifugal pumps working in the aggressive environment, scientifically proved choice of sets of the equipment and technologies will allow to accelerate their renovation – economic process of updating elements of fixed assets, means of production leaving due to physical operation -economic aging at the expense of the depreciation fund of their parts, mechanisms and units in general. The analysis of methods of strengthening of bearing necks of shafts of rotors of centrifugal compressors allowed to reveal reserves for improvement of their quality parameters due to improvement of a method of nitrocementation which is carried out by an electroerosion alloying (EIL) method. The use of a new method of nitrocementation, which in comparison with the traditional has a number of advantages: increasing the microhardness of the surface from 10500 to 10600 MPa and gradually reducing it in the transition zone; achieving 100 % of the integrity of the treated surface; increasing the depth of the zone of increased microhardness from 120 to 150 μm, as well as reducing the surface roughness (Ra) from 0.7 to 0.6 μm. The obtained advantages of the new method of nitrocementation over the traditional one allow to significantly improve the quality of the technology of manufacturing and renovation of bearing necks of centrifugal pumps involved in the technological cycle of irrigation.