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    Imported hydraulic piston pump line condition monitoring and predictive maintenance

      Published：2014/5/25 21:23:50 　　Hits：3560

    The introduction of complete sets of equipment in the metallurgical industry, most of its configuration Rexroth hydraulic station, American Parker, Europe, Japan and other countries, high production, high flow hydraulic plunger pump. In the equipment put into use, due to the introduction of no hydraulic piston pump specifications corresponding, online state monitoring method of not understanding the pump and maintenance method and use the soft life, (soft life, is provided for equipment design when the tenure of use). Therefore, some domestic enterprises equipment management that: foreign hydraulic piston pump performance is good, long service life, as long as the hydraulic pump in operation, system pressure can achieve, you do not repair, also did not establish corresponding hydraulic pump field inspection rules and regulations, management mistakes resulting in hydraulic piston pump inlet. Imports of machinery equipment and hydraulic piston pumps, are in service period. Correct monitoring service duration depends on the cleanliness of hydraulic medium and equipment operation, maintenance and maintenance. This article discusses the main pump line detection, predict the repair, maintenance, replacement and adjustment.

    The wear of hydraulic pump imported into the early wear, normal wear, abnormal wear three stages.

    Pump parts manufacturing process, the parts have some microscopic metal surface roughness (surface roughness) of the shaft or hole ellipticity and non existence of straightness, early in the relative motion of metal surface occurs, pump parts between the relative motion, the friction generated between the friction and wear parts in the early light, wear stage.

    After a period of running, generated between the friction pair of new, higher level of accuracy of the roughness, wear rate. Into a relatively long period of stability in use.

    At this stage, the metal material to achieve the rated life of fatigue cycle, the metal surface will produce fatigue, fatigue layer high temperature and pressure in the pump under the special use, the metal surface prone to granular loss, therefore, rapid wear growth, leading to component failure. Three pairs of friction vice relative motion in the operation of the pump (hydrostatic bearing relationship) between the wear parts, the gap between parts increases, pump leakage increase, and oil temperature also increased. Pump soft life is from the early period to the stable stage and then to fatigue spalling stage (severe wear stage). Cleanliness is the length of the three stages mainly depends on the use of hydraulic medium. The influence of the soft life of the pump there is also a decisive factor, is the pump bearing life. Because the bearing in the pump casing load axial rotation, three friction pump shell (1 cylinder surface and the valve plate; 2 plunger rod and cylinder bore; the 3 sliding shoe and swashplate) high-speed friction parts rotation, moving relative to the metal surface, the metal contact friction, adhesion and cutting, and because the local high temperature, resulting in large size metal oxide particles fatigue spalling, metal particles flaking due to inability to discharge pump shell and accumulated in the hydraulic pump shell.

    Due to the pump casing filled with hydraulic oil, hydraulic oil, deposition of metal particles and mixed in together with the pump shaft and the rotating cylinder and in the casing swirl drift, causing severe wear of pump bearings. Bearing wear to a certain degree clearance increases, bearing clearance increases and then decrease after turning precision bearings, can not guarantee that the relative motion precision cylinder and valve plate, thus destroyed the pump three pairs of friction between the hydrostatic equilibrium, hydrostatic bearing damaged (three pairs of friction vice) will accelerate the wear and tear.

    Even if the use of hydraulic medium to achieve cleanliness standards, there is a basic nominal bearing service life. The rated life of a bearing is divided into (1) nominal rating life; (2) rated life correction; (3) depth calculation of rating life.