Hydrostatic Suspension Research Articles

Sliding Thrust Bearings with Self-Generated Fluid Pivots

The article discusses the disadvantages of thrust sliding bearings with mechanical supports and mechanical balancing systems similar to the Kings-bury system. Requirements for the design of thrust bearings corresponding to the current level of development of dynamic equipment are formulated. The design of thrust bearings using a hydrostatic suspension is proposed to eliminate the disadvantages of thrust bearings with mechanical supports and balancing systems. The modern design of the bearing developed by TRIZ LTD with mechanical bearings, which meets the requirements of the optimal choice of bearing the best, is given in this article with its ad-vantages and disadvantages inherent in all mechanical systems. The given results of the TRIZ LTD work on the creation of thrust sliding bearings with the replacement of mechanical bearings and mechanical balancing of thrust elements with self-generated fluid elements are used with traditional oil systems. The developed original technical solutions made it possible to reduce the axial subsidence, the number of parts, axial dimensions, noise, axial vibration. Various designs of thrust bearings with self-generated fluid pivots, which most fully satisfy the requirements for the optimal choice of a thrust bearing design and their comparative characteristics in comparison with design of a thrust bearing with mechanical supports of bearing pads and a mechanical alignment system obtained during their testing at the bench are given. Thrust bearings with self-generated fluid pivots are recommended for new developments of rotary equipment, as well as for modernization of equipment operated to increase overhaul mileage, reduce maintenance time, increase reliability and efficiency of equipment due to higher bearing capacity, effective damping and practical axial subsidence from force.

The sedimentary facies and dynamic environment of the Diaokou lobe in the modern Huanghe River Delta of China

The Huanghe River captures the Diaokou River in 1964 and forms a deltaic lobe in the subsequent 12 a. The progradational process of the Diaokou lobe is in associated with complicated evolution of riverine sheet flooding, merging, and swinging. On the basis of 11 borehole cores and 210 km high resolution seismic reflection data set, the sedimentary sequence and dynamic environment of the Diaokou lobe (one subdelta lobe of the modern Huanghe River Delta) are studied. The stratigraphy of the lobe is characterized by an upward-coarsening ternary structure and forms a progradational deltaic clinoform. Totally six seismic surfaces are identifiable in seismic profiles, bounded six seismic units (SUs). These SUs correspond to six depositional units (DUs) in the borehole cores, and among them, SUs 4–6 (DUs D to F) consist of the modern Diaokou lobe. Lithological and seismic evidences indicate that the delta plain part of the Diaokou lobe is comprised primarily by fluvial lag sediments together with sediments from sidebanks, overbanks, fluvial flood plains and levees, while the delta front part is a combination of river mouth bar sands (majority) and distal bar and deltaic margin sediments (minority). As a result of the high sedimentation rate and weak hydrodynamic regime in the Huanghe River Delta, the sediments in the delta front are dominated by fine-grained materials. The grain size analysis indicates the Huanghe River hyperpycnal-concentrated flow shows the suspension, transportation and sedimentation characteristics of gravity flow, and the sediment transportation is primarily dominated by graded suspension, while uniform suspension and hydrostatic suspension are also observed in places. The strength of the hydrodynamic regime weakens gradually offshore from riverbed, river mouth bar, sidebank, distal bar subfacies to delta lateral margin and flooding plain subfacies.

Stabilization of vibrations of rotary machines in radial sliding bearings with integrated liquid

The use of radial bearings with segments on a self-generated hydrostatic suspension has been substantiated in order to satisfy the requirements for precision positioning of axes and efficiency of stabilization of shaft oscillations of power-consuming rotary machines. The methods of turbomachine dynamical analysis based on the modelling of the viscous friction forces process and inertia in lubricating films that balance the harmonic loads on the shaft by redistributing the lubricant flow parameters in the bearing gaps with integrated liquid dampers have been further developed. The complex approach for improving functional properties of turbomachine supporting block on the basis of multicriteria optimization of hydraulic tracts parameters and lubrication system operating modes is presented.

The Additional Error of Inertial Sensors Induced by Hypersonic Flight Conditions.

The emergence of hypersonic technology pose a new challenge for inertial navigation sensors, widely used in aerospace industry. The main problems are: extremely high temperatures, vibration of the fuselage, penetrating acoustic radiation and shock N-waves. The nature of the additional errors of the gyroscopic inertial sensor with hydrostatic suspension components under operating conditions generated by forced precession of the movable part of the suspension due to diffraction phenomena in acoustic fields is explained. The cause of the disturbing moments in the form of the Coriolis inertia forces during the transition of the suspension surface into the category of impedance is revealed. The boundaries of occurrence of the features on the resonance wave match are described. The values of the “false” angular velocity as a result of the elastic-stress state of suspension in the acoustic fields are determined.

Research on the Possibility of Replacing Oil with Water in Hydrostatics Units of Machine Tools

This paper deals with the possibility to replace the mineral oil with water in the hydrostatic units of machine tools. With this aim in view we try to make a technical-economic comparison between the hydrostatic drive that uses mineral oil in the range H38 - H46 and the drive with untreated water. Two simple units were taken for comparison, in principle, which use as hydraulic energy source one constant flow pump (qP= 4 cm3) for the actuation of two consumers and one constant flow pump (qP= 20 cm3) for making the hydrostatic suspension of the saddle of an AFP type machine.

Estimation of tibial shaft defect volume using standard radiographs: Development and validation of a novel technique

BackgroundNo simple clinical technique with which to measure the volume of bone gaps in the treatment of open fractures or nonunions of the tibia is currently available. It is difficult to compare the three-dimensional magnitude of bone defects in research studies on bone grafting without such a tool, and clinicians have no way of determining the magnitude of defects in clinical practice. The purposes of this study were to develop and to validate a technique with which to accurately measure bone gap volumes of the tibial shaft by using only simple measurements on already available clinical radiographs and a simple equation. We hypothesized that a technique could be developed using anteroposterior- and lateral-view radiographs of the tibia to accurately determine the volume of a tibial shaft fracture. MethodsWe created standardized fracture gap models using 45 synthetic tibiae cut in different locations and orientations, rendering 135 gaps. We developed and validated a hydrostatic suspension technique to determine the volume of each bone, which underwent anteroposterior- and lateral-view radiography after each cut. Radiographic measurements were used to calculate defect volumes based on a simple equation. Predicted volumes were compared with measured volumes. ResultsThe triangular prism equation matched well with the actual volumes. Linear regression analysis showed a slope of 0.92 and R2 of 0.97. ConclusionThe equation provides a simple technique with which to calculate three-dimensional gap volumes based on standard radiographs. The simplicity of the equation and availability of standard radiographs make this a practical research and perhaps clinical tool that might be useful in quantifying volumes of the tibial shaft defect.

Measurement method of compressibility and thermal expansion coefficients for density standard liquid at 2329 kg/m3 based on hydrostatic suspension principle

The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3 (DSL-2329) plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5×10−4 K−1 and 5.4×1010 Pa−1, respectively.

Method of accurately measuring silicon sphere density difference based on hydrostatic suspension principls

The micro density difference between silicon single crystal spheres is not only important for the research on the redefinition of Avogadro constant based on quantum standard, but also a key solution for quality control for the production of silicon single crystal with ultra-high purity in semi-conductor industry. To overcome the complexity of non-contact laser interferometer method and improve the accuracy of hydro-weight method, a method based on the hydrostatic suspension principle is realized. The silicon single spheres to be measured are immersed into mixture liquid including 1,2,3-tribromopropane and 1,2-dibromoethane, and floated freely by adjusting the temperature and pressure of the liquid. The micro density difference between two silicon single crystal spheres is calculated based on a mathematical model by using liquid temperature, pressure, and central floatation height difference in the floatation condition. The stable constant temperature liquid with maximal error ± 100 μ K is realized by two-cycle water bath and PID control system. The floatation height of silicon single crystal sphere is determined by binary image and iterative algorithm. The stable suspension is achieved by the PID pressure control system, and the temperature fluctuation due to Joule-Thomson effect is reduced. By means of linearity between changes of temperature and pressure in hydrostatic suspension model, the compressibility of mixture liquid is measured. The experimental results show that the influence from liquid surface tension is avoided by using the hydrostatic suspension method, and accurate measurement of density difference between silicon single crystal spheres can be achieved with an uncertainty of 2.1× 10-7 (expand factor k=1).

Procedures and practice for raising reliability of dynamic equipment

are a challenging task whose accomplishment requires consideration of all factors that assure trouble-free operation. Leading enterprises absolutely justifiably pay constant attention to development of diagnostic systems, refinement of methods, and enhancement of quality of technical services. However, it must be remembered that the base level of reliability of the unit underlying its design constantly falls in the operational process. In view of aging of the dynamic equipment park and growing cost of new equipment, its upgrading, which makes it possible to raise at a relatively small cost the reliability and efficiency indices through use of state-of-the-art units designed by using advanced technical solutions that ensure a qualitatively new level of the unit, is becoming increasingly urgent. At present, more than a hundred units of equipment upgraded by OOO TRIZ are in use in various enterprises of Ukraine, Russia, and Belarus. These are dynamically loaded centrifugal compressor and pump units, turbines, generators, and electric motors. For example, the compressor unit K-104 has been upgraded in all Ukrainian enterprises of the nitrogen industry without exception. Use of engineering solutions offered by OOO TRIZ for dynamic equipment of the petrochemical industry does not require high initial investment and fully guarantees: • decrease of emergency shutdowns; • increase of time between servicing cycles; • enhancement of efficiency; • lowering of vibration level by 1.5–3 times; • curtailment of operational cost; • lengthening of service life; • payback period not more than one year; • operational warranty period 24 months. Practical experience of operation of the upgraded units MTV 2-5, ATKP 435/1600, 340-81-4, 43VTs 160/9, and 4RSA-32 (made by the company UkrTATNAFTA in Kremenchug), and 5 VR (made by the company Galichina in Drogobych), the first ones of which underwent upgrading in 1995, confirms the above-listed factors. For 12 years TRIZ, in order to enhance the reliability of rotor machines, has been using radial bearings with self-adjusting bushings (bearing shells) on a hydrostatic suspension. More than 80 units with a rotor speed ranging from 1500 to 24,000 rpm and a shaft neck diameter ranging from 40 to 300 mm are being successfully operated with PDO-type bearChemical and Petroleum Engineering, Vol. 39, Nos. 1–2, 2003

Experimental study of the density of aliphatic alcohols at various temperatures and pressures

Using a hydrostatic suspension method, the densities of ethyl, n-propyl, isopropyl, n-butyl, and isobutyl alcohols were measured in the temperature range 200-570°K and in the pressure range 10.86-491.4 bar.