The use of anti-friction materials in moving units reduces the likelihood of component wear, increases reliability, service life of parts and mechanisms as a whole. The paper considered the effectiveness of molybdenum coating in the design of oil and gas fittings, namely, an axisymmetric check valve and a control valve. Tests for strength, thickness, microhardness of the coating in the rack and pinion mechanism of oil and gas fittings were carried out.
Keywords: molybdenum, plain bearing, rack and pinion mechanism for oil and gas fittings, coating parameters, tests
The article presents the results of the use of viscous additives based on polyisobutylene to improve the performance of railway greases LZ CNII. It is established that the introduction of this type of additives into the dispersion medium of lubricants allows to increase their colloidal stability and tribological properties without deterioration of the operational parameters essential for the application of these lubricants.
Keywords: plastic lubricant, friction, thickener, polyisobutylene, wear resistance, grease film, reliability
In the paper, on the basis of the equation of motion of an incompressible lubricant having the micro-polar properties for the case of a ""thin layer"", the equation of continuity, Darcy and the formula for the energy dissipation rate for determining the function Ф (θ), caused by the molten surface of the bearing bush covered with a low-melting metallic melt of a carrier asymptotic solution by the thermal parameter K. Using a self-similar solution for the zeroth approximation, i.e. without taking into account the melt of the low-melting metallic melt, and for the first approximation, taking into account the low-melting metallic melt, the velocity and pressure fields in the lubricating and porous layers are determined, and the basic performance characteristics of the radial slide bearing are determined. The characteristic permeability of the porous layer and the melt of the surface of the bearing bush, coated with a low-melting metallic melt, on the load capacity and frictional force are estimated.
Keywords: low-melting metallic melt, porous layer permeability, lubricant with micro-polar properties, sliding bearing
It is known that the presence of particles in the lubricating fluid additive or wear products, and also due to its molecular orientation of the wall near the solid support surface bearing lubrication is separation into layers of different viscosities. Laminar flow of a viscous incompressible fluid in the gap of the thrust and radial bearings considered in [1-16]. A significant drawback of the proposed methodology here is that the computational model is ignored pressure dependence of viscosity. For large values of the pressure in the lubricating layer of lubricant viscosity increases significantly, and there is a need to address the dependence of viscosity on pressure.
Keywords: double-layer lubrication, maintenance force adapted profile, stratified flow, pressure dependence of viscosity, viscoplastic grease
In the presence of liquid lubricant particles precipitate from wear products or additives, as well as from the wall of the adsorption and chemisorption on metal surfaces contacting bearing surfaces separation occurs at the layers of lubricants with different viscosity properties. For viscous incompressible stratified lubricant in the gap thrust and radial bearings seen in the works. A significant drawback of these studies is that the calculation model is ignored pressure dependence of viscosity. For large values of the pressure in the lubricating layer of lubricant viscosity increases significantly, and there is the need to address the dependence of viscosity on pressure.
Keywords: double-layer lubrication, maintenance force adapted profile, stratified flow, demfiruyuschie properties, pressure dependence of viscosity.
In this paper, based on a system of equations of motion of a viscous incompressible fluid with the viscosity depending on the pressure, and continuity equations, provides self-similar solution using the current functions of the stratified flow of lubricant in the thrust bearings. The proposed model is calculated in contrast with the existing three-layer stratification, further complicated by the dependence of the viscosity of the lubricant pressure. An analytical expression allows to obtain a description of three-layer stratified fluid lubricants and a graph of the effect of structural parameter and viscosity ratio stratified layers on the basic performance of the bearing. Numerical analysis of the dependence of the parameters of the adapted profile and load-carrying capacity of lubricating layers.
Keywords: three-layer lubrication, maintenance power circuit adapted slider, stratified flow, pressure dependence of viscosity.
In this paper, based on the Navier-Stokes equations in the case of a "thin layer" is a method of forming an exact self-similar solution of the problem of calculating the hydrodynamic thrust bearing with the adapted profile of the supporting surface, running on a two-layer lubrication, c considering the viscosity of lubricating fluid temperature. Found the velocity and pressure in the lubricating layers and using the expression for the rate of energy dissipation analytical expressions for the viscosity of the lubricating layer. The estimation of the influence of parameters characterizing the adapted profile of the bearing surface of the bearing, and temperature parameters, viscous layers of relationships and their length on the basic performance of bearings operating on stratified lubricants. The optimal values for these parameters to ensure the rational, for bearing capacity and strength of friction operation under consideration thrust bearing.
Keywords: Adapted profile, stratified flow, load-bearing capacity, the friction force, the Couette flow
In this paper, based on the Navier-Stokes equations , the continuity equation , taking into account the pressure dependence of viscosity , Darcy equation taking into account the dependence of the permeability of the porous layer of the pressure given by the exact method of forming a self-similar solution of the problem of calculating the hydrodynamic journal bearing operating at three-layer lubricant . As a result, found the velocity field and the pressure in the lubricating layer and the analytical expressions for the components of the supporting forces and friction. Found rational bearing capacity values characterizing different aspects of the functioning of the knot of friction , namely profile support surface ; special lubricating fluid interaction with the surfaces of the friction unit , taking into account the pressure dependence of viscosity ( the formation of intermediate layers with different lubricant viscosities ) .
Keywords: three-layer lubrication, maintenance force adapted profile stratified flow.
In this paper, based on Darcy equations that govern the lubricant in porous layers , and the modified Reynolds equation in the framework of a short bearing solve the problem of unsteady motion of a viscous incompressible lubricant in the bearing clearance double-layer porous . Here we consider the case when the permeability in porous layers in the axial direction is changed by the normal law , and the combined feed lubrication is performed simultaneously in the axial and perpendicular to the bearing axis directions. As a result, the pressure field found in porous layers and in the lubricating layer and analytical dependences for the efforts of the oil film . Compiled by the equation of motion tongue and solved the problem of the stability of the unsteady motion of a pin bearing , found that in the case of a combined bearing lubrication working more steadily compared with the cases or axial directions perpendicular to the axis lubrication . The results obtained can be offered for the development of cylindrical dampers with double-layer porous collar , effectively attenuating transmitted force imbalance in the combined feed lubrication.
Keywords: two-layer porous plug; permeability porous layers, load capacity; equation of motion of the stud; stability
As is known, currently in a model gidrodinaimcheskoy sliding bearing lubricant widely used micropolar lubrication. A major shortcoming of existing working models of bearings running on micropolar lubricant is that this does not take into account the dependence of viscosity characteristics of the micropolar lubricant on the pressure. Naturally, there is a need not only into account the dependence of viscosity characteristics of the pressure in the development of an analytical method for predicting the optimal carrying capacity characteristics inherent MICROPOLAR grease, but also predict the optimal profile of the reference surface of the radial bearing. [1-3 ]Solving this problem is devoted to this work.
Keywords: porous bearing, friction regime, the permeability of the porous layer, the viscoelastic lubricant.
The ability to choose the right anti-wear additives [1-6 ] allows you to create lubricants , which are thin layers have different properties than in large volumes. It is commonly assumed that the additives are functioning only in the zone boundary lubrication and are outside the scope of the hydrodynamic theory of lubrication . However, the beneficial effect of additives as indicated in many studies [1-5 ] we have in the " thin layer" of hydrodynamic lubrication .As is well known , lubrication bearings operate on different types of lubricants which are composed of base oil and additive compositions that provide the required functional properties of the oil . Additives polymers with high molecular weight oils impart viscoelastic properties . Analysis of existing studies [ 7-9] on the calculation of bearings running on a viscoelastic lubricant , shows that they do not take into account the dependence of the viscosity and shear modulus of the pressure and temperature, and mode of friction is assumed laminar. It is known [ 10 ] , high-speed bearings operating in turbulent friction , higher pressure and higher temperature, and so the development of methods for calculating the bearings running on a viscoelastic lubricant requires consideration of the above factors.In connection with the above written shall first develop the computational model of thrust bearings running on micropolar lubricant with the viscosity characteristics of the lubricant on the pressure in contrast to the existing theoretical models do not take into account these dependencies (task 1).And then consider the calculation model of extra load -bearing capacity , working on a viscoelastic lubricant for the dependence of its characteristics on the pressure (objective 2).
Keywords: thrust bearing with the abutment surface adapted, non-Newtonian lubricants
This paper considers the behavior of a hollow sphere loaded external and internal pressures. Furthermore, the cavity occurs uniformly distributed over the surface of corrosive wear, leading to an increase in the cavity volume. Solution of the problem is determined limit time corresponding to the achievement of the second invariant of the stress tensor limit value for points cavity.
Keywords: corrosion, wear, hollow ball, pressure limit, the time limit.
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