ВЛИЯНИЕ УГЛОВ ПОЛОЖЕНИЯ КАМЕР НА НАРУЖНЫХ И ВНУТРЕННИХ ЧАСТЯХ ГИДРОСТАТОДИНАМИЧЕСКОГО ПОДШИПНИКА СДВОЕННОГО ТИПА НА ЕГО НЕСУЩУЮ СПОСОБНОСТЬ

The task is to study the bearing capacity of the double type bearing at different angular positions of the chambers on the outer and inner working surfaces. It is given a mathematical model of a double type hydrostatodynamic bearing in a stationary formulation, which makes it possible to determine its bearing capacity. It is considered the cases of laminar and turbulent flow of the working fluid in the slit path of the double type bearing. Both gradient and portable flows of the working fluid are considered in recording the flow of working fluid along the contour of the 1st chamber. The expression for the flow rate of the working fluid at the entrance to the chambers is written for the case of using the jet as a pressure compensator. The cost balance equations and the Reynolds equations, written for both the outer and inner working surfaces of the double type bearing, were solved jointly. Applied assumptions are usually taken in the hydrodynamic theory of lubrication in writing the Reynolds equations. The most common V.N. Constantinescu method was applied for turbulence coefficients. The expression for the balance of expenditure equations and the Reynolds equations are expanded to the dimensionless type. The most effective numerical methods for the numerical implementation of the expenditure balance equations and Reynolds equations are analyzed and applied. The most economical finite-difference method in combination with the longitudinal-transverse sweep method was applied to solve the Reynolds equation. The accuracy of the solution was assigned when determining the pressures in the chambers and on the inter-chamber jumpers. Geometric and operating parameters of the double type bearing were assigned based on currently existing recommendations for the design of fluid-friction bearings. The results of the calculation of the bearing capacity of the double type bearing for different camera angles on the external and internal parts of this bearing are obtained. The results of the calculation of the bearing capacity of the double type bearing in the form of graphs are given. The analysis of the obtained results was made and conclusions were made on the obtained results, allowing designers to more efficiently design bearings of this type.

Joint Clearances With Lubricated Long Bearings in Multibody Mechanical Systems

Proper modeling of joint clearance is of great importance in the analysis and design of multibody mechanical systems. The clearance may be due to wear or imperfection in manufacturing. When there is no lubricant in the clearance, solid-to-solid contact occurs. The impulse due to contact between the links is transmitted throughout the system. The presence of a lubricant avoids such contact, as the hydrodynamic forces developed by the lubricant film support the loads acting on the bodies and prevent the bodies from coming into contact. In this paper, an analysis of revolute joint clearances in multibody mechanical systems with and without lubricant is presented. Squeeze as well as viscous effects are considered utilizing the hydrodynamic theory of lubrication in long bearings. Unlike the traditional machine design approach, the instantaneous lubricant forces are the unknown and evaluated in terms of the known geometrical position and velocity of the journal and bearing. In the case of analysis of a joint clearance with no lubricant, a modified Hertzian relation is used to model the impact or contact between the journal and bearing, which includes a hysteresis damping term to account for the energy dissipation during impact. The methodology is applied for the analysis of a slider-crank mechanism having a clearance in the piston pin. The simulations are carried out with and without lubricant and the results are compared. It is shown that the lubricant results in a steady motion with fewer peaks in the required cranking moment for the system. [S1050-0472(00)01804-3]

The Hydrodynamic Lubrication of Rough Journal Bearings

In a number of previous papers a hydrodynamic theory of lubrication of rough bearing surfaces has been developed. The present paper describes the application of this theory to the analysis of the full journal bearing of finite width. The analysis demonstrates how the roughness influences the characteristics of the bearing and also shows how roughness interacts with features of nominal geometry and operating factors to determine the bearing response.