scholarly journals The effect of the distribution of variable characteristics determining the asymmetry of the sealing rings sliding surfaces on the values of friction loss coefficients and other selected parameters of oil film

2017 ◽  
Vol 171 (4) ◽  
pp. 107-116
Author(s):  
Piotr WRÓBLEWSKI
Keyword(s):  
Friction Loss ◽  
Common Vertex ◽  
Cylinder Wall ◽  
Bearing Surface ◽  
Oil Film ◽  
Sliding Surfaces ◽  
Asymmetric Shape ◽  
Loss Coefficients ◽  
The Common ◽  
Mathematical Relationships

The article presents the results of research on the effect of the change in coordinates that determine the location of the common vertex of the parabolas and ellipses demonstrating the asymmetric shape of the rings sliding surfaces on the change in the thickness of oil film, the amount of scraped oil, and the oil left on the cylinder wall, once a set of selected sealing rings has passed, as well as the results concerning friction losses. Mathematical relationships of the asymmetric shapes of the rings sliding surfaces were presented, and the values of coefficients characterizing selected parameters of oil film and friction losses were determined. It was confirmed that there is a large dependence of the coordinate values of the vertices determining the asymmetric shapes of these surfaces on the condition and cooperation between piston rings and the cylinder bearing surface, and mainly on the amount of the oil scraped in the selected engine strokes.

Design and optimization of textures on the surface of crankpin bearing to improve lubrication efficiency and friction power loss of engine

2020 ◽  
pp. 135065012094200
Author(s):  
Zhenpeng Wu ◽  
Vanliem Nguyen ◽  
Vanquynh Le ◽  
Xuanlong Le ◽  
Vancuong Bui
Keyword(s):  
Power Loss ◽  
Asperity Contact ◽  
Bearing Surface ◽  
Film Pressure ◽  
Oil Film ◽  
Design And Optimization ◽  
Friction Power ◽  
Study Results ◽  
The Impact ◽  
Oil Film Pressure

The study proposes a design and optimization of textures on the surface of crankpin bearing to improve the lubrication efficiency and friction power loss (LE-FPL). A hydrodynamic lubrication model of crankpin bearing considering the impact of the external dynamic load and micro asperity contact is established. Based on the established model, the lubrication textures designed on the bearing surface are then simulated and optimized through the algorithms developed in Matlab environment and multi-objective optimization method. Increasing the oil film pressure and reducing the contact force ( Wac) in the asperity contact region, friction force ( Ff), and friction coefficient ( µ) of crankpin bearing are the objective functions to evaluate the LE-FPL. The study results indicate that the lubrication textures designed on the bearing surface have an obvious effect on improving the LE-FPL. Especially, with the optimized textures, the maximum oil film pressure is greatly increased by 44.8% while the maximum values of Wac and Ff are significantly reduced by 22% and 25%. Consequently, the lubrication textures added on the surface of crankpin bearing can greatly improve the LE-FPL.

[i][/i]THE IMPACT OF MICROGEOMETRY BEARING SURFACE OF THE PISTON ON THE PARAMETERS OF OIL FILM

2016 ◽  
Vol 23 (2) ◽  
pp. 431-436 ◽  
Author(s):  
Emil Wróblewski ◽  
Antoni Iskra ◽  
Maciej Babiak
Keyword(s):  
Bearing Surface ◽  
Oil Film ◽  
The Impact

An experimental investigation of the oil film distribution in an oil–gas cyclone separator

2016 ◽  
Vol 231 (1) ◽  
pp. 14-25 ◽  
Author(s):  
Lingzi Wang ◽  
Jianmei Feng ◽  
Shijing Xu ◽  
Xiang Gao ◽  
Xueyuan Peng
Keyword(s):  
Flow Pattern ◽  
Pressure Loss ◽  
Film Flow ◽  
Separation Efficiency ◽  
Flow Behavior ◽  
Outer Cylinder ◽  
Cylinder Wall ◽  
Cyclone Separator ◽  
Oil Film ◽  
Oil Gas

The film flow behavior in an oil–gas cyclone separator was experimentally studied to improve the separation efficiency in terms of the effect of the oil film on the cylinder wall. The oil film flow pattern was captured using a high-speed camera, and the cylinder wall was divided into seven regions to analyze according to the different oil film flow patterns. Along the cyclone cylinder height, the central part of the cylinder was the main flow area, in which droplet–wall collisions and oil film splashing were severe. Additionally, the oil film’s distribution characteristics under inlet velocities of 14.0, 16.0, and 18.0 m/s were compared, and the results showed that more splashing oil droplets were generated under higher inlet velocity. Moreover, changing the structure of the central channel and outer cylinder slightly changed the oil film’s area and flow pattern but exhibited a weak effect on the oil film thickness and re-entrainment. Then, an improved structure was proposed by adding a porous cylinder to the outer cyclone to avoid the generation of small splashing droplets from the oil film. The performance of the modified separator was measured in a real oil-injected compressor system, which demonstrated higher separation efficiency with no increase in static pressure loss. The separation efficiency increased by up to 2.7%, while the pressure loss decreased by up to 10%. Thus, the improved structure can improve the performance of oil–gas separators by changing the distribution and thickness of the oil film on the cylinder wall.

Friction Loss and Wear in a Meso Scale Wankel Compressor

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Yilin Zhang ◽  
Wen Wang
Keyword(s):  
Relative Error ◽  
Volume Ratio ◽  
Internal Surface ◽  
Friction Loss ◽  
Motor Speed ◽  
Eccentric Shaft ◽  
The Common ◽  
Contact Surfaces ◽  
Meso Scale ◽  
Eccentric Distance

In a meso scale Wankel compressor, the surface-to-volume ratio and the contact surfaces with friction are larger compared with conventional scale Wankel compressor. The analysis of friction loss is highly important for the design of a meso scale Wankel compressor. In this paper, we comprehensively analyze seven kinds of friction losses of a meso scale Wankel compressor. The rationality of the friction losses equations is verified by the friction loss and wear experiments that are based on a Wankel compressor prototype (the dimension of prototype is about 40 × 50 × 24 mm). The two greatest contribution of total friction loss are from the friction loss between the seal apex and internal surface of the cylinder and that among the end face of the eccentric shaft, end faces of the rotor, and endplates to total friction loss. The most sensitive parameter is eccentric distance. The relative error between the simulation and experimental results is relatively small when motor speed lies within the common range of the compressor.

Geometry in three dimensions over GF (3)

1954 ◽  
Vol 222 (1149) ◽  
pp. 262-286 ◽  
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Galois Field ◽  
The Other ◽  
Three Dimensions ◽  
Common Vertex ◽  
Line Geometry ◽  
Fundamental Properties ◽  
The Common ◽  
Three Dimensional Space

The object of this paper is to give some account of the geometry of the three-dimensional space S wherein the co-ordinates belong to a Galois field K of 3 marks. A description of the fundamental properties of quadrics is sufficiently long for one paper, and so an account of the line geometry is deferred. The early paragraphs (§§ 1 to 4) are necessarily concerned with geometry on a line or in a plane. A line consists of 4 points; these are self-projective under all 4! permutations. A plane consists of 13 points and has the same number, 234, of triangles, quadrangles, quadri-laterals and non-singular conics. A diagram is helpful, especially when we consider sections by planes in S . The space S has 40 points. Non-singular quadrics are of two kinds: either ruled, when we call them hyperboloids, or non-ruled, when we call them ellipsoids. A hyperboloid H consists of 16 points and has a pair of reguli; the 24 points of S not on H are the vertices of 6 tetra-hedra that form two allied desmic triads. The ellipsoid F is introduced in § 12; it consists of 10 points, the other 30 points of S being separated into two batches of 15 between which there is a symmetrical (3, 3) correspondence. Either batch can be arranged as a set of 6 pentagons, each of the 15 points being the common vertex of 2 of these. The pentagons of either set have all their edges tangents of F and, with their polar pentahedra, have significant properties and interrelations. By no means their least important attribute is that they afford, with F , so apposite a domain of operation for the simple group of order 360. In §§ 23 to 26 are described the operations of the group in this setting. Thereafter the 36 separations of the 10 points of F into complementary pentads are discussed, no 4 of either pentad being coplanar. During the work constructions for an ellipsoid are encountered; one is in § 16, another in § 30.

The Effect of Oil Evaporation From the Cylinder Wall on Oil Consumption of a Gasoline Engine

2009 ◽  
Author(s):  
Yasuo Harigaya ◽  
Kazuyoshi Yamasuga ◽  
Michiyoshi Suzuki ◽  
Naoki Iijima ◽  
Masaaki Takiguchi ◽  
...  
Keyword(s):  
Film Thickness ◽  
Gasoline Engine ◽  
Hydrodynamic Lubrication ◽  
Film Surface ◽  
Cylinder Wall ◽  
Oil Consumption ◽  
Oil Film ◽  
Evaporation Model ◽  
Low Load ◽  
The Relationship

A new oil evaporation model was developed, combining a thermo-hydrodynamic lubrication model with a conventional oil evaporation model considering the energy balance on the oil film surface. This model assumed that there was evaporation loss of the oil film on the cylinder wall. In addition, the effects of the oil film thickness and types of lubricant in the evaporated oil from the liner were examined. Moreover, the calculated evaporative oil was compared with the measured oil consumption of a gasoline engine. The relationship between the evaporated oil, the lubricant viscosity, and the oil film thickness were clarified using this model. The results showed that the calculated oil evaporation from the cylinder wall closely corresponded to the measured oil consumption under low load conditions.

Sign in / Sign up

Export Citation Format

Share Document