Ring Wear Research Articles

Analysis of Friction and Wear Properties of Friction Ring Materials for Friction Rings under Mixed Lubrication

Aiming at the problem of mechanical seal failure due to serious wear and tear in operation, the numerical model of the thermal–solid coupling wear of the seal ring is established by taking the friction sub-material as the research object, and the hardness, wear coefficient, and friction coefficient of different soft-ring materials are obtained by a test to verify the accuracy of the numerical model of wear. Additionally, the temperature field and deformation field of the seal ring of different materials are calculated, and the effects of the material parameters, such as elasticity modulus and thermal conductivity, on the temperature, relative deformation, and axial deformation trend are reported. The wear relation of the mechanical seal was optimized, and the correction coefficients of several materials were calculated. The results show the following: the main wear of the seal ring is due to adhesive wear leading to particle shedding and extrusion, adhesive wear causes material transfer, which alters the composition of the worn surface.in turn leading to cratering, which also causes the wear of the seal ring; the friction performance is better when the soft-ring material is graphite (C); the temperature, as well as the deformation, is smaller when the soft-ring material is silicon carbide (SIC); the correction coefficients for the life of SIC are calculated to be 0.23, for C, to be 0.14, and for stainless steel (Ss), to be 0.31, and the corrected equations can more accurately predict the corresponding material. The corrected equation can more accurately predict the service life of the corresponding material.

Study on the wear characteristics of cylindrical needle bearings on the crankshaft of RV decelerator

PurposeThe purpose of this study is to systematically analyze the wear of cylindrical needle bearings in rotary vector reducers under temperature rise and identify the influencing factors.Design/methodology/approachBased on the dynamic characteristics of the RV-20E reducer, the time-varying contact force of the cylindrical needle bearing and the entrainment speed of the inner and outer raceways were calculated. A mixed elastohydrodynamic lubrication model of the needle bearing, considering friction and temperature rise, was established using a dynamic rough tooth surface model. The model solved for the oil film thickness, contact stress and wear conditions of the bearing raceway contact area. The effects of the number of rolling needles, the diameter of rolling needles and surface strength on the wear characteristics were analyzed.FindingsThe results of this study show that the oil film thickness, oil film pressure and surface scratches of cylindrical needle bearings exhibit an uneven, patchy distribution under the combined effects of friction and temperature rise. When the radius of the rolling needle is less than 1.44 mm, inner ring wear is less than outer ring wear. Conversely, when the radius exceeds 1.44 mm, inner ring wear is greater. The optimal rolling needle radius is 1.6 mm. Increasing the number of rolling needles and enhancing the yield strength of the contact surface significantly extend bearing life.Originality/valueThis study provides valuable recommendations for optimizing bearing structural parameters and material characteristics in the design of rotary vector reducers.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0242/

Simplified Wear Model for Power Cylinder under Engine Operating Conditions

A simple numerical approach is developed to predict the wear and friction of piston ring pack and cylinder liner during the break-in period and under transient speed conditions. In the model, a solution of mixed lubrications using the load-shearing concept is presented based on the selected elastic-plastic equations of asperity contacts in conjunction with well-established elastohydrodynamic equations. The model takes shear-thinning, thermal effects in elastohydrodynamic lubrication (EHL) and lubricant starvation effects into account. Modified Archard’s wear coefficient to describe the piston ring against cylinder liner wear is introduced. The approach is valid for the calculations of the asperity pressure at low values of the ratio of oil film thickness to combined roughness of the interacting surfaces, that is, less than 0.5. Applications are discussed, including association of piston side thrust force on wear and friction characteristics of piston ring/cylinder bore, gas blowby through the ring pack on the cylinder liner wear, a strong coating dependence for the piston ring wear, and wear distribution across the stroke under engine operating conditions. A good agreement between the experimental and analytical data indicates that the proposed model can be used to predict the wear and friction of the piston ring pack sliding against cylinder liner.

Research on influence of wear ring clearance on energy loss of reactor coolant pump

Reactor coolant pump (RCP), the only rotating equipment in the nuclear island, directly determines the safety of the nuclear power system, has been likened to the “heart” of a nuclear power plant. The RCP needs to have very high reliability and stability. Its independent design and construction have always been the focus and difficulty of promoting the independent construction of nuclear power. To study the effect of the wear ring clearance on the energy loss characteristics of the RCP, the numerical simulation of the internal flow field of computation models with different wear ring clearance dimensions were conducted. The results indicate: As the wear ring clearance increases, the trend of performance reduction becomes more significant, especially under the large flow conditions; The increase of the wear ring clearance results in an increase of the pressure loss in the impeller and diffuser, and the variation in pressure distribution in different flow passages under different wear ring clearance dimensions is influenced by the position of the blade; The distribution of turbulent dissipation entropy production rate corresponds significantly to the distribution of direct dissipation entropy production rate, and the dissipation entropy production being more significantly affected by the wear ring clearance dimension closer to the shroud; The change of wear ring clearance dimension has limited impact on the wall shear stress entropy production of the impeller blade, while its effect on the diffuser blade is more pronounced; With the increase of the wear ring clearance, the scale of vortices near the impeller front shroud significantly increases, and the entropy production on the surface of vortex core at the impeller inlet gradually increases. This study is of great significance to ensure the secure and stable operation of the RCP, and provides an important reference for the hydraulic optimization design of the RCP.

Preparation and properties of FeS/iron-based self-lubricating materials by chemical nickel plating-mechanical alloying

PurposeThis paper aims to investigate the effect of chemical nickel plating and mechanical alloying on the mechanical and tribological properties of FeS/iron-based self-lubricating materials as well as the wear mechanism of the materials.Design/methodology/approachSurface modification of FeS powder was carried out by chemical nickel plating method and mechanical alloying of mixed powder by ball milling. The mechanical properties of the material were tested by tribological testing by M-200 ring block type friction and wear tester. Optical microscope was used to observe the surface morphology of the material and the transfer film on the surface of the mate parts, and scanning electron microscope and EDS were used to characterize the wear surface.FindingsMechanical alloying ball milling was carried out so that the lubricating particles in the matrix are uniformly dispersed; nickel-plated layer enhances the interfacial bonding of FeS and the matrix, and the combination of the two improves the mechanical properties of the material, and at the same time the friction side of the surface of the lubrication of FeS lubricant transfer film formed is denser and more intact, and the friction coefficient of friction side and the wear rate of the material have been greatly reduced.Originality/valueThis work aims to improve the mechanical and tribological properties of FeS/iron-based self-lubricating materials and to provide a reference for the preparation of materials with excellent overall properties.

Стендовые испытания нового уплотнения деталей цилиндропоршневой группы судового ДВС

The engine consists of a large number of parts, each of which is responsible for a specific function of its efficient operation. The reliability of a marine diesel engine is largely determined by the resource of its individual components and parts. Therefore, in order to increase the engine life, it is necessary to allocate the most responsible parts in it, which are subject to greater wear and find solutions to increase their durability. Such details include piston rings, which affect not only the technical and economic performance of the engine, but also its reliability and environmental performance. Of the entire set of sealing parts of the cylinder-piston group, the upper piston compression ring should be distinguished as the most loaded. The main function of piston rings is noted – the creation of tightness of the combustion chamber. The passage of exhaust gases is inevitable due to the presence of a “lock” in the structure, and during operation, the wear of the piston rings leads to an increase in it, which affects fuel consumption, oil, and a decrease in engine power. One of the most negative consequences of piston ring wear is the appearance of “flutter” type vibration, which leads to the destruction of not only the ring, but also the edges of the piston grooves, especially on aluminum pistons. Worn grooves are not repaired by resorting to replacing pistons. A method for extending the service life is proposed, which consists in the use of a new sealing unit for cylinder piston group parts. The new sealing unit allows you to extend the piston's operability by boring the upper piston groove of the piston until all chips are eliminated. The operability of this node and the effectiveness of the seal was confirmed by an experiment that was conducted on the stand in conditions close to real ones. A technology for restoring the operability of pistons made of aluminum alloys is proposed.

Insight into the tribological properties of cylinder liner-piston ring under the nano BNNs/Cu composite additive lubrication

To improve the tribological properties of the cylinder liner-piston ring, a two-dimensional hexagonal boron nitride/copper composite lubricant additive was prepared and characterized in detail. The tribological properties and lubrication mechanism of nano hexagonal boron nitride composites with different concentrations were studied through the reciprocating friction test on the Rtec friction and wear tester. The results show that copper is successfully reduced and attached to the surface of h-BN nanosheets through the self-polymerization of dopamine, and the spherical structure promotes the interlayer slip of the nanosheets during the reciprocating friction process. The appropriate concentration of nano composite additives has excellent anti-friction and anti-wear properties. At 1 Hz and 100 N, the friction coefficient and wear quality of the nano composite additive with a concentration of 2 wt% were reduced by 29.07% and 76%, respectively. The surface Sq value and Sz value of the cylinder liner sample decreased by 68.06% and 74.47%. At the same time, under the condition of high speed and heavy load, the average wear depth of the cylinder liner sample is reduced by 61.3%. The nano composite material additive forms an excellent friction protective film on the wear surface of the cylinder liner, which can better enter the wear surface of the cylinder liner and produce a filling and repairing effect. The research results provide a method for the use of nano hexagonal boron nitride composite additives to inhibit the wear of cylinder liner-piston ring of Marine diesel engines.

Study of frictional wear and desorption of nanoparticle‐rubber blend modified UHMWPE composites

AbstractTo address the issues of abrasive wear, impact wear, and soil adhesion that can lead to wear failure and excessive operational resistance in agricultural soil touching parts during farming. This study focuses on UHMWPE composites, modified by filling Nano‐SiC as a hard phase filler and XNBR as an elastic filler. These fillers were dispersed into the UHMWPE matrix through melt blending technology to create a high‐performance composite material for the surface protective material of soil touching parts. The study discovered that by adding hard and elastic fillers to the UHMWPE matrix, the density, hardness, flexural modulus and thermal stability of the materials were all increased. Specifically, the density increased by 5.67% and the flexural modulus increased by 107%. In the block on ring wear test the volumetric wear rate decreased by 98%, while in the mortar wear test the mass wear rate decreased by 64.64%. Additionally, the contact angle on the surface of the specimen after mortar erosion and wear increased to 102.76°, 18% higher than that of pure UHMWPE. These results demonstrate that the modified fillers can improve the abrasion and plastic deformation resistance and hydrophobic desorption of UHMWPE. UHMWPE composite material, serving as the surface protection for soil touching parts, resolves the issues of abrasion of soil abrasive particles and excessive soil adhesion resistance on these parts. This significantly prolongs the service life of soil touching parts of agricultural machinery and improves the operational efficiency and economy.Highlights Research on nanoparticles and elastomer‐modified composite materials. Research has shown the enhancement of UHMWPE composite materials by Nano‐SiC. XNBR improves the plastic deformation resistance of UHMWPE composites. Effects of Nano‐SiC and XNBR on the desorption behavior of composite materials. UHMWPE composites reduce soil contact wear and soil adhesion.

The effect of biomimetic laser surface treatment on the wear performance of high manganese steel

High manganese steel finds widespread applications in diverse friction and wear environments. The poor wear resistance of high manganese steel at low stress levels has prompted researchers globally to focus on studying its wear performance. Drawing inspiration from the protective features of pangolin scales, this study employed a pulsed radiation mode CO2 laser to conduct biomimetic laser surface treatment (BLST) on Mn13 high manganese steel. The BLST generated a biomimetic surface morphology consisting of tiny scales on the high manganese steel specimens. Subsequently, the biomimetic laser surface-treated (BLSTed) specimens underwent tests for surface morphology, microstructure, microhardness, and surface roughness. These tests employed metallographic microscopy, scanning electron microscopy, a microhardness tester, and a surface profilometer, respectively. A ring block friction and wear testing machine was utilized to evaluate the wear performance of the BLSTed specimens. Changes in laser power, laser frequency, and laser scanning velocity were found to alter the surface morphology of BLSTed specimens. The experimental results revealed that the microstructure of the BLSTed specimen surface comprised needle-like martensite. The increment in surface hardness and surface roughness of BLSTed specimens contributed to an elevation in their average friction coefficient. Furthermore, the surface hardness and wear performance of BLSTed specimens exhibited varying degrees of improvement with the increase in laser power, laser frequency, and laser scanning velocity. The tiny biomimetic scales, created through BLST, provided protection to high manganese steel akin to the protective scales on the body of pangolins. Finally, the study unveiled the wear resistance mechanism of BLSTed specimens.

The influence of ring clearance on the performance of a double-suction centrifugal pump

Due to the complex structure of a double-suction pump's suction chamber, the flow in the pump's cavity is often ignored in numerical simulations because of difficulties in structured hexahedral meshing. However, the wear ring clearance interlinking the pump chamber leads the fluid at the impeller inlet directly to the impeller area. This significantly impacts the pump's internal flow field, so the influence of the clearance on the internal flow of a double-suction pump cannot be ignored. This paper develops four three-dimensional double-suction pump models with different wear ring clearances to investigate their influence on pump performance, and structured hexahedral meshes were used for all the computational domains. The clearances varied from 0.2 to 0.5 mm in 0.1 mm increments. The influences of the clearance on the energy loss, external characteristics, and internal flow field distribution of the pump were simulated via a verified computational fluid dynamics method. The results show that the wear ring leakage decreases with the flow rate and increases with wear ring clearance. The increase in backflow leads to an internal flow disorder inside the impeller, resulting in a decreased head and efficiency. Energy loss is mainly caused by increasing the turbulence entropy production with an increasing wear ring clearance. Also, the low-pressure region in the pump cavity expands to the volute with increasing clearance, and the impeller outlet pressure decreases. This study's research on wear ring clearance provides a reference for the design and application of double-suction centrifugal pumps.

Influence of diamond-like carbon coatings and micro-texturing on friction and wear of seal interfaces: Experiment and simulation study

For mechanical seal friction vice in dry friction conditions, due to friction wear serious failure, is the slurry pump and other instruments in the operation of the process of the urgent need to solve the problem. In this paper, in order to optimize and enhance the friction and wear problem of mechanical seal end face of slurry pump. Surface treatment of mechanical sealing rings with diamond-like carbon (DLC) coating and surface microtexturing, and at different rotational speeds and normal forces, the surface hardness, wear coefficient and dry friction coefficient of the sealing rings were analyzed by experimental comparison, and the wear morphology was collected by electron microscopy, having analyzed the results of the sets of, the end face structure of the mechanical seal was optimized. Based on Archard wear model simulation calculations, the seal ring wear depth and wear quality were obtained. The results show: under dry friction conditions, the synergistic effect of the DLC coating and the surface micro-texture (MT), the coefficient of friction is reduced by approx. 68% and the quality and depth of wear is minimized. Excessive speeds and normal forces are more prone to wear behavior caused by abrasive wear. Simulation results of surface treatment groups, DLC / MT group maximum wear depth is the smallest; wear quality test and simulation of the maximum error within 15.7%. The results of the study can provide a basis for a phosphoric acid plant slurry pump mechanical seal design.

Blade Lift Hydraulic System Troubleshooting on Komatsu D70-LE Bulldozer (Troubleshooting Sistem Hidrolik Blade Lift pada Bulldozer Komatsu D70-LE)

A bulldozer is one type of heavy equipment used for cutting, pushing, and spreading material. It has a blade on the front side whose movement is controlled by a hydraulic system. The movement of the blade, combined with the weight and travel momentum of the bulldozer, creates the mechanical power used in the bulldozer's function.. Problems occurring in the hydraulic system could render the bulldozer useless. In this study, a Komatsu D70-LE bulldozer unit's hydraulic system is experiencing low power and cylinder drift, where the hydraulic cylinder cannot maintain its floating position and tends to return to its full-length rod position, thus causing the blade to drop on itself. This problem is then traced through the troubleshooting method to find the cause and solution to the problem. The cause of the low power problem in the lift cylinder is that the components of the lift cylinder have been worn out and damaged, resulting in a pressure leak in the lift cylinder, which causes the blade to drop by itself (hydraulic drift). The troubling components are the wear ring seal, piston ring seal, o-ring, dust seal, and rod seal. The way to solve the low power problem in the lift cylinder is to replace the lift cylinder seal kit with a new set of wear ring seal, piston ring seal, o-ring, dust seal, and rod seal.

Peculiarities of ship power plant diagnostics using the ERS-500 TechSim TRANSAS MIP LTD simulator complex in the process of ship engineers' training

This paper presents an analysis of the results obtained using the ERS 5000 TechSim Engine Room Simulator software. The software simulates remote control from the ship's central control station using virtual equipment panels, which are dedicated hardware combined into a separate console. The simulator covers the main areas of training in accordance with the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers with the Manila Amendments of 2010 and meets the requirements of IMO Conventions and Resolutions and IEC standards. The simulator is certified by the Norwegian classification society DNV/GL. Main engine diagnostics are performed using the Cylinder Combustion Quality diagnostic panel and the Indicator Diagram Comparison panel. Analysis of changes in gas turbine engine parameters and the indicator diagrams themselves at different levels of piston ring wear showed a decrease in compression pressure, mean indicated pressure and maximum combustion pressure, as well as an increase in the return oil temperature of the piston cooling system and the consumption of lubricating oil in the cylinder. The advantages of using simulators in the training process include the ability to perform laboratory work in a frontal method, which significantly improves the learning experience

Fault diagnosis of horizontal centrifugal pump orifice ring wear and blade fracture based on complete ensemble empirical mode decomposition with adaptive noise-singular value decomposition algorithm

Horizontal centrifugal pump orifice ring wear and blade fracture failure will not only affect the hydraulic performance but also affect the safety and stability of the whole unit. In this paper, the horizontal centrifugal pump orifice ring wear and blade fracture failure are studied, and carry out condition monitoring and fault identification through the vibration signal under the failure. Combined with the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise and Singular Value Decomposition algorithm of adaptive noise, a vibration feature extraction method of horizontal centrifugal pump based on intrinsic mode singular value is proposed. Through the BP neural network, based on the time domain, frequency domain, wavelet packet-AR spectrum, and intrinsic mode singular value characteristics of single-point and double-point vibration, the identification model is constructed and the identification effect is compared. The research shows that the vibration feature recognition effect of CEEMDAN-SVD decomposition is verified based on BP neural network model, and the BP neural network is improved by Particle Swarm Optimization to further improve the recognition effect and speed, which provides the diagnosis model for the design of subsequent diagnosis system.

Bionic Design and Optimization of the Wear-Resistant Structure of Piston Rings in Internal Combustion Engines

Internal combustion engines, during their operation, subject the piston to high-temperature and high-pressure conditions, requiring it to endure intense, continuous reciprocating motion. This strenuous process leads to significant wear and tear. Among the engine’s crucial components, the piston ring plays a pivotal role but is particularly susceptible to wear. Therefore, extensive research has been devoted to investigating the wear of piston rings, a critical sealing component within internal combustion engines. To address the high cost of existing coating methods, which hinders widespread application, we propose a bionic design approach inspired by groove structures observed on earthworm bodies, aimed at enhancing the wear resistance of piston rings. Bionic piston rings featuring optimally designed groove structures inspired by the earthworm’s anatomy were designed. These rings exhibited varying groove depths (1 mm, 2 mm, and 3 mm), groove widths (0.1 mm, 0.3 mm, and 0.5 mm), and groove spacings (0.1 mm, 0.2 mm, and 0.3 mm). We conducted thermal–structural coupling analyses on both standard piston rings and these bionic counterparts. The results revealed that the maximum stress was concentrated at the first piston ring, precisely at the opposing region of the end gap. Thus, the initial piston ring endured the primary frictional losses. Moreover, a comparison of stress levels between bionic rings and the standard ring revealed that the bionic groove structure substantially reduced stress and minimized stress concentration, thus enhancing wear resistance. Groove width had the most notable influence on wear performance, followed by groove depth and groove spacing. Optimal wear resistance was achieved when the groove depth was 3 mm, groove width was 0.1 mm, and groove spacing was 0.1 mm. Subsequently, we constructed a piston ring friction test bench to validate the wear resistance of the most effective piston ring. The results indicated that the wear resistance of the bionic piston ring exceeded that of the standard piston ring by up to 19.627%. Therefore, incorporating a bionic groove structure within the piston ring can effectively reduce surface friction and enhance wear resistance. This, in turn, can enhance the operational lifespan of internal combustion engines under favorable working conditions.

Wear performance of modified H-13 and H418E steels for TBM disc cutter ring

The wear failure of disc cutter rings is a crucial factor affecting the efficiency of TBM construction. At present, many tool manufacturers improve the content of the elements of the cutter ring material to improve its wear resistance and reduce the number of cutter changes. However, the enhancement of wear resistance by adjusting the elemental content in the cutter ring material relies mainly on experience, and the results can only be verified by improvements in macroscopic properties such as hardness and toughness. In contrast, the reason for the wear resistance improvement is unclear. Therefore, this study carried out scaled-down cutter ring and rock wear experiments, compares the wear behavior of the modified cutter ring material based on H13 steel, and analyzes the reasons for the improved wear resistance of the modified material by metallography and XRD. The result is obtained as follows: (1) Ni-H13 and H418E have better wear resistance than Modified H13, H418E has better abrasion resistance with a 34.9 % reduction in wear rate. (2) The wear mechanisms of Ni-H13 and H418E cutter ring samples were both micro-cutting and furrow wear. A few microscopic fracture wear mechanisms appeared in the Ni-H13 cutter ring. (3) The increased carbide content in H418E and its more refined and uniform tissue distribution are the main reasons for its excellent wear resistance. At the same time, the powder smelting material did not significantly improve the wear resistance of the cutter ring.

Implementation of a Reduced Order Model for rotating seal annular leakage flow inside a centrifugal pump

Sustainability and net zero emissions targets drive the importance of turbomachinery design, optimisation, and efficient operation in modern geoenergy systems. To further enable integration of advanced large-scale technologies, accurate and resource-efficient simulations of complex equipment and systems need to be completed readily. An approach to simulate internal leakage flows of centrifugal pumps is presented, an important factor that influences equipment operation efficiency.One significant challenge when internal leakage flow is investigated is achieving sufficient simulation detail in the flow regions separating rotating and stationary components where close-running clearances are present. Computational fluid dynamics (CFD) meshes typically require excessively fine resolutions of node points in these situations for accuracy. For example, the typical annular suction wear ring clearance ranges between 0.1–0.5 mm, whilst impeller diameters and other geometric properties have length scales from 600–1200 mm or even larger.A reduced order model (ROM) of an annular seal configuration was developed that allows for analytical calculation of the leakage flow by implementing user scripting in the CFD solver setup. The ROM implementation has a low symbol count and does not require any type of logic and/or recursive and iterative functionality. Thus, fine and resource-intensive meshing can be robustly eliminated and replaced by a sufficiently detailed ROM that contributes leakage flow effects to the overall simulation.Leakage flow through the suction wear ring of a high differential head (ΔH), high flow rate, double suction centrifugal pump with water as working fluid was used as a case study for ROM development. The calibrated model was verified against a commercial fluid dynamics software package and achieved a level of precision of 2.4% with σ=0.0118 in a wide operating range of 10m⩽ΔH⩽350m and fluid temperature (T) of 283.15K⩽T⩽353.15K.The leakage flow calculated by the ROM was proven to be accurate and therefore capable of accounting for a range of pressure heads, incorporating surface roughness effects and temperature variations, and adaptable for various fluids. Guidance for the implementation of the ROM in the Ansys CFX solver environment is also provided to aid future work.

TRIBOLOGICAL PROPERTIES OF PISTON RINGS DESIGNEDFOR SLIDING AGAINST COMPOSITE MATERIALSIN LUBRICATED CONTACTS

The paper presents basic information on the production, structure and tribological properties of a compositechromium-ceramic coating deposited electrolytically on a cast-iron piston ring for a combustion enginedesigned for sliding against a composite cylinder liner. The results of comparative tests of two contacts,i.e. cast-iron GJL-250/AlMC and GJL250+Cr-Al2O3/AlMC, are described. The deposition of the Cr-Al2O3coating on the cast-iron piston ring reduces almost trifold the wear of the piston ring and about 20% thefriction resistance in the contact due to the presence of aluminium oxide particles and fibres. The reinforcingphase removed from the chromium layer polishes the chromium and composite sliding surfaces. The placesleft by the removed particles serve as depots for oil, which reduces the friction forces and minimises oilconsumption. The Al2O3 wear debris decreases the roughness of the surfaces in contact, which additionallyreduces the friction forces according to the friction hypothesis of Ernst and Merchant.

Effects of different surface textures on tribological performances of the cylinder liner-piston ring: An experimental study

The tribological performance of internal combustion engines (ICEs) has an important impact on fuel efficiency and power consumption, and the wear of cylinder liner-piston ring (CLPR) system affects the operation reliability. The surface texture of CLPR can significantly improve the tribological performance of ICEs. Aiming at the friction and wear of CLPR, the different textures (dimple, equilateral triangle and square) are generated on the CLPR using laser processing, and the different tests are conducted on the UMT-TriboLab tester. The coefficient of friction, wear topography, surface roughness parameters and profiles are measured. The results show that, compared with the non-textured surface, the dimple texture surface of piston ring or cylinder liner has better tribological performance. If the textures coexist on the cylinder liner and piston ring, the tribological performances are better than single surface texture. Furthermore, the mixed textures can significantly improve the surface lubrication performance and the ability to store abrasive particles, and better surface quality can be obtained at the same operating conditions to enhance the tribological performance. This study can provide guidance for reducing the friction and wear of CLPR system of ICEs, and achieve energy saving and emission reduction of ICEs.

Research on the wear of novel sets of piston rings in a diesel locomotive engine

The paper describes the results of the wear test of innovative sets of piston rings intended, among others, to drive diesel locomotives operated in North America, including the USA. The main subject of research is an innovative set of piston rings, the first sealing ring containing a synthetic diamond embedded in a porous chrome coating. The developed multilayer coating is designed to reduce the wear of the piston rings and the combustion engine cylinder. This technology has been implemented at Piston Rings Manufactory "Prima" S.A. in Łódź. The tests were carried out using a two-stroke diesel engine of the EMD 645 type. This engine is manufactured by General Motors Corporation in the United States. The described research was carried out in the United States in San Antonio, Texas, at the Southwest Research Institute. The EMD 645 engine is widely used in power units of heavy diesel locomotives and inland waterway barges in the United States of America, India, and South Africa.