Pin Bearing Research Articles

Reliability analysis of 50000 kN hydraulic support test bench under shrinkage test conditions

The large mining-height hydraulic support test-bed serves as a crucial tool for heavy hydraulic support factory inspections and type testing. With the successful development of the ZY29000/45/100D hydraulic support, the need for a large high-mining hydraulic support test-bed has become evident. This paper combines the theory of rigid-flexible coupling in virtual prototypes and ADAMS multi-body dynamic simulation technology to analyze the strength of the 50,000 kN hydraulic support test-bed. ANSYS classic modules were employed to address the flexibility of key components within the test-bed. The fatigue life of the test-bed was analyzed using NSOFT software, the von Mises yield criterion, and the Goodman modified curve. The S-N curve of material parameters for the test-bed components was used to conduct a shrinkage test. The results indicate that the lowest position is the most vulnerable during the shrinkage test. Among the key components, the stress on the pin bearing is 356.6 MPa, which is 167.9 %, 123.3 %, and 41.6 % higher than that of the pillar, movable beam, and base, respectively. The fatigue life of the base under low, medium, and high shrinkage conditions is1.1×107, 4.0×108, and 1.7×108, with damage values of 8.8×10-8, 2.5×10-9, and 5.7×10-9, respectively. The base’s life under low shrinkage conditions is the shortest, followed by that under high shrinkage conditions. These research findings provide technical guidance and an optimization foundation for the successful development of a 50000 kN hydraulic support test-bed. They also offer a new method and approach for analyzing and predicting the fatigue life of key components in large-scale industrial and mining equipment operating under complex conditions, with promising practical applications.

Effect of cooling system and forming structure on grain sizes and mechanical properties of S43CMnV for non‐quenched and tempered steel crankshaft

AbstractTaking the given S43CMnV non‐quenched and tempered steel multi‐cylinder (3‐cylinder and 4‐cylinder) crankshaft as the research object, the intrinsic relationship between the forging process, temperature controlled cooling process of 3‐cylinder crankshaft and the global‐local grain evolution process was analyzed by Deform‐3D software. Meanwhile, the influence relationship between average grain sizes and comprehensive mechanical properties of the 3‐cylinder and 4‐cylinder crankshaft was compared and analyzed in details. The results show that for the 3‐cylinder crankshaft, the larger cooling rates can achieve the smaller grain sizes. When the temperature controlled cooling rate is 60 °C/min, the average grain sizes of the crankshaft pin bearing, main bearing and flange end are 61.5 μm, 96.9 μm and 70.7 μm respectively, which meets the requirements of production process (approximately 127 μm). Wherein, the grain sizes and mechanical properties of the 4‐cylinder crankshaft are better than those of the 3‐cylinder crankshaft, and the after‐forging elongation of the 4‐cylinder crankshaft can reach at approximately 16.6 %. Furthermore, the grain sizes evolution of 3‐cylinder crankshaft obtained by numerical simulations are basically consistent with the experimental grain size results, and it is feasible to predict and control the grain sizes’ evolution and mechanical properties of the crankshaft hot forging by using Deform‐3D.

Investigation on drilling response of Carbon-Graphene and Kevlar-Graphene composites

In this work, two sets of composites are fabricated - Carbon-graphene and Kevlar-graphene by hand lay-up method. The composites were drilled using four different drill bits with constant cutting speed of 1120 rpm and two different feed rates of 0.12 and 0.30 mm/s providing uneven damage outcomes. The drill damage area was assessed by enhanced radiography and using an image processing software GIMP, which helps in converting the radiographic images to binary images and assists in the reduction of noise from the resulting binary images. Using pixel area, we determine the damage area caused in each coupons and a comparative analysis is made between two different composites. Finally, the coupons are subjected to three experimental tests: 3point flexural (3 PB), 4-point flexural (4 PB), and Pin bearing. The Results obtained were correlated with the drilling-induced damage and mechanical resistance for both composites. The statistically tool was used to establish the model with relation between material resistance (3 PB and 4 PB) and the damaged area by drilling. In 3 PB flexural test, the flexural strength has not shown much variation with the damaged area. Alternatively, the 4 PB test, the flexural strength and in pin bearing test, the bearing strength decrease with increase in damage area. The brad drill tool appears to be more suited for drilling composite plates.

Öltransport und Reibungsbewertung innerhalb der Kolbenbolzenlagerung

Increased loads and lower oil supply of today’s low-consumption internal combustion engines lead to higher demands on mechanical and elastohydro-dynamical design methods of the piston pin bearing. The bearing is not lubricated directly but through spray oil or oil mist. A description of the lubrication mechanism within the bearing has mostly been researched theoretically. In order to understand the friction conditions and lubrication mechanisms, the bearing is tested on an external test bench with high loads and a hydrostatic bearing of the piston. An enginelike lubrication can be variably adjusted. By comparing the contact pattern between measurement and calculation, conclusions can be drawn about the behaviour of the lubricant within the bearing. Using computational fluid dynamic calculations (CFD) the amount of oil in the gap of different lubrication directions is regarded. After transferring the results to the test bench a directed transport of lubricant is determined. Final friction measurements with an adapted direction of lubrication show a good accordance to the calculation results. These results validate a multi body system calculation (MBS/MKS) with a lubricating film coupling.

Development of rocking isolation bearing system (RIBS) to control excessive seismic responses of bridge structures

AbstractRocking structures are recognized as an effective seismic response modification technique due to their peculiar dynamic characteristics. Meanwhile, in bridge structures, strong ground motions have frequently caused a rocking motion of pin bearings around their two toes, resulting in the pulling‐out of anchor bolts. This study, motivated by the promising features of rocking behaviors, seeks to develop a rocking isolation bearing system (RIBS) to control excessive response in bridges. An example bridge featuring such a RIBS, consisting of the pin bearings removing anchor bolts to release the rocking motion, the girder type superstructure, and an array of bridge piers, is characterized by a simplified model. Two coefficients of restitution (COR) models are used to investigate the effects of energy dissipation during impact: the Housner model, and a model which simultaneously modifies the velocities of the superstructure and substructures. The dynamic characteristics of RIBS and its control effectiveness on the bridge structure are discussed through a series of dynamic analyses, under both observed ground motions and the design ground motions specified in the Japan Road Association (JRA) design specifications for highway bridges. The simulation results demonstrate that the seismic performance of the bridge structure can be substantially improved, with decreased pier displacement at an allowable bearing rotation level.

Engine durability and lubricating oil tribology study of a biodiesel fuelled common rail direct injection medium-duty transportation diesel engine

Biodiesel has emerged as a viable alternative to mineral diesel in the transport sector to replace fossil fuels partially. However, long-term compatibility with engine hardware must be evaluated to ensure a smooth transition. Long-term material compatibility studies of Karanja oil methyl ester (biodiesel) blends with the hardware of a modern common rail direct injection system equipped diesel engine used in sports utility vehicles have been carried out in this investigation. A long-term endurance test was carried out in two phases, each lasting 274 h and utilizing (i) baseline mineral diesel and (ii) a 20% v/v Karanja biodiesel blended with mineral diesel (KB20). After completing the first phase, the engine was dismantled, and essential engine components were investigated for carbon deposits and physical wear using several techniques. Before proceeding with the next phase of the endurance test KB20, new engine components were installed in the engine, and then the test was executed. The KB20-fuelled engine exhibited lower wear on the valves and crankpins but higher wear of liners, piston rings, pistons, gudgeon pin, small and big end bearings of the connecting rod, and the main bearings. Fuel chemistry affected the lubricating oil efficacy and its residual useful life. Lubricating oil from the KB20-fuelled engine exhibited a higher increase in density and ash content. KB20 fuelled engine's lubricating oil underwent higher oxidation and polymerization. The surface roughness characteristics of the cylinder liner were measured before and after the endurance test for comparative wear evaluation during both phases of the endurance test. Carbon deposits on the cylinder head, piston top, and injectors were compared, and the pistons of the KB20 fuelled engine exhibited higher carbonaceous deposits. Biodiesel blends harmed the CRDI engine's fuel injection system. Biodiesel harms the fuel injection equipment (FIE) of the CRDI engine. Various tribological tests were performed on the lubricating oil samples collected regularly to examine the compatibility of KB20 vis-à-vis mineral diesel. This series of tribological tests on the lubricating oil samples assessed the effect of fuel chemistry on the lubricating oil's performance and residual useful life. Tests included variations in lubricant density, viscosity, flash point temperature, moisture content, pentane and toluene insoluble, and copper corrosion with time. The study summarily concluded that Biodiesel blends could be utilized in a CRDI engine without causing major engine durability or lubricating oil degradation issues.

On the tribo-dynamic interactions between piston skirt-liner system and pin assembly in a gasoline engine

Piston Skirt-Liner (PSL) system and Piston Pin Bearing (PPB), two key friction pairs in piston-assembly, interact with each other via impact and friction when transmitting the combustion load to crank train. Literature reporting such an interaction behavior in terms of tribology and dynamics is still rare, due to the complexity in a systematic modeling way. This paper proposed an efficient numerical model that fully couples these two friction pairs to investigate tribo-dynamic interactions between them. The model is built by coupling Reynolds-based mixed lubrication models for the friction pairs with Lagrange multibody motion equations for the piston-connecting rod-crank mechanism. Coupling effects between the piston skirt-liner system and the pin assembly are explored by comparing the cases contain the two friction pairs and one of them. Based on the above analyses, some design parameters including pin assembly clearance and pin offset, are further studied to disclose their influences on the tribo-dynamic performance of these two friction pairs. This work has a guiding significance for the systematic design of piston-assembly aiming to improve the dynamic property, economical efficiency and environmental-friendliness of engines.

Experimental analysis of the system behavior of a two-stage variable compression ratio (VCR) system in fired SI-engine operation

Especially for turbocharged SI engines, systems that allow to adapt the geometrical compression ratio offer advantages in terms of part load efficiency and maximum power output. In this study a conrod based two-stage VCR system with an eccentric piston pin bearing is investigated in fired engine operation by means of a specially designed measurement technique. For this purpose different sensor technologies were equipped to a VCR conrod and the oil supply system of a prototype crankshaft. The data transmission was realized by an optimized mechanical linkage system and a digital rotation telemetry system. The high-performance measurement technique presented in this paper enables a detailed analysis of the influencing parameters resulting from the fired engine operation, such as dynamic pressure stimulation in the crankshaft oil supply or the acceleration of the internal oil columns. The presented crank angle based measurement results of the system are obtained through fired testbench investigations on a three-cylinder full engine in the entire engine map, focusing on the speed range up to [Formula: see text] and loads up to [Formula: see text]. A detailed analysis of the conrod system behavior in high and low compression ratio is shown. A key finding is, that the so called “hydraulic pretension” of the support chamber is necessary to meet the requirements for a stiff force transmission in the low compression ratio stage. The in-depth investigation contributes to the build up of a comprehensive system understanding and represents a solid base to expand the development process of conrod based two-stage VCR systems.

Numerical study on failure process and ultimate state of steel bearing under combined load

The limit state and deformation performance of steel bearing under seismic load is one of the most critical points to consider the effective or rational design of bridge against strong ground motion. In the 2016 Kumamoto earthquake, various bridges are damaged by the earthquake. Among the components of the bridge, steel bearings are the most damaged part of the bridge, which affects the functionality of the entire bridge. Since the 1995 Southern Hyogo Prefecture Earthquake, several studies about the ultimate state of steel bearing during earthquake carried out. However, there are a few studies on analyzing the failure processes and ultimate state of steel bearing when various loads assumed at the time of the earthquake. Therefore, the study investigates the failure process and ultimate state of pin bearing and pin-roller bearing under combined load using static push-over analysis. First, the bridge axis and perpendicular bridge axis horizontal loading directions proposed depending on the actual earthquake directional behavior of the bridge. Then the analysis of each bearing conducted and clarified the failure process of each bearing that leads to failure based on the von mises stress yield criteria. Three-dimensional finite element method used to analyze the bearings. The analysis result found that set bolt and pin neck tensile failure were the probable failure mode of pin bearing, and failure mode of pin-roller bearing depends on vertical and horizontal loading direction. In the future, the result used to propose a new seismic resistance design and reinforcement method of bearings that satisfies the required performance.

Vibrations of a Piston Pin with Eccentric Center of Gravity

Combustion pressure boost in the cylinder of modern diesel engines increases the loads acting on the piston pin bearings and lubrication of the piston pin bearings becomes a serious problem. Using a piston pin with an eccentric center of gravity solves this problem. This article deals with the phenomenon of parametric resonant oscillations of the piston pin during the reciprocating motion of the piston. The purpose of the study is to use a phenomenon that increases the amplitude of the oscillations and, consequently, the sliding speed in the relative rotational movement of the piston pin.

Notch Tensile Strength of Carbon Fiber/Epoxy Composite Plate with a Center Hole under Static and Cyclic Loading

The tensile and fatigue properties of epoxy reinforced with 68 volume percent carbon fiber, CFRP, have been fully investigated. The effect of the presence of an open circular hole on tensile, fatigue residual strength, and fatigue strength of CFRP plates was studied experimentally and numerically. The results of pin bearing, i.e. bolt-loaded holes, tests were also investigated and evaluated. A three-dimensional orthotropic-elastic finite element code was developed to calculate the stress concentration factors of open circular holes or bolt-loaded holes in composite materials.The modulus of elasticity, tensile strength, and maximum elongation of CFRP are approximately equal to the values found in the technical data sheet of the supplier. A rule of mixtures type relation is adequate to predict the modulus of elasticity of such CFRP plate. This may be attributed to the high mechanical properties and high volumetric content of the fibers compared with the matrix, i.e. there is a marginal contribution of the strength of the matrix or the fiber-matrix interfacial bond strength. Based on the net stress analysis, there is no difference between the mechanical behavior of smooth and open-holed specimens, i.e. notch insensitivity. This is due to the incapability of the matrix to transfer the load from the discontinuous part. The same behavior was also found under cyclic loading. Due to the weakness in the bond between the fiber and matrix or in the shear strength of the matrix compared with the tensile strength of the fiber, the failure mode of all tested bolt-loaded unidirectional CFRP plates is shear-out. Further, the strength of such bolted joints is mainly dependent on the size of the contact area between the hole and the bolt.

Experimental Investigation of Mechanical Properties of Impact Modified Polyvinyl Chloride-Fly Ash Composites

The mechanical properties like tensile, pin bearing and impact properties have been studied for composites containing Fly Ash (FA) and Impact modifier (IM) in Polyvinyl Chloride (PVC) for furniture and pipe applications. Pin-bearing test is an important tool to evaluate the ability of the material to retain fasteners and the ability of the material to sustain load during the service life. The present paper evaluates the effect of variation of FA and IM on the pin bearing strength, tensile strength, modulus elongation at break and impact strength. Scanning electron microtopography indicates that the impact modifier forms a co-continuous phase at 10% of IM in PVC. Increase in void content decreases impact strength and tensile strength. As void content increases moisture absorption also increases. The results of pin bearing tests were analogous to tensile test and correlate well. Results were in accordance with impact modification theory. Moisture absorption was studied keeping in view outdoor applications.

Modeling a lubricated full-floating pin bearing in planar multibody systems

Abstract Lubricated full-floating pin bearings are being more and more widely used in the industrial products because of the advantages in terms of lubrication, scuffing resistance and durability. The present study develops a numerical model for the lubricated full-floating pin bearings in multibody mechanical systems by embedding the hydrodynamic lubrication and solid contact forces in the revolute joint clearance. The modified Coulomb law is employed to deal with the numerical difficulties caused by the pin stick-slip motion, while the MEBDF approach is applied to a high computation efficiency. An application example in a gasoline engine is then used to demonstrate the validity of the proposed model and reveal the friction reducing and anti-wear mechanisms for such pin bearings.

Analysis of damage outcome in the strength of polymer composite materials

The specific characteristics of composite materials, like carbon fibre-reinforced plastics, have been leading to their rising importance and widespread use. As these parts are normally produced in a near-net shape, secondary operations, like drilling, are necessary prior to their assembly in complex structures. It is still difficult to define a machining process that enables free-damage holes, due to the peculiar laminar nature of these materials. So, the definition of a drilling process that minimizes delamination and increases reliability in produced parts is combined with satisfactory cost and productivity is still of major importance in the composites manufacturing industry. In this paper, two sets of unidirectional coupons from plates with carbon fibre as reinforcement and epoxy resin as matrix are drilled using five different drilling tool strategies and two feed rates for uneven damage extension. One of the strategies is the use of a pre-drilling option. Then the delamination is assessed using enhanced radiography and, finally, three diverse mechanical tests are performed on the resulting coupons: three-point bending, four-point bending and pin bearing. The results allowed establishing and modelling, with the help of statistical tools, the relations between the damaged area caused by drilling and the material’s mechanical resistance. The three-point bending resistance does not vary greatly with the damage area. On the other hand, the bearing resistance and the four-point bending resistance decrease with the increase of the damaged area.

Evaluation of lubrication performance of crank pin bearing in a marine diesel engine

In this study, the lubrication performance of the crank pin bearing in a marine two–stroke diesel engine is evaluated to investigate the adhesional failure on the crank pin bearing. A numerical algorithm for the lubrication analysis considering motion analysis of the crank pin system is developed. The film pressure and thickness for three clearances and three lubricant temperatures are calculated. The results show that the lubricant temperature has a higher effect on film thickness than clearance. In terms of the film parameter, the operating condition that can result in solid–solid contact is investigated. We also suggest the desirable operating conditions of clearance and lubricant temperature to prevent the solid–solid contact.

Modeling and Analysis of the Tribological Evaluation of Bearing Materials under the Influence of Nano Based Marine Lubricant Using D-Optimal Design

The journal bearing is considered to be an important element of all rotating machinery. The journal and bearing are separated by a thin film lubricating oil, thus preventing metal-to-metal contact. In general, the journal bearing is a significant tribological component next to the piston ring-cylinder liner tribo pair in any of the marine diesel engines. The friction and wear of the journal bearing system is reduced by proper lubricating oil. The usage of fuel oil was considerably increased due to the rapid development in marine diesel engine which increases the operating cost. The power of the marine diesel engine is greatly improved by reducing frictional power which in turn rely on the tribological behavior between bearing materials and lubricants combination. In the present study, Response Surface Methodology (RSM) based D-optimal design was used to estimate the tribological behavior of various journal bearing materials (Bronze, AlSn40 and White metal) under the influence of nano based marine lubricants (SN 500 base oil). The pin on disc tribometer was used to estimate the frictional and wear characteristics of the various journal bearing materials lubricated with SN 500 base oil containing various concentrations of nano CuO. The experiments were conducted by selecting a various load and speed as numerical factors and journal bearing materials/nano based marine lubricants as categorical factors to perform the tribological behavior such as frictional coefficient and specific wear rate. From the present study, it was observed that the bronze bearing material with SN 500 base oil containing 0.5 wt% nano CuO showed the minimum frictional coefficient of 0.072 and minimum specific wear rate of 1.54X10-10mm3/Nm as compared with the other bearing materials/lubricating oil combination for a sliding speed of 2 m/s and bearing load of 100 N. Additionally the scanning electron microscopy (SEM) examination was conducted to estimate the worn surfaces of the tested pin (bearing) material, and it is showed that the bronze bearing material lubricated with the SN 500 base oil containing 0.5 wt% nano CuO is smoother wear surface than the other bearing materials/lubricants combination.

Optimization of the parameters of the piston pin bearing of the tractor engine taking into account the solution of the lubrication problem

The task of the investigation is to make the model, the algorithm, the program and the results of the calculations of optimization of the parameters of the bearing sliding of piston pin of the internal-combustion engine. An approximate mathematical model of dynamically loaded bearings of a piston pin of the internal-combustion engine was built up with the account of calculation methods of the statically loaded sliding bearings. The approximate mathematical model describes the relationship of output parameters of bearings of piston pin the operational and structural factors. The model is based on the method of M.V..Korovchinskiy of hydrodynamic calculation of statically loaded sliding bearings. The solution of optimization task was performed with the help of the author’s program in MATLAB environment. The optimization was produced by using the gradient release method. At each iteration a step was calculated in the condition of minimum of the function of the independent variable. The program of the calculation is a finished product and it can be used at the designing of the bearings of sliding engines.

Lubrication and frictional analysis of cam–roller follower mechanisms

In this work, a full numerical solution to the cam–roller follower-lubricated contact is provided. The general framework of this model is based on a model describing the kinematics, a finite length line contact isothermal-EHL model for the cam–roller contact and a semi-analytical lubrication model for the roller–pin bearing. These models are interlinked via an improved roller–pin friction model. For the numerical study, a cam–roller follower pair, as part of the fuel injection system in Diesel engines, was analyzed. The results, including the evolution of power losses, minimum film thickness and maximum pressures, are compared with analytical solutions corresponding to infinite line contact models. The main findings of this work are that for accurate prediction of crucial performance indicators such as minimum film thickness, maximum pressure and power losses a finite length line contact analysis is necessary due to non-typical EHL characteristics of the pressure and film thickness distributions. Furthermore, due to the high contact forces associated with cam–roller pairs as part of fuel injection units, rolling friction is the dominant power loss contributor as roller slippage appears to be negligible. Finally, the influence of the different roller axial surface profiles on minimum film thickness, maximum pressure and power loss is shown to be significant. In fact, due to larger contact area, the maximum pressure can be reduced and the minimum film thickness can be increased significantly, however, at the cost of higher power losses.

From bench to bedside: Can the improvements in left ventricular assist device design mitigate adverse events and increase survival?

ObjectiveIn vitro tests demonstrated that the new cone-bearing configuration of the Jarvik 2000 (Jarvik Heart Inc, New York, NY) left ventricular assist device exhibits better hydraulic efficiency than the previous pin-bearing design. We investigated the long-term outcomes of patients who received the Jarvik 2000 left ventricular assist device, depending on bearing design. MethodsA retrospective review of prospectively collected data from 18 centers included in the Italian Registry was performed. From May 2008 to September 2013, 99 patients with end-stage heart failure were enrolled. Patients were divided into 2 groups according to their Jarvik 2000 suspending mechanism: Group pin included patients with pin bearings (May 2008 to June 2010), and group cone included patients with newer cone bearings (July 2010 to September 2013). The 2 groups did not differ significantly in terms of baseline characteristics. ResultsA total of 30 of 39 patients (group pin) and 46 of 60 patients (group cone) were discharged. During follow-up, 6 patients underwent transplantation, and in 1 patient the left ventricular assist device was explanted. The cumulative incidence competing risk of the entire cohort for noncardiovascular-related death was 28% (20%-40%); the cumulative incidence competing risk for cardiovascular-related death was 56% (42%-73%): 71% in group pin versus 26% in group cone (P = .034). The multivariate analyses confirmed that the pin-bearing design was a risk factor for cardiovascular death, along with Interagency Registry for Mechanically Assisted Circulatory Support class. Right ventricular failures and ischemic and hemorrhagic strokes were significantly higher in group pin. ConclusionsPatients with the new pump configuration showed a better freedom from cardiovascular death and lower incidence of fatal stroke and right ventricular failure. Further studies are needed to prove the favorable impact of pump-enhanced fluid dynamics on long-term results.

An Investigation on the Pin Bearings’ Optimization of a Hermetic Reciprocating Compressor

A hermetic reciprocating compressor is the most energy consuming component of the refrigerators. Therefore performance improvement studies of the compressor play an important role to reduce overall energy consumption of the refrigerators. Design of bearings is one of the major study areas influencing reciprocating compressor performance.In this study crank pin and piston pin bearings in hermetic compressor applications are investigated and optimized. The effect of operating conditions, bearing offset between crank pin and piston pin, bearing clearance and bearing location along the shaft on the friction loss were investigated and optimal bearing designs were developed.Efficiency measurements of the compressor showed that the improved crank pin and piston pin bearing designs provide up to 3.8% increase in the COP as a result of reduction in mechanical loss that is significantly influenced by the length of the bearings, bearing location along the shaft and operating conditions.