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Internal combustion engines have been a major contributor to air pollution. Replacing these engines with electric propulsion systems presents significant challenges due to different countries' needs and limitations. An active, purely mechanical solution to the problem of irregular torque production in an alternative internal combustion engine is proposed. This solution uses an actuator built on a camshaft and a spring, which stores and returns energy during the engine operating cycle, allowing torque production to be normalized, avoiding heavy flywheels. Designed for control throughout the engine's duty cycle, this system incorporates a cam profile and a spring mechanism. The spring captures energy during the expansion stroke, which is then released to the engine during the intake and compression strokes. Simple, lightweight, and efficient, this system ensures smoother and more consistent engine operations. It presents a viable alternative to the heavy and problematic dual-mass flywheels that were introduced in the 1980s and are still in use. This innovative approach could significantly enhance the performance and reliability of alternative internal combustion engines without notable energy losses. [ABSTRACT FROM AUTHOR]

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The article presents the design of Complibot, a robot with a novel gripper for pipe climbing. The mechanism of the gripper involves the use of a bistable buckled beam, which is a type of bistable compliant mechanism. The bistable buckled beam in the gripper is alternately actuated between its gripped and ungripped states using a camshaft and lever mechanism, which is powered by a single DC motor. The design parameters associated with the gripper are obtained both experimentally and numerically. A proper selection of design parameters helps in the efficient functioning of the gripper. After the design of the gripper, two such grippers are fabricated and attached to each other by two stepper motor-driven lead screws to make a pipe climbing robot with inchworm locomotion. The mobility of the robot is controlled by an Arduino Uno microcontroller after the electronic components have been integrated. Finally, Complibot is subjected to a series of tests to establish its maximum load-carrying capacity when climbing a polyvinyl chloride (PVC) pipe. Complibot is found to perform satisfactorily without slipping while climbing a PVC pipe with a diameter of 105–115 mm, a velocity of 0.2 m/min, a power consumption of 18.58 W, a maximum load-carrying capacity of 114.64 N, and a payload to weight ratio of 0.52. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of the induction heating process of a camshaft in a marine diesel engine. A three-dimensional finite element model for dynamic induction heating is established using the finite element method of multi-physical field coupling, aiming to investigate the temperature uniformity of the cam during this process. Three elements are analyzed in this study: the moving speed, the gap between the induction coil and the workpiece, and the width of the induction coil. These factors allow for an analysis of the temperature distribution in the thickness direction and contour line direction of the cam under various conditions. On this basis, an equivalent parameter about the temperature uniformity in the thickness direction of the cam is proposed to guide the selection of the camshaft induction heating process parameters. [ABSTRACT FROM AUTHOR]

Due to their importance in many mechanical applications, Cams was the subject of many researches regarding the improvement strength to withstand dynamic contact stresses and wear based on cam geometry modifications and follower variables. This work assesses the effect of uniform acceleration cam variables on the induced dynamic forces and camshaft dynamic load factor. The equation of motion is formulated based on Newton's second law taking into account the geometry of cam lobe and follower motion to evaluate the dynamic contact force during the course of action in terms of camshaft angular speed and time. Theoretical analysis contains two parts these are; the evaluation of static and dynamic contact stresses based on Hertz and dynamic load factor formulation for single element camshaft as a continuous simply supported beam based on Euler- Bernoulli beam theory. FEM has been adopted to simulate the static and dynamic contact stresses and dynamic deflection for multi elements camshaft and to verify the result of theoretical solution. Results show that the increasing of damping ration and spring stiffness has appositive effect on dynamic load factor reduction while the increasing of follower mass has negative effect on dynamic load factor reduction. [ABSTRACT FROM AUTHOR]

The influence of the type (grits from an ingot, a quick-cooled plate) and size of the fraction of a modifier and the REM content on the structural of camshaft castings made of ChVG40 vermicular graphite iron (VGI) are studied. [ABSTRACT FROM AUTHOR]

The existence of friendly programming environments, which allow the transposition of models developed for different mechanical systems into numerical procedures, easy to access, make it necessary to develop models of mechanical systems used in industry. In this work, we propose to do this for an internal combustion engine. The offered model allows the unitary solution of problems of this type, which involves the calculation of the forces appearing in the engine elements. It offers the possibility to analyze different constructive types of engines. The model is a complex model that finally provides the forces existing in different elements of the engine as well as the developed engine torque. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper focuses on the study of the induction heating process of a camshaft in a marine diesel engine. A three-dimensional finite element model for dynamic induction heating is established using the finite element method of multi-physical field coupling, aiming to investigate the temperature uniformity of the cam during this process. Three elements are analyzed in this study: the moving speed, the gap between the induction coil and the workpiece, and the width of the induction coil. These factors allow for an analysis of the temperature distribution in the thickness direction and contour line direction of the cam under various conditions. On this basis, an equivalent parameter about the temperature uniformity in the thickness direction of the cam is proposed to guide the selection of the camshaft induction heating process parameters.

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Camshaft usually vibrates violently in swing grinding due to its complex contour, and the damping performance of device directly affects the surface quality of camshaft. Aiming at the problem that the traditional vibration damping device has been forced by installation constraints and it is difficult to control the vibration frequency in a specific range, the vibration damping structure for camshaft journal and grinder tailstock based on the local resonance bandgap (LRBG) mechanism is carried out in this paper, respectively. On the basis of the vibration data obtained from the experimental analysis, the corresponding finite element model is established, the resonant bandgap characteristics and the bandgap influence rules of each system structure are discussed. Comparing the damping performance of the system before and after vibration reduction based on the optimized vibration reduction model obtained from the influence rules, the vibration reduction effect of the local resonance (LR) structure designed in this paper is very significant. Compared with the homogeneous structure, the damping performance at the journal and tailstock is improved by 31.6% and 89.3% respectively. The design achieves the goal that controlling large wavelength with small size, which provides a good application prospect for the local resonance phononic crystals (LRPCs) in the vibration reduction field of camshaft swing grinding. [ABSTRACT FROM AUTHOR]

Problem. The most high-precision parts of the car engine are camshaft and crankshaft, parts that require two-sided processing of the end surfaces: piston pins, valve springs. Traditional processing methods are used in their manufacture and repair. Therefore, taking into account the large volumes of car production, the improvement of existing and development of new processing methods is very important. Goal. The purpose of this work is the analysis and improvement of existing methods and the implementation for new ones of processing the specified parts to increase the productivity and accuracy of their processing. Methodology. The processing of support necks and cams is expedient to be carried out in one installation during deep high-speed grinding with crossed axes of the circle and camshaft due to stabilization of the cutting depth and feed along the contour with uneven rotation of the part. The method of high-speed milling of camshaft cams with crossed axes of the tool and parts on CNC machines is also promising. Root and connecting rod necks of crankshafts can be processed in one installation by deep high-speed grinding with crossed axes of the circle and the part due to stabilization of the depth of cutting and feed along the contour with uniform rotation of the part. For end surfaces, it is possible to introduce single-pass processing on double-sided end grinding machines with oriented grinding wheels with calibration areas. Results. The obtained results indicate a 25-30% increase in productivity and processing accuracy of the specified parts. Originality. It is used when processing the effect of the intersection of the axes of the tool and the part and carrying out a special correction of the tool, which allows to obtain a calibration area. Practical value. The proposed methods improve the parameters of accuracy, roughness and productivity of processing, which is an important scientific and practical task, whose solution will allow to increase the service life of car components and assemblies, reduce the cost of their production, and raise the level of competitiveness of products and services.

The generation of grinding cracks during the grinding process will adversely affect the service performance of the workpiece and even cause the workpiece to be scrapped. However, the microscopic formation mechanism of grinding cracks is still unclear at present. In this regard, the morphologies of grinding cracks on the surface of the cam were characterized, and the initiation and propagation behaviors of grinding cracks were analyzed from the perspectives of element composition, micro-structure and surface work hardening. Based on the experimental results and analysis, the generation mechanism of grinding cracks is clarified, and measures to prevent the grinding cracks are proposed. [ABSTRACT FROM AUTHOR]

Arbomex S.A. de C. V. is one of the largest worldwide manufacturers of ductile cast iron camshafts, produced by means of the phenolic urethane no-bake sand mold casting method and cold box by stack molding technology. As a result of the development of high-strength ADIs, low alloyed with vanadium, for camshaft manufacturing, previous results were published on the as-cast process and the austempering heat treatments applied to the camshafts. In the present work, camshafts of ADIs, low alloyed with 0.2 and 0.3 wt.% V, were produced at austempering temperatures of 265 and 305 °C. The performance of the new camshafts was evaluated by wear testing to ensure the function and durability of the camshafts by means of the block-on-ring wear test and a valve train system to evaluate the volume loss of material removed and the geometrical changes of the camshaft, respectively. The ADIs heat treated to 265 °C showed a microstructure constituted of fine ausferrite that aided in obtaining the highest wear resistance in the block-on ring wear test. No wear or pitting evidence was detected on the camshaft lobes and roller surfaces after the OEM test protocol during the electric spin ring test at low and high conditions for the ADI alloyed with 0.2 wt.% V heat treated at 265 °C. [ABSTRACT FROM AUTHOR]

Large grinding contact area tends to generate high grinding heat, resulting in the tolerance out of residual stress and influencing the service life of the camshaft. In the swing grinding process, a narrower grinding wheel makes pure rolling motion along the cam contour, and a periodic reciprocating motion along the sand wheel axis is utilized, which is conducive to reducing the grinding contact zone and diminishing the tolerance out problem of residual stress. However, the influence of swing grinding parameters on the residual stress variations of camshaft is not clear at present. In this study, the ABAQUS user subprograms of DFLUX and DLOAD were developed to simulate the grinding heat and the grinding force in swing grinding processes, and the residual stress finite element model under multi-field coupling was established to discuss the influence of process parameter on the residual stress distribution. The verification experiments were carried out by the X-ray diffraction method; the results showed that the simulation model is reasonable and reliable, and the error between the finite element model and the testing results is less than 16%. Increasing the swing frequency and swing amplitude can play an auxiliary role in the machining; the swing grinding can increase the residual compressive stress by at least 20.9% when compared with the ordinary plunge grinding. The residual stress in the camshaft after the swing grinding is linearly related to the initial residual stress before the grinding. The study can provide a reference for the parameter optimization of swing grinding process. [ABSTRACT FROM AUTHOR]

In conventional grinding (CG), camshafts with wide profiles suffer from poor quality and low efficiency because the large contact area between the grinding wheel and camshaft profile limits the diffusion of grinding temperature, leading to burning defects. Swing grinding (SG) can mitigate these problems as it involves a reciprocating motion along the axis of the grinding wheel; however, the lack of understanding of machined surface topography has restricted its application. Therefore, in this study, a surface topography prediction model was proposed that based on the distribution, shape, and trajectory of grains. The model was verified through experiments, and the mean error was 12% for Rax and 9% for Ray; the roughness along the grinding direction was Rax, and the roughness along the vertical grinding direction was Ray. Compared to CG, SG has a 3% lower Ray. The influence of the wheel speed and feed rate in SG is consistent with that in CG. Rax exhibited a periodic trend with an increase in the swing amplitude and a monotonically decreasing trend with an increase in the swing frequency. The variation trend of Ray with the swing amplitude was the same as that of Rax. Furthermore, Ray exhibited a nonlinear increasing trend with an increase in swing frequency. [ABSTRACT FROM AUTHOR]

Induction hardening (IH) is a popular choice for automotive components such as camshafts for its ability to harden portions of a component selectively. The camshaft will contact the tappet, connected to the rocker arm, to open and close the valve whenever the engine is running. This contact between the camshaft and the tappet causes wear on the camshaft surface. IH of the camshaft is required to improve wear resistance and service life, as well as core elasticity to absorb high torsional stresses. It is known that studies about IH on camshafts are still very limited. This study aims to determine the effect of the induction hardening and tempering treatment on the mechanical properties of the camshaft made of HQ 705 steel. The induction hardening carried out in this study uses different parameter settings such as heating time and output current. The camshaft specimen is hardened by static induction and then quenched in oil. The specimens are tempered after induction hardening with different temperatures and holding times to adjust the hardness level and reduce brittleness. Hardness, macro photographs, micrograph, and wear tests were conducted to determine the mechanical properties of the camshaft specimen after the induction hardening and tempering process. This study indicates that induction hardening with an output current of 747 A for 15 seconds followed by tempering at 150 °C for 15 seconds on specimen 1 produced the best mechanical properties. On the surface of these specimens found more martensite content while there was no microstructural change on the inside. The surface hardness of these specimens is 44 HRC (Rockwell C Hardness), while the inside is 26 HRC. Meanwhile, specific wear decreased by 45.45%.

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Featured Application: The rotation motion of the valves is important because it ensures the good functioning of the gas exchange process and a longer life for the valve, the valvetrain mechanism and the engine, respectively. The results obtained in the study can be applied easily in engineering practice, particularly in the manufacture of internal combustion engines. The valve performs an alternating translational motion along its axis of symmetry, which is accompanied by a rotation about its own axis, possibly due the valve body's cylindrical geometry and due to the conjugate element, the guide, which is also a cylindrically shape body. By ensuring this rotational motion of the valve, a number of advantages are obtained, mainly related to the increase of the operating period of the valve and implicitly of the engine. Following the critical analysis of the current state of research on the valvetrain systems and the rotational motion of the valves, the advantages and the disadvantages of valve rotation during engine operation were established. To this end, it has been established that, in addition to the theoretical approach to the problem, it is necessary to create a virtual model of the valvetrain mechanism to do a thorough analysis of the problem. Based on the model, the influence of the camshaft speed, temperature and lubricating oil pressure were monitored by changing the coefficient of friction, the influence of the cam position relative to the tappet and the influence of the valve spring. In this paper, the authors want to determine the rotational motion characteristics of internal combustion engine valves and to suggest measures that can be taken to ensure valve rotation at all operating modes without the use of auxiliary devices for generating rotational motion. [ABSTRACT FROM AUTHOR]

Mekanis sebuah katup sepeda motor yang menggunakan double over head camshaft (DOHC) memiliki kelebihan performa mesin yang lebih ringan, terutama pada putaran tinggi. Suzuki Satria Fu 150 merupakah salah satu sepeda motor yang menggunakan DOHC. Penelitian ini menfokuskan pada karakteristik dinamik pada camshaft Suzuki Satria Fu 150 terhadap sebelum dan setelah pemasang needle bearing, dengan menggunakan metode bump test. Respon getaran diukur dengan menggunakan sensor accelerometer pada 48 titik, dengan rentang frekuensi adalah 1 – 20 kHz, yang dihubungkan dengan alat FFT analyzer. Hasil penelitian didapatkan modus getar global apabila posisi cover terpasang dan terlepas. Frekuensi pribadi yang terjadi pada 4 Hz, 8 Hz, 12 Hz, 16 Hz, 20 Hz, 24 Hz, 28 Hz, 40 Hz, 44 Hz, 52 Hz, 60 Hz, 68 Hz, 92 Hz, dan 100 Hz merupakan modus getar yang terjadi ketika cover terpasang, sedangkan modus global pada posisi cover terlepas diperoleh frekuensi pribadi sebesar 4 Hz, 8 Hz, 12 Hz, 16 Hz, 28 Hz, 32 Hz, 40 Hz, 44 Hz, 52 Hz, 68 Hz, 76 Hz, 84 Hz, dan 116 Hz. Selain itu, diperoleh adanya modus getar lokal pada frekuensi pribadi sebesar 111 Hz. Dengan metode FRF diketahui frekuensi pribadi pada poros camshaft, dimana hanya muncul satu kali, sedangkan frekuensi global merupakan frekuensi yang terjadi pada poros camshaft akan muncul permukaan dengan dan tanpa cover, baik dengan bearing atau tanpa bearing. Hal tersebut merupakan hal yang harus diperhatikan pada saat pengukuran karakteristik getaran ketika motor-torak dioperasikan. The mechanic of a motorcycle valve that uses a double over head camshaft (DOHC) has the advantage of lighter engine performance, especially at high rotation. Suzuki Satria Fu 150 is a motorcycle that uses DOHC. This research focuses on the dynamic characteristics of the Suzuki Satria Fu 150 camshaft before and after installing the needle bearing, using the bump test method. Vibration response is measured using an accelerometer sensor at 48 points, with a frequency range of 1 - 20 kHz, which is connected to the FFT analyzer. The results showed that the global vibration mode is when the cover is attached and detached. Personal frequencies that occur at 4 Hz, 8 Hz, 12 Hz, 16 Hz, 20 Hz, 24 Hz, 28 Hz, 40 Hz, 44 Hz, 52 Hz, 60 Hz, 68 Hz, 92 Hz, and 100 Hz are vibrating modes what happens when the cover is attached, while the global mode in the cover position is detached, the personal frequency is 4 Hz, 8 Hz, 12 Hz, 16 Hz, 28 Hz, 32 Hz, 40 Hz, 44 Hz, 52 Hz, 68 Hz, 76 Hz, 84 Hz, and 116 Hz. Besides, there is a local vibration mode at a personal frequency of 111 Hz. With the FRF method, it is known that the personal frequency on the camshaft shaft, which only appears once, while the global frequency is the frequency that occurs on the camshaft shaft surface with and without cover, either with a bearing or without a bearing. This is something that must be considered when measuring the vibration characteristics when the piston motor is operated.

Arbomex S.A. de C. V. is one of the largest worldwide manufacturers of ductile cast iron camshafts, produced by means of the phenolic urethane no-bake sand mold casting method and cold box by stack molding technology. As a result of the development of high-strength ADIs, low alloyed with vanadium, for camshaft manufacturing, previous results were published on the as-cast process and the austempering heat treatments applied to the camshafts. In the present work, camshafts of ADIs, low alloyed with 0.2 and 0.3 wt.% V, were produced at austempering temperatures of 265 and 305 °C. The performance of the new camshafts was evaluated by wear testing to ensure the function and durability of the camshafts by means of the block-on-ring wear test and a valve train system to evaluate the volume loss of material removed and the geometrical changes of the camshaft, respectively. The ADIs heat treated to 265 °C showed a microstructure constituted of fine ausferrite that aided in obtaining the highest wear resistance in the block-on ring wear test. No wear or pitting evidence was detected on the camshaft lobes and roller surfaces after the OEM test protocol during the electric spin ring test at low and high conditions for the ADI alloyed with 0.2 wt.% V heat treated at 265 °C.

Interference joint is one of the most advanced assembly methods for camshaft. The joining force in the assembly process and the connection strength after assembly are the key aspects of the camshaft assembly system. In this paper, the mechanism of joining force and connection strength are analyzed from two aspects of elasticity and plasticity using thick-wall cylinder model. Joining and torsion experiments are done to determine the joining force and connection strength. Joining forces fluctuating increase in the joining process, which is composed by friction force Fs and shearing force Ff. Fs is 0.87 KN, and Ff is 6.23 KN when the assembly interference is 0.15mm. Joining force linear increases with the interference, and torque exponential increases with it. The empirical formulas between the torque capacity, joining force, and interference of the camshaft are provided by the experiment results. The assembly interference limit of 0.3mm is estimated for the case of this paper. Metallographic observation reveals the changes of metal flow line of the knurled tube. The top of knurled tooth turns over and an inverted triangle formed after joining process. [ABSTRACT FROM AUTHOR]

This paper presents aspects related to the quality of the camshaft. The measures that reduce the camshaft wear on internal combustion engines have been identified and classified. The authors present the use of a modern quality management tool - tree diagram. A shaft diagram has been developed which gives a suggestive picture of the measures to be applied to reduce the camshaft wear on internal combustion engines.

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The valve performs an alternating translational motion along its axis of symmetry, which is accompanied by a rotation about its own axis, possibly due the valve body’s cylindrical geometry and due to the conjugate element, the guide, which is also a cylindrically shape body. By ensuring this rotational motion of the valve, a number of advantages are obtained, mainly related to the increase of the operating period of the valve and implicitly of the engine. Following the critical analysis of the current state of research on the valvetrain systems and the rotational motion of the valves, the advantages and the disadvantages of valve rotation during engine operation were established. To this end, it has been established that, in addition to the theoretical approach to the problem, it is necessary to create a virtual model of the valvetrain mechanism to do a thorough analysis of the problem. Based on the model, the influence of the camshaft speed, temperature and lubricating oil pressure were monitored by changing the coefficient of friction, the influence of the cam position relative to the tappet and the influence of the valve spring. In this paper, the authors want to determine the rotational motion characteristics of internal combustion engine valves and to suggest measures that can be taken to ensure valve rotation at all operating modes without the use of auxiliary devices for generating rotational motion.

Different processing routes have been developed to increase the strength and hardness of camshafts for automotive applications. In this work, two carbidic austempered ductile irons (CADIs), alloyed with 0.2 and 0.4 wt% Cr, were evaluated to determine their suitability in the camshaft production by microscopy techniques and mechanical tests. The CADIs were produced at austempering temperatures of 265 and 305 °C, during 30, 60, 90, and 120 min. The microstructural characterization was carried out by optical microscopy, while Rockwell C Hardness, tensile, Charpy impact, and block-on-ring wear loss tests were evaluated for mechanical characterization from the camshaft and standard keel block. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by X-ray diffraction measurements. The process window was found in the range from 60 to 120 min, for both austempering temperatures, while the highest amount of ausferrite was obtained at 90 min. The formation of carbides was increased as the chromium content was increased. The highest hardness (49 HRC) and wear resistance (0.252 mm3) were obtained for the lower austempering temperature (265 °C, 90 min) and higher chromium content (0.4%). The highest austempering temperature (305 °C, 90 min) and lowest chromium content (0.2%) allow for obtaining the highest toughness (22.91 J) and elongation (4.2%), while the highest tensile strength (1027 MPa) was obtained for the CADI containing 0.2% Cr heat-treated to 265 °C.

Problem. The power and speed increase of modern internal combustion engines (ICE) leads to increasing of dynamic loads in power transmissions of machine units. Analysis and suppression of dangerous oscillations require taking into account in models development technological and constructive nonlinearities, which are the main reason for a varie-ty and complexity of dynamic processes: resonances shifts, deformation of resonance curves, multivalence of oscillations, and the appearances of subharmonic regimes. The known approaches to dynamic loads analysis in power transmissions of cars with ICE do not allow explaining the nature of certain phenome-na. The means for their study are not sufficiently de-veloped. Goal. To develop the nonlinear dynamic drive model for determining causes of dangerous dynamic loads; to find parameters of the device, which lead to dynamic loads reduction. The follow-ing problems solution: modeling of gaps in gears connections; schematization of the periodic disturb-ance of a non-harmonic character; chosing the form of the mathematical description for steady dynamic processes, taking into account the features of the nonlinear drive model; chosing the effective algorithm for solving the corresponding motion equations; carrying out calculation and experimental studies to reduce the drive dynamic loads. Methodology. For study of the established dynamic processes in nonlinear models of machine units, it is proposed to use the integrated equations of the movement which are written down by means of pulse-frequency characteristics (PFC) of the linearized models: the number of the nonlinear equations is equal to number of nonlinearities. Labor input of the solution of the task practically doesn’t depend on number of freedom degrees of system that is essential to numerical algorithms of the solution of the nonlinear tasks having iterative character at the solution of problems of synthesis and optimization. The algorithm of the solution of the nonlinear integrated equations is based on an iterative method of Newton-Kantorovich of the solution of the operator equations. During the numerical implementation of the algorithm for resolving linear integrated equations on every step of iteration process, the method of quadrature formulas in pair with the idea of interpolation of a desired solution is used. Results. A nonlinear dynamical model of the camshaft drive of the fuel pump of transport diesel has been created in the form of integral equations written by using of PFC. By calculation and experimental studies it has been established that: 1) an increase in the torsion shaft diameter leads to an increase in the maximum elastic moments; 2) increasing the inertia moment of the camshaft shift the resonant oscillations into the operating range; subharmonic oscillations are possible under action of a defined load; 3) the average moment in the drive not significantly affects the maximum elastic moments; 4) the one-way outputs realization to the drive retainer does not lead to the necessary dynamic loads reduction in the drive; 5) the maximal reduction of the maximum elastic moments can be done by using a spring with 15 mm diameter, which in combination with durable gears give the necessary drive reliability. Originality. The motion integral equations for the study of steady-state dynamic processes in non-linear models of machine units, written using PFC, have a number of principal advantages over the use of traditional models in differential form: the number of equations is equal to the nonlinear elements number, therefore, the solution time of problems is practically independent from the number of freedom degrees of models. Practical value. The studies carried out have allowed establishing the mechanism of dangerous dynamic loads appearance and giving recommendations on the drive parameters change, which provides its working capacity. The proposed approach is perspective for the dynamic processes study in models with nonlinear spring linkages, the number of which is less than the number of freedom degrees.

The present paper analyzes the damage of surfaces at spots of frictional contact, namely, the friction nodes on a camshaft and the connecting rod pins of a crankshaft. The resulting wear of the monitored friction nodes reduces the technical life of the machines, which can lead to the decommissioning of the machine. Wear was assessed by measuring roughness and microhardness and by observing the microstructures of the materials. The results of the experiments show that the rotating parts displayed visible wear on the cams, as well as on the connecting rod pins. The experiments revealed that wear was caused by the heating of the material to a high temperature during the operation of the machine and that there was a gradual cooling and tempering of the material, which led to a reduction in the microhardness of the monitored object. Lower microhardness values can be a cause of greater wear of the monitored objects. When comparing the microhardness of the used and the new camshaft, the hardened layer of the new camshaft from secondary production has a significantly smaller thickness compared to worn cams, which leads to the finding of a different material quality compared to the original parts from primary production. This fact indicates that the wear of a new camshaft as a spare part can contribute to the shortening of the technical life of friction nodes.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The capacity to minimize vibrations in grinding by the selection of appropriate process parameters is a significant benefit in the process optimization of cam grinding. This paper presents survey methods to characterize and quantify the vibrations and waviness in a camshaft grinding application. First, a modal analysis was conducted to study the dynamic characteristic of a camshaft grinding machine. Then, developed methods were applied to study the influences of various parameters on vibrations in the high-speed grinding of a camshaft. Furthermore, the influence of each grinding process condition on surface waviness in high-speed camshaft grinding was studied. The results show that the vibrations and the surface waviness change with the increase of grinding depth, and an appropriate grinding wheel speed combined with a workpiece speed has, for most grinding conditions, a reducing effect on vibration magnitudes and waviness. Finally, the specific indications about the optimal grinding process parameters in terms of dynamic characteristics of the grinding machine were given, and the speed ratio=1.2 is a novel choice. [ABSTRACT FROM AUTHOR]

The article presents a tool for the synthesis of engine mechanisms based on DASY and the use thereof for designing the parameters of an experimental single-cylinder engine. The tool includes a parametric engine model based on DASY. The model will make it possible to simulate the engine thermodynamics and its mechanisms. It consists of sub-models which deal with the thermodynamics, kinematics and dynamics of the valve timing mechanism, its belt drive, and hydraulic circuit for camshaft adjustment. The methodologies of synthesis of mechanisms were used to determine the values of the calibration parameters. The parameters of the sub-models were subsequently validated by experimental data, and the values thereof are included in DASY. The sub-models were used to assemble the model of an experimental single-cylinder engine which validates the design thereof, makes it possible to optimize its parameters and predict its behavior in different simulated conditions.

• Lateral nonlinear vibration of the camshaft considering the structural clearance and load force is analyzed. • Numerical computation scheme for attractors is developed by using the Magnus expansion. • Attractors coexistence and tongue-shaped fractal basins reveal the global stability. • Bi-parameter dynamics decide the multi-parameter matching solutions for stable motion. To reveal the influence of variations in dynamic characteristics on the working performance of the camshaft, the lateral nonlinear vibration of the camshaft considering the structural clearance and load force is studied. By using the Magnus series expansion method, the response of lateral nonlinear vibration is solved, and the numerical computation scheme applied to the global evolution characteristics of attractors and their basins is developed, which solves the problems of inadequate accuracy and long-term numerical unreliability in numerical solutions and simulations. By analyzing the attractors and basins, single-parameter bifurcation, and bi-parameter dynamic characteristics, the influence of different parameters on the nonlinear dynamic characteristics of the camshaft system is revealed. The results show that as the structural clearance increases, the attraction basins of both periodic and chaotic attractors exhibit tongue-shaped fractal features, and the camshaft system changes from the coexistence of two types of period-3 attractors to chaotic attractors, which reveals the mechanism of global vibration instability of the camshaft system. In addition, when the camshaft system evolves from the flutter to forced vibration conditions, the period-doubling bifurcation behavior occurs, and the parameter ranges for stable operation of the system increase. More importantly, the bi-parameter dynamic characteristics confirm that the parameter ranges for the periodic motion of the system are enlarged when the load force increases, and there exist multi-parameter optimal matching solutions for the stable motion of the camshaft system. The research results reveal the evolution mechanism of the lateral nonlinear vibration of the camshaft, which can provide a theoretical reference for suppressing the vibration and improving the working performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

This paper presents aspects related to the quality of the camshaft. The measures that reduce the camshaft wear on internal combustion engines have been identified and classified. The authors present the use of a modern quality management tool - tree diagram. A shaft diagram has been developed which gives a suggestive picture of the measures to be applied to reduce the camshaft wear on internal combustion engines. [ABSTRACT FROM AUTHOR]

Purpose. Today the issue, connected with diesel traction remains relevant for the majority of industrial enterprises and Ukrainian railways and diesel engine continues to be the subject of extensive research and improvements. Despite the intensive process of electrification, which accompanies Railway Transport of Ukraine the last few years, diesel traction continues to play an important role both in the main and in the industrial railway traction rolling stock. Anyway, all kinds of maneuvering and chores are for locomotives, they are improved and upgraded relentlessly and hourly. This paper is focused on finding the opportunities to improve technical and energy parameters of diesels due to the development of modern control method of the fuel equipment in the diesel engine. Methodology. The proposed method increases the power of locomotives diesel engines in the range of crankshaft rotation (from idle running to maximum one). It was based on approach of mixture ignition timing up to the top «dead» center of piston position. Findings. The paper provides a brief historical background of research in the area of operating cycle in the internal combustion engine (ICE). The factors affecting the process of mixing and its quality were analyzed. The requirements for fuel feed system in to the cylinder and the «weak points» of the process were presented. A variant of the modification the fuel pump drive, which allows approaching to the regulation of fuel feed system from the other hand and to improve it was proposed. Represents a variant of embodiment of the complex system with specification of mechanical features and control circuits. The algorithm of the system operation was presented and its impact on the performance of diesel was made. Originality. The angle regulating system of fuel supply allows automating the process of fuel injection advance angle into the cylinder. Practical value. At implementation the angle regulating system of fuel supply components of the diesel engine remain unchanged It allows installing the system on diesel engines of the existing fleet of locomotives and railroad industries. The system, considered in the modeling process, has demonstrated its desirability and feasibility of practical application for diesel engines.

Study of surface quality and machining accuracy of a deep hole in the camshaft in manufacturing environment is conducted to make recommendations to eliminate emerging stress concentrators on the hole surface after machining and arising cracks while the engine is in operation.So it is important to conduct a comprehensive task-driven study to determine qualitative and quantitative values of arithmetical mean deviation of the surface roughness profile (parameter of height) and available stress concentrators, as well as to define regularities of changing accuracy parameters for deep-hole length such as deviation size, radial run-out, and geometric tolerance in cross section. A guide diameter of the drill bushing and an outer diameter of the cutting part of one-sided cut have been determined too.A camshaft casting from ductile iron HF 65-48-1 was processed in the automatic line on the machine "Hȕller" by a drill with the cutting head from the hard alloy VK6 with simultaneously rotating workpiece and tool. The drill was guided through drill bushing from solid alloy VK 15.The measurement results showed that in 53% of samples there were tears and scratches up to 0.15 mm in depth, which could serve as stress concentrators and in the process of operation encourage growth of cracks in the bulk of the camshaft material.A significantly increasing value of the radial run-out size and all six studied harmonic components show that there is a deviation of the hole axis (run) from the nominal (specified) position and faceting available with their copied (increased) values along the entire length of the hole. This is a qualitative confirmation that in processing the holes in parts made from grey cast iron, there is a mechanism of copying errors earlier available.It is found that the size of a clearance between guide diameter of drill bushing and diameter of tool gage ribbon makes 0. 150 mm and almost 3 times exceeds the recommended value.All this reduces resistance, promotes a wear of the guide elements and a gauge part of the tool. In turn, these reasons create favorable conditions for built-up edge on calibrating and cutting parts of the one-sided cuts which contribute to tears and scratches on the surface of the camshaft hole.Thus, the causes and the mechanism of appearing stress concentrators and their possible growth in the bulk of the material during camshaft operation have been defined.As the wear mechanisms of guide bushing of various drill bits are different, it is advised to settle no more than 80 processing cycles for bushing and at most 63 cycles for drills.The technological operation content on deep drilling to be made has to contain a mandatory checking of the diametral clearance between the drill bushing hole and the calibrating part of the drill, which must be of 0.055 mm at most.It is recommended to introduce a drill size m=0.26 0.39 mm in its working drawing because it is unavailable there. It allows to reduce deviation of drill cutting part from the nominal position, tool vibration, run of axis and faceting the camshaft holes.The elaborated recommendations can be used in the development of similar drilling operations.

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This work shows a sequence of numerical models for the simulation of the Presta joining process: a well-established industrial process for manufacturing assembled camshafts. The operation is divided into two sub-steps: the rolling of the shaft to widen the cam seat and the joining of the cam onto the shaft. When manufactured, the connection is tested randomly by loading it with a static torque. Subsequently, there are three numerical models using the finite element method. Additionally, a material model of finite strain viscoplasticity with nonlinear kinematic hardening is used throughout the whole simulation process, which allows a realistic representation of the material behavior even for large deformations. In addition, it enables a transfer of the deformation history and of the internal stresses between different submodels. This work also shows the required parameter identification and the associated material tests. After comparing the numerical results with experimental studies of the manufacturing process for steel-steel connections, the models are used to extend the joining process to the utilization of aluminum shafts. [ABSTRACT FROM AUTHOR]