Rocker Arm Research Articles

Method to examine how geometry affects the release and retention of alpine touring boot-binding systems

ObjectivesDevelop a method to examine the effects of component geometry and force-deflection on the release process of Tech/Pin alpine touring (AT) ski boots and bindings. Design and methodsFor seven AT boots, we measured the critical geometric dimensions of the metal inserts at the toe region of the boots. Binding geometry (including the pins and rocker arms) and the force-angular deflection curves of typical AT bindings were measured. A kinematic model was derived to predict the contact force between the metal inserts of the AT boots and the pins of the AT bindings, dependent on angular displacement of the binding rocker arms. By combining the kinematic model, the force-angular deflection curves, and moment equilibrium, we determined the force and binding rotation angle needed to release the AT boot in a direction normal to the ski. ResultsThe metal AT boot insert geometry and AT binding pin geometry and dimensions can affect significantly the contact states and kinematics of release. Two load-deflection curves of similar peak loads can result in significantly different maximal forces and angles to release the binding, even when the geometry and dimensions of the binding pins and boot inserts remain unchanged. ConclusionsThe geometry and dimensions of the binding (pins and rocker arm) and the boot inserts define the kinematics of the binding release. The model can be used to test the effects of varying parameters on the release and retention characteristics of Tech/Pin boot-binding systems to optimize the release and retention characteristics.

Optimum design and 3D printing of a rocker arm of 4 cylinder Engine Using FEA

Rocker arm is vital component in valve actuating mechanism of an IC engine. [2] There is research is going on in industries for optimum design i.e. reduction in weight and increase in strength. Also failure of rocker arm is major concern, so in this project we have modeled the rocker arm in CAD software and done FEA analysis of the same model for different materials.[5][6] After that we have taken better material for modification to get optimum results, in this case we have taken structural steel material.

Reinforcement Learning control of an onshore oscillating arm Wave Energy Converter

The paper discusses the application of Reinforcement Learning to the control of an onshore Wave Energy Converter (WEC). The proposed WEC features a simple and low-cost architecture. It is characterized by an oscillating floating rocker arm which moves a four bar linkage in the vertical plane. A mechanical rectifier, based on two one-way clutches and a multiplier gearbox, transforms the low speed oscillating motion of the four bar into a higher-speed unidirectional rotation of the electrical generator. The dynamic model of the WEC, based on multibody approach and Linear Wave Theory, is presented. Then a Reinforcement Learning (RL) algorithm, a Q-learning method, is applied to dynamically adjust the generator speed-torque ratio as a function of the sea state. Simulation results show the effectiveness of this model-free adaptive control in tuning the system in order to maximize the generated power. Starting from a simple monochromatic model of the sea, the presented approach is verified according to sea conditions of increasing complexity, and finally to long term time series, obtained from measurements of real sea states in the considered geographical region. The tuning of the hyper-parameters of RL algorithm with respect to the speed of convergence and optimality of generated power is also discussed.

Influence of the Clearance of the Transmission Mechanism of the Transmission Characteristics

The transmission mechanism is composed of a bearing cover, a rocker arm cover, a rocker arm, a shaft sleeve, a sleeve, a bushing, and a bearing. For a small space and weak rigidity servo drive mechanism, its clearance has a greater impact on static servo characteristics such as swing angle response and loop width. In this paper, the clearance of the transmission mechanism and the play clearance of the bearing are analysed, and the influence on the servo characteristics is obtained.

Technology of steel jackets load-out in deep-water offshore platforms from the barge

Currently, great attention is paid to the development issue of the shelf’s fuel and energy resources foremost in the oil-gas fields of the Caspian Sea. The problem solution requires the studying of great majority of scientific-technical issues. One of the significant problems is the lead-out of steel jacket from the offshore platform as a major element of oil-gas field hydro-technical facilities meant for the operation in the deep water. The calculations for the execution of operations with steel jacket of deep stationary platform from the block with the detailed chara- cteristics by the mass and gravity center coordinates alongside line data have been carried out with “SACS” and “STAAD.PRO” software programs. The steel jacket is pushed astern with the push-pull equipment on the barge. Due to the shift of gravity centre the jacket changes the trim in the stern. Through the elevation of trim angle brought in alignment with the friction ration between the jacket and barge, the jacket slides further itself. Herewith, the trim increases until the gravity centre of steel jacket on the barge is not in alignment with rotation centre of the large rocker arms. The studies helped to fix the position of the jacket’s gravity centre from the aft perpendicular, the trim moment, the trim of the barge, the draft with the bow and stern and the trim angle as well.

Exploitation of field assisted sintering technology (FAST) for titanium alloys

Field assisted sintering technology (FAST), also known as spark plasma sintering (SPS), is increasingly utilised to process powders/particulates of engineering alloys and metal-based composite materials. FAST is currently extensively used at laboratory scale by research institutes and universities as a rapid and cost‑effective process to consolidate powders. This includes investigating new alloy compositions and material combinations, improving established materials’ properties, and consolidating materials considered challenging/impossible through conventional sintering techniques. FAST is gaining traction for industrial applications with possible benefits as an alternative to hot isostatic pressing or conventional melt-wrought processing. FAST preform complexity is improving and near-net-shape components are becoming a possibility. Demonstrator components for the aerospace and automotive sectors, including aeroengine blades, brake callipers and rocker arms, have been produced from titanium alloy powders. FAST has also been demonstrated as an effective intermediate step for consolidating a range of feedstocks, including recycled materials, into shaped billets that can be further processed to refine shape and/or properties. Hybrid processes such as FAST‑forge and FAST‑DB have been developed that can produce affordable titanium components with forged properties. This paper presents the current status, emerging developments, and challenges of FAST for titanium-based powders and particulates.

ПРИМЕНЕНИЕ ДИАГРАММЫ ПАРЕТО ДЛЯ ОЦЕНКИ ВНУТРЕННИХ ПОТЕРЬ ПРИ РЕМОНТЕ ДВИГАТЕЛЕЙ

In the repair industry, when restoring the operability of machinery and equipment by eliminating failures and extending operational life, discrepancies may occur resulting in internal losses detected during the testing phase of repaired machinery, equipment and units. When assessing internal losses from defects in repair production, it is advisable to apply the Pareto chart, which allows clearly detecting the main troubles, and, based on this, identify the causes of discrepancies and develop measures to reduce the risk of their further occurrence. The authors recommend applying two types of the Pareto chart: by the number of defects and by the cost of discrepancy. When applied during testing of repaired KAMAZ 6522 engines to assess internal losses resulting from faults, the Pareto chart identifi ed the need to eliminate the cause of discrepancies in the oil supply mode to the valve rocker arm bearings, leaky nozzle seals in the cylinder heads and improper oil pressure in the lubrication system.

Structure optimization design of mine crawler robot with two rocker arms

Structure optimization design of mine crawler robot with two rocker arms

A feature extraction method based on composite multi-scale permutation entropy and Laplacian score for shearer cutting state recognition

In the field of coal mining, accurate cutting state recognition of shearer is the basis and premise for achieving automatic coal cutting. In this paper, a novel shearer cutting state recognition method is presented based on composite multi-scale permutation (CMPE), Laplacian score (LS) and fly optimization algorithm-based support vector machine classification (FOA-SVM). CMPE is proposed to overcome the shortcomings of MPE and can extract the hidden state characteristics from the vibration signals of shearer rocker arm. Some simulations are provided to select the appropriate parameter settings and prove the superiority of CMPE to MPE. In addition, LS algorithm is employed to sort the extracted features over different scales according to their importance and the sensitive feature combinations can be generated scientifically. The FOA-SVM classifier is constructed to achieve intelligent recognition of shearer cutting state. Finally, some experiments are presented and the comparison results indicated that the proposed method can realize the recognition of shearer cutting state with higher accuracy than the existing methods.

Novel Spring-Buffered Variable Valve Train for an Engine Using Magneto-Rheological Fluid Technology

Vehicle manufacturers have been attempting to increase engine efficiency and decrease pollution through various methods. Variable valve actuation technology is one of these methods. Several mechanisms have been established already and have been used to develop this technology. However, these systems have common problems such as complex design, large volume, low response rate, and high-energy consumption. In this study, a novel variable valve actuation device that is compact and requires less energy was developed using magnetorheological (MR) fluid technology. The main components used in this device are an MR valve, passive buffer spring, cam, and rocker arm. This study was divided into three parts. First, an MR valve train was designed. This valve train can be constructed easily, and has fewer hydraulic and mechanical components and consumes less energy than other technologies. Second, the magnetic plate block design was optimized to obtain the required control force at optimal volume and energy. Finally, dynamical simulations pertaining to the springs and the structure were executed to analyze the dynamic condition of the valve. The simulation results indicated that the proposed MR valve could effectively provide functions of variable valve timing and variable valve lift by dynamically controlling the external current in the magnetic coil.

Simulating the anchor lifting maneuver of ships using contact detection techniques and continuous contact force models

Designing the geometry of a ship’s hull to guarantee a correct anchor maneuver is not an easy task. The engineer responsible for the design has to make sure that the anchor does not jam up during the lifting process and the position adopted by the anchor on the hull is acceptable when it is completely stowed. Some years ago, the design process was based on wooden scale models of the hull, anchor and chain links, which are expensive, their building process is time consuming and they do not offer the required precision. As a result of this research, a computational tool to simulate the anchor maneuver of generic ships given by CAD models was developed, and it is proving to be very helpful for the naval engineers. In this work, all the theory developed to simulate anchor maneuvers is thoroughly described, taking into account both the behavior of the anchor and the chain. To consider the contact forces between all the elements involved in the maneuver, a general contact algorithm for rigid bodies of arbitrary shapes and a particular contact algorithm for the chain links have been developed. In addition to the contact problem, aspects like the dynamic formulation of the equations of motion or the static equilibrium position problem are also covered in this work. To test the theory, a simulation of the anchor lifting maneuver of a ship is included as a case study. In spite of the motivation to develop the theory, the algorithms derived in this work are general and usable in any other multibody simulation with contacts, under the scope of validity of the models proposed. To illustrate this, the simulation of a valve rocker arm and cam system is accomplished, too. The computational and contact detection algorithms derived have been implemented in MBSLIM, a library for the dynamic simulation of multibody systems, and MBS model, a library for the contact detection and 3D rendering of multibody systems.

Failure Analysis with Material Variations in Rocker Arm using Finite Element Method

Rocker arm is one of the important components in an internal combustion engine. The rocker arm is driven by a camshaft which functions to push and open the inlet and exhaust valves. This allows fuel and air to be drawn into the combustion chamber during suction steps and exhaust steps. During the working process the rocker arm receives a force from the valve due to the valve spring-back force, so that at one time the rocker arm has a failure of both fatigue and component cracks. In this article the material used is titanium alloy which is usually used for racing vehicles, the method used for testing is FEM. The maximum stress value in red is 227.74 MPa. The maximum deformation is 0.28267 mm, while the result of the crack test is the largest SIFS (K) value in the horizontal crack, which is -65.869 MPa.mm0.5. Maximal J-Integral is found on horizontal crack that is equal to 0.083512 mJ/mm2. From the results above the rocker arm crack occurs due to design errors and material failure

Analysis of Rocker Arm Failure on Diesel Engines Using Finite Element Method

Rocker arm is a reciprocating lever that is used as a tool for internal combustion of the engine to transfer the pushrod movement to the valve stem. Finite Element Method (FEM) uses ANSYS Workbench software to predict stress, deformation and fracture that occurs in the rocker arm hole with two loading models. Rocker arm design using Autodesk Inventor Software and the material used is gray iron cast. The force inputted to the simulation is 550 lbs equal to 2446.52 N. The simulation results show that the equivalent stress, main stress, and maximum shear stress on the loading model 1 are higher than the load model 2. For deformation the value is very low because of the brittle material properties, including the crack simulation test cannot produce J-Integral values and stress intensity factors (K1).

Analysis of the effect of load application eccentricity on the stiffness of supports consisting of stack of elements

During the removal of building deflections, temporary supports, consisting of a stack of repeatable elements, are used. Hydraulic jacks which force the vertical displacement of the building are used, as well. Depending on the phase of deflection removal, the entire weight of the building, or part thereof, is rested on temporary supports. As a consequence of inaccuracies in the installation of a stack of elements, the building weight is transmitted onto supports in an eccentric manner. In addition, the supports are loaded with horizontal forces. The forces result from the wind load, from kinematic excitations of non-axially installed jacks, from 2nd order deformations of supports and from exceptional loads. Deformations in the vertical direction, with a positive sign, occur due to the activity of the eccentric load and horizontal forces in the supports. However, the unbounded hexagonal elements forming the stack are unable to transmit the tensile stresses. As a consequence, the stiffness of the supports depends on the load. The stiffness of temporary supports in the horizontal direction was analysed considering the existence of unintended eccentricity and the horizontal load. A support model was defined for this purpose, whose material does not transmit tensile stresses. It was shown that the scheme of the support is changing depending on the application eccentricity of the vertical load and on the horizontal load value. Eight schemes were distinguished, which may be executed by a support. It was found that if the eccentricity and the horizontal load value are increased, this will decrease the support stiffness. This stiffness varies from zero, when a rocker arm is the support scheme, to the maximum value that is corresponding to the stiffness of cantilever rod. The analysis is limited to stocky supports by assuming that the load is much smaller than critical. Moreover, the influence of the support’s vertex displacement on the eccentricity was not taken into account.

A Predictive Maintenance Method for Shearer Key Parts Based on Qualitative and Quantitative Analysis of Monitoring Data

Appropriate predictive maintenance is critical to shearers under poor working conditions to prevent major safety accidents and casualties. A predictive maintenance method for shearer key parts based on qualitative and quantitative analysis of monitoring data is proposed. Firstly, a high-fidelity model and hyper-realistic behavior simulations of the shearer key parts are implemented based on offline monitored data and online monitoring data, the obtained position, posture, trajectory and other information can be used for qualitative analysis. Subsequently, an autoencoder (AE) combined with a deep bidirectional gated recurrent unit (bi-GRU) prediction model is constructed to predict the RUL based on online monitoring data for quantitative analysis. The adjusted_R 2 value obtained for the deep bi-GRU model was 0.9916, determined in a model-accuracy verification test. Finally, taking the rocker arm of shearer as an example, its working status is visualized using digital mirror from physical space to virtual space, and then its RUL is predicted based on the AE bi-GRU prediction model. The decision-making that guides predictive maintenance can be obtained based on the synthesis of qualitative and quantitative analysis. The application test results demonstrate that the proposed method can be effective for improving the intelligence of predictive process and the accuracy of predictive results.

Finite element analysis of the vertical roller mill based on ANSYS Workbench

By using of element analysis software ANSYS Workbench, the static analysis of lower rocker arm and column, and the modal analysis of column are carried out. The three-dimensional models of lower rocker arm and column were imported into the ANSYS Workbench for meshing. The loads and constraints were imposed on the meshed model to solve for the stress and deformation. The contour plots of stress and the total deformation of the lower rocker arm and column indicate that the structure meets the design requirements in strength and stiffness, which verifies the reliability of the structure. Through the modal analysis of column under free and constrained states, the first eight natural frequencies and vibration modals under free and constrained states are obtained, which can intuitively reflect the dynamic characteristics of the column itself, help to avoid structural resonances in engineering applications, and provide a theoretical basis for the optimisation design and fault detection of the column.

Finite element analysis of the vertical roller mill based on ANSYS Workbench

By using of element analysis software ANSYS Workbench, the static analysis of lower rocker arm and column, and the modal analysis of column are carried out. The three-dimensional models of lower rocker arm and column were imported into the ANSYS Workbench for meshing. The loads and constraints were imposed on the meshed model to solve for the stress and deformation. The contour plots of stress and the total deformation of the lower rocker arm and column indicate that the structure meets the design requirements in strength and stiffness, which verifies the reliability of the structure. Through the modal analysis of column under free and constrained states, the first eight natural frequencies and vibration modals under free and constrained states are obtained, which can intuitively reflect the dynamic characteristics of the column itself, help to avoid structural resonances in engineering applications, and provide a theoretical basis for the optimisation design and fault detection of the column.

KINEMATIC SYNTHESIS AND POWER ANALYSIS OF CONVEYOR BELT FORM REGULATION MECHANISM

For the rational design and operation of the upgraded equipment, it is necessary to investigate the operation of the mechanism for regulating the shape of the belt cross-section, to determine its geometrical parameters at which productivity will be maximum. In order to increase work efficiency and expand the functionality of belt conveyors during the transportation of both bulk and piece goods the conveyor, containing a device for quickly adjusting the shape of the cross section of the tape is designed. The middle roller with supports is fixed on the rigid frame of the conveyor and pivotally connected to external rollers, which in turn are fixed to the free ends on the ropes. The flexible rope suspension is mounted on lever devices, allow them to move branches in the cross section of the conveyor. This design allows to expand the possibilities of transporting various types of goods by creating for them the best operating conditions. A kinematic synthesis of the mechanism has been carried out, the forces that arise in kinematic pairs have been determined, and recommendations have been formulated for designing a mechanism for regulating the shape of a conveyor belt. It was established that the dimensions of the links decrease with increasing stroke of the leading link; the dimensions of the links decrease with increasing both the angle of inclination of the rocker arm in the lower position and its span; parameters of the compact tape changing mechanism are defined. For each structural group of the mechanism, force analysis has been carried out; its purpose is to determine the geometrical dimensions of the mechanism, at which the effort with which it will be necessary to move the control element will be the smallest. In order to design a mechanism for regulating the shape of a conveyor belt with the smallest overall dimensions and lesser driving force, it is necessary to bring the maximum possible values to the angle of the rocker arm amplitude and angle of rocker arm inclination in the lower position. It has been determined that the smallest force that must be applied to the device for quickly adjusting the cross-sectional shape of the belt will have a mechanism with a maximum swing arm angle of 42 0 and a greatest angle of inclination of the rocker arm in the lower position 30 0 .

Effects of droplet formation patterns on the atomization characteristics of a dust removal spray in a coal cutter

To improve the coverage of an external spray in a coal cutter and enhance the coal dust capture efficiency, the atomization characteristics of a dustproof spray were investigated using a self-constructed experimental system by considering different droplet formation patterns. In addition to the droplet diameter, the spray solution consumption, droplet number density and atomization angle were used to more comprehensively analyze the effects of spray pressure and nozzle structure on the atomization characteristics. It was found that the spray field formed by a nozzle with a 1.5 mm outlet diameter and a spray pressure of 5 MPa, had the optimal atomization characteristics, i.e. the droplet diameter was not significantly reduced over 5 MPa, while the solution consumption was optimal (7.69 L/min) at an outlet diameter of 1.5 mm. Droplet diameters were slightly reduced as the solution surface tension decreased. A novel nozzle distribution device, with two nozzles (the optimal distance between them was 15 cm), was designed and installed on the rocker arm of a coal cutter, enhancing the coverage of the dust removal spray. Field application verified that compared to a traditional spray, the total dust and respirable dust control efficiency of the optimized spray field were enhanced by over 8%, effectively improving the working environment in the underground coal mine.

A sensing identification method for shearer cutting state based on modified multi-scale fuzzy entropy and support vector machine

Accurate identification of shearer cutting state is a prerequisite for achieving safe and efficient production in coal mines. In this paper, a novel state diagnosis method is put forward based on modified multi-scale fuzzy entropy (MMFE) and support vector machine (SVM). On the basis of multi-scale entropy and fuzzy entropy, MMFE is designed to obtain stable and accurate estimation for short time series over a range of scales. Therefore, MMFE is employed to extract the feature information of vibration signals of shearer rocker arm and the complexity of time series can be reasonably embodied through some simulation analysis. Besides, the Fisher score (FS) method is utilized to sort the obtained features according to their importance and the first five features with the most important information are selected as the feature vectors. Subsequently, an improved fruit fly optimization algorithm (IFOA) is presented to optimize the parameters of SVM and the IFOA–SVM based multi-classifier is constructed to fulfill an automatic state identification. The experiment results indicate that the proposed state identification method is outperforming others and can effectively distinguish different cutting states of shearer with different operation conditions.