Power Transmission Shaft Research Articles

A novel concept for multi-objective optimization of composite power transmission shafts

A novel concept for multi-objective optimization of composite power transmission shafts

Analysis of the Impact Resistance Characteristics of a Power Propulsion Shaft System Containing a High-Elasticity Coupling

In research concerning the impact resistance characteristics of ship power transmission shaft systems incorporating a high-elasticity coupling, a significant challenge lies in ascertaining the displacement compensation metrics for the high-elasticity coupling. This study constructs a finite element model of the ship power transmission shaft system with an entity equivalent model of the high-elasticity coupling. Utilizing the Dynamic Design Analysis Method (DDAM) and the time-history method, the dynamic responses of the high-elasticity coupling, the propulsion shaft system, and its critical cross-sections under explosive impact loads are analyzed. The findings indicate that the maximum impact displacement of the propulsion shafting system, as calculated by DDAM, is 22.47 mm in the vertical direction at the driven end of the high-elasticity coupling. In contrast, the maximum impact displacement determined by the time-history method is 15.23 mm in the same direction. The study corroborates the precision of the high-elasticity coupling equivalent model establishment methodology and confirms that the entity equivalent model of the power transmission shaft system with a high-elasticity coupling is capable of fulfilling the criteria for a swift evaluation of impact resistance characteristics. This provides theoretical backing for the forecasting of impact resistance performance in ship propulsion shaft systems.

In-situ microstructure monitoring during tempering of quenched AISI4340 steels using a high temperature electromagnetic sensor

AISI 4340 steels are used in applications where high strength and toughness are required, for example, in power transmission gears and shafts, aircraft landing gear and other structural components. The required mechanical properties are achieved by hot rolling and quenching and tempering (Q&T) heat treatment. For optimum process efficiency and quality control, it is desirable to monitor the microstructural development during tempering in situ, as the microstructure is directly linked to the mechanical properties. Electromagnetic (EM) sensors have been shown to be sensitive to steel microstructural changes due to the associated changes in magnetic and electrical properties. This study reports on using a high-temperature laboratory EM sensor that operates inside a furnace to assess microstructural changes that occur during tempering at 250°C for AISI4340 steel samples. The sensor operates at low magnetic field and low frequency where the signal is affected by changes in magnetic permeability due to microstructural changes. The microstructure and hardness have been characterised to correlate to the measured EM sensor signal. The results have shown that the EM sensor signal is affected by temperature and microstructural changes on the slow heating to the tempering temperature and then is sensitive to the continuing microstructure changes that occur during the isothermal hold. The results show the potential for in-situ EM sensor monitoring during heat treatment.

Contribution to the research of the possibility of application of two-parameter frequency analysis in the experimental identification of torsional vibration parameters of elastic shafts in vehicles power transmissions

During exploitation, motor vehicles are exposed to vibrational loads that lead to fatigue of users and materials of their aggregates. Therefore, vibrations must be studied even in the earliest stages of design, using mathematical models, experiments, or their combinations. In theoretical considerations, vibrations of concentrated masses are usually observed , although, with the recent development of numerical methods (especially finite element methods), attention is also being paid to vibrations of vehicle elastic systems. This usually involves idealizations, especially regarding exploitation conditions and interconnections of motor vehicle aggregates. In this paper, an attempt has been made to develop a method for identifying real vibrational loads of elastic power transmission shafts in vehicles (engine, rail, etc.) under exploitation conditions. Namely, 2D Fourier transformation was used for two-parameter frequency analysis. The possibilities of applying the procedure were illustrated on an idealized elastic torsionally loaded shaft. The conducted research showed that two-parameter frequency analysis can be used in generating torsional vibrations of elastic shafts of vehicles in laboratory conditions.

Nonlinear dynamics of flexible diaphragm coupling’s rotor system during maneuvering flight

In this paper, the flexible multi-diaphragm coupling which is used as flexible power transmission shaft of the aeroengine accessory is taken as the research object, and the coupling stiffness matrix and axial nonlinear stiffness of the diaphragms are considered in the coupling rotor system. On this basis, in order to consider the influence of aircraft maneuvering load, in non-inertial system the bending-pendular-axial coupled differential equations of flexible diaphragm coupling were established by Lagrange method. The modal characteristics of the flexible diaphragm coupling were analyzed and compared with the finite element solutions, and the correctness of model is verified. Runge-Kutta method is used to solve and analyze the influence of different maneuvering flight conditions on the vibration characteristics of the flexible diaphragm coupling. The research indicates that the coupling between diaphragm’s axial and radial stiffness leads to the right shift of resonant region, the increase of resonance peak value, and the nonlinear characteristics of amplitude-frequency curve such as jump and multi-value. In the non-inertial system, only the installation distance a of the flexible diaphragm coupling along the wingspan leads to the increase of the axial deformation offset of the flexible diaphragm coupling in the rolling flight state. The increase of climbing or diving angular velocity makes the flexible diaphragm coupling’s vibration changes from single period to multi-period, bifurcation or chaos state; With the increase of diving angular velocity and rolling angular velocity, the axial critical speed gradually increases; Each flight condition not only affects the vibration characteristics, but also causes the axial, radial and angular deformation of the flexible diaphragm coupling to a certain extent. This study provided a theoretical basis and method for the design and analysis of diaphragm coupling.

Torque Ripple according to The Number of Permanent Magnet Poles of Magnetic Gear

The power transmission of magnetic gears, based upon the at-tractive force of magnets, does not involve direct contact between the power transmission shafts. Thus, vibration or noise, due to friction, can be reduced. However, magnets and iron cores, which are the main components of magnetic gears, generate cogging torque. This increases torque ripples that are the cause of the noise and vibration of permanent-magnet (PM) machines. In this study, a torque ripple reduction method, using the combination of number of poles and number of pole pieces was proposed. This method uses the structural characteristics of magnetic gears only. This method was suggested instead of the existing torque ripple reduction methods for PM machines to reduce the torque ripples of magnetic gears. Furthermore, the correlation between the numbers of poles, pole pieces, and torque ripples was analyzed. From this analysis, a design guideline that minimizes torque ripples in the initial design of magnetic gears was proposed.

Investigating behavior of VLCC ship’s diesel engine on handling stormy waters

The behavior of ship engine encountering stormy waters with different sea wavelengths has been investigated. In this study, a mathematical model is developed using governing equations for various parts of the ship, that is the hull, engine, power transmission shafts from the engine to the propeller also the propeller of the ship itself were implemented in MATLAB/ Simulink software environment. The model consists of the torsional vibrations of the transmission shafts; this enables a more accurate analysis of the engine behavior which is the source of power generation in the ship's propulsion system. The simulation results showed that the wavelength of sea waves has a significant effect on the dynamic performance of the engine. In this research, the effect of different ratios of wavelength to ship length (λ/LPp ) including 0.5, 1, 1.5 and 2 in violent stormy sea conditions with a wave height of 11.5 m and wind speed of 28.5 m/s has been investigated. The results showed that with the exception of λ/LPp of 1.5, at another ratios of λ/LPp , changes in engine performance parameters such as torque, fuel and air consumption, CO2 emission and power are decreasing with increasing wavelength. Most variations in engine speed are related to λ/LPp of 2. The results showed that by reducing the wavelength, the period of oscillations is reduced. As the ratio of wavelength to ship length increases, the number of oscillating points in the engine behavior increases and the lowest number of oscillating points can be seen at λ/LPp of 1.5. This study highlights the importance of effects of sea wavelengths as one of the most important physical parameters of the sea which should not be ignored in the design phase of the ship propulsion system and engine selection.

Simplified and Precise Design of Crossflow Turbine Power Transmission Components

Despite the merits of small hydropower (SHP), coupled with the perennial inadequate and unreliable electricity supply in SSA, the huge SHP potential in the region is hugely untapped. This is largely attributed to the lack of adequate technical components for the development of SHP turbines, which are: technical personnel, and production facilities in the region. The hydraulic power possessed by flowing water in SHP resources can be harnessed and transformed into usable electrical energy via the deployment of a hydro turbine plant. Commonly used hydro turbines include crossflow (CFT), Pelton, Turgo, and Francis turbines. Amongst these turbines, CFT is mostly applied in low head sites and has efficiency ranging from 70–85%. The CFT power transmission subsystem is considered vital to its performance; the shaft, which transmits the generated motion to drive the alternator, is the most critical part of the CFT transmission subsystem and it requires careful design and production processes. This study centres on the development of a simplified systematic design process for power transmission shaft, pulley, and belt, to facilitate CFT power generation efficiency. .Further, the study is geared towards boosting CFT technology capacity domestically for the benefit of local production. The hydrological properties of the Ayiba SHP site in Osun state, Nigeria, were adopted for this work as a case study. The head and power for this resource are 11.8 m and 122.4 kW, respectively, and are served as the fundamental parameters for the design of the power transmission subsystem. The design computation shows that a shaft of diameter 65 mm and a D-type of V-belt with a corresponding pulley will be required to transmit the generated turbine power to the alternator. A 3-D model was created based on the design values and this was used to validate the integrity of the shaft by static stimulation. The simulation result, which is based on von Mises was satisfactory as the highest stress obtained in the shaft was 205 N/mm2; resulting in a 2.6 factor of safety.

Development of a non-isothermal forging process for hollow power transmission shafts

This paper presents a new forging process for hollow power transmission shafts. The key aspect of the process is altering the flow characteristics of the material via differential heating of the tubular stock. The process is conceived in three main stages namely, partially heat the tubular stock with induction heating; upset the heated section of the tube to form a solid section; and finally shape the solid section into a flange or a conical head by further upsetting the workpiece. Parametric study was also carried out for various internal diameter to external diameter (ID/ OD) tube ratios. With the aid of finite element analysis (FEA), the feasibility of the process was evaluated based on formability, forming loads and dimensional accuracy. FEA results showed that it is feasible to produce hollow axle shafts, stepped gear shafts, and pinion gear shafts. Scaled down models of hollow axle shaft and hollow pinion gear shaft were successfully fabricated using the proposed methodology.

Implementation of the Operational Modal Analysis technique in a power transmission shaft

In this paper, we investigate the application of modal identification techniques used in civil structures, in which the excitation forces are not known, and extrapolate them to mechanical elements in operating conditions. A methodology is proposed to identify the modal parameters of a power transmission shaft under rotation. The methodology is based on the comparison of theoretical and experimental results. First, a simulation of the element under study is carried out, using a numerical model based on the Finite Element Method, to evaluate its theoretical dynamic characteristics. Then, an Experimental Modal Analysis (EMA) is performed and the theoretical model is verified by comparing theoretical and experimental results. Moreover, an algorithm based on the non-parametric technique “Peak Pickin” of an Operational Modal Analysis (OMA) is developed and, from the records of accelerations obtained in the bearings, we identify the modal parameters of the shaft. These results are compared with the theoretical values, calculated previously and, thus, verify the effectiveness of the implemented technique.

Manufactura de bicicleta de bambú con transmisión de engranes

The present project deals with the construction of a bicycle with a Bamboo structure, a cultivation plant preferably in the southwest of Mexico, however a bamboo cultivated in the Mexican Bajío was used. A transmission based on helical gears was also included, replacing the traditional transmission chain. Solidworks modeling was performed as well as finite element analysis to quantify bicycle safety factors as well as Von Mises efforts. Regarding the assembly and construction of the bamboo bicycle, different cuts of the plant's rods were made to adapt them to the tubular parts of the bicycle frame, in addition to the handlebar. The transmission was assembled with helical gears by coupling them with a power transmission shaft. Also tests were done, already armed the bike, both resistance and speed. And considering testing the transmission with gears.

한국형 기계식 동력전달 축과 다단계 기계식 퓨즈 장치의 기초연구

한국형 기계식 동력전달 축과 다단계 기계식 퓨즈 장치의 기초연구

Ergonomic optimisation of machining operations of power transmission shaft

Workstation efficiency and operator satisfaction are two main factors which influence the overall productivity of a production unit. Considering ergonomic factors while designing a workstation will help to develop a better environment for working and will help to avoid unsafe working conditions. This paper describes a study conducted in a machining station to find out the various factors which may result in serious health issues to the operator and reduction of productivity. According to the study various modifications are made by considering ergonomic factors and results show that efficiency and operator satisfaction have been improved after implementing the recommendations.

Preliminary Design of a Power Transmission Shaft under Fatigue Loading Using ASME Code

Power transmission shafting is a vital element of all rotating machinery. A complete shaft design involves many iterative phases and fundamental to this is the determination of preliminary dimensions of the shaft. This paper presents a comprehensive fatigue analysis approach of determining the initial dimensions of a power transmission shaft under fatigue loading based on American Society of Mechanical Engineers (ASME) Standard B106.1M:1985. A countershaft running at a constant speed is designed using this approach. Stress analysis at potential critical locations are conducted to determine the shaft sizes. The sizes from these locations are then used to estimate the sizes at low stress locations. Adjacent sizes are blended using the largest size. To help visualize, a CAD model of the preliminary designed countershaft is provided.

Experimental investigation into the surface integrity and tribological property of AISI 1045 steel specimen for barrel finishing

Surface integrity is one of the important parameters that affect mechanical properties of an assembly like friction between mating parts and wear resistance. In this research, the effects of different barrel finishing conditions such as rotational speed, diameter of media and load of media on the surface integrity and tribological properties were systematically investigated for AISI 1045 steel, which is widely used for power transmission gears and shafts, aircraft landing gear and other friction pair parts. Their percentage change in surface roughness Ra, hardness and topography were analyzed by MarSurf roughness tester, a Vickers micro-hardness tester and ZeGage Plus optical profiler, respectively. The tribological property was analyzed using a ball-on-flat micro-tribological tester. Results indicated that barrel finishing process improved surface integrity of AISI 1045 and slightly decreased friction coefficient. The optimum process parameters were the diameter of 2 mm, the rotational speed of 360 r/min, and the load of 70 %. The predicted model of the %ΔRa was obtained by regression analysis and validated by the experimental observation.

Development of a Non-isothermal Forging Process for Hollow Power Transmission Shafts

This paper presents a new forging process for hollow power transmission shafts. The key aspect of the process is altering the flow characteristics of the material via differential heating of the tubular stock. The process is conceived in three main stages namely, partially heat the initial tubular stock with induction heating; upset the heated section of the tube to form a solid section; and finally shape the solid section into a flange or a conical head by further upsetting the workpiece. Parametric study was also carried out for various ID/ OD tube ratios. With the aid of finite element analysis (FEA), the feasibility of the process was evaluated based on formability, forming loads and dimensional accuracy. The FEA results showed that it is feasible to produce hollow axle shafts, stepped gear shafts, and pinion gear shafts.

Crane system with remote actuation mechanism for use in argon compartment in ACPF hot cell

The Advanced spent fuel Conditioning Process Facility (ACPF) at the Korea Atomic Energy Research Institute (KAERI) has recently been successfully renovated. One of the highlights of this renovation project was the installation of a small argon compartment within the atmospheric hot cell of the facility. Even though a crane system was considered necessary for the remote handling of the processing equipment inside the argon compartment, no suitable commercial cranes were available. This was because a limited amount of space had been reserved for the installation of the crane. Moreover, a master-slave manipulator (MSM), the only available means of maintenance of the crane, was unable to reach it in the limited workspace. To address the difficulties in the design of this crane, in this study, a remote actuation mechanism is devised where the mechanical and electrical parts of the crane system are separated, positioned far away from each other, and connected through power transmission shafts. This approach has two main advantages. First, the electrical parts can be placed inside the workspace of the MSM, hence allowing for remote maintenance. Second, the space occupied by the electrical parts and their cables, which are separate from the crane in the proposed design, can be considered and exploited in designing the mechanical parts of the crane. This enables the construction of a short, special crane in order to maximize the workspace. Furthermore, the mechanical parts for the MSM located outside the workspace are designed to possess a high safety margin to ensure durability. An accurate servo-control system is also developed based on absolute positioning measurement. This allows for the safer performance of perform through automatic operation.

Calculation of Stress Intensity Factors KI, KII and KIII of Cracked Components Submitted to Flexural and Torsional Loads

Components subjected to flexural and torsional loadings, such as power transmission shafts, are elements that sometimes fail due to fatigue crack propagation. Other example of mechanical element that occasionally fail and that can be simultaneously submitted to bending and torsion are endodontic files, which are being widespread used in mechanized endodontic treatments.With the intent of analyzing the influence of bending and torsion on the Stress Intensity Factors (SIF), KI,II,III, at different crack geometries (a/r), two CAD 3D models were created, namely one cylindrical shaft and one endodontic file. The evaluation of KI, KII and KIII for the two components under study was carried out at several points along the crack front using the Finite Element Method (FEM) together with Linear Elastic Fracture Mechanics (LEFM) concepts.The Finite Element Analyses (FEA) carried out shown that flexural loads have a preponderant impact on KI values, although torsion may have influence on it depending on the order of magnitude of the torsional loading values applied on the component. However, when pure torsion loading was considered, KII and KIII values become dominant at crack tip.Finally, numerical results obtained revealed that geometric complexity and reduced dimensions of components can play an important role when analyzing SIF, being this particularly relevant on the case of endodontic file.

Wear and Grip Loss Evaluation of High Chromium Welding Deposits Applied on Sugar Cane Rolls1

Wear on sugar cane rolls is an expensive maintenance problem for the sugar cane industry. Wear produces loss of sucrose extraction and loss of grip of the roll on the bagasse. This paper presents the evaluation of wear and loss of grip of hypoeutectic and hypereutectic high chromium welding deposits applied on ASTM A-36 steel and gray cast iron. A modified ASTM G-65 standard test was used. Wear was produced by the abrasive action of wet bagasse with three levels of mineral extraneous matter. Silica grains with sizes in the range of 0.212-0.300 mm (AFS 50/70) were used as mineral extraneous matter. Grip was evaluated by measuring the torque on the power transmission shaft that moves the specimens. Worn surfaces were characterized by using scanning electron microscopy. Wear was found to increase proportionally related to the mineral extraneous matter content. Geometric changes of the weld deposits related to wear caused grip loss. For low mineral extraneous matter level, wear resistance of carbon steel was greater than that of gray cast iron; whereas the opposite was found for high mineral extraneous matter level.

Design Criteria for High Power Engines Crankshafts

The reliability of any mechanical system, in which the linear displacement of a piston is converted into the rotation of a power transmission shaft, strongly depends on the reliability of the crankshaft. The crankshaft is the critical component and any damage occurring to the crankshaft may put the mechanical system out of order. The numerical finite element simulation of crankshafts with multiple rods is often time consuming even if quite accurate if the aim is to evaluate the stress-strain behavior at the notched area and verify the component. The development of a simplified numerical model would prove effective to reduce the time needed to reach a good approximation design of the crankshaft. The aim of this paper is to give the designer a numerical procedure that allows to determine the strain and stress state and verify crankshafts having two or more rods.