Machine Shaft Research Articles

New Forging Drive System for Radial Forging Based On Double Stroke Mechanism

A new type of stroke-limited forging drive system has been developed by GFM for its radial forging machines. As opposed to eccentric shaft machines, this new drive creates two strokes per shaft revolution. Hence the stroke rates are doubled and allow for distinctive higher throughput and tighter tolerances. A prototype with eight synchronously working tools has been built in house for proving the concept and to run trials. The machine is designed and dedicated mainly for the forging of thin walled tubes. The results reveal that the ratio of outer diameter to wall thickness may be heavily increased so that this eight tool forging machine will broaden the product range of seamless tubes that are covered by a machine size. The paper presents the various trials, its results, and the consequences of process advancements based on this new machine concept for the forging market.

A new analytical model to predict the transversal deflection under load of stepped shafts

Shaft deflection is a common phenomenon in machine design that has an important influence on the behavior of many transmission elements supported by the shafts, like gears, pulleys, sprockets, etc. This deflection can be estimated efficiently by using 1D models associated to beam theories, but machine shafts are usually stepped shafts and it has been demonstrated that classical beam theories do not predict accurately the deflection of this type of shafts. Thus, in this work, an equivalent model of the shaft to be used in conjunction with the Timoshenko beam theory has been proposed to improve the accuracy of the computed deflections. The new model substitutes the steps of the shaft by a linear variation of the diameter of the cross-section, removing the discontinuities caused by these steps. The slope of the linear variation provides new variables that are optimized locally and globally for the best coincidence with the deflection obtained with a realistic finite element model of the shaft. Then, two different approaches (with locally and globally optimized slopes) are proposed and their accuracy is investigated with 56 cases of study and with the analysis of a realistic gear drive. The results demonstrate the higher accuracy of the proposed model and the improvement with respect to the direct application of the Timoshenko beam theory.

Implementation of MCDM model in lean manufacturing using grey relational analysis in automotive industry

The present economic situation shows the consistent demand for profitable solutions that allow business organizations to gain better ad-vantage. Due to this reason, many organizations search for methodologies that allow them to improve their products and services improve their processes, reduce costs, and improve the profit and customer satisfaction. This has been implemented through lean techniques in their managerial and production methods. As we know Lean production system mainly emphasizes on the waste elimination, using simple and visual techniques. This paper is an attempt to optimize process layout and waste expulsion for automotive powertrain in a leading automo-tive company by using lean manufacturing techniques. In this paper, the existing process in place for machining of cam shaft is analysed and process layout is optimized to reduce cycle time and lead time. In order to reduce the cycle time, the process parameters such a speed, feed and depth of cut are optimized for increased material removal rate (MRR) and decreased surface roughness (RA) by using Grey Relational Analysis (GRA) technique. As MRR is inversely related to cycle time, optimization of parameters for higher MRR reduces the cycle time. Grey Relational Analysis is done by using Design Xpert software.

Torque Cancelation of Integrated Battery Charger Based on Six-Phase Permanent Magnet Synchronous Motor Drives for Electric Vehicles

This paper proposes a torque cancelation strategy for a nonisolated three-phase integrated battery charger topology for light and medium duty electric vehicle drives based on six-phase permanent magnet (PM) synchronous machines. The charger requires a three-phase grid interface and utilizes the machine windings as the input filter inductances after minor reconfiguration. The drive power electronics are used to control the currents drawn from the three-phase grid. The current flowing through the machine windings induces a torque on the PM machine rotor which is eliminated by the proposed torque cancelation strategy in battery charging mode. The torque cancelation strategy is general and works with both symmetric and asymmetrically wound six-phase PM machines. The strategy is also capable of eliminating the torque when the rotor is displaced from the stator $d$ -axis. The linear quadratic regulator with the integral action control scheme is used to accommodate for the asymmetry caused by the dependence of winding inductance on the rotor position. Co-simulation results with Finite-Element Analysis and hardware experiments show the topology based on six-phase PM machines can be used to charge or discharge the battery for grid support functions while the torque on the machine shaft remains canceled.

Geometric and computer-aided spline hob modeling

The paper considers acquiring the spline hob geometric model. The objective of the research is the development of a mathematical model of spline hob for spline shaft machining. The structure of the spline hob is described taking into consideration the motion in parameters of the machine tool system of cutting edge positioning and orientation. Computer-aided study is performed with the use of CAD and on the basis of 3D modeling methods. Vector representation of cutting edge geometry is accepted as the principal method of spline hob mathematical model development. The paper defines the correlations described by parametric vector functions representing helical cutting edges designed for spline shaft machining with consideration for helical movement in two dimensions. An application for acquiring the 3D model of spline hob is developed on the basis of AutoLISP for AutoCAD environment. The application presents the opportunity for the use of the acquired model for milling process imitation. An example of evaluation, analytical representation and computer modeling of the proposed geometrical model is reviewed. In the mentioned example, a calculation of key spline hob parameters assuring the capability of hobbing a spline shaft of standard design is performed. The polygonal and solid spline hob 3D models are acquired by the use of imitational computer modeling.

Design and finite element analysis of a fatigue life prediction for safe and economical machine shaft

In materials engineers, it is important to determine the cause of failure of a machine component, to prevent prospect occurrences and increase the performance of the component structure. In this study, the parameters of the fatigue life of machine shafts are investigated. An analysis of the nut cracking machine shaft was conceded for plastic deformations. The optimum safe and economical design of a machine shaft was proposed. The 3D model of a shaft was produced with Inventor® using absolute coordinate. The results of the commercial finite element analysis (FEA) and calculations are compared with results obtained earlier by other methods. The analysis of 30mm shaft diameters under the maximum torque of 72.0Nm shows a factor of safety of 10, while the 20mm shaft diameter under the same torque gives a factor of safety of 2. This will provide designers guidelines to forecast the design on fatigue strength of a machine shaft.

The Effect of Shaft Hole Length on the A-IMS Tubular Shaft Machining

The Effect of Shaft Hole Length on the A-IMS Tubular Shaft Machining

Improving the accuracy of machining of non-rigid shaft

So far, due to much more strict events of operating parameters requirements, the reduction of pieces steel intensity allows to produce multiplying quantity of the highly precise Non-Rigid Pieces (NRP); most of them are supposed to be the shafts in amount. The creation of Automatic Control Systems (ACS) by mechanical operating also involves highly precise NRP production. In present paper there is Self-Centering Rest (SCR) operating hydrocylinder piston rod control system presented; it causes influence directly to the rest centering accuracy. The plant processing does not require hydrostation and pipeline; it possesses highly precise centering and it is able to function either in shaft support mode, or in active dampening one. There is the original scheme of double acting sealed hydrocylinder presented. There is the functional control scheme of hydraulic power cylinder presented. There are results of the non-rigid shaft axle research while turning presented. Thus, the beat reduction of the rigid shaft while turning in SCR system reaches 3...16 times in comparison.

Design and Fabrication of Spring Rolling Machine

This paper is to examine to outline and manufacture of a manual spring moving machine by a basic system game plan for the creation of shut and open loop helical springs. This machine is worked by manual technique. This machine produces shut curl helical spring of various width and distinctive length. Rolling is the way toward bowing metal wire to a bended shape. The article in the state of round is made by spring roller shaft. Moving operation should be possible close by or control worked moving machine. It can make a spring from a pole. A pole is a pivoting machine component which is utilized to transmit control starting with one place then onto the next. A course is machine component which underpins another moving machine component. Guider is utilized to manage the crude material (spring wire). This guider precedes onward the pole consequently. This self-development is accomplished by the lead of spring. Handle is utilized to work the moving machine physically, without electric power outline is conveys an all parts of the machine, it is comprised of mellow steel. A work holding system is utilized to hold the mandrel; it is connected to the principle shaft of machine. Mandrel is fitting in the work holding instrument, the mandrel's external distance across is known as inward breadth of the spring

A method for real-time wireless monitoring of the efficiency and conditions of three-phase induction motor operation

Concerning the primary aim of attending to the requirements used in the monitoring of induction motor efficiency, along with prioritizing a low intrusion level, the Literature presents various methods that need only the voltages, currents and some rotor speed cases. In a general sense, these methods estimate the torque on the machine shaft, along with calculate the output power and efficiency, through the use of a variety of different techniques. In this context, the present study proposes a real time wireless monitoring method over the operation conditions and efficiency of the three-phase induction motors. The method proposed herein estimates through the values measured on the three-phase voltages and currents and the equivalent circuit of the machine, the torque and speed of the shaft. Based on these estimates, both output power and efficiency can be calculated. The equivalent circuit of the machine is estimated through an iterative algorithm that uses only the data from the machine plate and the resistance of the stator, as will be shown in this study.

Failure analysis of a carbon steel roller shaft of continuous pad steam machine

This paper presents the failure analysis of carbon steel roller shaft of continuous pad steam machine used in textile industry. The fracture position was located at a stepped diameter. The failed component was the shaft made of carbon steel AISI 1040. Standard procedure for failure analysis was employed in this investigation. Visual examination, chemical analysis, hardness and tensile strength measurements, microstructural characterization, fractography analysis by Scanning Electron Microscopy (SEM) and Finite Element Analysis (FEA) were used for the failure analysis. Using this failure analysis approach, we pinpointed the root cause of failure and developed a means of solving this type of failure in the future. Firstly, the chemical composition of the shaft is done by an Optical Emission Spectroscopy (OES) method, the found chemical composition was matching with required standard value. Mechanical testing consists of two test i.e. tensile test and hardness test and it was found out that the strength and hardness of specimens were within the required capacity. For metallurgical analysis, the microstructure of the shaft was developed by using an optical microstructure. Equal distribution of ferrite perlite shows that heat treatment was performed well and carbon percentage in a material is satisfying the standard values. Thus, it proves that the material used was of good quality and indicates that failure is not due to material property. Further for the fractography, the fractured surface was examined by SEM. The cross-section was taken in a quarter segments and divided into four regions i.e. A, B, C, and D. Fractography morphology mainly showed that the failure of roller shaft was caused due to fatigue. To examine the stress distribution at the fractured surface the Finite Element Method (FEM) was also carried out. Based on the shaft size, a precise ANSYS model was developed. The result of FEM shows that stress concentration was significant at roller shaft step which could reduce the material reliability to some extent. Based on the failure analysis it could be concluded that due to stress concentration a micro crack is initiated along the weak interface and further it converted into the major fatigue failure. Fractography morphology of failed roller shaft also confirms the fatigue failure.

A proposition of application of the complex functions in the design of the machine shaft based on the stiffness criterion

This article presents an algorithm for determining the theoretical outline of the shaft using the differential equations of a static shaft deflection in the form of a complex-valued function. The method which has been proposed is based on the Euler-Bernoulli formula and enables to obtain a universal relation to determine the shape of the shaft on the basis of the expected deflection. This approach greatly simplifies the design of the machine shafts, eliminating the iterative step of choosing diameters that fulfilled the design criteria. Furthermore, based on the proposed model, it is possible to determine the stiffness of the shaft, which is necessary to determine the critical speed of the rotor.

Influence of Water and Mineral Oil on the Leaks in Satellite Motor Commutation Unit Clearances

Abstract The article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working chamber during the transition from the filling cycle to the emptying cycle are included. The pressure in the motor’s working chamber changes linearly as a function of the shaft rotation angle, which has a significant effect on the leakage in the commutation unit clearances. The paper presents new mathematical formulas in the form: Q=f(Δpγ) to calculate the flow rate of water and mineral oil in the commutation unit clearances. The γ factor is described as a function of fluid viscosity and clearance length (the motor shaft rotation angle). The coefficients used in these formulas were determined based on the results of laboratory tests of a motor supplied with water and mineral oil.

Diagnosis of Stator Faults Severity in Induction Motors Using Two Intelligent Approaches

Three-phase induction motors are the primary means of transformation of electrical energy into mechanical energy in industry, since they are robust and present low cost. However, despite being robust, these machines are subject to electrical or mechanical faults. Thus, identifying a defect in a running motor may decrease the risk of possible damage. This paper proposes an alternative approach to identify defects in the stator of these motors, by analyzing current signals in the time domain. In addition, it presents the determination of the consequent fault severity by means of two proposals: 1) a multiagent system with a classifier behavior; and 2) a neural estimator. The faults observed are related to short circuits between turns in the stator coil of 1% to 10%. Experimental results are observed with motors of different powers, under various adverse situations of electrical feed and a wide range of load conditions on the machine shaft.

Development of a non-contact torque transducer based on the laser speckle contrast method

Abstract. When a torque measurement is required, torque transducers show many drawbacks during their use: the usual limits are the need for contact and the effects on shaft line parameters. A new approach is proposed in this work: a non-contact torque meter for a machine shaft has been developed. It carries out torque measurements evaluating the torsional displacement between two distinct sections of the shaft, through the monitoring of their roughness. The sensing principle employed is the classical laser speckle contrast method. The outcoming intensity scattered by the rough surface is processed by a cross-correlation function. In this way, the angular torsion of two distinct sections is obtained. It is therefore possible to point out the applied torque knowing the shaft torsional stiffness.

The hydrodifferential rectifier of the moment of inertial automatic transmission of mobile machines

The article considers the possibility of using torque in the inertial-pulse automatic transmissions of a hydrodifferential rectifier, in the design of which hydraulic machines are used as free-wheel clutches. Unlike mechanical freewheel clutches, where the weakest of their links are the jamming bodies, in the proposed construction the jammed body is hydraulic fluid, which allows to eliminate the above-mentioned drawback and reduce wear. A kinematic scheme of inertial transmission with a hydrodifferential torque rectifier is given and the working process is described on three characteristic operating modes: stop, torque and direct transmission. Dependences for calculation of basic parameters of hydraulic clutches of a free wheel are given, and also theoretical and experimental results of researches of working capacity of the inertial hydrodifferential torque transformer are presented. An analysis of the results showed that with increasing internal leakage of the working fluid, which increase as a result of wear of the hydrodifferential torque rectifier, the power and torque on the shaft of the hydraulic machine will decrease, which in turn will decrease the efficiency of the hydrodifferential rectifier. The analysis of the results showed that at the beginning of operation the efficiency of the hydrodifferential rectifier is about 93% in the entire operating range. During operation, the efficiency of transmission decreases linearly and at a radial gap of 300 ÷ 350 μm is only 68 ÷ 63%. With further deterioration (radial clearance 350 ÷ 400 μm), the efficiency is practically not reduced. This indicates that the hydrodifferential rectifier of the torque has completely worn out and its replacement is required.

Concept of Product Complexity Modeling in the Development of a Machine Shaft

AbstractIn the paper product and design process modeling on the basis of speed reducer is presented. The paper proposes to build the product and process models and parallel to that carry out the project activities as these models reflect the detailed structure of the projects.The most important feature of the proposed approach is its possibility to model only important parts of the models and to keep track of the development of their chronological paths. The approach may be treated as a partial CPM/MOKA model or as network-integrated CPM/MOKA models.

Measurement of torsional vibration to detect angular misalignment through the modulated square wave of an encoder

One of the widely used processes to measure torsional vibration focuses on the analysis of a square signal from a device set in the machine shaft. The tools used for this purpose usually consist of a toothed wheel connected to an appropriate transducer, of an electromagnetic or optic type, which provides a square wave signal. If the rotation velocity is constant, the signal pulses are the same width, but when the velocity changes, the width of the pulses changes too, lengthening or shortening its width, resulting in a frequency modulated signal. When the shafts of the machines are misaligned angularly, the average speed changes due to variable torque action, so that spectral features of modulated signal show frequency components that are explained by the Bessel Functions. This work shows that these components are caused by a carrying (constant average speed) and a modulator signal (variable turning speed) between the harmonics surrounding the central frequency. Besides, it may also test their relationship with the presence of angular misalignment in the coupled-machine shafts. In addition, an iterative method is applied to construct the frequency spectral diagram of the induced square signal, once the appropriate modulation indices of the Bessel functions have been calculated. To compare and validate the method, different bench tests have been performed using pulse signal and laser interferometry.

Hob mill for spline shaft, profiled by generating trajectories method. Graphical application in CATIA

The hob mill is a cutting tool with a wide application for generation in machining of splined shafts. A method for profiling the hob mill for generation of square splines is presented in this paper. The analytical development was done based on a complementary theorem of surface enwrapping — the method of generating trajectories. A numerical application for a standardized spline shaft is presented. Based on the same theorem is presented a graphical application, developed in the CATIA design environment, for profiling the hob mill which generated standardised square splines.

Design, Manufacture and Performance Evaluation of an Effective Dual Operated Groundnut Decorticator with Blower

A manual (hand operated or bicycle paddle) groundnut decorticating machine attached with a blower is designed, manufactured and its performance assessed. The main components of the machine were the frame, hopper, neck feed control gate, shelling drum, shaft running on bearings, a pneumatic type mechanism, concave sieve and a blower. The rest are pulley and sprocket, discharge outlet and belt drive. The assembled angle iron parts were welded together whiles the sheet metal parts were riveted to hold in position. Testing of the decorticating machine was assessed at three different moisture contents of groundnut (0, 5.1 and 9.3%) and three different levels of machine shaft speed (10, 20 and 30 rpm) all at an average feed rate of 25kg/hr. The results revealed that the decorticating machine’s optimum performance was at 20 rpm machine shaft speed with groundnut moisture content of 0% (purely dry), machine cracking efficiency and percentage groundnut fully cracked was 71.2% and 85.3% respectively. There was reduction in machine performance at machine speeds of 10 rpm and 30 rpm with 45.1%, and 49.7% machine cracking efficiency respectively for the same feed gate rate openings. This was because at a speed of 10 rpm, the nuts were partially cracked (41.6%) and that of 30 rpm and cracked (39.3%), the quantum of groundnut losses through the blower increased considerably leading to a reduction in the quantity of groundnut collected.