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Design and Analysis of Automotive Serpentine Belt Drive Systems for Steady State Performance
Abstract
Serpentine belt drive systems with spring-loaded tensioners are now widely used in automotive engine accessory drive design. The steady state tension in each belt span is a major factor affecting belt slip and vibration. These tensions are determined by the accessory lends, the accessory drive geometry, and the tensioner properties. This paper focuses on the design parameters that determine how effectively the tensioner maintains a constant tractive belt tension, despite belt stretch due to accessory loads and belt speed. A nonlinear model predicting the operating state of the belt/tensioner system is derived and solved using (1) numerical, and (2) approximate, closed-form methods. Inspection of the closed-form solution reveals a single design parameter, referred to as the ''tensioner constant,'' that measures the effectiveness of the tensioner. Tension measurements on an experimental drive system confirm the theoretical predictions.
... The belt material nonlinearity was characterized in some nonlinear rotation models [19,21,122,[130][131][132] . Based on the linear rotation model of a typical power transmission belt drive system, a nonlinear rotation model that captures the material nonlinearity of the belt was established by Shangguang et al. [19,21,122] . ...
... Maxwell elements are used by them to model viscoelastic properties of the rubber material in the belt. Beikmann et al. [131] established a nonlinear model for predicting the working state of the belt-pulley system, and separately investigated the effect of the tensioner on maintaining the belt tension by numerical and approximate closed-loop methods. ...
In this paper, studies on dynamic modeling, simulation and experiment of power transmission belt drives are comprehensively reviewed. In the past few decades, many investigations are conducted on dynamicmodeling, simulation and experiment of different kinds of power transmission belt drive systems. In the dynamic modeling and simulation of the belt drive systems, surveys are focused on vibrations of a single axially moving belt span, rotational vibrations of pulley components, coupled belt-pulley vibrations and contact mechanics between the belt and pulley as well as some experimental investigations. Influences of tensioner dry friction and one-way clutch on dynamics of the belt drive systems including system rotational vibrations and coupled belt-pulley vibrations are separately reported. The investigations are also surveyed on modeling and predicting complicated belt-pulley contact behaviors like belt creeps and slips on pulleys, contact force distributions of the belt and pulley, and variation of wrap angles ofa belt around pulleys, etc., which are categorized by different approaches including the creep theory, shear theory, multi-body dynamics and finite element methods. Fatigue life estimation and failure analysis of power transmission belt drives are discussed in detail as well. In addition, experimental techniques are reviewed on parameters identifications, and measurements of static and dynamic performances including energy/power loss, system vibration, dynamic belt tension, belt deformation, stress and strain distribution in the belt and pulley, and contact friction force, etc. Finally, conclusion of this work is summarized and topics of future potential studies on the power transmission belt drive systems are suggested.
... In the underlying investigations, specialists displayed the pulley-belt framework by considering the belt as a string that does not have twisting solidness. Beikmann [1,2] displayed the belt as a string and explored the dynamic attributes of a three-pulley framework made out of two pulleys and a tensioner. They broke down the impacts of the tensioner on the characteristic frequencies and mode shapes and led an examination exploring the tensioner plan with a specific end goal to keep a consistent pressure connected to the belt paying little heed to changes in the moving pace and frill torque of the belt. ...
During its operation, a power transmission belt can undergo axial, transverse and torsional motion. A detailed vibration analysis of 5-axis articulated robot was conducted. Results show thatpower transmission belt drives majorly contributed to the vibration in robots. Experiments were conducted through which we concluded that belt elongation due to applied tension caused vibrations. The system was further analyzed to know the elongation and natural frequency of the belt. Modifications done to the system by using spring loaded idler that would automatically adjust the belt tension, reduce vibrations in the system, increase life of the belt and in turn reduce the maintenance cost of robot.
... Belt drives systems are found in many sectors : automotive industry, mining career, appliances ... Several studies have attempted to model the forces when belt transmits power to other rotating elements. Some have studied this type of transmission system consists of two pulleys and others have added a tensioner [10,11]. These investigations have shown that the belt was subjected to lateral, longitudinal, transverse and torsional vibrations. ...
[FRENCH]
Nous étudions les signaux de vibration à l'aide de la Transformée en Ondelettes Continue basée sur la Transformée de Fourier (CWTFT) et de la Transformée de Fourier à Court Terme (STFT). Cette étude montre les avantages de la représentation temps-fréquence pour l'analyse des signaux non-stationnaires tels que la localisation, l'extraction et la surveillance des bandes de fréquence intéressantes. La nouvelle approche est le diagnostic des variations de courroie. Le rapport énergie/kurtosis calculé le long des échelles (fréquences) à partir des coefficients CWTFT et STFT permet une bonne discrimination.
[ENGLISH]
We study vibration signals with Continuous Wavelet Transform based on the Fourier Transform (CWTFT) and Short-Time Fourier Transform (STFT). This study shows the benefits of time-frequency representation for the analysis of non-stationary signals such as location, extraction and monitoring of interesting frequency bands. The new approach is belt changes diagnostic. The energy to kurtosis ratio calculated along scales (frequencies) from CWTFT and STFT coefficients allows a good discrimination.
... These tensions are determined by the accessory loads, the accessory drive geometry, and the tensioner properties. Keeping proper belt tensions to provide adequate torque without belt slip is important for the durable, quiet operation of serpentine drives and it creates forces on alternator and pump center (Beikmann et al. 1997). These belt forces are applied on finite element model to check the strength of the support bracket which is mounted on the engine block with 4 M8 bolts. ...
Decreasing fuel consumption and tailpipe emissions have been an important issue nowadays for automotive industry after new regulations. Fuel consumption is also an important parameter that highly affects the customers’ choice. Reduction of total vehicle weight with optimization is one of the common methods to improve fuel consumption and emissions. There are a lot of studies on body, interior, and engine components of the vehicle to improve fuel efficiency and emissions including design modifications, using alternative material and architectural optimizations. In this article, the optimization of an aluminum support bracket that carry alternator and hydraulic steering pump is studied. First, design space is determined with layout analysis defining constraints and fixing points. Then, topology optimization method is applied in order to explore the load carrying path of the component. Final design is frozen through computational analysis verifications and industrialization phase modifications. A comparison of the new design with the actual production showed that the mass of the current design could be reduced by 37%, while all product expectations were met.
div class="section abstract"> The dynamic performance of the engine front end accessory drive system is one of the important factors affecting the NVH level of the vehicle and the service life of the system itself. Obtaining the dynamic response of the system is the basis for studying its dynamic performance. This paper takes a vehicle engine serpentine belt drive system as a study object, the dynamic simulation model of the drive system is established based on Simdrive 3D. Engine bench tests were conducted to test the dynamic response of the system under acceleration, single speed and start-stop conditions, including the angular displacement of the tensioner arm, the slip rate of the pulley and the belt transverse displacement. The simulation results and measured results are compared and analyzed, and it is judged whether the design of the drive system meets the requirements. Based on the simulation model, the influence of the tensioner damping ratio on the dynamic response of the serpentine belt drive system is studied. The analysis methods and conclusions in this paper have engineering practical significance for the design and development of the tensioner and the serpentine belt drive system.
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High-strength fiber ropes have a number of advantages over steel ropes, therefore they currently enjoy great research interest in conjunction with rope winches. However, what is lacking in the art are suitable drives, since concepts for steel ropes cannot be easily transferred to high-strength fiber ropes. A promising innovative principle is the belt wrap capstan, although adequate and validated models for predicting optimal rope force with the lowest possible belt force are still missing. This paper aspires to contribute towards closing this gap by presenting a validated model of a double layered belt wrap capstan First, a general law of friction is considered. Then, special focus is given to power law friction. This law of friction implies the zero force phenomenon which is also discussed.
Nanotechnology is stated as the utility of nanomaterials for human profit. Nanomaterials contain distinct attributes because of their physical as well as chemical features at the nanoscale. Nanotechnology has a vast domain of usages and has been utilized in providing new products in the industrial section, electronic as well as energy. In this paper, the properties of fluids with nanoparticles are reviewed. Furthermore, the developed models with nanoparticle consortium are studied.
This paper presents the analysis and computer simulation of the rotational and transverse oscillations present in a circular motion transmission system through the relationship of pulley-ribbed belt, widely used in the industrial robots. The analysed system is a pulley-ribbed belt coupled with rigid pulleys. The analysis is based in the mathematical model developed for serpentine belt drive systems. The analysis includes: (i) the geometric characteristics, (ii) the behavior of the transmission in steady state, and (iii) the dynamical response of the system. Dynamic analysis of these type of systems is complex because: (i) it has coupled rotational and transverse vibration modes in a non-linear form, and (ii) includes a circular motion transmission system acceleration-deceleration profile. The proposed analysis allows to determine a priori the frequency, the phase shift and the oscillation amplitude of a section of the ribbed belt excited by any forced velocity profile.
This theoretical and experimental study identifies a key nonlinear mechanism that promotes strongly coupled dynamics of serpentine belt drive systems. Attention is focused on a prototypical three-pulley system that contains the essential features of automotive serpentine drives having automatic( spring-loaded) tensioners. A theoretical model is presented that describes pulley and tensioner arm rotations, and longitudinal and transverse belt vibration response. A recent investigation demonstrates that infinitesimal belt stretching creates a linear mechanism that couples transverse belt vibration to tensioner arm rotation. Here, it is further demonstrated that finite belt stretching creates a nonlinear mechanism that may lead to strong coupling between pulley/tensioner arm rotation and transverse belt vibration, in the presence of an internal resonance. Theoretical and experimental results confirm the existence of this nonlinear coupling mechanism. In particular, it is shown that very large transverse belt vibrations can result from small resonant torque pulses applied to the crankshaft or accessory pulleys. These large amplitude transverse vibrations are particularly sensitive to seemingly small changes in the rotational mode characteristics.
The vibration of an automotive serpentine belt drive system greatly affects the perceived quality and the reliability of the system. Accessory drives with unfavorable vibration characteristics transmit excessive noise and vibration to other vehicle structures, to the vehicle occupants, and may also promote the fatigue and failure of system components. Moreover, these characteristics are a consequence of decisions made early on in the design and arrangement of the accessory drive system. The present paper focuses on fundamental modeling issues that are central to predicting accessory drive vibration. To this end, a prototypical drive is evaluated, which is composed of a driven pulley, a driving pulley, and a dynamic tensioner. The coupled equations of free response governing the discrete and continuous elements are presented herein. A closed-form(1) solution method is used to evaluate the natural frequencies and modeshapes. Attention focuses on a key linear mechanism that couples tensioner arm rotation and transverse vibration of the adjacent belt spans. Modal tests on an experimental drive confirm the theoretical predictions.
This paper presents a method for determining the lateral and torsional natural frequencies of multiple-pulley V-belt systems which may have more than one belt. The method, which takes into account belt bending stiffness, axial and tensile moduli, centrifugal forces and belt wedging gives results which compare well with experimental values. In an effort to predict actual amplitudes of belt vibration and shaft bearing forces, a simple model which includes belt damping and the coupling between lateral and torsional vibrations is also presented. Experimental damping ratios are used as inputs for the model.
Slip measurements on a thick flat belt reveal that the slip is much higher than can be predicted with classical creep theory. By including shear creep (and appropriate material data) the deviation to some extent can be explained. Obviously other mechanisms are present as well. The behaviour in the seating and unseating regions changes the direction of the frictional forces in these regions on the driver pulley, which violates the assumptions in the creep and shear theories. When considering creep, shear, seating/unseating and compliance, measurements and theory fit very well.
Theoretical analysis was performed for the lateral vibration of an axially moving linear material which is supported by pullies. The oscillation of this kind has some peculier characters, by the effect of centrifugal force the oscillation degenerates to unstable character, the modes of natural oscillation take a form of wave motion, the frequencies of free oscillation deminish with increasing velocity and there occur self excited vibrations over the critical speeds. The boundary conditions in the analysis are assumed to be constant curvature at two points of support ends. The method of solution is to simplify the characteristic equation and to unify the unknown variables. The numerical calculation by the iterative method leads to the solutions of frequency curves. Another method of analysis by the complex Fourier series gives an approximate but clear perspective of the solution.
Band saw flexural natural frequencies decrease continuously with increasing band velocity at a rate dependent upon the pulley mounting system—minimum if the band is allowed to extend under the dynamic loading with the initial static load held constant, and maximum if the band length is fixed. The Galerkin and the flexible band solutions provide bounding fundamental frequency approximations that are simple and accurate.Small periodic band tension variations may induce a large amplitude equilibrium as in the case of the classical string. However, the most probable occurrence of instability is not the classical string subharmonic (fundamental frequency equals tension excitation frequency), but occurs at two other excitation frequencies that depend upon the band velocity and pulley mounting system.
In this paper the natural frequencies of a travelling chain are determined by treating the chain as a uniform string. For a constant chain tension the natural frequencies decrease progressively to zero as the chain speed approaches the velocity of transverse wave propagation. In practice such a condition is not obtained since the chain tension increases with speed owing to centrifugal effects. Formulae are obtained for the amplitude of forced vibration of the chain when excited by a transverse displacement at one end. The effect of damping is considered and exact and approximate methods of determining resonant amplitudes are given.
Dissertation (Ph.D)--University of Michigan.
Thesis (M.S.)--Ohio State University, 1968. Includes bibliographical references (leaf 56).