Belt Length Research Articles

Research of Line-Friction Multi Driving Belt Conveyor

On the basis of analyzing the line friction belt conveyor transmission mechanism of driving forces, the calculation method of driving force, as well as the design essentials of this conveyor system were pointed out. According to the conditons that the line friction drive motor power, the driving belt tensile strength and its minimum tension, the calculation formula of transmission belt length were obtained respectively. Meanwhile according to the maximum tension that supporting belt permitted, the position of the driving belt would be confirmed. Line friction driving mode may reduce the conveyor belt maximum tension, that is, the belt with a lower intensity levels could be selected, thereby the cost of conveying belt would be greatly reduced.

Modeling and Validation of Rotational Vibration Responses for Accessory Drive Systems—Part I: Experiments and Belt Modeling

Experimental and modeling techniques for belt longitudinal static stiffness, longitudinal dynamic stiffness and damping coefficient, bending stiffness, and friction coefficient between a pulley and a belt are presented. Two methods for measuring longitudinal dynamic stiffness and damping coefficient of a belt are used, and the experimental results are compared. Experimental results show that the longitudinal dynamic stiffness of a belt is dependent on belt length, pretension, excitation amplitude and excitation frequency, and the damping coefficient of a belt is dependent on excitation frequency. Two models are presented to model the dependence of longitudinal dynamic stiffness and damping coefficient of a belt on belt length, pretension, excitation amplitude and excitation frequency. The proposed model is validated by comparing the estimated dynamic stiffness and damping with the experiment data. Also, the measurements of belt bending stiffness are carried out and the influences of the belt length on the belt bending stiffness are investigated. One test rig for measuring friction coefficient between a pulley and a belt are designed and fabricated, and the friction coefficient between the groove side belt with the groove side pulley, and the flat side belt with a flat pulley is measured with the test rig. The influences of wrap angle between pulley and belt, pretension of belt and rotational speed of the pulley on the friction coefficient are measured and analyzed. Taking an engine front end accessory drive system (FEAD) as the research example for the accessory drive system, experimental methods and the static and dynamic characteristics for the FEAD with seven pulleys, a tensioner, and a serpentine belt are presented.

OPTIMUM DESIGN AND COST CHARACTERISTIC OF SMALL CONVEYOR

Although there are many works dealing with the economic analysis of a long conveyor, the information about a short conveyor is insufficient. This study, thus, deals with the short conveyor by studying the effect of belt width, belt length, convey capacity, and conveyor inclination angle on the cost characteristic of short conveyor. The study was done by calculating the conveyor belt widths and their supports that could service a given convey capacity, conveyor length, and inclination angle. The cost of conveyor corresponding to each belt width was, later, determined. After the total cost of each conveyor had been already calculated, the lowest total cost of conveyor for a given convey capacity, inclination angle, and conveyor length was found. The relationships between the belt widths, belt length, convey capacity, inclination angle and the lowest total cost was, finally, analyzed. In addition, the increase of the lowest total cost, when an overdesign of convey capacity was made, was also investigated. The study was done by case study of conveyor of convey capacity of 50-500 ton h-1, the belt width of 400-1500 mm, the conveyor length of 10-100 m and conveyor inclination angle of 0-30°. The results showed that the lowest total cost was found, for all given values, at the belt width range of 400-500 mm. The lowest total cost increased with the increase of the belt length. For normal convey capacity of 50 ton h-1, an overdesigned value of 50 ton h-1 caused the lowest total cost to increase more than 7% compared with the lowest total cost in case of normal convey capacity. For normal convey capacity more than 100 ton h-1, an overdesigned value of 50 ton h-1 made the increase of the lowest total cost less than 2%.

3109 取付張力時の歯付ベルトの回転伝達誤差に及ぼす共振の影響(OS-13 ねじ・軸受・シール・カップリング/OS-12 ベルト・チェーン)

Synchronous belt drives generate resonance on the belt spanning between the driving and driven pulleys when the transverse natural frequency of the belt approaches the meshing frequency of the pulley and belt teeth. This resonance affects the accuracy of the rotation transmission device installed in the drive system. In a previous report, it was found that the transmission error caused by first mode vibration due to resonance in synchronous belt drives was generated with a period of 1/2 of the pitch of the pulley. However, transmission errors are also generated with a period of one pitch of the pulley, a case which has not yet been examined. In the present study, a transmission error comprising both periods of one pitch and 1/2 of the pitch of the pulley in a synchronous belt drive was experimentally investigated for the case in which the belt at the span generates first mode vibration due to resonance. The installation tension was varied while the rotation speed of the pulleys was fixed, maintaining a speed ratio between the pulleys of 1:1. Analyses of the transmission error based on the experimental results were carried out, and the calculated results of the transmission error were compared with the experimental results. The agreement obtained confirmed the validity of the analyses. It was found that the transmission error of a period of one pitch of the pulley was generated by the difference in belt length between the upper and lower spans due to the resonance.

Tension monitoring in a belt-driven automated material handling system

The extension of the useful life of manufacturing equipment is one of the keys to sustainable manufacturing. The high uptime requirements of the semiconductor industry result in the need for conservative preventive maintenance schemes, which leads to replacement of key components before the end of their useful life. This paper presents the results of research toward a more intelligent condition based maintenance scheme for belt monitoring in a belt driven automated material handling system. An experimental study of belt dynamics showed that transverse belt vibrations were sensitive to changes in belt length, belt tension, belt misalignment, and excitation location. Based on these findings, a novel, contact based device was designed to consistently excite belt vibrations in the material handling system with greatly reduced variations in belt length and initial condition location. On average, standard deviations of tension estimates using the device were 65% lower than that of a trained technician performing the current standard technique on three different robots. This design was then further adapted to facilitate a non-contact belt excitation and monitoring approach that did not require bringing the material handling system offline in order to obtain sensor readings. Such a procedure greatly eased and accelerated the monitoring process.

Development of a new index for the assessment of hydromorphological alterations of the Mediterranean rocky shore

The assessment of the status of coastal waters is required by the European Water Framework Directive. The aim of the present study was to test the response of benthic invertebrates to hydromorphological (HM) alterations and to develop a new index for the assessment of HM alterations of the rocky shore, based on benthic invertebrates. Fifty samples were collected, 10 from pre-classified HM classes 1, 3, 5; 15 from class 2, and 5 from class 4. Seven HM variables describing habitat conditions were used to test the benthic invertebrate response and to develop the HM stressor gradient: material, texture, structure, belt length, sedimentation, water retention and artificially induced mobility. Abundance, some diversity (Shannon–Wiener, Simpson's and Evenness) and richness (number of taxa) metrics showed low correlation values ( r < 0.5) against HM variables and HM stressor gradient, indicating that tested metrics have limited value in assessment of the HM degradation impact on coastal benthic invertebrates. On the other hand, significant differences in the structure of benthic invertebrate assemblages among HM classes were observed (One-way ANOSIM global test r = 0.53, P < 0.0001). In the partial canonical correspondence analyses each of seven HM variables statistically significantly ( P < 0.05) explained individual portion of the benthic invertebrate taxa variability. HM indicative values ranging from 1 to 9 were defined for each of 229 taxa, according to its distribution along the five HM classes. HM indicative weights ( WHM) between 1 and 5 were defined according to the valences distribution among HM classes. HM indicative values, WHM and log 5 abundance classes were combined in a new Benthic Index for Rocky Shore (BIRS), using the weighted average approach. The combination of all three parameters in the BIRS showed a statistically significant ( P < 0.05) response of the new developed index to HM stressor gradient, with a high Pearson correlation coefficient ( r = 0.97). Further work has to be done in order to develop a WFD compliant method with five classes’ boundary values. Nevertheless, the new developed index has a good potential to contribute to existing coastal assessment systems. Especially, as impact of hydromorphological alterations on coastal communities was almost neglected so far, despite being one of the main threats to coastal water integrity.

Experimental Investigation on Dynamic Characteristics of a FEAD System: Affected by Serpentine Belt Length

Serpentine belt is widely used in the front end accessory drive (FEAD) system of automotive engine. Experimental setup and dynamic behaviors of a FEAD system are demonstrated in this paper. Some dynamic characteristics are investigated, subjected to multifrequency excitations and different crankshaft (CRK) loads. Experimental results show that the parametric instability of belt transverse vibration occurs mainly in the frequency regions of secondary resonance, and the instability regions are shifted to lower frequencies according to the increasing of CRK speed. With the same CRK load and speed, the rotational angle of tensioner arm, the hubload of tensioner pulley and the slip rate of ALT pulley in the short-belt system are smaller than that in the long-belt system. But with the increase of CRK loads, the parametric instability of belt transverse vibration in the short-belt system is stronger than that in the long-belt system, the higher CRK speed, the greater belt transverse displacement.

Drying of Woody Biomass for Bioenergy Using Packed Moving Bed Dryer: Mathematical Modeling and Optimization

Woody biomass in the form of chips has been recognized as one of the most promising resources for future energy. The woody biomass in a fresh state has an initial moisture content of 100–150% (dry basis) and this has to be reduced to 5–20% depending on the conversion technology used. A packed moving bed dryer was used in commercial drying of the woody biomass. In this work, a mathematical model was developed and numerically solved to simulate the packed moving bed drying process. From the model, wood temperature, moisture content, air humidity, and temperature were predicted as a function of bed depth and along the belt length reflected by drying time. The model has been applied to improve dryer design and drying operation. The results show that optimized drying can be achieved by using a countercurrent reversed flow configuration; thus, lower air flow rate can be used to achieve the required drying.

An approach to reliability evaluation of multiple V-belt drives considering the deviation of belt length

Multiple V-belt drives are applied widely to the mechanical engineering industry. To improve their performance and reduce their risk in the course of running, some reliability models of multiple V-belt drives have been presented in recent years. In these models the lengths of individual belts in a multiple V-belt drive were regarded as identical. However, in practice the length deviations among individual belts in a multiple V-belt drive do exist. In this paper, the effect of belt length deviation on the transmitted power of a multiple V-belt drive is analysed in detail. The operation risk of a multiple V-belt drive is defined as the probability that the actual transmitted power is less than the rated power that ensures the multiple V-belt drives to perform its intended task. Then an approach to risk evaluation of a multiple V-belt drive is presented by using the universal generating function technique and the reliability model of a multistate weighted k-out-of- n system. Finally, the effectiveness of this approach is demonstrated by an example.

Parametric Instability of an Axially Moving Belt Subjected to Multifrequency Excitations: Experiments and Analytical Validation

This paper experimentally investigates the parametric instability of an industrial axially moving belt subjected to multifrequency excitation. Based on the equations of motion, an analytical perturbation analysis is achieved to identify instabilities. The second part deals with an experimental setup that subjects a moving belt to multifrequency parametric excitation. A data acquisition technique using optical encoders and based on the angular sampling method is used with success for the first time on a nonsynchronous belt transmission. Transmission error between pulleys, pulley/belt slip, and tension fluctuation are deduced from pulley rotation angle measurements. Experimental results validate the theoretical analysis. Of particular note is that the instability regions are shifted to lower frequencies than the classical ones due to the multifrequency excitation. This experiment also demonstrates nonuniform belt characteristics (longitudinal stiffness and friction coefficient) along the belt length that are unexpected sources of excitation. These variations are shown to be sources of parametric instability.

Time-dependent constitutive modeling of drive belts – I. The effect of geometry and number of loading cycles

This paper presents constitutive modeling of dynamically loaded elastomeric products such as power transmission belts. During the normal operation of the belts certain segments of the belt structure are loaded with a tooth-like periodic (cyclic) loading. When the time-dependent properties of the elastomeric material “match” the time-scale of the dynamic loading a strain accumulation process occurs. The critical angular velocity is proportional to the ratio of the belt length to the common diameters of the pulleys. The magnitude of the strain accumulated in each loading cycle decreases with an increase in belt length. For a given belt geometry the critical angular velocity increases with the number of loading cycles. At the same time the magnitude of the accumulated strain decreases non-linearly as the number of loading cycles increases. However if the belt operates at or in the close vicinity of its critical angular velocity it will almost certainly fail!

Continuous weighing on a multi-stage conveyor belt with FIR filter

Today higher speed of operation and highly accurate weighing of packages during crossing a conveyor belt has been getting more important in the food and distribution industries etc. Continuous weighing means that masses of discrete packages on a conveyor belt are automatically determined in sequence. Making the proper use of new weighing scale called a multi-stage conveyor belt scale which can be created so as to adjust the conveyor belt length to the product length, we propose a simplified and effective mass estimation algorithm under practical vibration modes. Conveyor belt scales usually have maximum capacities of less than 80 kg and 140 cm, and achieve measuring rates of 150 packages per minute and more. The output signals from the conveyor belt scales are always contaminated with noises due to vibrations of the conveyor belt and the product in motion. In this paper digital filter of finite-duration impulse response (FEB) type is designed to provide adequate accuracy. The experimental results on conveyor belt scales suggest that the filtering algorithm proposed here is effective enough to practical applications. As long as spaces between successive products are set within a specified range, the products can be weighed correctly even if products having different lengths are transported in random manner.

コンベアライン上での連続質量測定

The continuous mass measurement of packages on a conveyor belt will become greatly important. In the mass measurement, the sequence of products is generally random. An interesting possibility of raising throughput of the conveyor line without increasing the conveyor belt speed is offered by the use of two or three conveyor belt scales (called a multi-stage conveyor belt scale). The multi-stage conveyor belt scale can be created which will adjust the conveyor belt length to the product length. The conveyor belt scale usually has maximum capacities of less than 80kg and 140cm, and achieves measuring rates of more than 150 packages per minute and more. The output signals from the conveyor belt scale are always contaminated with noises due to vibrations of the conveyor and the product to be measured in motion. In this paper an employed digital filter is of Finite Impulse Response (FIR) type designed under the consideration on the dynamics of the conveyor system. The experimental results on the conveyor belt scale suggest that the filtering algorithms are effective enough to practical applications to some extent.

Method, apparatus, and program for estimating noise generation for a synchronous belt

A method, apparatus, and program for estimating noise generation for a synchronous belt having a length and teeth spaced along the belt length. The method includes the steps of: calculating belt displacement transversely to the belt length at or near a first location at which teeth on the belt mesh with teeth on a first cooperating toothed pulley; calculating a belt fluctuation velocity by correlating the belt displacement to a time frame; and calculating a radiated sound pressure level using the belt fluctuation velocity.

How the Conveyor Belt Length Affects Belt Weigher Accuracy

The length of a conveyor belt is analyzed as a function of where the belt weigher is located and recommendations are made for optimizing the choice of location, taking the belt stiffness into account.

An experimental study for measuring the natural frequency of the timing belt

A method to identify the natural frequency of a timing belt is developed. The method is simple and based on applying a lateral load at a suitable (middle) point between the camshaft wheel and the crankshaft wheel. The tension measurements together with the belt density and length provide necessary information in order to identify the natural frequency. The analytical method is also validated by experimental measurements of natural frequency. Results were found to be in a good agreement.

多連秤を用いた高精度質量計測(機械力学)

In the automatic weighing of packages in motion, the sequence of products is generally completely random. Long, short, heavy and light products are passed over the conveyor belt scale in any kind of random sequence. Through the multi-stage conveyor belt scale, a weighing scale can be created which will adjust the conveyor belt length to the product length. Our interest is directed to solve many technical problems when we put the multi-stage conveyor into practical use. Consequently, our weighing algorithm proposed here will give us an accurate and desirable performance with the possible improvements.

Analysis of the accessory belt lateral vibration in automotive engines

Having established the measurement technology to measure accessory belt behavior using laser displacement measurement methods, we were able to clarify the mechanism of the belt lateral vibration, which is one of the causes of a belt running off the pulley, by analyzing the correlation between the belt's behavior and fluctuations in input to the belt and by performing belt behavior simulation. We confirmed that the belt vibrates laterally if the accessory belt's natural frequency is equal to 1 2 of the frequency of belt vibration length fluctuation caused by crankshaft torsional and the value of the belt lateral vibration becomes larger in proportion to the value of the belt length fluctuation. We also found that lateral vibration occurs due to the existence of a natural vibrational mode in the lateral motion of the belt itself.

Modular Application of Moving-Belt Plasma-Facing Components for Particle and Heat Removal from a Steady-State Fusion System

Discussed in this report is the possibility of modular application of moving-belt plasma-facing components for a steady-state magnetic fusion device. Individual modules will provide specific functions such as particle control and heat removal. Modular-by-modular operational windows concerning belt length, moving speed, plasma exposure length and surface temperature have been analyzed in detail.

Contact-Induced Nonlinearity in Oscillating Belts and Webs

This study is motivated by issues in belt dynamics and paper forming where the oscillatory motion of the contact point between the belt and pulley or the web and roll is important. The objective is to evaluate the influence of the nonlinear contact boundary conditions on the dynamics of the belt or web. To accomplish this objective, two models are analyzed using perturbation methods. The first model represents a string on an elastic foundation (an approximation of the paper forming process) and the second model represents a tensioned beam (accessory drive belt). The first correction to the fundamental natural frequency and the dynamic belt/web length are determined as a function of the governing parameters. For both models, the change in belt length is found to be proportional to the radius of the pulley/roll and the initial belt/web energy.