Flat Belts Research Articles

Modelling the Belt – Envelope Interactions during the Postal Mail Conveying by a Sorting Machine

The purpose of this study is to predict the trajectory of an envelope when conveyed between two flat belts in a mail sorting machine. Each of the two sides of the envelope is in contact with one belt. The friction coefficient can vary between the two sides, e.g. for the cases of a postcard or a plastic windowed envelope. The two belts are assumed to travel horizontally with the same velocities, but in real world small velocity differences can occur. Also, some deviation from the horizontality of the belts can be observed. These phenomena can lead to unexpected situations where the relative position of the envelope to the belt changes during transportation. The work focuses on the belt-envelope mechanical interactions in order to predict the envelope position during its conveying. A 2D model is developed which considers the dynamic equilibrium of the envelope and simulates the transient behavior at different locations in the sorting machine. In the dynamic friction model, the contact surfaces between the envelope sides and the belts have to be determined at each time step. The belt/envelope friction forces are applied at the centers of these contact surfaces One side of the envelope is considered stuck (in adhesion) to the belt while the other is considered slipping. The position of the envelope center of gravity and the angle with the horizontal axis are calculated. For evaluation of the proposed dynamic model, several cases of operation are simulated.

Effect of Flat Belt Thickness on Steady-State Belt Stresses and Slip

A necessary condition for high-fidelity dynamic simulation of belt-drives is to accurately predict the belt stresses, pulley angular velocities, belt slip, and belt-drive energy efficiency. In previous papers, those quantities were predicted using thin shell, beam, or truss elements along with a Coulomb friction model. However, flat rubber belts have a finite thickness and the reinforcements are typically located near the top surface of the belt. In this paper, the effect of the belt thickness on the aforementioned response quantities is studied using a two-pulley belt-drive. The belt rubber matrix is modeled using three-dimensional brick elements. Belt reinforcements are modeled using one-dimensional truss elements at the top surface of the belt. Friction between the belt and the pulleys is modeled using an asperity-based Coulomb friction model. The pulleys are modeled as cylindrical rigid bodies. The equations of motion are integrated using a time-accurate explicit solution procedure.

Design and Fabrication of a Real-Time Measurement System for the Capsaicinoid Content of Korean Red Pepper (Capsicum annuum L.) Powder by Visible and Near-Infrared Spectroscopy.

This research aims to design and fabricate a system to measure the capsaicinoid content of red pepper powder in a non-destructive and rapid method using visible and near infrared spectroscopy (VNIR). The developed system scans a well-leveled powder surface continuously to minimize the influence of the placenta distribution, thus acquiring stable and representative reflectance spectra. The system incorporates flat belts driven by a sample input hopper and stepping motor, a powder surface leveler, charge-coupled device (CCD) image sensor-embedded VNIR spectrometer, fiber optic probe, and tungsten halogen lamp, and an automated reference measuring unit with a reference panel to measure the standard spectrum. The operation program includes device interface, standard reflectivity measurement, and a graphical user interface to measure the capsaicinoid content. A partial least square regression (PLSR) model was developed to predict the capsaicinoid content; 44 red pepper powder samples whose measured capsaicinoid content ranged 13.45–159.48 mg/100 g by per high-performance liquid chromatography (HPLC) and 1242 VNIR absorbance spectra acquired by the pungency measurement system were used. The determination coefficient of validation (RV2) and standard error of prediction (SEP) for the model with the first-order derivative pretreatment method for Korean red pepper powder were 0.8484 and ±13.6388 mg/100 g, respectively.

Determination of the belt force before the gross slip

The mechanics of belt friction before the state of gross slip is considered. The variation of the belt force within the contact region is evaluated based on the assumption of gradual growth of slip from the pull-end to the hold-end of the belt, as the pull force increases towards its Euler's value. The local pressure and friction forces exerted by the belt on the cylinder are also determined. Both flat and V-shaped belts are considered. The total pressure and friction forces are evaluated at an arbitrary stage of slip growth. They are neither proportional nor orthogonal to each other, unless the state of gross slip is reached throughout the contact range.

Cleaning of Conveyor Belt Materials Using Ultrasound in a Thin Layer of Water

Cleaning of conveyor belts in the food industry is imperative for preventing the buildup of microorganisms that can contaminate food. New technologies for decreasing water and energy consumption of cleaning systems are desired. Ultrasound can be used for cleaning a wide range of materials. Most commonly, baths containing fairly large amounts of water are used. One possibility to reduce water consumption is to use ultrasonic cavitation in a thin water film on a flat surface, like a conveyor belt. In order to test this possibility, a model system was set up, consisting of an ultrasound transducer/probe with a 70-mm-diameter flat bottom, operating at 19.8 kHz, and contaminated conveyor belt materials in the form of coupons covered with a thin layer of water or water with detergent. Ultrasound was then applied on the water surface at different power levels (from 46 to 260 W), exposure times (10 and 20 s), and distances (2 to 20 mm). The model was used to test two different belt materials with various contamination types, such as biofilms formed by bacteria in carbohydrate- or protein-fat-based soils, dried microorganisms (bacteria, yeasts, and mold spores), and allergens. Ultrasound treatment increased the reduction of bacteria and yeast by 1 to 2 log CFU under the most favorable conditions compared with water or water-detergent controls. The effect was dependent on the type of belt material, the power applied, the exposure time, and the distance between the probe and the belt coupon. Generally, dried microorganisms were more easily removed than biofilms. The effect on mold spores was variable and appeared to be species and material dependent. Spiked allergens were also efficiently removed by using ultrasound. The results in this study pave the way for new cleaning designs for flat conveyor belts, with possibilities for savings of water, detergent, and energy consumption.

Analysis on Skew of Flat Belts in Two-Pulley Drives

A troublesome problem in flat belt transmission is a phenomenon known as skew, where the belt moves along the axial direction of the pulleys in operation. Skew usually is caused by angular misalignment of pulleys. Angular misalignment can be classified in two types, in-plane misalignment and out-of-plane misalignment. The former is where the axes of a pulley pair, driving and driven, are in the same plane but not parallel. The latter is where the axes of pulleys are not in the same plane. In this paper, both cases of the belt skew caused by out-of-plane and in-plane misalignment are addressed. Theoretical analyses are provided following discussions of the simulation results by finite element method. It is found: (1) in case of out-of-plane misalignment, the skew ratio, an index describing the degree of skew, is determined by a very simple formula in which only three geometrical parameters are required; (2) in case of in-plane misalignment, the skew is much more complicated than that in case of out-of-plane misalignment, and the skew ratio is determined by a system of nonlinear simultaneous equation. An iteration method for solving the system of nonlinear simultaneous equations is proposed. The theoretical analyses for both cases are verified with the FEM results and factors that influence the skew are discussed.

Calculation of trough conveyor belts

The solution of an initially stressed trough conveyer belt using a Chernenko model is suggested. The bending load of an initially flat belt on the working area on a cylindrical shell was found by the expansion method. The usage of the Bubnov-Galerkin variational method permitted the deduction of the analytical dependence of deflection values, with allowance for loads caused by the initially flat belts bending at the shallow cylindrical shell.

Synthesis of trans-1,4-cyclohexanedisulfonic acid and its zinc salt – A belt-like metal–organic coordination polymer with tetrahedrally and octahedrally coordinated zinc ions

Diastereomerically pure trans-1,4-cyclohexanedisulfonic acid H 2CDS was prepared in three steps from 1,4-cyclohexanediol ( cis/ trans-mixture) as a new linker molecule for metal–organic coordination polymers. The crystalline zinc salt contained two molecules DMF per formular unit. Infinite polymeric belts were observed in the solid state structure of [Zn(CDS)(dmf) 2]. These flat belts were formed by connecting two chains of Zn(dmf)-CDS-polymers bearing tetrahedrally coordinated Zn 2+ ions in one chain and octahedrally coordinated Zn 2+ centers in the second. Thermal analysis of this polymer revealed its stability up to 400 °C, above which it decomposed cleanly under formation of crystalline ZnO.

Influence of tangential pliability of the contact layer on the tractional properties of a flat-belt transmission

For drive belts, we obtain the formulas required to plot the slip curve in the range from zero to the critical tractional coefficient. If we know the frictional coefficient of the belt at the pulley and the elastic modulus of the belt in tension, we may use the formulas to design transmissions based on flat belts made of different materials, without the need for expensive slip tests.

S1101-1-2 μ-V特性を用いた摩擦伝動ベルトの伝達性能予測(伝動装置の基礎と応用セッション1)

It has already reported in previous paper that the performance of a factional power transmission belt such as flat or V-ribbed belts at 2 % slippage can be analytically predicted and the results well coincide with the measured ones. In this report it is shown that the performance curve relating slip ratio and transmitted torque can be obtained by using the analytical expression and μV characteristics relating friction coefficient and slip velocity.

Simulation of Flat Belt Running

This paper deals with the lateral running behaviour of flat belts which can be found in industrial production processes (such as steel, paper or plastics) as continuous running process bands as well as transport bands for conveying purposes. Without any guidance measures, flat belts supported and driven by cylindrical pulleys run in an unstable condition, therefore angled pulley systems are employed for flat belt guidance. This paper deals with a mechanical simulation model for the guiding effect of a three‐pulley configuration with the focus on the geometrical‐mechanical relations. The belt's lateral movement as well as its bending stress during the guiding process is calculated. The aim of this investigation is to select pulley positions and shift directions that have adequate steering features despite low belt strain. To avoid instable lateral running conditions when applying an automatic controlled guidance system, proper positions for the belt edge detector are discussed. This paper is a cooperation between Vienna University of Technology, Upper Austria University of Applied Sciences and industrial partners who employ angled pulleys for flat belt guidance. The presented simulation method has been successfully applied for the optimisation of the configuration of the pulleys for a flat steel process belt in the new development of a drying system.

Microslip friction in flat belt drives

The microslip shear model of belt mechanics is extended to fully incorporate belt inertia effects and used to analyse the steady state of a two-pulley drive. The belt is modelled as an axially moving string consisting of a tension-bearing member and a pliable elastomer envelope. Relative displacement between the tension-bearing member and the pulley surfaces shears the elastomer envelope, transferring the friction from the pulley surface to the tension-bearing member. The belt-pulley contact arcs consist of adhesion and sliding zones. Static friction exists in the adhesion zones, whereas kinetic friction exists in the sliding zones. An iteration method involving one outer and two inner loops is proposed to find the steady mechanics, including the sliding and adhesion zones, belt-pulley friction, and belt tension distribution. The outer loop iterates on the tight span tension similar to that used in published creep models. Two inner loops iterate on the tight span and driven pulley speeds respectively, necessitated by the speed differences between the tension-bearing member and the pulley at the entry points in the shear theory. Comparisons between the shear and creep models are conducted. Dramatic differences in belt-pulley mechanics between these two models are highlighted. Nevertheless, the key system performance measures such as the belt tight/slack span tensions, the maximum transmissible moment, and efficiency differ only modestly for the most normal operating conditions. Correspondingly, the adoption of the creep model for flat belts in industry is well justified because it is well developed and simple, although the shear model seems more relevant for modern belts with grid layers.

Finite element analysis of belt skew caused by angular misalignment of rollers

In machines that handle flexible media with flat belts, it is necessary to prevent belt skew for the machines to operate at higher precision and maximum efficiency. However, the skewing mechanism has not yet been clarified. Therefore, in order to establish a method that could be used to analyse the skew of a flat belt, a simulation system is developed using a commercial finite element code (MARC). Also, the skew mechanism in two- and three-roller systems is also studied through simulations and clarified to show that the skew rate equals the spiral angle of the belt wrapping around the roller. Moreover, it is found that a steering roller that is set in an optimal position is needed to reduce belt skew efficiently. The analytical method and the findings from this study are useful in designing any flat-belt mechanism.

Mechanical Design of Machine Elements and Machines: A Failure Prevention Perspective

Mechanical Design of Machine Elements and Machines: A Failure Prevention Perspective

Gap Control System for Transported Paper Sheet with a Pair of Flat Belts.

A machine that transports paper sheet by using a pair of flat belts, handles various paper sheet with regard to size, thickness and texture. This often causes the gap between the sheets to change when it is transported over a long distance. If the gap becomes shorter than a certain threshold value, it causes sheet jam. We have therefore developed a gap control system that determines the transport distance of sheets and measures the gap change before the sheets reach the gap controller. Using thses information, it estimates the gap change after the gap controller and sets a target value. The contoller varies the transport velocity in an optimum pattern and controls the gap to the target value. We applied the system to a transport route and it reduced the standard deviation of gap into 2/3.

Three-dimensional Stokes flow in a cylindrical container

Consider a cylindrical container of circular section filled with a viscous fluid. We consider flow in such a cylinder driven by the motion of flat belts across the partially open end walls of the container. The flow field is determined by the use of a vector eigenfunction expansion. The critical points that are exhibited in the plane of symmetry include elliptic points, foci, and saddles. As the parameters are varied one can have bifurcations in which one type of critical point bifurcates to a collection of others. An example of a limiting surface is also demonstrated. Since the flow fields considered have little symmetry, the three-dimensional streamlines are for the most part not closed. As a consequence the flow fields tend to globalize structures that would otherwise have been isolated. This feature can have important consequences for mixing.

An introduction to flexible couplings

The basic function of a coupling is to transmit torque from a prime mover (eg. electric motor, steam turbine) to a functional machine (eg. pump, compressor). Indirect coupling of machinery, using flat or V-section belts or chain drives, is used extensively in some industries, but friction losses and slippage losses tend to reduce their efficiency. Direct coupling of machines overcomes these problems and also results in a more compact machinery layout.

Belt Slip—A Unified Approach

Slip measurements on thick flat belts, V-belts and V-ribbed belts running on small pulleys reveal that the slip is much higher than can be predicted with classical creep theory. Shear creep plays an important role and special care must be taken when analyzing the shear deflection of the V-belt and the ribs of the V-ribbed belt. Other mechanisms are present as well. The behavior in the seating and unseating regions changes the direction of the frictional forces in these regions on the driver pulley. A unified slip theory is presented for flat belts, V-belts and V-ribbed belts considering creep, shear, seating/unseating and compliance. Measurements and theory fit very well for practical tension levels. At low tension the measured slip is higher than the predicted one for V-belts and V-ribbed belts, which probably depends on the poor fit between the belt and the grooved pulley.

Rice Grain Threshing by Flat Belts Rubbing Mechanism

Rice Grain Threshing by Flat Belts Rubbing Mechanism

Transpression and extensional collapse: Steep belts and flat belts in the Appalachian Central Mobile Belt, northern New Brunswick, Canada

Models of the Appalachian-Caledonian Orogen infer oblique collision and an enigmatic reversal from sinistral (Silurian) to dextral (Devonian) transpression. The Miramichi Highlands in Canada are relevant to such models because (1) they are a subductional thrust complex in which the inferred reversal coincided with recumbent folding, and (2) its kinematic indicators include rotated thrust structures and conjugate sets of coeval structures. Both are easily mistaken as evidence for sinistral and dextral transpression. The thrust complex is part of the Appalachian Central Mobile Belt and is partitioned into steep belts and flat belts according to the attitude of the schistosity. We argue that the steep belts are coeval with Late Silurian plutonism and low-pressure metamorphism, representing transpressional zones (D 2 ) in which the extension lineation of D 1 thrusting was tilted twice: first from gentle to steep, then back to a gentle plunge. The transpression was synchronous with exhumation as well as sedimentation. Flat belts represent a later flattening (D 3 ) that probably resulted from extensional collapse and preceded Early Devonian dextral transpression (D 4 ) along the Central Mobile Belt. Our model for the flat belts differs principally from models proposed for equivalent flat belts in Newfoundland.