Contact Roller Research Articles

Dynamic behavior analysis of the winding system during filament reversing pushed by the traverse mechanism

The filament bundle is a kind of fiber assembly with an ultrahigh length–diameter ratio. For textiles, the filament is an intermediate product in the textile production process. For ease of storage, transportation and subsequent processing, the filament is wound to form a disc-shaped package with a certain size. During winding, the high-speed moving filament is placed precisely on the cylindrical surface of the package with the spiral shape by the traverse mechanism. Unfortunately, uneven tension of the filament during reversing is caused by the action of the traverse mechanism, which directly affects the quality of the filament package. In this article, the approach of modeling and simulating the filament winding system was proposed, of which the element model of the filament was established by the absolute node coordinate formulation, considering its viscoelasticity, as well as the effect of gravity. The contact model between the filament and the rotary vane, as well as the contact roller, was established by the Hertz law. The equations of motion for the system were derived by the Lagrange equations, and the algorithm for solving the differential-algebraic equations was further derived. Then, the dynamic behavior of the winding system during reversing was simulated and analyzed, and the results show that the moving filament is in non-contact with the rotary vane at the moment of reversing, and the small fluctuation in contact force between the rotary vane and the filament causes the large fluctuation in the filament tension. Finally, the validity is tested through an experiment.

Identification of dynamic contact parameters between contact roller and filament package

During the high-speed winding of polyester filament, a contact roller must be applied to press on the filament package’s surface to ensure the filament is placed stably and precisely on the package surface. Thus, a twin-rotor system with contact coupling characteristics between the contact roller and the filament package is formed. Identifying the contact parameters between the contact roller and the package are prerequisite to precisely analyze the dynamic behavior of the winding system, as well as to determine the technical parameters. In this paper, an approach was proposed to identify the equivalent contact stiffness and contact damping coefficients by means of coordination through experiment and simulation. First, based on the forced non-resonance method of a single-degree-of-freedom system, the testing scheme was drawn up in consideration of the winding process parameters. Then, an experimental device for the twin-rotor system was developed, and the dynamic contact parameters just in the working frequency band corresponding to low linear speed of winding were obtained by the experiment, due to the requirement of the forced non-resonance theory and economic limitations of the experimental device. Third, the basic parameters including equivalent radial Young’s modulus and damping ratio of the package were obtained through experimental test. Furthermore, the contact parameters in the working frequency band corresponding to high linear speed of winding were obtained through simulation. Finally, the curve fitting of contact parameters was finished; in addition, the comparative results between the simulation and the experiment are in good agreement. The dynamic contact parameters present nonlinear frequency variation characteristics.

A dynamic modeling approach for a high-speed winding system with twin-rotor coupling

This paper continues the previous study and presents a dynamic modeling approach for a high-speed winding system. To meet the requirements of high-speed winding, a twin-rotor coupling structure is adopted in the winding system. It is a complex spindle system, due to its high speed, heavy load, frequency-dependent coupling parameters, and time-varying rotational speed. In this paper, an approach to establishing a finite element model of the winding system is proposed to predict its dynamic behavior characteristics during the winding process. First, the spindle and contact roller models of the discrete single component are developed based on Timoshenko beam theory. Bending, transverse shear effects, and gyroscopic moment are considered in the models. The contact stiffness between the contact roller and the packages to be wound on the spindle is simplified by a nonlinear spring. The contact stiffness is identified by dynamics analysis in ANSYS® 17.0. Next, a fully dynamic model of the winding system, which consists of the spindle subsystem, the contact roller, and the flexible coupling elements, is established. Third, the Newmark method is used to develop the program to solve the dynamic equations in MATLAB® 2013b. Finally, the effects of the supporting system and contact state on the winding system's dynamic response are investigated. The results indicate the model of the winding system presented in this paper is suitable for predicting dynamic performance during the winding process.

Modelling deep groove ball bearing localized defects inducing instantaneous angular speed variations

Instantaneous angular speed (IAS) analysis has been presented as an advantageous tool for non-stationary machinery surveillance. The physical analysis indicates that the instantaneous rotating speed variations are caused by torque perturbations. In a previous work, a method for introducing angular periodic disturbances in rotating systems dynamic models was presented. This analysis was based on the introduction of a parametric perturbation applied to the system as an external torque. The current work introduces an original formulation to induce tangential forces to the shaft due to the bearing components dynamics by means of a Hertzian contact roller bearing model. The methodology takes into account rotational bearing races and rolling elements degrees of freedom, making the model suitable for non-stationary conditions.

Technology in Contact Roller Charging Device of Electrophotographic Printer

Technology in Contact Roller Charging Device of Electrophotographic Printer

엔지니어링 세라믹스의 경면연마를 위한 효율적인 슈퍼피니싱 조건의 결정

The Engineering ceramics have some excellent properties as materials for modern mechanical and electrical components. It is, however, not easy to polish them efficiently because they are strong and hard. This study is carried out to obtain a mirror surface on engineering ceramics by surperfinishing with high efficiency. To achieve this, we conducted a series of polishing experiments using representative engineering ceramics, such as <TEX>$Al_2O_3$</TEX>, SiC, <TEX>$Si_3N_4$</TEX> and <TEX>$ZrO_2$</TEX>, using diamond abrasive film from the perspective of oscillations peed, the rotational speed of the workpiece, contact roller hardness, contact pressure and feed rate. Furthermore, the polishing efficiency and characteristics for engineering ceramics are discussed on the basis of optimal polishing time and surface roughness. Our results confirmed that efficient superfinishing conditions and polishing characteristics of engineering ceramics can be determined.

Influence of Different Viscosity Lubricant to Finite Line Contacts on Elastohydrodynamic Lubrication (EHL) under Oscillating

To make further researches into the elastohydrodynamic lubrication properties of a finite line contact roller, oscillating experiments were carried out on made overload experimental rig for oil film measurement using optical interference technique. Film thickness and shape were measured in two kinds of viscosity polyisobutylene. This study indicates that both lubricant viscosity and roller entrainment velocity play an important role on EHL of finite line contacts. On motion, the more increase in viscosity or speed, the thicker the oil film thickness, simultaneity edge effect is distinctly intensified and film thickness increases less on roller end, difference of the film thickness is increased between roller end and the central. Above two parameters are significant for logarithmic profile roller in crowning design.

Haptic Edge Sharpness Perception with a Contact Location Display.

The effect of contact location information on virtual edge perception was investigated in two experiments. In Experiment 1, participants discriminated edge sharpness under force-alone and force-plus-contact-location conditions using a 4.8 mm radius contact roller. Virtual objects were 2D profiles of edges with two adjoining surfaces. For both conditions, the Just Noticeable Difference (JND) in change of edge radius increased from 2.3 to 7.4 mm as edge radii increased from 2.5 to 20.0 mm; there was no significant difference between the two conditions. A follow-up experiment with contact location alone resulted in higher edge sharpness JNDs. In Experiment 2, the same edge sharpness discrimination task was performed using a smaller contact roller (R = 1.5 mm) to investigate the effect of roller size. The JNDs for the smaller roller were not statistically significant from those of the larger roller. Our results suggest that 1) contact location cues alone are capable of conveying edge sharpness information, but that force cues are dominant when both types of cues are available; and 2) the radius of the contact roller does not significantly affect the user's ability to discriminate edge sharpness, indicating that the participants could use the changes in contact location to judge curvature.

Spherical Head Surface Roughness Analysis and Experimental Research Based on the Abrasive Belt Grinding

Surface roughness is one of the most important parameters in grinding, which directly affects the quality of the processed surface and has quite a lot of effect on the shape and position accuracy, installation accuracy of the workpiece. In the grinding process, the surface roughness is formatted from the abrasive which effects on the surface of spherical head, and is the result of mutual interference between abrasive and spherical head. Many factors affect the surface roughness, such as the shape and size of contact roller, abrasive morphology, grinding method, the stiffness of machine tool and workpiece, abrasive wear and vibration in the machining process. All of these have an impact grinding surface roughness. In this paper, analyzed the belt speed, workpiece speed, abrasive size, workpiece diameter, sand-planting density on the surface roughness of spherical head in experimental. And the effect trend of factors on surface roughness of workpiece was analyzed. Some valuable information was provided for selecting suitable parameter in spherical head grinding.

The Design of a Milner CVT using Simulation Based Design of Experiments

The Milner continuously variable transmission (MCVT) is a traction drive transmission based on rolling contacts analogous to those found in angular contact roller bearings. The MCVT is applicable to very high power density applications or those with demanding packaging constraints, due primarily to the existence of multiple traction contacts on each of the rolling elements. The transmission has been modeled analytically and then Design of Experiments (DoE) techniques have been applied to create response surface model sets describing performance criteria over a wide range of design input factors. The response surface models have then been interrogated to find optimal solutions. The results show that it is possible to create a transmission with a significantly higher ratio range (10:1), compared with 5:1 that is typical for existing designs. The results also indicated that the traction patch spin factor could also be reduced over the existing designs and it is hypothesized that this should lead to an increase in efficiency. Finally, research into the stresses set up by the rolling contact indicated that stress is highest at the greatest reductions in ratio and that maximum stress appears to be proportional to the ratio range of the transmission. Hence a design optimization tool has been developed allowing engineers to rapidly optimize geometries of the MCVT to achieve desired trade-offs between ratio range, ratio position, transmission life/durability and transmission efficiency.

Design and Fabrication of Micro Optical Film by Ultraviolet Roll Imprinting

With increasing demand for large-scale functional optical films with microstructure in the field of flat panel displays, a technology capable of fabricating large-scale polymeric micro-patterns has received much attention. To fabricate large-area micro-optical films, we designed and constructed an ultraviolet roll imprinting system consisting of a roll stamp, a material dispensing unit, a pair of flattening rollers, a contact roller, and a releasing roller. Two methods for fabricating roll stamps were considered: direct machining of the roll base and wrapping a flat stamp around the roll base. As practical examples of the roll imprinting process, we designed and fabricated a lenticular lens array, a pyramidal pattern, and a microlens array, and measured and analyzed their geometrical and optical properties. Our results suggest that the proposed UV roll imprinting process is a feasible method for mass producing large-scale functional optical films.

Experimental and Numerical Study of Multibody Contact System with Roller Bearing–-Part II: Semi-Finite Element Analysis and Optimal Design of Housing

A typical roller bearing system consists of five contact parts: the housing, outer ring, inner ring, roller set, and the shaft. A finite element calculation procedure is described to analyze a five-body contact roller bearing system. If an analytical solution is used to calculate the deformations of the roller and the ring/shaft combination, a semi-finite element governing equation can be derived by simplifying the five-body contact bearing system into a three-body contact system. The semi-finite element calculation results correlate closely with the test results obtained in Part I of this paper (1). The analysis indicates that the initial gap between the housing and the outer ring and the loading positions have significant influence on the load distribution in the bearing. By optimal design of the housing, the load distribution becomes more uniform and the fatigue life of the bearing can be increased. Presented at the 50th Annual Meeting in Chicago, Illinois May 14–19, 1995

Pitting of a thermally refined steel roller. Further investigations by specific sliding varying-type contact roller tests.

Thermally refined steel rollers were fatigue-tested under varying specific sliding conditions using a newly developed specific sliding varying-type contact roller testing machine to which an eccentric gear mechanism was applied. The test results were discussed in relation to factors such as specific sliding and frictional torque changes. The surface durability of the roller under a varying specific sliding condition was lower than that under a constant specific sliding condition. The surface durability under a condition where specific sliding was negative on a non-uniform velocity roller was lower than that under a condition of negative specific sliding on a uniform velocity roller. The pitting easily occurred in the negative specific sliding region under high tangential force and at the deceleration process of the rotating roller.

Surface durability and surface failure of a thermally refined steel roller using a variable specific sliding type contact roller testing machine : Yoshida, A. and Fujita, K.JSME Int. J. III Mar. 1989 32, (1), 106–112

Surface durability and surface failure of a thermally refined steel roller using a variable specific sliding type contact roller testing machine : Yoshida, A. and Fujita, K.JSME Int. J. III Mar. 1989 32, (1), 106–112

A monitoring system for contact fatigue crack testing

A new monitoring system is developed to detect crack initiation and propagation in the surface layer during contact fatigue running. The magnetic head of a commercial tape recorder is used as a probe. A combination of leakage and eddy current methods is ussed for the contact roller specimen on the JPM-1 machine. Experimental results show that this system is very sensitive to artificial defects and can distinguish defects on the surface from those beneath the surface. The defect signals agree well with their positions. Testing of an ion-nitrided specimen shows that a tiny subsurface crack (∼ 1 μm), which can only be examined under a microscope with 200 × magnification, is observable with this system.

Surface durability and surface failure of a thermally refined steel roller using a variable specific sliding type contact roller testing machine.

Thermally refined steel rollers are fatigue tested under three sliding-rolling contact conditions while varying the specific sliding during the rotation of a test roller by using a newly produced variable specific sliding type contact roller testing machine. With this method, the surface durability under each condition is elucidated. The test results obtained here are compared with the results obtained by a conventional rolling contact fatigue test with constant specific sliding. The relationships between the characteristics, such as frictional torque under each variable specific-sliding condition, and the surface roughness and pitting distribution on the test roller are discussed. The surface durabilities under variable specific-sliding conditions are lower than those under a constant specific-sliding condition. The roller surface roughness tends to be lower at a position of higher absolute value of specific sliding, and the amount of pitting tends to be greater at a position of higher absolute value of frictional torque.

Surface durability and surface failure of nitrided steel roller by using a specific sliding varying type contact roller testing machine.

Nitrided steel rollers were fatigue-tested under three kinds of specific sliding varying conditions using a specific sliding varying type contact roller testing machine. The surface durability under each condition was elucidated. The test results under these specific sliding varying conditions were compared with the result obtained under a constant specific sliding condition. The relationships between the characteristics such as frictional torque change and the spalling failure and surface roughness on the rollers were examined. The surface durabilities under specific sliding varying conditions were lower than that under a constant specific sliding condition. The spalling failure tended to occur at a position of higher absolute value of frictional torque. The roller surface roughness tended to be lower at a position of higher absolute value of specific sliding.

Surface durability and surface failure of a thermally refined steel roller using a specific sliding varying type contact roller testing machine.

Thermally refined steel rollers were fatigue-tested under three sliding-rolling contact conditions while varying specific sliding during the rotation of a test roller, using a newly produced specific sliding varying type contact roller testing machine, and the surface durability under each condition was elucidated. The test results obtained under these varying specific sliding conditions were compared with the results obtained by a conventional rolling contact fatigue test with a constant specific sliding. The relationships between the characteristics such frictional torque change under each varying specific sliding condition and the surface roughness and pitting distribution on test rollers were discussed. The surface durabilities under varying specific sliding conditions were lower than those under a constant specific sliding condition. The roller surface roughness tended to be lower at a position of higher absolute value of specific sliding, and the pitting tended to be more formed at a position of higher absolute value of frictional torque.

Trial production of a specific sliding varying type contact roller testing machine and its characteristics.

In the case of a general roller testing machine which is- employed at researching the tooth surface fatigue of gear materials, the specific sliding on test roller is constant during a rotation of the test roller. In this report, a new roller testing machine which can give a continuously varying specific sliding to the test roller was developed using an eccentric gear mechanism and its characteristics were elucidated. In this new type machine, the specific sliding of the test roller changes continuously in the ranges of -125% to 0%, -50% to +33% and 0% to +56 %. The minimum oil film thichness between the test rollers changes during a rotation of the roller with the change of circumferential velocity ratio of the roller pair. The change of the tangential force between the rollers during a rotation of the roller depends upon the changes of the normal force and the friction coefficient between the rollers.

Surface Durability and Surface Failure of Rolling Contact Roller Rotated at Non-uniform Velocity

In the case of a common rolling contact fatigue testing machine, the roller is rotated at uniform velocity. In this research the roller was rotated at non-uniform velocity by applying an eccentric gear mechanism to the machine in order to bring about a contact condition of rollers close to that of gears. Specific sliding of the roller was so adjusted as to change continuously from 0 % to -125 % during one rotation. Under this condition the rolling contact fatigue tests were performed using thermally refined and induction-hardened steel rollers. The roughness change of the roller and the surface failure were discussed in relation to the specific sliding.