Wiper Blades Research Articles

Effect of elastic deformation on squeezing film lubrication properties of soft tribocontacts with microstructured surface

PurposeInspired by the high-friction performance of the soft toe pads of tree frogs, this study aims to investigate the effect of elastic deformation on the lubrication properties of squeezing films inside soft tribocontacts with microstructured surface under wet conditions.Design/methodology/approachA one-dimensional hydrodynamic extrusion model was used to study the film lubrication characteristics of conformal contact. The lubrication characteristics of the extruded film, including load-carrying capacity, liquid flow and surface elastic deformation, were obtained through the simultaneously iterative solution of the fluid-governing and deformation equations.FindingsThe results show that the hydrodynamic pressure is approximating parabolically and symmetrically distributed in the contact area, and the peak value appears in the center of the extrusion surface. Elastic deformation increases the thickness of the liquid film, weakens the bearing capacity and homogenizes the liquid flow rate of inside soft friction contact. The magnitude of this effect greatly increases as the initial liquid film thickness decreases. Moreover, the elastic deformation directly affects the average film thickness of the extrusion contact. Narrow and shallow microchannels are found to result in a more prominent elastic deformation on the microstructured soft surface.Originality/valueThese results present a design for soft tribocontacts suitable for submerged or wet environments involving high friction, such as wiper blades, in situ flexible electrons and underwater robots.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0049/

Vibration response analysis of boneless wiper-windshield system based on multi-body dynamics model

The vibration and noise generated by the boneless wiper-windshield system during its actual operation bother the occupants. Exploring the dynamic characteristics of the boneless wiper-windshield system is a prerequisite for understanding vibration and noise. In this paper, the dynamic characteristics of the boneless wiper-windshield system are investigated, and a rigid-flexible coupled multi-body dynamic model matching the real boneless wiper-windshield system is constructed. The friction characteristic of the dynamic model is studied through the wiper test bench experiment. The nonlinear dynamic response of the dynamic model is calculated with the Adams and results of the frictional vibration are well reproduced in real motions. The parallel analysis of the simulation calculation results and the real vehicle test results confirms the validity of the model. The results show that the vibration generation mechanism at the moments before and after the reversal can be explained by the instability of the wiper blades due to the negative friction characteristic. There are differences in the magnitude of the reversal impact force and the moment of reversal at each position of the wiper blade. The effect of the speed-gears on the system vibration is analyzed through the simulation results. The analysis method and simulation results in this article can provide reference for the research on vibration and noise control of boneless wiper systems.

The influence of contact distribution shaping on the dynamic response of a wiper blade

The primary function of windscreen wipers is to remove water and debris from the windscreen, ensuring the driver has a clear view of the road ahead. Predicting wiper performance at the design stage is therefore important to ensure their safe operation. There is hence a need to develop physics-based models of wiper performance that can be used as evaluative tools early in the design stage. This paper presents an analysis of the impact of changing screen curvature on the contact force distribution of a wiper blade and the subsequent effects on the transient dynamics. The contact distributions for three distinct screen curvatures and three loading points are calculated via FEA (finite element analysis) and subsequently analysed via multiple connected mass spring dampers to model the wiper blade lip transient dynamics. By analysing time and frequency domain data for several calculated contact distributions it is found that decreasing the screen curvature reduces the contact force at the centre of the blade, however, increases the amplitude of vibrations and range of frequencies observed. Additionally, it is found that moving the loading point towards the tip of the blade reduces the amplitude of vibrations, a result analogous to that of increasing the screen curvature. Based upon the understanding gained through this work the influence of design criteria on wiper blades can now be assessed, and several suggestions made as to how to reduce windscreen wiper noise.

Texture design of microgrooves to improve the tribological properties of wiper blades

Improving the tribological properties of windscreen wipers to achieve high visibility and low wiping noise is crucial for safe and comfort driving on rainy days. This study systematically investigated the effects of microgrooves on the tribological properties of rubber, similar to that used in wiper blades, sliding against glass in the presence of water. It was found that grooves with an orientation angle of 0° were highly beneficial for the wiping process of rubber blades. At low velocities, the grooves reduced the frictional resistance and restrained the propagation of Schallamach waves; however, at high velocities, frictional resistance existed, restraining forced wetting. These findings have significant implications for the development of high-performance windscreen wipers.

METHOD FOR ASSESSING WINDSCREEN ABRASIVE WEAR

This study addresses safety issues surrounding windscreens use and identifies factors affecting the wear rate for windscreens and windscreen wiper blades. Moreover, it presents an original method for bench-testing the windscreen wear process. The method allows tests to be carried out under near-operational conditions. The paper also describes an automated bench equipped with an abrasive dispenser and methods for measuring windscreen wear. Tests were conducted for the effects of quartz sand, marine sand and electro-corundum on the windscreen. It was demonstrated for marine sand and electro-corundum that even the short-term effect of these forcings on the windscreen reduced light penetration to a level of 70%, i.e., a critical value for windscreens. The change in the roughness Ra value during the impact of quartz sand on the pane was characterised by a much greater variability compared to the interaction of marine sand and electro-corundum. It was also demonstrated that the condition of wiper blades was related to the roughness of the windscreen. The summary presents conclusions concerning the research method described and the study results.

Experimental investigations and empirical modeling of rubber wear on concrete pavement

Material loss due to wear plays a key role in the service life of rubber components in various tribological applications, such as tires, shoe soles, wiper blades, to name a few. It also adversely affects energy consumption, economy, and CO2 emissions around the globe. Therefore, understanding and modeling the wear behavior of rubbers are important in the design of economic and environment-friendly rubber compounds. In this study, we investigated the effect of normal load and sliding velocity on the wear rate of rubber compounds widely used in the tire treads and evaluated the wear models previously proposed for rubbers to determine the best model to predict the rubber wear rate. The sliding wear rates of different types of Styrene-Butadiene Rubber (SBR) and Isoprene Rubber (IR) compounds on a broom finish concrete slab were measured for different sliding velocities and normal loads. The experimental results were used to evaluate and discuss different wear models proposed in the literature. A new empirical model was proposed to predict the wear rate by considering mechanical properties associated with rubber wear. The experimental results revealed that the wear rate of rubber compounds non-linearly depends on the normal load or friction force, while the effect of sliding velocity on the wear rate is not significant in the 20–100 mm/s range. Moreover, traces of both mechanical (abrasion) and chemical (smearing) wear were observed on all rubber compounds.

Design of Trash Removal System in Water Bodies Using Oil Skimmer

Abstract: Due to increase in populations, scenario of sanitation according to waste management treatment is degrading or deceasing tremendously. The river and ocean carry an enormous amount of garbage which creates unhygienic environment which highly affects the surroundings. The floating oils, dust and mass wastages on the river water surface will cause a serious problem to the environment which merely affects the future. Those detached wastes will not be submerged easily in water. So, these kinds of unsuspended objects will cut off the oxygen regulation in aquaculture medium so the oxygen deficiency occurs in the water surface which directly affects the marine life of animals and polluted the water. The idea that we proposed in this paper can be executed for both running and stagnant water in river. The major advantage of this paper is that the people of control station need not have to go to every nook and corner to clean wastes, instead can monitor from one point itself. After the oil skimmer machine laid on the surface of the water, the skimmer belt starts to revolve through motor set up and they suck all micro level wastes and dust particles like plastics, pins, etc in the water bodies. Oil skimmers are also used to remove oils that float on the surface of a liquid. Oil skimmers are essential one to remove oil from a liquid. In few scenarios, although, they may be used to pre – treat a fluid. In these cases, they eliminate as much of the oil as possible before expensive and time-consuming measures are implemented. The belt then proceeds through peculiar wiper blades, that eliminates the oil from both sides of the liquids Keywords: Trash removal, Marine life, Oil skimmer, Water Pollution, oxygen deficiency etc

A Review Paper on Design and Fabrication of Belt Oil Skimmer

Oil Skimming Although designs vary, all oil skimmers rely on specific gravity, surface tension and a moving medium to remove floating oil from a fluid’s surface. Floating oil and grease cling to skimming media more readily than water, and water has little affinity for the media. This allows skimming media in the shape of a belt, disk, drum, etc. to pass through a fluid surface to pick up floating oil and grease with very little water. This oily material is subsequently removed from the media with wiper blades or pinch rollers. Oil skimmers are simple, dependable and effective tools for removing oil, grease and other hydrocarbons from water and coolants. Often, an oil skimmer by itself can achieve the desired level of water purity. In more demanding situations, oil skimming is a cost-effective means of removing most of the oil before using more complicated and costly treatments such as coalescers, membrane filters and chemical processes. Grease skimming involves higher viscosity hydrocarbons. Oil skimmers must be equipped with heaters powerful enough to keep grease fluid for discharge. If the floating grease has formed into solid clumps or mats, a spray bar, aerator or mechanical apparatus can be used to break up grease mats and facilitate removal. This topic describes the development of the OS with typical working model.

An Automated Retrofittable Street Light Solar Panel Cleaner

Solar energy is the most abundant and constant source available, across the surface of the Earth. A Solar panel or PV module is an essential component that is being used for the conversion of sunlight directly into direct current (DC) electricity. A major drawback of solar panel system is its extremely low efficiency of conversion of light energy to electrical energy and its further drop when there is laxity of care and maintenance of the panels. This project is focused on designing and developing a sensor-based street light solar panel cleaning mechanism which can be added as a retrofit and requires minimal human interference to operate. The water-based system with a pair of wiper blades is mounted on a pair of lead screws which are rotated by a pair of servo motors which are powered by current drawn directly from the panel. The water is supplied by a tank fixed on the underside of the panel and a catchment dugout at the bottom end of the panel allows the run-off water to get collected after the cleaning operation. The system operates based on the information collected from a timer, voltage sensor, current sensor, and humidity sensor. The operational frequency of the system is based on the information provided by the sensor and varies based on the accumulation rate of particulate matter on the panel and the reduction in transmittance because of the same.

Technical pathways for distributed recycling of polymer composites for distributed manufacturing: Windshield wiper blades

Centralized waste plastic recycling is economically challenging, yet distributed recycling and additive manufacturing (DRAM) provides consumers with direct economic incentives to recycle. This study explores the technical pathways for DRAM of complex polymer composites using a case study of windshield wiper blades. These blades are a thermoplastic composite made up of a soft (flexible) and hard (less flexible) material. The distributed manufacturing methods included mechanical grinding to fused granular fabrication, heated syringe printing, 3-D printed molds coupled to injection molding and filament production in a recyclebot to fused filament fabrication. The particle size, angle of repose, thermal and rheological properties are characterized for the two sub-materials to define the conditions for the extrusion. A successful pathway for fabricating new products was found and the mechanical properties of the resultant components were quantified. Finally, the means to convert scrap windshield wiper blades into useful, high-value, bespoke biomedical products of fingertip grips for hand prosthetics was demonstrated. This study showed that the DRAM model of materials recycling can be used to improve the variety of solutions for a circular economy.

Computer simulation in producton process of wiper blades for cars

Computer simulation in producton process of wiper blades for cars

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Solar Powered Luo Converter for Wiper Motor Application

Objectives: This paper is to design a positive output elementary luo converter whose output can be used to power the wiper motor. Method/Statistical Analysis: The perturb and observe algorithm is used to obtain the maximum power from the solar panel. The positive output luo converter is simulated using MATLAB/Simulink software. Findings: In conventional converters the output voltage increases in arithmetic progression. But, in luo converter the output voltage increases in geometric progression, thus the voltage gain of the converter is enhanced than conventional converters. The output of the luo converter is validated with r-load and motor load. With the help of luo converter, the ripple content in the output can be highly reduced in the output. Applications: Wiper motors are used for applications such as to operate wiper blades in car, automatic parking system, wheel movement in robots etc.

Does theory work in practice? Two case studies

ABSTRACTCase studies offer an opportunity to review what worked and what didn't and to draw conclusions about what changes to make in future projects. This article presents two different studies. Each study explored the properties of a production process and each had a number of issues to be resolved before experimental runs could be performed. In the first case, the process was a continuous rubber extrusion line, producing windscreen wiper blades. Planning involved people on three different continents, so issues of building trust were paramount. Only a narrow time window was available for experimentation, so flexibility and a quick response to problems as they arose were needed. The second study was an off-line batch process aimed at producing polymers suitable for artificial corneas. There were two competing variables of interest. Previous attempts to improve the product had been piecemeal and unsuccessful, but a fractional factorial experiment provided guidance on a way forward. Subsequent runs then aimed to optimize the primary variable whilst holding the second variable constant. By comparing and contrasting these studies, many valuable lessons can be learned.

A Simple Mechanical Model for a Wiper Blade Sliding and Sticking Over a Windscreen

From the mechanical standpoint, wiper blades may be thought of as belonging to a category of systems in which some components are forced to slide with friction over each other or over some rough surface. Such systems, which are in widespread use in all areas of modern engineering, exhibit complex dynamic behavior, even when only a small number of degrees of freedom are involved. In this paper we reconsider a well-known, simple mechanical model in which a rigid block connected to a linear spring is free to slide over a rough surface. The surface moves according to a prescribed sinusoidal law. The model, despite its apparent simplicity, proves to be quite useful for studying the main dynamic features of such systems. In particular, herein the equations of motion are solved analytically and the exact sequence of sticking and sliding phases found. The influence on the solution of three dimensionless parameters chosen to describe the system is investigated, and some early indications provided on the set of possible long-term system responses. Lastly, a first evaluation of the different limit cycles for the block’s motion is illustrated.

Investigation of the dynamic behaviour of an automobile wiper system

A rigid-flexible multi-body system dynamic model of a passenger vehicle windscreen wiper system is established in this study to investigate the systems dynamic behaviour. To simulate the impact forces applied by the blades on the windshield and the pressure force distributions along the wiper blades, the blades are modelled as flexible bodies in consideration of their bend and twist deformations. On the basis of the dynamic analysis results, structure improvement measures, including changing the torsional stiffness of the neck of the blade segment and modifying the positions of the pivot points on the blades, are implemented to reduce the reversal impact and improve the wiping uniformity.

An Improved Axiomatic Design Approach in Distributed Resource Environment, Part 2: Algorithm for Functional Unit Chain Set Generation

To technologically achieve the transformation from functional requirements (FRs) to design parameters (DPs) in the axiomatic design (AD) theory, this paper employed the basic hypothesis, definitions and model developed in PART 1 of our study to establish an algorithm for functional unit chain set (FUCS) generation. This algorithm is established on two mappings from the developed conceptual foundation to the graph theory, i.e. treating functional units (FUs) as nodes, and treating connections between FUs as edges. With this two mappings, a graph consisting of FUs can be created, which is called the functional unit graph (FUG). Based on the depth-first search (DFS) strategy in the graph theory, the algorithm generating FUCSs from the FUG was finally established. As an additional function, a preliminary evaluation for the generated FUCSs was also proposed. To prove the feasibility of this algorithm, a solar-powered wiper blades, and the load module of a friction-abrasion testing machine were designed as illustrations.

Alan D. Roberts: 2014 Charles Goodyear Medalist

Dr. Alan Roberts, retired in 2005 from the Tun Abdul Razak Research Center (TARRC; formerly the Malaysian Rubber Producer's Research Association [MRPRA]), where he most recently served as Deputy Director, has been named the 2014 Charles Goodyear Medalist. The award was made in recognition of his outstanding research contributions in rubber physics, particularly in the area of contact phenomena.Dr. Roberts began his research on the friction and lubrication of elastomers at the Cavendish Laboratory in the Physics Department of the University of Cambridge, England. He worked there under the supervision of tribologist Professor David Tabor and completed the PhD in 1968.One of Dr. Roberts' initial contributions—his 1971 paper with K. Kendall and K. L. Johnson—is now among the most widely cited papers in the scientific literature and forms the basis of modern theories of adhesion mechanics. This work was concerned with the contact area between an optically smooth transparent rubber hemisphere and a glass surface, and in the paper, the authors proposed a modified Hertz equation that accounts for adhesion. The observed dry contact diameter made with the glass was found to be greater than that predicted by the classical Hertz equation, especially under small applied loads. The extended contact was accounted for in terms of the equilibrium work of adhesion between the solid surfaces. Although originally intended for soft contacts, the JKR equation has been used to interpret results for harder materials, such as metal micro-contacts. In recent times, it has enjoyed a renaissance with the rise of nanotechnology. The equation is often employed to interpret results from the surface force apparatus and the atomic force microscope.In 1974, Dr. Roberts was recruited by Professor Alan G. Thomas as a Principal Scientist into the Applied Physics Group at MRPRA. He worked initially on the viscoelastic aspects of rubber friction and made discoveries that clarified and advanced the field. He looked into the sliding friction of rubber on wet surfaces or on ice, the effects of pH and salt concentration, and the minor constituents in the rubber compound.In 1983, Dr. Roberts was promoted to Assistant Director of MRPRA and the following year to Deputy Director. The year 1984 marked the start of a considerable undertaking of bringing together accounts of the various strands of research activity at MRPRA. This was completed and published as a book to mark the lab's golden jubilee in 1988.Over the years, Dr. Roberts' work has accumulated significant impact in many practical areas, including tires on wet and dry roads and at high speeds, windshield wiper blades, and rubber seals and other rubber products. His ideas were instrumental in the commercialization of a popular testing instrument for rubber friction. He was recognized by the award of the Lavoisier Medal of the French Society of the Chemical Industry in 1998. He has published 125 papers in peer-reviewed journals including Nature, Wear, Proceedings of the Royal Society, Proceedings of the Institution of Mechanical Engineers, Tribology International, Rubber Chemistry and Technology, and Journal of Physics D: Applied Physics.Since his retirement, Dr. Roberts has maintained an active interest in the tribology of rubber articles, and he continues to pursue small-scale experiments on the boundary lubrication of elastomers. He has also co-authored a book bringing together descriptions of work at TARRC on natural rubber bearings for civil engineering and published in 2013.

RUBBER CONTACT PHENOMENA

ABSTRACT Research on rubber wiper blades led to the establishment of the now widely used Johnson, Kendall, Roberts (JKR) equilibrium equation that determines the strength of adhesion between surfaces. The equation was adapted to allow for the viscoelasticity of rubber, leading to explanations of how adhesion can impact on tack; rebound resilience; and rolling, static, and sliding friction. The adhesion of rubber to ice was found to depend on salt concentration in the ice, thus providing insight into winter tire performance. The development of optical techniques has greatly aided studies, particularly for measuring the thickness of thin liquid films sandwiched between rubber surfaces. Measurements on water films squeezed between rubber and glass revealed the action of repulsive surface forces that can reduce adhesion and friction. The efficacy of water lubrication depends upon whether surfactants are present and upon the acidity or alkalinity of the water. Improved understanding of adhesion and friction mechanisms offers design guidance for a range of rubber articles.

Role of hydrophobicity on interfacial fluid flow: theory and some applications.

The fluid flow through a seal interface depends on the percolating non-contact channels morphology, size and length, and on the interfacial surface energies. In particular, hydrophobic interfaces may expel fluids and decrease the fluid flow of seals, while increasing the sliding friction. We present results of interfacial fluid flow experiments on a hydrostatic column device which demonstrate how interfacial hydrophobicity can block fluid flow at interfaces and reduce the leak rate of seals. The presented results may help to understand the role of interfacial hydrophobicity in many practical applications, some of which we discuss briefly in this paper, e.g., rubber wiper blades on hydrophobic (usually wax-coated) glass, the locomotion of insects on surfaces in water, and syringes.