This paper reviews recent patents in the field of vibrational energy harvesting. The area is still not mature and there is a great potential for improving existing energy harvester designs. Piezoelectric transducers are seen to offer superior energy densities and the majority of patents discussed utilise such electromechanical systems. The bulk of work being carried out in this area is focused on increasing performance levels of the conventional cantilevered design. The patents reviewed are targeted at improving strain distribution along beams, techniques for tuning, widening the bandwidth of devices and improving performance for low amplitude and frequency sources. Conclusions are drawn regarding the future potential of various designs and the vibrational energy harvesting field in general.
After a brief description of the most important “automatic” solutions, this paper explores the advantages of automated manual ones, particularly in the dual-clutch transmission (DCT) configuration. This mechanical architecture offers gear shifts without interruption of power (the so-called “torque gap”), by applying the engine torque to one clutch just as the engine torque is being disconnected from the other one. The result is jerk-free gear change with the same driving style found in a conventional automatic combined with the efficiency of a manual transmission. It is as smooth as the most automatics, but more economical; it is as easy to drive as a standard auto, faster and more responsive than even the sportiest manual gearbox. The two clutches are engaged alternatively in different speeds and power transmission continues during a shift through the control of clutch slippage. This outstanding design allows automakers to achieve what previously had seemed impossible: to improve both comfort and sportiness, whilst at the same time fulfilling the essential requirement of reducing fuel consumption. Historical evolution, future market forecast and recent patents complete the paper, while recent modelling approaches and proposed control strategies are referenced.
Several recent patents on energy dissipation structures for building and vehicle safety systems are reviewed and summarized within this manuscript. The safety of buildings or vehicle occupants can be greatly improved through application of energy dissipation structures. Use of these specialty devices typically results in reduction of damage to susceptible regions of building structures and more importantly the reduction of injury and/or fatality probability. These energy dissipation devices act as critical structural members within the load path of the system and absorb impact energy to prevent the structural damage to the main building structures or vehicular components to ensure no compromise of the occupant compartment of a vehicle. The main mechanism for structural energy dissipation is associated with plastic, hysteric, or irreversible deformation of sacrificial materials/entities. Brief comments on future development directions for energy dissipation mechanisms have also been presented.
This review reports the most recent and important research trends on the rolling contact fatigue (RCF) performance of thermally sprayed WC cermet coatings. In order to do so, the inventions, methods, techniques and designs related to this area are discussed. Recently, durability or rolling contact fatigue life of thermally sprayed WC cermet coatings under rolling/sliding contact conditions has been the study of much investigation. Test results revealed that the performance of these coatings is application dependent. Researchers showed that RCF life of WC cermet coatings depends not only on the coating and substrate properties but also on the contact configuration, coating thickness, slip ratio, substrate surface finish, mating surface roughness, lubrication etc. In general, it is the combination of the coating and substrate material and the various tribological conditions during the tests which govern the performance of the coatings. In this article, an attempt is made to provide an opportunity for the future researchers to identify the recent trend of these areas. It is expected that the applications of these results will contribute for optimizing the design of surface engineered components in rolling/sliding contacts. This review article also includes some relevant patents.
A detailed knowledge of the basic engineering material properties is of fundamental importance for fabrication purpose as well as for proper design and reliability estimation of any kind of engineering structure. In particular, knowledge of elastic properties, such as Youngs Modulus and Poissons Ratio allows to assess the static and/or dynamic performances of a structure and provides information on the quality achieved during the fabrication process. Various methodologies have been proposed through the years for the elastic characterization of engineering materials. Vibrationbased methods allow to determine the material properties combining experimentally measured natural frequencies of suitable samples to analytical or numerical models relating the natural frequencies to the geometrical dimensions, mass density and the unknown elastic properties. Vibration-based methods are today commonly employed because of the nondestructive nature of frequency measurements and the simple operating procedures involved. The efforts provided by research scientists and engineers in this field are currently enclosed in a huge number of meaningful journal papers and patents devoted to the subject. The aim of the present work is to review recent progresses and selected patents in the field of vibration based methods for the elastic characterization of isotropic materials.
The most recent and important research trends along with recent patents on erosive wear behavior of different types of composite and polymer materials are demonstrated in this paper. For this the invention, methods, techniques, and design related to this area are discussed. The different trends of erosive wear behavior of composite and polymer materials under different operating conditions are observed. In general, the erosive wear behavior of material depends on various operating parameters, such as velocity and angle of impact, particle size, shape, flux rate, etc were reviewed. In this article, an attempt is made to provide an opportunity for the future researchers to identify the recent trend of these areas. It is expected that the applications of these results will contribute to the improvement of different concerned mechanical processes.
Global research and development on an innovative engine concept known as Homogeneous Charge Compression Ignition (HCCI) is being pursued aggressively and the gas engines employing this concept are expected to become commercially viable soon. The U.S. government is expected to institute the emission standard by 2009 and the same needs to be complied thereafter. Gas engines using HCCI will be gaining around 20 percent in fuel consumption. The present paper aims at mapping the patented technologies related to this engine concept. Global patent search retrieved a total of 171 patent families and an attempt is made in this paper to undertake mapping of these patents to get a clear idea about the major players in this area, technologies developed and country-wise patenting activity.