Recent Patents on Mechanical Engineering - Volume 4, Issue 3, 2011

Bubbles are widely used for various purposes, such as product cleaning, medical treatments, food processing, and fishery operations. There are several ways to produce smaller bubbles, such as using venturi tube cavitation, pressure discharge, ultrasonic waves, and swirl flows.?? In a number of recent patents, micro/nano-bubbles generated by a swirl flow have been used in several applications because this method involves low cost and simple design and provides high performance as well as the ability to generate very small bubbles. In recent years, the controllable bubble size generator, which enables the bubble size to be changed according to the sequence of operations, has been devised, and this swirl-type generator can be used to vary the bubble size and production rate. The swirl-type generator, which is operated using air and water as fluids, makes bubbles that are divided into smaller bubbles by means of the shear stress produced by the swirl flow. In the present paper, micro/nano-bubble applications and technology mentioned in recent patents are reviewed, and the applicability of the swirl-type generator was discussed. Various applications in six fields, i.e., industry, fishery, medicine, agriculture, home amenity, and miscellanea, were surveyed and introduced for the novel inventions, methods, techniques and design centered on the recent patents using the fine bubble characteristic properties such as electrical charges, suspended floating particles, and large surface area volume ratio. The present article analyzes and compares recent patents involving the use of micro/nano-bubbles and gives the extension/vector of the micro/nano-bubble utilization in profitable business prospects.

This paper reviews recent patented developments in active vibration isolation. First of all, the fundamental limitations of passive vibration isolations are established, to understand the motivations to introduce active control in vibration isolation. Then, the main different active strategies are presented using simple systems and compared. Finally, several specific issues are listed and briefly discussed.

In recent years, significant patents have been devoted to developing non-destructive techniques for damage identification in structures. A crack in a structural member induces a local flexibility which affects the dynamic and static behavior of the whole structure. In this paper, an approach that is able to derive the flexibility parameters in beams with an edge crack based on the strain energy density theory is presented. The method takes into account that the crack in a beam does not propagate in a collinear manner, but due to the presence of the mixed mode, it changes its direction. This allows a description of the phenomenon of the non collinear propagation of the crack similar to the experimental evidence. The crack is assumed to be vertical before the loading, and then it runs in the direction of the minimum of the strain energy density. Then, the crack is supposed to follow the direction of the principal tensile stress in the section. Comparisons are made to the evaluation of the energy released during the whole crack process in the case of incorrect collinear propagation of the crack in mixed mode. Preliminary results are presented for different positions and initial length of the crack.

A calibration method of parallel robots for semi-physical simulation platform of space docking mechanism is presented in this paper. To calibrate the parallel robot, a coordinate measuring machine to measure the distance between three standard spheres on the moving platform and three standard spheres on the base platform is attached to the base platform and the pose calculation is established by the distance information. By treating each sub-chain of the parallel robot as a joint-link train, the pose error model in which kinematic parameter errors are considered is established from the kinematic equations and the loop properties of parallel mechanism. Using least squares and iterative algorithm the solution of kinematic parameters has been realized. The factors that influence the accuracy of kinematic calibration are studies in detail. The corresponding simulation calculation demonstrates that to find out a coefficient matrix with a good condition number is a precondition of the calibration algorithm. Some examples and calibration experiment are given to demonstrate the effectiveness of this approach. The position error RMS of the parallel robot is reduced from 4.2mm to 0.4mm and the orientation error RMS is also reduced from 0.6° to 0.1°. In this article, we have discussed some recent patent on kinematic calibration of parallel robots.

This review gives an introduction to the problems (carbonation-induced corrosion and chloride-induced corrosion) associated with the use of carbon steel reinforcing bars (rebars) in concrete. The various strategies and some recently patented technologies for preventing/mitigating rebar corrosion (such as cathodic protection and the use of corrosion inhibitors), together with their strengths and weaknesses, are presented. The viability of using stainless steels as rebars is then discussed. The new generations of stainless steels (together with some recent patents on them), i.e., the low-Ni/Nifree austenitic and duplex stainless steels, which are applicable as concrete rebars, are introduced at the end of the article.

Energy conservation is one of the important and prime concerns in the present world. In automobile sectors, there is immense energy loss during various modes of riding the vehicle, such as braking. During braking, the kinetic energy of the vehicle is converted into heat energy that is dispersed in the air. In this article various patents (available in public domain) on regeneration of power that is lost in various sources are reviewed and there highlighted working principles. In order to conserve and reutilize the energy that is lost during braking of vehicle, in this paper, a new system is presented, so called “Regenerative Hydraulic Power Transmission System”. The present system overcomes the drawbacks associated with the conventional regenerative braking systems. Furthermore, the present system may serve dual purposes such as power transmission as well as regeneration of braking power.

Residual stresses that develop during the bending correction process of T-shaped elevator guide rails have become increasingly important. This paper reviews in various recent patents on elevator guide rail and rail straightening. The rail has a special cross section that is symmetrical in horizontal major axis of inertial direction but nonsymmetrical in vertical minor axis of inertial direction. In order to study the residual stress in straightening, considering the special cross section of the rail, an ideal elastic-plastic material model is used to analyze the residual stress distributions of the rail and the analytical expressions are obtained, and the possibilities of reverse yielding during the step of unloading are also analyzed. The results show that maximum of the residual stress can be found at the boundary of the elastic and plastic regions, but when the plastic deformation is further decreased, it is the highest at the outer surfaces which have the farthest distance from the neutral layer. Finite element analyses are also carried out to determine the accuracy of the mathematical model presented.

The demand of stringent environmental laws on exhaust emission and the manufacturers' growing desire to cut down the total cost of the catalytic converter by employing lesser amounts of precious elements, needs for the development of improved catalytic exhaust treatment devices. Till now the converters in practice consist of Pt group metals as catalysts, which inherently have very high light-off temperatures for CO oxidation, around 150°C to 300®C [1], which in turn is the major pollutant of the exhaust emissions. This is where Au particles exhibit their importance, accounting to their inherent property to stimulate the oxidation reactions at even below room temperature. This article discusses the exhaust treatment device developed by Moroz et al., with Au nanoparticles as the prime component and explains why it is better than the other patented methods used for the purpose. Brief comparisons are made between these patents. Also discussed are the factors stimulating low temperature CO oxidation on Au catalyst, the reaction mechanism and how it is different from that on Pt group metals, and the use of catalysed HC trap to reduce the HC inhibition of catalytic activity.

Thermo vapor compressor (TVC) is simply a steam ejector employed in multi-effect desalination (MED) system. A well understanding of flow phenomena inside an ejector is important for improving the ejector performance. To optimize the performance of the ejector used in thermo vapor compressor, a three dimensional model for the computational fluid dynamics (CFD) was conducted. The results due to the CFD were verified with the results data obtained by a new analytical model developed using the equations of continuity, momentum and energy. The present results investigated recent patents of the effect of the condenser, evaporator and boiler pressures and also the effect of ejector geometry on the thermo vapor compressor performance. A comparison between the present CFD and the analytical results at the same operating conditions, gave good agreement between them with an acceptable deviation ranges from -5 to 16 %.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different analytical methods, designs, manufacturing and analysis of automobiles, aircrafts, manufacturing plants, industrial instruments, machines, heating and cooling systems and processes involved and related to mechanical engineering....