Recent Patents on Mechanical Engineering - Volume 7, Issue 1, 2014

The ever increasing demand for better performance of aircraft aerodynamics, from the fundamental understanding of flight, requires enhanced circulation. Circulation Control and hence its enhancement can be achieved by surface blowing in the form of Coanda jet and have always been referred to in the consideration of various flow control methods to enhance aerodynamic performance, along with continuous, synthetic and pulsed jets, compliant surface, vortex-cell, and the like. Coanda jet has also been applied in the development of novel aircrafts for short takeoff, while another circulation enhancement technique known as Trapped Vortex Cavity (TVC) is currently being given significant considerations. It is with such motivation that salient features, progress and development of various techniques in circulation control are here identified, including some of the recent inventions that have been registered as patents in this area. The present work reviews the influence, effectiveness and configuration of airfoil surface blowing of Circulation Enhancement and Control of aerodynamic surfaces. The crux of the TVC active research is their stabilization, while Coanda enhanced lift enhancement technique has, to a certain extent reached a stage that it can be easily implemented with advantage.

The plasticizing and injection devices are among the main components of injection molding machines. The injection seat moves forward by injection-shift oil cylinders to joint the nozzle and the gate of mould tightly. The single oil cylinder and the double oil cylinders are adopted in the traditional injection molding machine. The paper reviews various patents of injection-shift structures through adopting new structures and new devices in recent years. A new type of the single injection-shift structure of injection molding machines is invented to solve high injection pressure, long-time holding pressure, the warpage of the nozzle and the joint fracture of shift piston rod for the traditional injection-shift device. The new type of the injection-shift structure is more compacted, reliable and especially suitable for multiple material injection molding. Moreover, when the length of injection-shift rod is shortened, the cost will be reduced.

A fractal-based expression for particle size distributions of coal and gangue was presented, and experiments were undertaken to study the impact of the structural parameters of the rotating crushing mechanism on the separation of coal from gangue. The results of the experiments using cylindrical rod drums with different rod-diameters showed that the crushing effect of a cylindrical rod drum with a rod diameter of 22mm was the best; the results of crushing experiments using different types of rod drums showed that the crushing effect of the triangular rod drum proved fruitful. Because of their higher gangue crushing rate, cylindrical rod drums were more suitable for squirrel-cage selectivity-type underground coal and gangue separation equipment. In addition, the particle size distributions of coal and gangue were obtained and the mass ratio equations of gangue separation under different distribution conditions were deduced. The rotating crushing mechanism has been found to be more efficient than other recent patents for the separation of coal from gangue underground.

A large number of patents have recently been devoted to the development of minimum quantity lubrication (MQL) grinding techniques that can significantly improve both grinding fluid alternatives in terms of environmental consciousness, energy saving, cost effectiveness, and sustainability. Among these patents, one is for a supply system for MQL grinding that turns the lubricant into pulse drops with fixed pressure, constant pulse frequency, and the same drop diameter. The drops are produced and injected into the grinding zone in the form of jet flow under high-pressure gas and air seal. With the growing demands of our environment, MQL has become widely used in the grinding and cutting machining processes. Based on the dangers of suspended air microparticles from machining to health and the environment, the sources, classification, and characteristics of suspended air microparticles were analyzed in this research. Taking account the features of microparticles, we explored the dangers posed by suspended microparticles to health and identified the common diseases attributed to these microparticles. With the use of the machining process, we analyzed the formation mechanism of suspended air microparticles and conducted research on the distribution characteristics of suspended air microparticles formed from the atomizing nozzle during MQL grinding. The relationship between jet parameters and microparticle size of sprays was explored. The results showed that atomized microparticle size has a linear relationship with nozzle caliber and gas-liquid flow ratio. Atomized microparticle size is directly proportional to the nozzle caliber but inversely proportional to gas-liquid flow ratio. We also analyzed the distribution rules of spray droplets and determined the amount of spray microparticles and volume distribution function.

Elastic constants are fundamental to characterise the stress-strain behaviour of materials which is essential for an accurate design of mechanical components against fatigue failure. In this paper, the first objective is to address recent patents on the determination of elastic constants and on fatigue life prediction methods. The second objective aims at studying the effect of errors in elastic constants on fatigue life prediction. Elastic constants are determined using dynamic and static methods, namely the Impulse Excitation Technique (IET) and the Three-Point Bending Test (3PBT). Then, high-cycle fatigue tests in notched round bars subjected to different bending-torsion loading scenarios are conducted to obtain experimental fatigue lives. Finally, experimental fatigue lives are compared with fatigue life predictions obtained for the different Young's moduli obtained previously. Results demonstrated that predictions based on the IET are more accurate than those obtained from the 3PBT. Recent patents on the determination of elastic constants and on fatigue life prediction methods are also addressed.

In recent decades, there has been an ever-increasing need to reduce the weight of the weapon systems carried by combat personnel in the United States Army. This need is the thrust behind the weight reduction initiative for the disruptor systems used by the Army's Explosive Ordinance Disposal (EOD) community. This work evaluates the conflict between weight reduction in dismounted disruptors and the dynamic performance of these systems during operation. This work also describes a recently-patented dismounted disruptor system designed to satisfy both the need for system weight reduction without compromising the dynamic performance of the system. The recently-patented disruptor is a variation of the Mk 2-the standard caliber .50 disruptor currently used by EOD teams of all military services in the United States.

Fluid assisted injection molding (FAIM) technique greatly improves the quality of the molded plastic articles through the introduction of pressurized fluid. The FAIM has two main realizations: the gas assisted injection molding (GAIM) and the water assisted injection molding (WAIM). The characteristics and practical applications of GAIM and WAIM are discussed in detail in this article. Besides that, several optimization techniques of GAIM and WAIM are also briefly introduced, including cooling gas assisted method, vibrated gas-assist molding method, plastic expulsion process (PEP) method, external gas assisted method, and WAIM-GAIM method. For each method, the article quotes one or several patents to illustrate its features. Finally, the future development of the FAIM technique is also discussed.

To enhance the efficiency of wind power generation and power generation capacity of the energy storage system, a compressed-air energy storage (CAES) power generation system test platform is developed to study load shifting capacity and power generation quality of the system. The results show that the variation of energy storage system's loaded and unloaded voltage-pressure is basically identical. Meanwhile, a comparative study on the load shifting capacity of the CAES power generation system is presented. We come to the conclusion that when the open time interval is 30s, the system has strong filtering capacity, with the absolute value of the maximum voltage deviation is 7.09%, indicating that the quality of the CAES power generation system can fully meet the requirements of the power network. The research findings will be beneficial to further enhance the development of the wind power generation technology and will provide a theoretical reference for application and promotion of the CAES generation. The purpose of this study is to provide an overview about the CAES power generation through addressing recent patents and scholarly articles on this subject.