Recent Patents on Mechanical Engineering - Volume 8, Issue 3, 2015

Lane changing is a significant research topic about micro transportation simulation and safety assistant driving. It has massive influence on transportation operation and safety. Lane changing and warning model researches can highlight operational laws of intelligent vehicles. So such researches are meaningful forintellectualization of vehicles and realization of automatic driving. This text analyzes lane changing models, impacts and lane changing warning methods thoroughly and discusses performances of existing lane changing models by addressing recent patents and scientific papers. Analysis of basic process in lane changing safety warning methods is also conducted. Merits and drawbacks of extant lane changing safety warning methods are discussed. Finally, a conclusion for universal problems in lane changing models, impacts and safety warning methods is drawn by this text, moreover current research trends and situation in lane changing research field are shown, in order to enhance these researches.

In-Mold Labeling (IML) during injection molding is a relatively new injection molding technology, which is used to improve the surface quality of the plastic products in order to achieve a variety of surface design, etc. In the IML process, the film is made of a mold cavity and connected to one side of the mold wall, then the molten polymer is filled in the cavity. This paper introduces the basic principle and equipment of IML injection molding technology. The paper reviews various patents of In-Mold Labeling injection molding process in recent years, such as molding equipment, film and materials. The common defects of decoration of the plastic parts explained the causes and solutions such as the ink washout, wrinkle, weld line, sink marks, bubbles. It is put forward to optimize the process and mold design for In-Mold Labeling technology.

RF MEMS switches have attracted widespread attention in recent years. Compared to PIN diodes and FET switches, RF MEMS switches have many advantages including low insertion loss, high isolation, low power consumption, high linearity, small size, low cost, wide band and easy integration. In this paper, the working principle of RF MEMS switches is introduced. Then, the failure mechanisms and reliability analysis of the RF MEMS capacitive switches are introduced from dielectric charging, temperature and pull-in voltage. While the failure mechanisms and reliability analysis of the ohmic RF MEMS switches are introduced from material, pull-in voltage, temperature and structure. In this paper, various recent patents to improve the reliability of the RF MEMS switches are also presented and discussed. The factors affecting the reliability of the RF MEMS switches are summarized and several methods are proposed to improve the reliability of the RF MEMS switches. Finally, the current and future developments of the RF MEMS switches are discussed in this paper.

Life cycle assessment (LCA) is a scientific assessment method to promote recourse saving and environmental protecting behavior. LCA has been applied extensively to investigate issues related to shortage of resources and environmental degradation. In order to specify the development and benefits of LCA in current and future industrial environment, this paper provides a systematic review by addressing recent patents using LCA to assess environmental impacts and scholarly articles on the issues of boundary identification, allocation problem, databases, approaches for compiling life cycle inventory, and life cycle impact assessment. With regard to the perspective section, key challenges in LCA scope expansion are explored: from environmental to social and economic issues and its integration with 3D design software. Then, the current limitations and weaknesses of LCA are discussed at the end of the paper.

The basic reliability concepts - parametric ALT plan, failure mechanism and design, acceleration factor, and sample size equation were used in the development of a parametric accelerated life testing method to assess the reliability quantitative test specifications (RQ) of mechanical systems subjected to repetitive stresses. To calculate the acceleration factor of the mechanical system, a generalized life-stress failure model with a new effort concept was derived and recommended. The new sample size equation with the acceleration factor also enabled the parametric ALT to quickly evaluate the expected lifetime. This new parametric ALT should help an engineer uncover the design parameters affecting reliability during the design process of the mechanical system. Consequently, it should help companies improve product reliability and avoid recalls due to the product failures in the field. As the improper design parameters in the design phase are experimentally identified by this new reliability design method and recent patents are addressed, the mechanical system should improve in reliability as measured by the increase in lifetime, LB, and the reduction in failure rate, λ.

The electric-mechanical continuously variable transmission which is driven by electric motor is a perfect type of transmission for electric vehicle. In this paper, the first objective is to address recent patents on the configuration of electric-mechanical continuously variable transmission. The second objective is optimization of the energy consumption of all-electric vehicle equipped with electric- mechanical continuously variable transmission. Global optimization of electric vehicle equipped with EMCVT running in New European Driving Cycle has been carried out based on dynamic programming. In this optimization state of charge and transmission ratio these are state variable and decision variable, respectively. Ratio shifting model was built to estimate energy consumption during shifting. New optimal control strategies were achieved by taking shifting energy consumption as cost function. Test results show that shift times and energy consumed are both reduced with this control strategy. Recent patents on the configuration of electric-mechanical continuously variable transmission are also addressed.

The paper shows concentric journal bearings formed between smooth shafts and smooth journals registered in patents, which are objected by conventional hydrodynamic lubrication theory. Such bearings can be constructed by physical adsorption or by the boundary slippage. In the inlet zone of the bearing, on the stationary bearing surface, a coating is normally covered so that the lubricant significantly more strongly adheres to that surface or the lubricant slips on that surface; On the stationary bearing surface in the outlet zone, the interaction between the lubricant and the bearing surface is otherwise significantly weaker or stronger. It is a new invention of journal bearing by applying the interfacial adsorption or the boundary slippage technologies. The design method, load-carrying mechanism and friction coefficient results of the bearing are given. The invented bearing possesses the merits of high supporting precision, low friction coefficient and easy manufacturing.

Some factors affecting the high-speed lathe motorized spindle optimal machining performance are: the big deformation of the spindle front-end, the poor cooling and heat dissipation, and the low processing precision. In this paper, first, a review is performed about recent patents on the structure design of motorized spindles and on the measurement and analysis of vibration and noise generated by motorized spindle operation. Second, an investigation is developed about an optimal design of the spindle system based on the theory of finite element optimization design and taking into account front-end overhanging volume, rotor position, and bearing span. Third, based on the theory of heat transfer and fluid dynamics, the performance of three cooling water channel geometries (annular, single spiral and double spiral) is investigated. Finally and accordingly to the three previous steps, a motorized spindle prototype is produced and tested corroborating that experimental values for temperatures at critical motorized spindle hot sources disagreed with those temperatures for a numerical model by less than 1%. Moreover, the vibration and the noise generated by the operation of this spindle prototype satisfy the Chinese national standards for motorized equipment.

In this paper, two sets of H7014C/HQ1P4 bearings underwent test for high-speed performance under spray lubrication. The influence rules of rotation speed, pre-tightening force and oil pressure on the bearing temperature rising and host vibration were analyzed by adjusting the bearing rotation speed, axial pre-tightening force as well as oil pressure and measuring bearing temperature and host vibration. It has been found that the bearing temperature rises sharply as the rotation speed increases. At low rotation speed, the pre-tightening force has little influence on the bearing temperature rise, but at high rotation speed, the pre-tightening force should not be too small and can severely affect the bearing temperature rise. Increasing the amount of lubricate oil can reduce the extent of the bearing temperature rise while excessive addition cannot further improve this effect. It has been found that the bearing experiences an excellent high speed performance within the rotation speed of less than 24000r/min. This paper reviews various recent patents on high speed bearing test over the past three years. The list of patents reviewed here is by no means supposed to be complete or extensive but shows nevertheless evolution trends concerning high speed bearing test. An analysis of the reviewed patents repartition that allows conclusion of the expected future developments in this domain.