Applied Mechanics and Materials Vol. 163

Abstract: Antikythera mechanism is an ancient Greece machine excavated in 1900. The damaged remains and ingenious mechanical structure resulted in mans thirst to decode this mechanism. This paper reviews the historical development regarding reconstruction designs of Antikythera mechanism. The origin, the recovering process and the related historical records are introduced first. Available reconstruction designs, which are classified into the orientation of mechanism, the decoding of modern technology including the appearance, the functions of the exterior dials and the interior structure, other research and the authors work are presented. Then, based on the viewpoint of mechanisms, the mechanism analysis of one feasible reconstruction design with the complete interior structure, by the authors, is presented. This new design to generate all known output functions also provides a possible embryo of Antikythera mechanism.

Abstract: Based on historical documents and field survey, the wood bellow of No.3 iron smelting furnace in Liao Dynasty was reconstructed at Shuiquangou, Yanqing in Beijing. Its ultimate wind pressure and the speed were estimated. The ventilate ability for its portion was calculated respectively. Furthermore, the flow field in the furnace blasted with the wood bellow was simulated with software FLUENT. The effect on the iron smelting techniques for single-tuyere blast furnace with this blast ability of the bellow was discussed.

Abstract: We discussed the coolant composition which can guarantee both the excellent fluid abilities as the cutting fluid and the good treatability as the recyclable material toward the development of sustainable cutting fluid system. We prepared three distinctive coolants; amine-free (EX-102), mineral-oil and amine free (α-1000) and amine-containing (EM-L) coolants. All of the coolants have excellent emulsion stability for standing in the natural condition butα-1000 and EM-L showed a good anti-rust properties while EX-102 showed a rather poor anti-rust property for the cast iron chips. The vegetable oil has a rather poor stability in lubricating performance than that of the mineral oils and synthetic ester. The alkaline substances dissolved in the amine-free coolant can be separated by the surfactant treatment as well as the oil contents, while some alkaline substances, maybe di-ethanol amine, are still retained in the recovered water from the amine-containing coolant. The activated carbon treatment showed no significant change for all of the coolant. Amine-containing coolant forms no stable emulsion; the recovered water cant utilize as a diluents of newly water-soluble coolant while the amine-free coolants can form a stable emulsion to a certain extent. The most direct attack to make the cutting fluid sustainable would be developing a new emulsifier and corrosion inhibitor that can substitute for amine compounds and can show a good treatability like the amine-free cutting fluid.

Abstract: In order to investigate the effect of friction on gear system featuring confluence transmission, a non-linear dynamic model of three-gear system having two gear pairs was built. The influence of gear systems dynamic characteristics caused by changing of friction coefcient was researched. With the changing of friction coefcient, left-right gear pairs show dynamic behavior with coexist of same periodic motion, coexist of different periodic motion and chaos. With the increase of friction coefcient, the jump phenomenon of amplitude occurred, the impact of gear system became larger.

Abstract: Compliant actuators are widely used in industrial robots due to the fact that the compliant elements have the capacity to absorb excessive collision force and guarantee the robot safety. Moreover, the compliant elements can be also employed as force/torque sensors in the control loops. Therefore, the research on the compliant actuators is of importance in the theory and application sides. Specifically, it is required that the robot systems should have a low stiffness when the subjected collision force is greater than the prescribed injury tolerance. But, in the normal status, the systems maintain the required capability. In this paper, the system stiffness of a compliant actuator is defined as a mechanical impedance (the ratio between output force and output shaft angle). A cascade controller is well designed by following the results on analyzing the characteristic of compliant actuator impedance stability and collision. At the end, simulation results show the effectiveness of the analytic results and designed controller.

Abstract: In the moving process of four-legged walking robot, the robot uses the random 3 foots to support its body, and the rest 1 foot to swing. This process is carried on alternately to complete the robot moved forward. If the robot's foothold position, the independent drive joint variables and the length of leg linkage are inaccurate, the robot's swing leg would deviate from the desired position, which led to the robot will deviate from the target track. The robot's swing leg trajectory is analyzed in this paper. On this basis, the swing leg trajectory accuracy is discussed under the condition that the errors of the robot's foothold position, drive joint variables and leg's linkage length are given. The analysis process is illustrated by an example. The error analysis has significant meaning for four-legged walking robot control .

Abstract: In order to obtain a better filling way with suitable adhesive to enhance the reliability of 3D PLUS solder joints. Finite element analysis of random vibration method was carried out. By means of the method, the effect of filling way on the stress distribution in solder joints was investigated under the condition of two types adhesives 55/9 and GD414. Stress distribution and its maximum value of 3D PLUS solder joint at peak time were acquired. Comparative analysis of the maximum stress between under filled adhesive and side filled adhesive with 55/9 or GD414 respectively. The results showed that under filled adhesive 55/9 can effectively improve the solder joint stress.

Abstract: As an important component of the fasteners members, threads quality, depending on whether its geometric parameters meet requirements or not, will affect the reliability of the whole machine system. Therefore, geometrical parameters measurement of the thread is especially important. Aiming at the characteristics of the thread teeth type, this paper adopt a machine vision measurement method based on the universal tool microscope and CCD .This paper also analyzes the causes and influences of the teeth shading and proposes a corresponding improvement method, specific to the shading problem in the process of backlighting projection. After experimenting, this method can effectively improve the accuracy and efficiency of the male parameters measurement.

Abstract: Removed due to authors request.