Key Engineering Materials Vols. 480-481

Abstract: This paper studies the application of computer games in the popularization of forestry science knowledge and proposes a method of 3D game development based on Virtools platform, which creates 3D models in 3ds max and Maya, and then realizes the game functions in Virtools. This paper designs and develops a 3D game for the popularization of forestry science, gets a better balance between knowledge and game play, and enhances the users' interaction experience by adding the gamepad, which has great reference and practicability value. Computer games will play an increasingly important role in the popularization of forestry science.

Abstract: Heat generation of a bearing was studied based in this paper. Computational models of power loss were built. The total heat generation was gotten. Influences on total heating were analyzed at various inner ring rolling velocities and applied loads. The results show that bearing rolling velocity and axial load affect heat generation strongly. Meanwhile sliding friction, which exists between balls and the cage pocket, cages and the surface of outer ring, is the main factors of bearing heating. Bearings with shaft are mainly used in gyro motors of aviation, aerospace, marine navigational systems, which own a long life and high reliability. Heat generated by friction affects its performance, life and reliability, and consequently influences control precision and life of gyro motors. If the rate of heat dissipation is less than the rate of the heat generation, the system temperatures will raise, the hardness of bearing ring and rolling element steel decrease, and resulting in plastic deformations, lubricant deterioration occurs, ultimately, heat imbalance failure leads to breakage of bearing components and bearing seizure[1,2].So precise evaluating heat generation of bearings with shaft is important for design, manufacture and application of bearing. The heat generation of bearing comes from power loss of friction. The traditional methods contain the local method and integral method [3]. Palmgren who used the integral method based on experimental results advanced an empirical formula of total friction moment [4]. The calculation result is lower than the fact because ignoring infection of lubricant flux. Astringe and Smith improved the above formula .But it was just for roller bearing. Harris established a local method for the ball bearing and rolling bearing [5]. Pouly et al [6, 7] analyzed part power loss of the high speed rolling bearing based on local method. Compared with the integral method, the local method calculated heating of all heat sources. The results were more accurate. Liu Zhi-quan, Han Min-zheng et al computed the heat of high speed rolling and ball bearing by the local method [8, 9]. This paper studies heat generation mechanism of bearing with shaft from a gyro motor. Different heat sources from bearings are calculated by a self-made program. All factors which influence heat generation would be gotten by analyzing at different working conditions. It would offer a theoretical basis for optimal design and proper use of bearings with shaft.

Abstract: Today's computer depends on network more and more, thus collaborative design has become an important way of workflow. Because of cumbersome and complicated state of animation design which needs huge numbers of staff work, the combination with collaborative design is the only alternative to develop animation design. As animation design is always non-parametric and has a complex variety of objects, the problems forward in collaboration are doomed to be different from other design process. Based on this, this article discusses the possible problems of collaboration in animation design.

Abstract: Based on the quasi-static analysis and the power loss analysis, the temperature distribution is calculated by ANSYS.The different part temperatures of bearing are obtained. The influences of rotational speed, axial load and radial load on the temperature distribution are analyzed. The results reveal that axial load and rotational speed affect temperature distribution strongly. The effect of radial load is not signifcant,and the maxtemperature of bearing is at the point between balls and the inner ring. Bearings with shaft are widely used in gyro motors of aviation, aerospace, marine navigational systems. In a few applications, however, heat generated by friction can affects its performance, life and reliability, and consequently influences control precision and life of gyro motors[1]. So it’s important to evaluate heat generation of bearings with shaft for the design, manufacture and its application. A few researchers [2, 3] have analyzed the concentrated contact temperature. Their researches have been mainly focused on the temperature of contact surface. In addition, some researchers (Chinese and foreign) have calculated the temperature of bearing under the thermal network method [4, 5]. The above methods are easy to carry out, but only can the temperatures of some point be found. Compared with the thermal network method, the finite element model can get the temperature of the whole model. The temperature analysis has been pursued by some foreign and Chinese researchers under the method [6, 7]. The steady temperature field of bearing with shaft from a gyro motor is studied in the paper. The speed of ball and the temperature distribution are analyzed and studied by VC6.0++ and ANSYS. The temperature distribution under different axial load, speed of inner ring and radial load is calculated. Therefore the main effect of temperature distribution can be found.

Abstract: A nonlinear dynamics analysis mathematical model for the high-speed cylindrical roller bearing was built up. Dynamic performance parameters were got by Newton - Raphson method . The rotational velocity regularities of rollers were analyzed at different radial loads. The distribution of minimum oil-film thickness and contact load between rollers and bearing ring raceway were obtained. The results showed that number of loaded rollers increased with the increase of radial loads at a certain speed. Rollers slip seriously at lower radial loads. The rotation speed was low. The minimum oil-film thickness between loaded rollers and inner raceways was less than that of outer raceways. The results were compared with the results of SHARBERTH and comparison was made with testing results. It showed that the dynamic characteristics analysis method of high speed cylindrical roller bearing was accurate, reliable,simple and convenient for practical engineering application.

Abstract: Rolling bearing failures account for most of rotating machinery failures. Fault diagnosis of rolling bearings according to their running state is of great importance. In this paper current research situation and existing problems of fault diagnosis are summarized firstly. Then several different diagnosis approaches in terms of the measuring medium are reviewed. After analysis of fault mechanism, feature extraction based on non-stationary signal process is elaborated. Finally, the development tendencies are pointed out.

Abstract: This essay analyzes the concurrent activities in the injection product development. Taking the myopia therapeutic apparatus as an example, the essay gives a designing and manufacturing procedure of the injection concurrent engineering. Conditions of the introduction of concurrent engineering technology are pointed out.

Abstract: With the economic becomes globalization and integration. Animation is a high-tech industry. It contains some factors, such as capital-intensive, labor-intensive, technology-intensive and knowledge-intensive and so on. With the advantages of quick startup, expansion and strong, great space for development, as well as zero pollution, animation became the most important entertainment industry and can keep pace with videos and music.

Abstract: With the rapid development of telecommunication, the competition of telecom market becomes more and more drastic. It is very important for telecom operator to research how to keep from the telecom churn. In the paper, a model used to simulate the behavior of customers is constructed based on system dynamics. The causal loop diagram and flow diagram of the telecom churn is proposed and some simulation results are obtained. According to these simulation results, we give some suggestions to reduce the customer churn, which are valuable for telecom operators to maintain users, formulate marketing strategies and reduce operating costs.

Abstract: Most routing decisions or diversion plans in the literature are made based on the current traffic situation and little attention is paid to future. Such kinds of greedy strategy consistently suggest en route diversion at any point where the alternative route choice is better than the ongoing one. Hence, in the constantly varying real world, excessive diversions may appear and are much likely to create a sort of ‘zig-zag’ effect, eventually leading to a higher cost. A forward-looking diversion strategy considering both real-time and future information is proposed in this paper, and the potential benefits, limitations and difficulties of several diversion strategies are evaluated through microscopic traffic simulations. The research will help logistics companies to assess the benefits of en route guidance system in their day-to-day operations.