Advanced Materials Research Vols. 945-949

Abstract: Large diamond circular saw blade is a plane with large diameters and thin thick, so there are serious vibration problems in the process of sawing stone under the high-speed. By using the force hammer producing incentive experiment method, the effect of the inner and outer diameters to the vibration modal and frequency of diamond circular saw blade are analyzed. Through comparing inner and outer diameter, it can be found that the inner diameter has greater influence on the natural frequency, while the outer diameter has greater influence on the amplitude. The result supplies reliable data for eliminate or reduce resonance damage.

Abstract: To reduce the influences of vibration of large erecting system in the process of erecting, this paper firstly built a simulation model, then an erect angle velocity was planned so that it can minimize the velocity at the stage of beginning, multi-stage cylinder stage changing and arriving, thus the velocity at the other stages can be increased . Meanwhile the fuzzy adaptive PID controller was applied to track the erect angle curve. Finally, the simulation validates that the vibration and shock are effectively reduced by this method. Fast and stable erection of the load is realized. Compared with the original PID controller, the fuzzy adaptive PID controller can be proved to have a better control performance.

Abstract: The use of sandwich structures in various engineering fields is growing rapidly because of advantageous features such as low weight and high strength-to-weight ratio.The existing theories are all based on soft core assumption. In this case, the in-plane stress and the stiffness of the core are not included. It has been shown that Ressiner theory is inadequate for the analysis of hard-core sandwich plates. Different revision factors were put forward in this paper to revise the bending, buckling and free vibration results of soft-core Reissner theory for hard-core sandwich plates. The results show that the revised results go well with the hard core theory, so that its validity is confirmed.

Abstract: Kinematics analysis is important to analyse and design planar gear transmission mechanism. Planar gear transmission mechanism is composed of two basic loop units. The kinematics analysis equation of the basic loop units is established based on the constituent characteristics of planar gear transmission mechanism and the motion relationship of every component in each basic loop unit. The kinematics analysis mathematical model of planar gear transmission mechanism is constructed by using the basic loop group units of planar gear transmission mechanism. With Windows XP as the platform, Visual Basic 6.0 as a tool and object-oriented programming method, a set of common software has been developed for kinematics analysis on planar gear transmission mechanism. The software has many advantages, such as simple operation, strong man-machine interaction, friendly interface and strong commonality.

Abstract: Internal lubrication condition affects dynamic characteristics of rolling ball bearing in operation.According to the calculating problem of the elastic fluid lubricant film stiffness in point contact zone, the oil-film stiffness calculation model was set up based on the elastohydrodynamic lubrication theory (EHL) ,which considers the oil-film distribution and the pressure characteristic of the whole contact region. The stiffness of the oil-film was obtained from this model and compared with the experiment. The results indicate that the data calculated by the model fit the experiment very well, improving the calculation accuracy of the oil-film stiffness.

Abstract: First analylzes the ZF-9HP Automatic Transmission gears dynamic route and establish the equivalent lever diagram of ZF-9HP Automatic Transmission. Then analylzes the shift process of ZF-9HP Automatic Transmission based on the expend method of existing method of leverage, and verify the new lever method is correct by calculation.

Abstract: Worm and worm gear is widely used in modern mechanical industry, it has a lot of advantages including large transmission ratio, compact structure, strong bearing capacity, stable transmission and self-locking performance etc. However, the kinematics characteristic is very important for the performance of equipment. So this article to the worm as the research object, which of the lifting mechanism in rail transport. First, making 3D modeling by Solid Edge V20, Then put the 3D model into the ADAMS, and start the kinematics simulation about transmission mechanism. This paper mainly simulates the angular velocity and angular acceleration of worm when its working, then comparing the change law of the motion curves, and analysis of the results. It can shorten design cycle, improve the design accuracy, reduce the cost of product development, and also create the conditions for the follow-up mechanism optimization and finite element analysis.

Abstract: The meshing contact analysis of double circular-arc spiral bevel gears for nutation drive is considered. Based on gear meshing theory, the mathematical models and meshing equation of the double circular-arc spiral bevel gears are developed. The contact trace satisfies the tooth surface equations and meshing equation simultaneously, and then the contact trace is solved by using mathematical software. The analysis of tooth surface contact pressure is simulated by finite element analysis software.

Abstract: Focusing on the quantitative research on feed system with installation errors, a theoretical analyses model is developed to analyze the influence of parallelism error and coaxiality error of the system. The change law of stress, deformation and contact angle is discussed based on the analysis with hertz contact theory. The theoretical analysis is verified by the simulation with FEM software. The result shows that bias load, deformation of guide and compress variation of the ball decrease as the deviation from bearing for the coaxiality error, while these changes remain small for the first half stroke and dramatically increase later for the parallelism error. The analysis above may be helpful for the installing of the ball screw and for improving the machining accuracy.

Abstract: This paper puts forward a new type of gear anti-backlash drive mechanism, in view of traditional’ manufacturing is difficult and production cost is high. This mechanism uses the structure of a pair of worm gears which are against each other and double gears to eliminate the back clearance volume. The dynamic model of the mechanism in this paper is established by the method of lumped mass, and the model’s numerical solution is solved by fourth-order Runge-Kutta. Then the nonlinear dynamic characteristics of system are simulated and analyzed. The studies show that this mechanism whose backlash has been eliminated has a good dynamic characteristics, and increasing system’s meshing damping can shorten the vibration attenuation time and improving the average meshing stiffness can reduce vibration amplitude of the system.