Advanced Materials Research Vols. 889-890

Abstract: Based on the theory of quadruple-arc gears and the bevel gears process principle, meshing analysis of quadruple-arc profile bevel gears in the process of cutting tooth is carried out. The surface equation of generating gear and the equation of action line in the process of cutting tooth as well as the general tooth surface equation of quadruple-arc profile bevel gears are obtained.

Abstract: Arc-gear is sensitive to central distance error, but there havent any literature give detailed proof for how does it sensitive to central distance error. In this article, contact line was analysised, and find that meshing point will move along tooth profile, tansmission ratio will change, overtaking phenomenon appears when there has central distance error, this will cause vibration and noise. The research results is useful for improve arc-gear drive performance.

Abstract: This article described the structure and movement principle of planetary roller screw; established the equation of screw thread surface and roller surface, solved the meshing points of crossing thread engagement using numerical methods, while the screw and roller meshing at pitch diameter; studied meshing relationship between screw and roller comparing the distribution of simulated meshing point under various design parameters. The conclusion provides a theoretical basis for choosing parameters of planetary roller screw.

Abstract: Gears play an important role in every aspect of power and motion of transmission from historical period to modern day period . Due to this , gear design has become a complicated art.A considerable amount of research has been carried out to determine the amount of dynamic gear tooth loads acting.The findings of the dynamic load between the gear teeth results in difficulty for the designer.In this paper, an effort has been made to formulate a simple design procedure for calculating the dynamic load .Earlier the stiffness characteristics and deformation of the gear tooth were studied to predict the dynamic load acting. This was developed with the tooth assumed as a short cantilever.Whereas in reality, an involute profile exists in a spur gear tooth.Based on this reality, work has been done to model the exact profile of the tooth.Later ,the stiffness characteristics were carefully analysed and an improvement was thus made. It was proved that FEA is one such technique that can be used for predicting dynamic loads acting on a gear tooth.

Abstract: The paper summarizes the principle of applying velocity graphic method to analyze Simpson planetary gear mechanism, which provides guidance for analysis procedure. The movement of each element in the mechanism can be intuitively understood through drawing the linear velocity vectors of three constant velocity points. The similar triangle principle is used to calculated transmission ratio of each transmission scheme in the linear velocity vector diagram, and the correctness of the analysis method and process is verified by the transmission ratio calculated by velocity graphic method and analytic method.

Abstract: In order to lower down the fault rate of bearings and gears, tighten up the mechanical components safety and lengthen their lifetime, a new design method ^[ has occurred by matching bearings with gears. Whereas, this methodology is based on the simple transmission system, and it seems not applicable in more complicated transmission systems, such as gearboxes in doubly-fed wind turbine generators, which really need to be further studied, and thats where the topic of this article lies. By doing research on the bearing-gear matching design of planetary gear system in gearbox of wind turbine generator, equations are worked out. Succeedingly, by verifying the data from simulating experiments and on-site cases, it turns out that the spectrum characteristics of those two kinds of data match with each other correctly, and as a consequence, the new matching design is thus proved to be available.

Abstract: In turning process, one of the effective ways to obtain the best cutting characteristics is the real-time adjustment tool cutting edge inclination. This paper designs a real-time adjustment tool cutting edge inclination of the head; the motion analysis by software, the tool structure is optimized further, so that in the premise of turning accuracy, can be adjusted real time tool cutting edge inclination.

Abstract: Based on 3-D potential flow theory, sources and sinks are brought in, distributed upon the wet surface of ship hull. Three-dimensional non-speed frequency domain Green function is also introduced to determine the flow field velocity potential. As a result, added mass, damping coefficient and ship motion response of this deep water pipe-laying vessel are calculated under the regular wave condition. After compared these calculation results to model tank test data, we can see that the theoretical calculation fit well with experimental data. These calculations could provide prediction and guidance for vessel design and marine engineering operation.

Abstract: As ships gradually getting larger, more special, tug assisted operation of the ship in and out of Port , berthing and unberthing becomes increasingly prominent, Tug-related training and safety assessment is increasingly important, increasing the tug unit for marine simulator is urgent.In tug unit, the cable is an important part, to establish the mathematical model of cable is key. Mooring strain satisfy Hooke's law, using the catenary equation and Hooke's Law deduces mooring unstressed length formula, according to the Department to calculate the cable unstressed length and the corresponding relations of the actual length of the mooring to calculate the tension of the mooring; Otherwise, ignoring the weight of the mooring by mooring strain curve fitting polynomial to calculate the tension of the mooring, and calculated the level of tension and vertical tension of the mooring. calculating example to verify the correctness and practicability of the model.

Abstract: Axial contact stiffness increase of ball screws can reduce the vibration and enhance machining precision of CNC machine tool during machining process. On the basis of Hertz contact theory, calculation formula of axial contact stiffness was deduced with consideration of helix angle for 5010 single-nut and double-nut ball screws, influence factors comparison and analysis was carried out, and contrast curve was obtained. The result shows that the axial contact stiffness of preloaded double-nut ball screws is higher than that of single-nut ball screws. Ball number, contact angle and curvature ratio has obvious influence on the axial contact stiffness of double-nut ball screws: ball number increase can enhance the axial contact stiffness; increase of contact angle and curvature ratio can lower the axial contact stiffness. The axial contact stiffness of single-nut and double-nut ball screws does almost not vary with axial force and helix angle. The conclusion provides certain theoretical basis for design and selection of ball screws.