Advanced Materials Research Vols. 712-715

Abstract: In oilfield exploitation, automatically directional steering can only be achieved with rotary steerable system (RSS). The designed well trajectories have become more complicated e.g. horizontal wells, extended reach drilling wells and 3D multi-target wells. To drill these complicated wells, new drilling tools are urgently needed. This paper proposed a new steering mechanism for point-the-bit RSS. The new steering mechanism uses a set of universal joints to avoid the high alternative strain on drilling mandrel, and it uses a specific eccentric planetary gear train to offset the drilling mandrel to achieve directional steering. Design procedure, Solid modeling, Force analysis and dynamic simulation have been discussed for further dynamic analysis towards the confirmation of the steering performance.

Abstract: During optimization of transmission ratios, dimension difference of power performance and fuel economy indicators exists. Aiming at this problem, large bus model based on Matlab is built and verified, a normalization processing method of optimization goal is proposed. Through normalization processing of power performance and fuel economy indicators of the optimization goal, the dimension difference problem is eliminated. An optimization example is conducted, proving the method is feasible.

Abstract: The effect of asymmetric sinusoidal motion on plunging airfoil aerodynamics was studied by numerical simulations for 2-D flow around a NACA0012 airfoil at Re=1.35×10⁵. Various unsteady parameters (nondimensional plunging amplitude, h, reduced frequency, k) were applied to investigate the effect of asymmetry parameter S on the instantaneous force coefficient and flow pattern. It is found that more thrust can be generated by asymmetric sinusoidal plunging motion compared with pure sinusoidal case, and the thrust force generated increases with asymmetry. Moreover, a significant difference in the wake pattern at different values of S is observed. The trailing wake is displaced downward relative to the free stream for S less than 0.5, and displaced upward for S larger than 0.5.

Abstract: In this paper, a two-node beam element (as a simplified modeling approach) has been presented to investigate the vibration characteristic of rotor system with a complicated geometry. The decline of stiffness near the region of discontinuity is investigated on the basis of stain energy, and the conclusion is applied to the 2-node beam element analysis. In addition, the bending critical speeds and corresponding mode shapes of an integral rotor of 1000MW turbine have been investigated as an example. Verification results show that the simplified modeling approach by this 2-node beam element meets the accuracy requirement.

Abstract: This paper aims at the structure of the beam pumping unit structure, it is simplified into the corresponding crank rocker mechanism model. According to the beam pumping unit in actual working condition, the article study the main component motion regularity of the beam pumping unit, and using Matlab software to the motion law of calculation and simulation, I draw its angular displacement, angular velocity, angular acceleration curve, for analysis and research of walking beam type oil pumping machine main structure mechanical characteristics and the main moving parts of the failure of foundation.

Abstract: Straw fuel is a renewable organic fuels which has good combustive, its substitutable action of the raw coal meets the national strategic goals of sustainable development demand. Design proposal that is five-plunger-type straw fuel forming machine has been put forward according to three-plunger-type straw fuel forming machine which had been succeed in developing, its main purpose can meet the rapid growth of market demand for straw fuel, overcome disadvantage of three-plunger-type straw fuel forming machine which have not much higher productivity, give play to produce straw fuel advantages of compact structure, high combustion efficiency, and maximize favourable factors and minimize unfavourable ones. feasibility analysis for five-plunger-type straw fuel forming machine mainly revolves around several areas to unfold including productivity effect, design optimization and stability of motions and so on. Analysis results can be directly certified the project's necessity and economic value.

Abstract: This research designed and tested the efficiency of a scroll pump. The fixed and orbiting scrolls mathematic models were used in designing and constructing the scroll pump. The coordinates of the curves along the fixed and orbiting scroll wraps were calculated by SCILAB 5.1 program. The scroll coefficient is 3.0 mm while discrepancy of starting roll angle is radian. The scroll pump was modeled by Solid Work program and manufactured by a CNC machine. The testing facilities were design and constructed under the Japanese Industrial Standards (JIS B 8301) and used 0.5 horsepower, 3 phase AC motor, and motor speeds were controlled by a frequency inverter. The test speeds of motor were 700, 800, 900, 1000 and 1,100 rpm. The results were displayed as the relationship between water flow rate and pressure head (Q-H Curve). The Q-H curves were highly sloped. The maximum efficiency of the scroll water pump were 67.56 % at the volume flow 20.46 L/min. and pressure head 11.48 psig

Abstract: The research on the dynamics modeling in theory and experiment for the rolling bearing-motorized spindle system including bearing modeling and spindle-bearing system modeling is reviewed. The main factors influencing the motorized spindle system dynamics are analyzed combined with the pratical engineering, which include thermal characteristics, high-speed effects and electromechanical coupling. The methods for dynamics modeling including the transfer matrix method and finite element method are related. Finally, the research directions on the dynamics of rolling-bearing motorized spindle system are forecasted.

Abstract: Crawler crane is widely used of large special equipment in the lifting process, its operating positioning accuracy and safety will directly affect the operational efficiency. Therefore, the dynamic characteristics and dynamic response law of crawler crane structure is revealed, the dynamic design is particularly important. Finite element modal analysis method is adopted for the crawler crane latticed main boom structure to obtain the boom natural frequencies and modes are obtained under the order modal. Through analysis of the frequency and the corresponding external load on the boom, the power modifications and avoidance measures have been proposed in order to avoid operating external excitation with the natural frequency of the structure occurring resonance, and to develop and improve the same type of crane to provide a reference.

Abstract: To research fluid pressure mixed cylinder design, fluid pressure control system. Discuss cylinder and piston manufacturing technology, leakage and pressure loss, affect the product's work efficiency and service life problems through the analysis of material mechanical properties and parts processing and assembly accuracy. To fight the different material and different work environment, can transform the corresponding attack frequency and amplitude. Through the dynamic analysis and calculation of mechanical system optimization design lays the foundation for intelligent broken hammer.