Advanced Materials Research Vols. 118-120

Abstract: Zero-tooth-difference internal gear mechanism is applied in thrust-eccentric gear coupling designed particularly for oil-submerged motor driven progressing cavity pumping system. The petroleum output of pump depends on the distance (eccentricity) between the canters of external and internal gears proportionally, while the eccentricity is affected by the profile-shift coefficient (abbreviated hereafter as PSC). Larger PSC can increase the amount of eccentricity but decrease the strength of gear, especially for small numbers of teeth. The optimum coupling relationship of radial and tangential PSC is just what to be found here. The work presented in this paper focuses on a method for determining the PSC of gears in the mechanism. The domain of initial values is prepared at first based on developed mathematical model. Then, according to tooth profile engagement equation and additional constraint conditions, a reasonable set of PSC is approached for different eccentricities. Moreover, the PSC can be modified and readjusted with optimum method until satisfied result is obtained finally.

Abstract: For large gear with the characteristic of large structure, quality and modulus, its profile precision is usually measured by in-site measurement. Based on large gear on-machine measuring described, involute helicoid and its characteristic are studied. The definition of medium rack in the framework of gear meshing transmission is put forward, the scheme of on-machine measurement based on rack-shaped-edge probe is formed, which can be divided into rolled angle (phase angle) and pressure angle (meshing angle) measurement according to the rotation of gear and prob. Measurement grid is determined by measuring straight generatrix deviation of gear profile, furthermore total tooth profile deviation and total helix deviation are separated.

Abstract: The characteristic of servo system is an important data to influence the mechanical working properties of NC machine tool. In this paper, based on servo system characteristic, the cause of following error has been studied. It discussed the effect on machining precision of following error on part contour when machining circular contour. Then some calculation equations have been worked out. In order to reduce the following error, the method of compound control has been advanced in the last, and it has been proved to be a feasible way to reduce the influence of follow error on machining contour of NC machine tool.

Abstract: According to the forming principle of equidistance curves, a mathematical model was concluded to calculate the curve contour of the cross section of the metal stator which has an inner helicoids and has an equal thickness rubber bushing using the primitive parameters of hypocycloid. By studying the cutting manufacturing technology of complex inner surface in slim parts, the feasibility of manufacturing large lead spiral inner surface by planning is studied and an NC envelop planning processing technology is proposed to manufacture the motor stator. The study of cutting simulation and cutting test provides the necessary theoretical support to the design of NC equipment and to cutting parameter optimization.

Abstract: Rolling technology is employed for the automated laser welding equipment to compensate for the clearance between the tailor-welded blanks which have different thicknesses. The thick blank is plastically deformed to the thin one by rolling. Two main parameters, namely, the depth of rolling and the position of rolling, have been discussed. The broadside displacement has been determined by theoretical calculations and ABAQUS simulations. Reasonable rolling technological parameters have been obtained, which provide good theoretical guidance for improving the speed and quality of laser welding.

Abstract: A lot of research has been done regarding the vaporization rates of alloying elements in general. However, not as much has been done on vaporized alloying element condensates. This paper investigates the drop wise pattern under a controlled thermal environment using some existing models with a few modifications to suit experimental results. From the analysis it was found that the condensation factors for Mg2+ and Al+ ions were 0.7 and 0.98 respectively. These results show that Mg2+ ions are more volatile than Al+ , and that any ions left which are usually unaccounted for would usually have been lost to spatter, or alternatively absorbed by the plasma ions within the laser welding environment. The conduction mode of heat transfer was found to be a dominant factor especially in the vicinity of the cooler regions of the metal. A vapor temperature of 2537oC was also calculated. This amounted to about 2% more than the expected boiling temperature. This paper has effectively and quantitatively analyzed the condensation process of 5456 aluminum alloy. It explicitly elucidated the approximate values of vaporized alloying elements and clearly shows how their molecular weights were affected by temperature.

Abstract: A model of the optimal maintenance period for repairable product after warranty expiration under renewing warranty is proposed. In the process to fulfilling warranty, the failures of product within warranty period happen randomly, the replacements of products successively failed with warranty period form a renewing process. Given failure rate of product, the period of fulfilling warranty is function of warranty period. User purchasing a product is considered an investment; the period of fulfilling warranty and the maintenance period after warranty make up the life cycle of product investment. Taking various cost factors into account, making model of the cost rate in life cycle of product investment under renewing warranty, the cost rate is function of maintenance period. Give the failure rate of product is an increasing function, it is derived that there is unique optimal maintenance period minimizing the cost rate. Finally, numerical example is given for illustration.

Abstract: To cope with the challenges of product quality design system applied in networked collaborative product development (NCPD), a new method of quality control for NCPD-collaborative quality design mode, which integrates voice of customer, quality function deployment (QFD) and failure modes and effect analysis (FMEA) , and corresponding functional modules and framework were all put forward. This mode dealt mainly with constructing and running collaborative quality design system, integrated several enabling technologies such as the integration of QFD and FMEA, task distribution of quality design, integrated technology of computer-supported-collaborative work (CSCW). On the basis of these, applying Java, JSP and JavaServlet to the system, improve working efficiency and shorten the development cycle so as to respond to the fluctuation of market demands as quick as possible. The quality design of some automobile was introduced as an example to verify that the system developed would efficiently meet the requirements of NCPD.

Abstract: The hydraulic lifting system of 450t schnabel car is more complex variable geometry mechanism. A simple technique for solving variable geometry mechanism is presented. The technique is based on energy conservation principle of hydraulic lifting process. The lifting principle and geometrical models are analyzed and formulated. The lifting pressure is calculated. The static strength design and bulking stability checking are introduced for cylindrical pressure cylinder. Results show that the maximum rated oil pressure meets cylinder lifting requirement, the static strengths of cylinder and piston reach lifting safety and reliability, and anti-bulking stability can be guaranteed under the loading and working conditions.

Abstract: Machine tools as a main device in manufacturing and production lines are widely used nearly in all branches of industries. Precision continuation of these systems with times and against inspected shocks is necessary and very important. Turning as a main kind and high usage machine tool is used in many industrial parts production, especially those with rounded sections. Spindle, tailstock and bed in machine tools play engraving role in dimensional accuracy. In this paper the vibration effects on the tailstock of a turning machine during its operation, is analyzed. For this purpose, a LZ330 VS machine from Weiler Co. in Germany is modeled with Solid Works software. This model with IGES format is transferred to ANSYS 5.4 analytical software. In this area, the model is analyzed via modal and transient dynamic analysis. The results show that, the more tailstock’s sleeve length, the less critical frequency amount.