Advanced Materials Research Vols. 199-200

Abstract: As well known, graph theory is a powerful tool for mechanism design. The enumeration of planet gear trains can be converted the synthesis of graphs while a planetary gear train is converted to a graph. During the enumeration of graphs, the problem of isomorphism should be solved. This paper proposes a novel algorithm used to generate non-isomorphism graphs and thereby omits the part of isomorphism detection. The vertex characteristic is firstly defined in this paper that is the core of the enumeration algorithm. This paper also gives an example of the application for the algorithm.

Abstract: Elastohydrodynamic lubrication theory is adopted in rolling bearing type planetary friction transmission mechanism in this paper. Operation performance and using life-span are improved. Minimal oil film thickness formula is deduced based on the elastohydrodynamic lubrication theory. Relationship curve between minimal oil film thickness and rotate speed is presented. Variation law between minimal oil film thickness and work parameters is given.

Abstract: A wood-based Ni-P coating electromagnetic shielding material was prepared in an ytterbium oxide-added electroless plating bath. The kinetic model was established and confirmed to be in accord with the experiment and can be used to predict the deposition rate within a certain range. The experimental results showed that the Ni-P coating prepared with the addition of Yb₂O₃ were smoother, denser and brighter than that prepared without addition of Yb₂O₃. The deposition rate and electromagnetic shielding effectiveness of the former were 2.662mol×10^-4/(cm²h) and 56.48 dB which is about 13% and 9% higher than those of the latter under the same bath compositions and operation conditions.

Abstract: This paper introduces a pin-cycloid planetary gearing reducer in two teeth difference applied in propeller pitch variator. To be considered, the main factors are pin-cycloid gear meshing efficiency, bearing efficiency and output mechanism efficiency. Finally, the transmission efficiency of this new-type reducer is calculated by the inverted mechanism method, which is the foundation of prototype test in future.

Abstract: This article use Automation Studio simulation software to make analysis on rib tube welding machine hydraulic system.Briefly introduces the software, theoretically analye welding machine hydraulic system, using software to make a detailed analysis on push (pull) acting hydraulic cylinder to push and pull two movements operation By analyzing the stable running speed, equal in size and opposite in direction which is consistent with reality step process.

Abstract: Lanthanide oxide was added into the common Watt bath to make a thick nickel on the Ni-P-B coating on the quartz optical fiber surface by response surface method. The experiment showed the optimum concentrations of NiSO₄•6H₂O, CH₃（CH₂）₁₁OSO₃Na and La₂O₃ as well as current density were separately 220g/L, 0.08g/L, 0.9g/L and 1.0 A/m² under which the deposition rate reached 24.2μm/h. The established model had an agreement with the experimental values and can be used to predict the deposition rate within the experimental range. The experiment also showed that the deposition rate, structure and other physical properties of the Ni coating prepared with addition of La₂O₃(0.9g/L) were greatly improved compared with the sample prepared without addition of La₂O₃ under same conditions.

Abstract: The osmosis pressure was introduced to improve the conventional electroless plating process for preparing porous ceramic supported Pd/Ag inorganic composite membrane. The effects of temperature (t), molar ratio of hydrazine to total metal ions(y), molar ratio of silver ions to palladium ions(x), concentrations of ethylene diamine tetraacetic acid (EDTA) and sucrose solution on the metal deposition rate, silver content in alloy film, surface morphology of film and permeation properties of the membrane were investigated and their optimal conditions were determined to be: [MET]=5mM, x = 20%, y = 1, [EDTA] = 40g•L^-1, t = 40 °C, pH =11 and sucrose solution concentration of 6 M. Under these optimal conditions, the prepared Pd/Ag alloy film with thickness of 7.9 μm demonstrated good permeation properties with nitrogen free and hydrogen permeation rate of 8.8×10^-3m³•m^-2•s^-1 at 0.3 MPa and 473 K.

Abstract: The bicycle is invented so far more than 200 years. Now, bicycles are used as exercising equipments and traffic vehicles. Planetary gear trains can be used as the transmission systems with multi-speed for bicycles. The purpose of this work is to propose a design methodology for the design of multi-speed internal gear hubs with planetary gear trains for bicycles. Based on the concept of train value equation and the kinematic relationship of the members between the train circuit, we propose a design methodology for the kinematic design of multi-speed gear hubs. One multi-speed internal gear hubs is designed to illustrate the design methodology. Based on the proposed methodology, all multi-speed gear hubs with planetary gear trains can be synthesized.

Abstract: A new type of reducer based on traveling wave driver principle was put forward. The initial structure of the reducer was designed and the theoretical model was built up. An initial reducer was manufactured and some performances were tested. The experiment results illustrated that the new type reducer has a feature of large ratio, and the testing results accord with the theoretical model through adjusting some test parameters.

Abstract: The definition of process system reliability was provided. The study focused on the process reliability model with the quality parameter as index. Taking into account the effect of error propagation in working procedures on the whole process, it proposed the calculating methods of working procedures and process system reliability, which can effectively evaluate the ability of process subsystem in fulfilling design requirement.