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This paper explores the mechanism design of a balloon machine representing a vending machine where consumers can select their desired shapes, as well as avoid bursting caused by manual inflation. Inside the machine, balloons are placed on the mechanism designed based on a waterwheel which rotates at a constant speed generated by motion among different sizes of gears. When rotating to the corresponding shaped balloon, the inflator will move under the opening to pull it out from the display point and start to inflate the balloon for the set number of seconds. After the inflation is completed, the glass door will open and the customer can take out their balloon. The main purpose of our development and design of the balloon machine is to improve the general balloon blowing and it is easy to prevent over-exposure and blast. The balloon machine can automatically inflate and detect the blowing time to improve the shortcomings of the balloon’s blast. In this way, it can effectively decrease sudden explosions and the number of frightened people.

In this paper, nonlinear dynamic model of spur gear pairs with fractional-order damping under the condition of time-varying stiffness, backlash and static transmission error is established. The general formula of fractional-order damping term is derived by using the incremental harmonic balance method (IHBM), and the approximate analytical solution of the system is obtained by use of the iterative formula. The correctness of the results is verified by comparing with the numerical solutions in the existing literature. The effects of mesh stiffness, internal excitation amplitude and fractional order on the dynamic behavior of the system are analyzed. The results show that changing the fractional order can effectively control the resonance position and amplitude in the meshing process. Both the mesh stiffness and internal excitation can control the collision state and the stability.

This study investigates the effects of sliding ratio on the tribological response of the contact between the teeth of a metal/polymer gear in the regions close to the pitch point. For this purpose, a new twin-disc test rig was developed on the basis of two discs of different diameters rotating one above the other at the same angular speed. Two different materials were used: non-alloyed structural steel (C45) and polyamide (PA66). The effect of the slip ratio (4%, 12%, 20% and 28%) was studied at a constant pressure of 34 MPa and a constant angular speed of 300 rpm. In addition, the contact conditions were controlled with measurements of the two discs surface temperatures. The results indicate that the wear and the friction are closely related to the contact temperature generated by the sliding phenomenon. At low slip ratio (4% and 12%), the coefficient of friction and the temperature are characterized by a quasi-linear increase with time, and the wear increases slowly. At higher slip ratio (20% and 28%), the coefficient of friction and the temperature presents a steady state, and the wear increases dramatically. During the test, a film of transferred PA66 is formed on the steel surface causing the development of adhesive interactions between the contacting discs which increase the friction coefficient and the contact temperature. The high thermal conductivity of steel as compared to that of the polymer can reduce enormously the contact temperature generated by the sliding process.

For any nontrivial abelian group $A$ under addition a graph $G$ is said to be $A$-magic if there exists a labeling $f:E(G)\to A-\{0\}$ such that the vertex labeling $f^{+}$ defined as $f^{+}(v)=\sum f(uv)$ taken over all edges $uv$ incident at $v$ is a constant. An $A$-magic graph $G$ is said to be $Z_k$-magic graph if the group $A$ is $Z_k$ the group of integers modulo $k$. These $Z_k$-magic graphs are referred to as $k$-magic graphs. In this paper, we prove that the graphs such as subdivision of ladder, triangular ladder, shadow, total, flower, generalized prism, $m{\mathrm{\Delta }}_n$-snake, lotus inside a circle, square, gear, closed helm and antiprism are $Z_k$-magic graphs. Also we prove that if $G_i(1\le i\le t)$ be $Z_k$-magic graphs with magic constant zero then $G^t$ is also $Z_k$-magic.

In the present study a single degree of freedom oscillator with clearance type non-linearity is considered. Such oscillator represents the simplest model able to analyze a single teeth gear pair, neglecting: bearings and shafts stiffness and multi mesh interactions. One of the test cases considered in the present work represents an actual gear pair that is part of a gear box of an agricultural vehicle; such gear pair gave rise to noise problems. The main gear pair characteristics (mesh stiffness and inertia) are evaluated after an accurate geometrical modelling. The meshing stiffness of the gear pair is piecewise linear and time varying (in particular periodic); it is evaluated numerically using nonlinear finite element analysis (with contact mechanics) for different positions along one mesh cycle, then it is expanded in Fourier series. A direct numerical integration approach and a smoothing technique have been considered to obtain the dynamic scenario. Bifurcation diagrams of Poincaré maps are plotted according to some sample case study from literature. Optimization procedures are proposed, in order to find optimal involute modifications that reduce gears vibration.

The during the gear fault detection and diagnosis, the fault feature extraction is the key of diagnosis, but it is multifarious for the method of fault feature extraction. On the basis of continuous wavelet transform, this paper mainly introduces that the basic principle of wavelet transform and its application in feature extraction for fault diagnosis are set forth. It is aimed at no steady state pulse signal feature when transmission gear have fault, select suitable wavelet, apply wavelet transformation successfully to diagnose crackle fault of transmission gear, which indicates the advantage of wavelet analysis. The results show that the continuous wavelet transform is a useful tool in diagnosis of crack in gears. The new method for prognosis and diagnosis of incipient small crack can be applied to engineering practice effectively.

In order to overcome the shortcomings in the traditional wavelet analysis, a new approach based on Laplace wavelet transform (LWT) time frequency plot is proposed for detection and diagnosis defects in gearbox. The Laplace wavelet is a complex, analytical, and single sided damped exponential function and is self-adaptive to non-stationary and nonlinear signal, which can detect the singularity characteristic of a signal precisely under strong background noise condition. The basic principle is introduced in detail. The gear wear fault vibration signal is firstly decomposed using Laplace wavelet transform. In the end, the Laplace wavelet transform time frequency plot is obtained and the characteristics of the gear fault can be recognized according to the LWT time frequency spectrum. The experimental results show that the Laplace wavelet transform time frequency plot can effectively detect the gear fault.

In order to study the thermal equilibrium process of rocker arm's gear system, the flexible virtual prototype coupling model of shearer's rocker arm system was established, the load file outputted by dynamic simulation software ADAMS was loaded. The temperature-structure coupling analysis and fatigue life prediction of gear had been done by using the finite element software ANSYS, the temperature field nephogram and structure field nephogram of gear were obtained. Combining multi-field coupling technique and neural network could predict the safe working condition data of the low speed and heavy load gear of shearer, the error was 1.25e-5, providing a unequivocal basis for the design and optimization of gear type parts, which can improve the working reliability of this kind of parts effectively, this method also has instruction significance to shearer's practical productions.