Zhang Y.L.,Sany Heavy Equipment Co. |
Zhang Y.M.,Northeastern University China
Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science | Year: 2013
Univariate dimension-reduction integration, maximum entropy principle, and finite element method are employed to present a computational procedure for estimating probability densities and distributions of stochastic responses of structures. The proposed procedure can be described as follows: 1. Choose input variables and corresponding distributions. 2. Calculate the integration points and perform finite element analysis. 3. Calculate the first four moments of structural responses by univariate dimension-reduction integration. 4. Estimate probability density function and cumulative distribution function of responses by maximum entropy principle. Numerical integration formulas are obtained for non-normal distributions. The non-normal input variables need not to be transformed into equivalent normal ones. Three numerical examples involving explicit performance functions and solid mechanic problems without explicit performance functions are used to illustrate the proposed procedure. Accuracy and efficiency of the proposed procedure are demonstrated by comparisons of the estimated probability density functions and cumulative distribution functions obtained by maximum entropy principle and Monte Carlo simulation. © 2012 IMechE.
Jia C.,China University of Mining and Technology |
Jia C.,Sany Heavy Equipment Co. |
Li W.,China University of Mining and Technology |
Yu L.,Shenyang University
Advanced Materials Research | Year: 2012
To solve the problem of support speed of hydraulic support flipper, the match relations between the flipper throttle control and shearer cutting coal speed are analyzed, the AMESim simulation model of the throttle optimal control for hydraulic support flipper jack is established, the simulation results show that flipper can be supported timely by speed optimal control of flipper jack which improve the reliability of the system and provide certain theory basis to meet the miner safety and high efficiency production. © (2012) Trans Tech Publications.
Cong M.,Dalian University of Technology |
Wen H.,Dalian University of Technology |
Du Y.,Dalian University of Technology |
Dai P.,Sany Heavy Equipment Co.
Chinese Journal of Mechanical Engineering (English Edition) | Year: 2012
Compared with traditional mechanical seals, magnetic fluid seals have unique characters of high airtightness, minimal friction torque requirements, pollution-free and long life-span, widely used in vacuum robots. With the rapid development of Integrate Circuit (IC), there is a stringent requirement for sealing wafer-handling robots when working in a vacuum environment. The parameters of magnetic fluid seals structure is very important in the vacuum robot design. This paper gives a magnetic fluid seal device for the robot. Firstly, the seal differential pressure formulas of magnetic fluid seal are deduced according to the theory of ferrohydrodynamics, which indicate that the magnetic field gradient in the sealing gap determines the seal capacity of magnetic fluid seal. Secondly, the magnetic analysis model of twin-shaft magnetic fluid seals structure is established. By analyzing the magnetic field distribution of dual magnetic fluid seal, the optimal value ranges of important parameters, including parameters of the permanent magnetic ring, the magnetic pole tooth, the outer shaft, the outer shaft sleeve and the axial relative position of two permanent magnetic rings, which affect the seal differential pressure, are obtained. A wafer-handling robot equipped with coaxial twin-shaft magnetic fluid rotary seals and bellows seal is devised and an optimized twin-shaft magnetic fluid seals experimental platform is built. Test result shows that when the speed of the two rotational shafts ranges from 0-500 r/min, the maximum burst pressure is about 0.24 MPa. Magnetic fluid rotary seals can provide satisfactory performance in the application of wafer-handling robot. The proposed coaxial twin-shaft magnetic fluid rotary seal provides the instruction to design high-speed vacuum robot. © Chinese Mechanical Engineering Society and Springer-Verlag Berlin Heidelberg 2012.
Xie F.,Jiangsu University |
Zheng G.,Jiangsu University |
Wang H.,Sany Heavy Equipment Co. |
Yang X.,Jiangsu University |
Zhao Y.,Jiangsu University
Recent Patents on Mechanical Engineering | Year: 2012
Patents record the continuous development of the disk brake. The disk brake is widely used as a brake device in the car and other vehicles. To enhance the braking stability of the disk brake, and acquire optimal structure parameters, we built the finite element (FE) models of the disk brake to conduct the constrained modal analysis; the first six order natural frequencies and vibration mode of each part were obtained, which indicated the third-order frequency of the friction disk and the second-order frequency of the caliper to be very close, easily leading to resonance of the system. The collaborative optimization was then carried out by using optimization algorithm; the optimal results showed the probability of the resonance to be reduced, where the braking stability of the system is enhanced. © 2012 Bentham Science Publishers.
Wenlin Y.,China University of Mining and Technology |
Wenlin Y.,Sany Heavy Equipment Co. |
Zhongbin W.,China University of Mining and Technology |
Binglei Y.,Sany Heavy Equipment Co.
Applied Mechanics and Materials | Year: 2013
The load on the cutting boom of roadheader changes violently because of the changes of rocks hardness. The power of cutter motor is related to the hardness of rock and propulsive force. The propulsive force is determined by the moving speed of cutting boom. The hydraulic control system of arcing cylinders is an electro-hydraulic proportional control system. The adaptive control model is build by Simulink. A PID control is used and the power of cutter motor is keep at a constant state by adjusting the speed of arcing cylinders. © (2013) Trans Tech Publications, Switzerland.