Key Engineering Materials Vols. 579-580

Abstract: In the process of agricultural modernization, agriculture will realize its socialized production, and its specialization, collaboration and new technologies in the agriculture industry will give birth to a new group of professional farmers, young farmers will be the main part of those professional farmers. At present, the phenomenon that agricultural labors are successors is becoming more serious, the scientific and cultural quality of farmers is low, and theirs market-oriented awareness is not strong enough, they are lacking of a sense of dignity. Those distress human capitals make it urgent to strengthen the cultivation of young professional farmers ,to form a social environment which is conducive for cultivating young professional farmers ,to build a young professional farmers cultivation and to create the conditions for the conditions for the cultivation of young professional farmers.

Abstract: According to stiffness measurement of feedback rod and spring tube in electro-hydraulic servo valve, this paper proposed the measured piece displacement method based on CCD image sensors. On this basis, developing a stiffness measurement instrument based on CCD and giving the overall program design. Because ambient noise affect the image quality seriously, reduce measurement accuracy, image pre-processing is the core of software systems. The system can achieve automatic loading, measure, evaluate and output the result. This article select three types measured piece to experiment and calculation, then, calculate and analysis of experimental data.

Abstract: In order to obtain the heat dissipation regularity of heavy-duty vertical lathe workbench with a large radius, mathematical model of convection heat transfer is established. According to the model, convection heat transfer process of the workbench is analysed at the velocity of 10~80rpm. The results show that velocity increasing not only impacts a greater influence on the temperature rising of hydrostatic bearing than the temperature rising of workbench, but also drives the heat increased the heat dissipation, degenerated the heat concentration phenomenon. Experimental results shows consistent to the workbench temperature numerical simulation results, the maximum error is 5%, which indicating that the numerical results conform physical regularities, the heat transfer mathematical model extends the range of applications of rotation convection heat transfer, so that vertical lathe heat dissipation situation analysis can be easier and more accurate.

Abstract: This paper is to solve the problems existed in the traditional tenoning, such as the poor flexibility, low accuracy, low efficiency, high labor intensity and so on. The HUST controller can provide multiple interfaces to connect various peripheral devices, and it is with the embedded PLC, multiple execution mode and control function, self-diagnosis and error prompt. So, the NC Tenoning Machines Control system based on the HUST H2 controller can automatically machine multiple tenons, including cross waist round tenon, vertical waist round tenon, round tenon, square tenon.

Abstract: This paper described a miniature refiner plate and its manufacturing. The plate was used for preparation of timber microfibril. Grinding teeth used Archimedes spiral groove as a path, the path effectively increased grinding trajectory path; all grinding teeth and alveolus unit were in the same equal length, effectively increasing the flow and easy to manufacture. The semifinished plate was processed in an ordinary lathe, then the processed surface was quenching, ensuring hardness, wear resistance and fatigue strength.

Abstract: This paper firstly starting mechanism of vibration and noise from gear, gear noise mechanism is explained, and analyze the factors and the impact of noise on the gear reducer. Secondly, the establishment of a complete solid model of gear reducer and reducer model for finite element model, the reduction gear box gear reducer of modal analysis and finite element modal calculation, and points out the dynamic analysis of structure, size and weight factor is proportional to the reciprocal of the modal frequencies of each mode is the with the frequency is low, that is, the greater the weight. Once again, the main measure of load and control of gear noise of gear is analyzed, including the calculation, for exciting force reduction gear reducer gear load computation. The analysis and calculation are the theoretical basis of gear structure design and its performance evaluation.

Abstract: In the paper, for high-power marine overflow valve of low pressure big traffic problems, the design of the inside leaking mouth leaks in parallel structure ,that is suitable for the different oil and water flow, using additional flow beam, guiding type low pressure large flow overflow valve was developed and the experimental study, obtained the dynamic and static parameters of the valve. Invented the inside leaking and leaked mouth parallel connection structure, inside leaking and leaked mouth parallel connection is established the mathematical model of the overflow valve. Results show that compared with the traditional straight moving type overflow valve, the type overflow valve through a larger flow, has better dynamic and static performance and cavitation resistance.

Abstract: No surface in engineering is absolutely smooth. It is important to analyze and calculate the real contact area for a better understanding of friction, wear, lubrication and thermal conductance. To obtain the accurate real contact area between rough surface and smooth surface, a rough-non-rigid-smooth surface contact finite element model is proposed in which the rough surface is characterized by fracture theory. In finite element modeling and analyzing process, MATLABEXCEL and AutoCAD are used to process data, and the smooth surface is considered to be non-rigid body. Compared with the traditional modeling, this method can obtain data quickly and is closer to the actual situation.

Abstract: This paper mainly consider the friction plate finite element modeling frictional contact conditions between the slices of components, friction plate assembly of the strength and stiffness of the. Through modal analysis of force and its distribution in different layers of friction plate assembly friction plate, a friction plate component analysis layers, friction plate by the effect of preload on the friction plate assembly strength, and in this state analysis of the friction plate stiffness. On the contact state under different friction plate layers, different pre tightening force under stress, stiffness were compared, the effect of contact on the stiffness and friction plate component strength.

Abstract: The DGZX - 1425 high-speed milling motorized spindle which is made and designed independently by Hao Zhi electrical and mechanical company in Guangzhou China is made as the research object, the method of establishing numerical simulation model for the spindle units dynamic performances is established, and the design of the spindles structure has been verified reasonable. Modal analysis of the spindle has been completed in ANSYS Workbench to get the first six natural frequencies and mode shapes. Harmonic analysis of the spindle is also completed to obtain the dynamic stiffness at the highest speed. Modal test and vibration test of the assembled spindle are also processed, which have verified the accuracy of the finite element method. The paper has provided a theoretical basis for the motorized spindles design, structural optimization and the improvement of the dynamic performances.