Papers by Keyword: Static Characteristic

Abstract: Performance of current temperature sensor is not satisfactory on monitoring transient temperature of cutting edge. A temperature-testing cutter is presented in this paper and analysis of Seebeck coefficient on thin film thermocouple is proposed with experiments. Thin film thermocouple is embedded into the cutting edge using magnetron sputtering technology. According to the fact that electrical conductivity can be replaced by the multiplication of electron mean free path λ and effective Fermi surface area A, a universal formula of thermoelectric power is given based on the diffuse thermoelectric power equation put forward by Mott and Jones. Using the expression of electron mean free path in gas model λ, the relationship of thermoelectric power between thin film and bulk material can be deduced. Result shows that the main influential factor of Seebeck coefficient is film thermal junction thickness. In addition, the Seebeck coefficient of different junction size and film thickness were tested by LabVIEW automatic calibration system. The experimental data indicates that Seebeck coefficient is determined by thermal junction thickness, and the sensor is found to be linear from room temperature up to 600°C while the Seebeck coefficient of thin film thermocouple becomes closer to standard thermocouple as the film thickness increments. However, junction size does not have a major influence on the Seebeck coefficient which is agreed by both theoretical analysis and test.

Abstract: In this article, the necessity of static characteristic test of high temperature pressure sensor was discussed; the principle static characteristic test of high temperature pressure sensor is illustrated; the static testing of high temperature pressure sensor is completed; the static experimental model of high temperature pressure sensor is established; the main technical indexes was established, it provides an important theoretical basis for the application and test of high temperature pressure sensor.

Abstract: In this paper, using the finite element method,check for the Ken Swart project sand flushing water all operating tower in static stability. First of all, select unit and a calculation model, establish the finite element model; Then analys the displacement distribution and stress distribution of the structure in the five conditions.

Abstract: The static-state error is existed in the pressure valve, coupled with the characteristics of high vaporization pressure, low viscosity, and small compressibility, so that the fluid dynamics and friction force of hydraulic pressure valve are increased. The pressure valve will easily come up with produce cavitation erosion and wire drawing. Those appearances would seriously affect the performance of the pressure valve and its life cycle. A new type of static water pressure reducing valve is designed in this paper. It has a special structure which can complete the internal dynamic pressure feedback of the valve. The static mathematical model of value is established. And the static characteristic is analysed by using MATLAB simulation, which provides the static pressure characteristic curve, static pressure flow curve. It comes up with a result that this valve has good static pressure, and high precision pressure regulator.

Abstract: Most of the studies about tilting pad journal bearings are for load-on-pad or load-between-pad tilting pad journal bearings, and for the other loading forms, the performance are often estimated by the performance of the two limited conditions, that may reduce the reliablity of bearing design or lead to waste materials in design. To obtained the influence of the load directions on the static and dynamic characteristics of the tilting pad journal bearing, which is called eccentric load effect in this papers, the performance calculation of the tilting pad journal bearing in different load directions is operated with a self-designed program. The results show that the load directions have considerable effects both on the static and dynamic characteristics of the tilting pad journal bearing, for the operating condition that load direction changed rapidly, it need performance analysis of the bearing in its special loading forms to enhance the precision and efficiency of bearing design, espacially where the dynamic performance of the tilting pad journal bearing is demanding.

Abstract: The article contains information about the function and basic properties of the actuator based on pneumatic artificial muscles. It describes the design method of control structure of such actuator and shows the configuration of the non-linear actuator together with non-linear (compensation) control unit. The second upgrading method is based on the other mechanical configuration of the actuator. The artificial muscle force is transmitted by free pulley and has the practically linear static characteristic. The resulting position servosystem with linearized overall static characteristics has favorable results and better operation abilities. They are presented by experimentally measured step responses.

Abstract: This paper presents the results of research and development of two types diode structures based on wide bandgap 4H-SiC: drift step recovery diodes (DSRDs) and field emission diodes (FED). Diodes’ structure and manufacturing methods are reviewed. Diode’s characteristics were obtained (static current-voltage characteristics and capacitor-voltage characteristic, switching properties’ characteristics for DSRDs). Field emission 4H-SiC structures illustrated high (≥10² А/сm²) current densities at electric field intensity of approximately 10V/um. 4H-SiC DSRDs in the generator structure with a single oscillating contour allowed to form sub nanosecond impulses at a load 50 Ohm and 1,5-2kV amplitude for a single diode (current density at V=2kV J= 4•10³ А/сm²),what is significantly higher than similar DSRD’s parameters obtained for silicon.

Abstract: Based on various combinations of ACs of the slider and disk, the influence of ACs, were investigated by researchers. In the present paper, the static characteristics of air bearing film with the linear ACs are investigated. Pressure distribution and shear stress distribution are obtained by solving the free molecular MGL equation numerically by a mesh-free method, called Least square finite difference (LSFD). The simulation results show that with different ACs the shear stress and pressure are different, and on shear stress the influence of AC of slider is more obvious than that of disk in close to disk read-and-write head.

Abstract: Relying on HTC3250µn and HTC2550hs high-speed precision CNC turning center, this paper analyzes the static and dynamic characteristics of CNC machine tool spindle with finite element analysis software. Based on the results and using ANSYS software, this paper considers the volume and amplitude of vibration model as the objective function to optimize the size of the spindle. According to the optimized size of spindle, this paper analyzes the static and dynamic characteristics of the CNC machine tool spindle again and concludes the optimization results.

Abstract: In cutting temperature survey, in order to reflect the temperature change of cutting area accurately, the cutting tool sensor should have good technical characteristic. In this paper, one kind of automatic calibration system has been developed which could be used to investigate the technical characteristic of the multi-layered laminated thin film thermocouple cutting temperature sensor, this system selects Platinum-chip temperature sensor (concrete model: EN60751) as the standard temperature sensor, uses the AD524 precise amplifier chip building amplifying circuit and compiles the software with LabVIEW. This paper intends to investigate the static characteristic of the multi-layered laminated thin film thermocouple cutting temperature sensor system, the result shows that the Seebeck coefficient is 66.9 μV/°C, and the nonlinear error of fitting is smaller than 0.32%. This research has paved the way for future studying of thin film thermocouple cutting temperature sensor technology characteristic.