1995 Vol.8(1)
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1995, 9(1).
Abstract:
The present work has studied the effect of various parameters on the efficienty when lapping Mn-Zn ferrite material with fine diamond grains. The main factors affecting the efficiency were made clear and the optimum lapping condition was discussed. It was found that the efficiency can be affected greatly by the parameters in terms of the number of active grains per time, while the surface roughness finally obtained is generally almost the same for a given grain size.
The present work has studied the effect of various parameters on the efficienty when lapping Mn-Zn ferrite material with fine diamond grains. The main factors affecting the efficiency were made clear and the optimum lapping condition was discussed. It was found that the efficiency can be affected greatly by the parameters in terms of the number of active grains per time, while the surface roughness finally obtained is generally almost the same for a given grain size.
1995, 9(1).
Abstract:
The appearance of adhering layer formed on tool face, its composition and distribution are analysed when Ca-S free-cutting stainless steel is meachined. Cutting temperature field and its relation with formation of the layer is also studied. The result shows that, the layer can be formed under proper temperature condition, the stable cutting temperature field keeps the stable layer, its thickness and composition distribution along rake face depend on the corresponding cutting temperature field. The theoretical model of the layer formation is set up.
The appearance of adhering layer formed on tool face, its composition and distribution are analysed when Ca-S free-cutting stainless steel is meachined. Cutting temperature field and its relation with formation of the layer is also studied. The result shows that, the layer can be formed under proper temperature condition, the stable cutting temperature field keeps the stable layer, its thickness and composition distribution along rake face depend on the corresponding cutting temperature field. The theoretical model of the layer formation is set up.
1995, 9(1).
Abstract:
An articulated vehicle is simplified as a multibody system, tires are simplified as paragraphic linear springs with damping, and the differentical equations of system motion are given. Taking the ZL10 loader as an example, and measuring three-dimensional dynamic stiffness and damping of the tires, seven orders of natural frequencies and related natural modes stiffness and damping of the tires, seven orders of natural frequencies and related natural modes are obtained by modal analysis, and shown on the computer with three-dimensional moving pictures. The following conclusions are obtained: the first order frequency relates to the horizontal stability, the second order frequency relates to the vertical stability, and each order of frequency relates to the comfortability. All results of this work can be applied to monitor stability and evaluate comfortability.
An articulated vehicle is simplified as a multibody system, tires are simplified as paragraphic linear springs with damping, and the differentical equations of system motion are given. Taking the ZL10 loader as an example, and measuring three-dimensional dynamic stiffness and damping of the tires, seven orders of natural frequencies and related natural modes stiffness and damping of the tires, seven orders of natural frequencies and related natural modes are obtained by modal analysis, and shown on the computer with three-dimensional moving pictures. The following conclusions are obtained: the first order frequency relates to the horizontal stability, the second order frequency relates to the vertical stability, and each order of frequency relates to the comfortability. All results of this work can be applied to monitor stability and evaluate comfortability.
1995, 9(1).
Abstract:
A model recognition method for the on-line optimal control of the parameters of three-cone blast drills is developed. It takes a few of on-line measurements and has a rapid optimization speed. The mathematic model for on-line optimal control of the parameters and the determination of the parameters in the model are also presented.
A model recognition method for the on-line optimal control of the parameters of three-cone blast drills is developed. It takes a few of on-line measurements and has a rapid optimization speed. The mathematic model for on-line optimal control of the parameters and the determination of the parameters in the model are also presented.
1995, 9(1).
Abstract:
Surface quality is an important subject in the study of machining technology. Because the surface quality of the ceramic parts has direct effect on their life and reliability, to improve the reliability of structural ceramic parts is an urgent problem which needs to be solved for their further wide-spread. The authors have done a systematic investigation in the macro-state, geometrical topography, surface roughness, deteriorative layer, residual stress and phase change of machining surface of engineering ceramic zirconia and sialon ceramics. Some findings and conclusions of improtant referential value have been obtained.
Surface quality is an important subject in the study of machining technology. Because the surface quality of the ceramic parts has direct effect on their life and reliability, to improve the reliability of structural ceramic parts is an urgent problem which needs to be solved for their further wide-spread. The authors have done a systematic investigation in the macro-state, geometrical topography, surface roughness, deteriorative layer, residual stress and phase change of machining surface of engineering ceramic zirconia and sialon ceramics. Some findings and conclusions of improtant referential value have been obtained.
1995, 9(1).
Abstract:
A non-overload centrifugal pump has been invented to solve the long-existing overload problem of low specific speed centrifugal pumps when operating at greater flow and lower head than normal. The performance characteristics of non-overload centrifugal pumps and the ordinary ones are introduced, and the test results are given here. By I.Khalil's numerical method, in hub-shroud plane using potentical flow calculation to determine flow surface position and in blade-blade plane using revised k-ε turbulence model, the inner flow of non-overload centrifugal pumps and the ordinary ones are respectively calculated. The nmuerical simulation shows that the inner lfow situates are completely different under the tow cases. And there exists remarkable inner flow characteristics of non-overload centrifugal impellers but with neither flow separation nor apparent wake flow, therefore, the lower efficiency attributes to the larger hydraulic friction loss due to larger blade wrapping angle.
A non-overload centrifugal pump has been invented to solve the long-existing overload problem of low specific speed centrifugal pumps when operating at greater flow and lower head than normal. The performance characteristics of non-overload centrifugal pumps and the ordinary ones are introduced, and the test results are given here. By I.Khalil's numerical method, in hub-shroud plane using potentical flow calculation to determine flow surface position and in blade-blade plane using revised k-ε turbulence model, the inner flow of non-overload centrifugal pumps and the ordinary ones are respectively calculated. The nmuerical simulation shows that the inner lfow situates are completely different under the tow cases. And there exists remarkable inner flow characteristics of non-overload centrifugal impellers but with neither flow separation nor apparent wake flow, therefore, the lower efficiency attributes to the larger hydraulic friction loss due to larger blade wrapping angle.
1995, 9(1).
Abstract:
Dynamic equations of elastic linkage are formed by means of Kane equation and finite method. Eight main influential factors on the dynamic respones of elastic linkage are considered in these equations. Model error caused by the eight factors are investigated. Some useful conclusions about model error are derived from theoretical analysis and the numercal calculation of twenty-six examples.
Dynamic equations of elastic linkage are formed by means of Kane equation and finite method. Eight main influential factors on the dynamic respones of elastic linkage are considered in these equations. Model error caused by the eight factors are investigated. Some useful conclusions about model error are derived from theoretical analysis and the numercal calculation of twenty-six examples.
1995, 9(1).
Abstract:
A stepped double arc spiral bevel gear tooth profile is examined. The development of conjugate tooth surface of double are profile spiral bevel gears is described. The design and manufacture of the cutter is also discussed. Experimental results show that these gears have high load carrying capacity and that they are suitalbe for heavily loaded transmission. It is asserted that such gears have higher power-to-weight ratios, are longer-lived, and provide more reliable performance than ordinary spiral bevel gears.
A stepped double arc spiral bevel gear tooth profile is examined. The development of conjugate tooth surface of double are profile spiral bevel gears is described. The design and manufacture of the cutter is also discussed. Experimental results show that these gears have high load carrying capacity and that they are suitalbe for heavily loaded transmission. It is asserted that such gears have higher power-to-weight ratios, are longer-lived, and provide more reliable performance than ordinary spiral bevel gears.
1995, 9(1).
Abstract:
A criterion is proposed to the feasibility on radial copying grinding, I.e.the pressure angle applying to a point on the workpiece contour to be profiled should be smaller than its angle limit. Therefore, the expressions of the angle applying to copying grinding and the angle limit to copying mechanism are derived, with the measures taken for the quality improvement of copying movement in contour grinding discussed.
A criterion is proposed to the feasibility on radial copying grinding, I.e.the pressure angle applying to a point on the workpiece contour to be profiled should be smaller than its angle limit. Therefore, the expressions of the angle applying to copying grinding and the angle limit to copying mechanism are derived, with the measures taken for the quality improvement of copying movement in contour grinding discussed.
1995, 9(1).
Abstract:
A computer software named VDAS (Vehicle Dynamic Analysis Simulation) is presented. Based on the mathematical modelling for a military vehicle as a 3-D dynamic system, the software creates random excitation resulting from double side road-surface roughness by statistical simulation, and solves for the time series of the system response from the system state equations, and gives out the results in probability statistics as well as performance evaluations.
A computer software named VDAS (Vehicle Dynamic Analysis Simulation) is presented. Based on the mathematical modelling for a military vehicle as a 3-D dynamic system, the software creates random excitation resulting from double side road-surface roughness by statistical simulation, and solves for the time series of the system response from the system state equations, and gives out the results in probability statistics as well as performance evaluations.
1995, 9(1).
Abstract:
The mechanism of spherical hob's cutting internal gear is explained and the new concept of generating gear of spherical hob is presented. The reason why there is theoretical error and the new method of decreasing the error are also analysed. Some new equations about the main parameters, the equations of helicoids, the equations of cutting edges and the flank angles of spherical hob are given.
The mechanism of spherical hob's cutting internal gear is explained and the new concept of generating gear of spherical hob is presented. The reason why there is theoretical error and the new method of decreasing the error are also analysed. Some new equations about the main parameters, the equations of helicoids, the equations of cutting edges and the flank angles of spherical hob are given.
1995, 9(1).
Abstract:
A very useful new method of tooth contact finite element analysis (TCFEA) for spiral bevel and hypoid gears is presented, combines 3-d finite element contact stress analysis with LTCA (Loaded Tooth Contact Analysis). The TCFEA uses mixed finite element method to analyze the 3-d contact stress. The related formulas are derived and an efficient analyzing method as several pairs of teeth in contact occurs is presented, which greatly reduce the computational amount. It is of great significance that the tooth stress, geometry, contact condition and load are all considered in the same model. Finally the related experimental results are used to verify the solution of TCFEA.
A very useful new method of tooth contact finite element analysis (TCFEA) for spiral bevel and hypoid gears is presented, combines 3-d finite element contact stress analysis with LTCA (Loaded Tooth Contact Analysis). The TCFEA uses mixed finite element method to analyze the 3-d contact stress. The related formulas are derived and an efficient analyzing method as several pairs of teeth in contact occurs is presented, which greatly reduce the computational amount. It is of great significance that the tooth stress, geometry, contact condition and load are all considered in the same model. Finally the related experimental results are used to verify the solution of TCFEA.
1995, 9(1).
Abstract:
Sucdessful cutting power monitoring and adaptive control strategies are based on the correct understanding of the relationships among measured power signals, mechanical systems, tool condition, and various process parameters such as spindle speed, feedrate, cutting depth, and so on. Input power of a spindle driving AC asynchronous motor in milling will be modeled to provide a basis for the investigation of these realtionships. The model is verified with simulation and milling experiments.
Sucdessful cutting power monitoring and adaptive control strategies are based on the correct understanding of the relationships among measured power signals, mechanical systems, tool condition, and various process parameters such as spindle speed, feedrate, cutting depth, and so on. Input power of a spindle driving AC asynchronous motor in milling will be modeled to provide a basis for the investigation of these realtionships. The model is verified with simulation and milling experiments.
1995, 9(1).
Abstract:
Electric fields induced by ring and pin electrodes in electrostatic charged powder spraying technique are analysed. The fundamental formulae to describe these fields have been built up. These formulae could be used to design electrostatic charged podwer spraying system. The charging effectivencss of ring and pin electrode is experimentally investigated and compared each other. The performance of ring electrode is better than that of pin electrode.
Electric fields induced by ring and pin electrodes in electrostatic charged powder spraying technique are analysed. The fundamental formulae to describe these fields have been built up. These formulae could be used to design electrostatic charged podwer spraying system. The charging effectivencss of ring and pin electrode is experimentally investigated and compared each other. The performance of ring electrode is better than that of pin electrode.
1995, 9(1).
Abstract:
By means of the analysis of the internal flow within inlet passage of large pumping station, and analysis of 3-D direct boundary element for the flow has been presented on the potential flow assumption, and a calculation and an experimental proof for the inlet passage of 30°angle-type axial pumping station have been made. Based on the analysis of the calculations and the experiments, the calculation method is feasible and believable.
By means of the analysis of the internal flow within inlet passage of large pumping station, and analysis of 3-D direct boundary element for the flow has been presented on the potential flow assumption, and a calculation and an experimental proof for the inlet passage of 30°angle-type axial pumping station have been made. Based on the analysis of the calculations and the experiments, the calculation method is feasible and believable.
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