1996 Vol.9(1)
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1996, 10(1).
Abstract:
The phenomena of interference in the course of assembling curved bevel gears are analysed and the corresponding prediction program of interference is extablished taking Klinglnberg bevel gear as an exmple. The factors influencing interference are discussed and the concept of critical cutter radius is proposed. Finally, a simplified approximate function between the critical cutter radius and the other factors is derived, and the designing method of avoiding interference is provided. The analysis and calculation are proved to consistent with a case of actual product.
The phenomena of interference in the course of assembling curved bevel gears are analysed and the corresponding prediction program of interference is extablished taking Klinglnberg bevel gear as an exmple. The factors influencing interference are discussed and the concept of critical cutter radius is proposed. Finally, a simplified approximate function between the critical cutter radius and the other factors is derived, and the designing method of avoiding interference is provided. The analysis and calculation are proved to consistent with a case of actual product.
1996, 10(1).
Abstract:
A multi-purpose simulation method for the roll-forming is proposed. The forming processes of welded pipes are systematically simulated by using the method. The three-dimensional curved surfaces of sheet metlsa in forming processes are mathematically expressed by using the shape function S(X) which represents flow pattern of each part of sheet metal. Through optimising the parameter n in S(X), the best approximation of the deformation of sheet metal is derived and the minimum power of deformation is obained. A mathematical procedure of this analysis is systematically formulated. The simulation method can be applied to the analysis and sumulation for various roll-forming processes of welded pipes observed in commercial production line.
A multi-purpose simulation method for the roll-forming is proposed. The forming processes of welded pipes are systematically simulated by using the method. The three-dimensional curved surfaces of sheet metlsa in forming processes are mathematically expressed by using the shape function S(X) which represents flow pattern of each part of sheet metal. Through optimising the parameter n in S(X), the best approximation of the deformation of sheet metal is derived and the minimum power of deformation is obained. A mathematical procedure of this analysis is systematically formulated. The simulation method can be applied to the analysis and sumulation for various roll-forming processes of welded pipes observed in commercial production line.
1996, 10(1).
Abstract:
Faced with the key problems of machinery-induced vibration and stucture-borne noise when dynamic machines are mounted on flexible foundations such as upper floors of factory buildings, the vibration and noise transmission mechanism and optimal control for the flexible system are systematically studied by the novel approach of power flow. A more general system of machinery-isoaltors-flexible foundation is modelled. Based on substructure transfer matrix technuque the power flow input and transmitted are formulated in closed forms, and the effects that the flexibility of foundation and the asymmetricity of system have upon the power flow transmission spectra are revealed. Also the inverse problems of isolation design are discussed by using an optimum method. Optimum design for a typical example about a force fan mounted on a concrete buiding floor is successfully performed to show that the model is practical, the theory and the optimisation developed are reasonable and effective. Thereby, theoretical bases for accurate prediction of isolation effectiveness and an optimum method for practical design of a general flexible isolation system are provided.
Faced with the key problems of machinery-induced vibration and stucture-borne noise when dynamic machines are mounted on flexible foundations such as upper floors of factory buildings, the vibration and noise transmission mechanism and optimal control for the flexible system are systematically studied by the novel approach of power flow. A more general system of machinery-isoaltors-flexible foundation is modelled. Based on substructure transfer matrix technuque the power flow input and transmitted are formulated in closed forms, and the effects that the flexibility of foundation and the asymmetricity of system have upon the power flow transmission spectra are revealed. Also the inverse problems of isolation design are discussed by using an optimum method. Optimum design for a typical example about a force fan mounted on a concrete buiding floor is successfully performed to show that the model is practical, the theory and the optimisation developed are reasonable and effective. Thereby, theoretical bases for accurate prediction of isolation effectiveness and an optimum method for practical design of a general flexible isolation system are provided.
1996, 10(1).
Abstract:
A new ball lapping method is presented. By using the method, there is a distance between the centre line of circular groove and the rotating axis of lapping plate. The proper distance can make the lapped probability of each point on ball surface as consistent as possible. This method is expecially adapted for lapping high hardness ceramic balls due to its high material removal rate.
A new ball lapping method is presented. By using the method, there is a distance between the centre line of circular groove and the rotating axis of lapping plate. The proper distance can make the lapped probability of each point on ball surface as consistent as possible. This method is expecially adapted for lapping high hardness ceramic balls due to its high material removal rate.
1996, 10(1).
Abstract:
The superharmonic resonances of elastic linkages are studied by using the mathod of multiple scales under the excitation of its inertial force. The analyses demonstrate that the superharmonic resonances caused by the quadratic and cubic nonlinearities due to large elastic deformations of the flexible links and multi-frequencies of the inertial force of linkages are the reason to produce the critical speeds. The results of explaining of the lower order harmonic resomances by "1/n" method are verified theoretically.
The superharmonic resonances of elastic linkages are studied by using the mathod of multiple scales under the excitation of its inertial force. The analyses demonstrate that the superharmonic resonances caused by the quadratic and cubic nonlinearities due to large elastic deformations of the flexible links and multi-frequencies of the inertial force of linkages are the reason to produce the critical speeds. The results of explaining of the lower order harmonic resomances by "1/n" method are verified theoretically.
1996, 10(1).
Abstract:
The deformation principles of the steady-state and the unsteady-state of open-die cold extrusion for involute spline shafts are analyzed by means of experiments. On one hand, based on the deformation principles of the steady-state, data for determining structural parameters of the die, the size of the billet and the constraint condition of this technique are given. On the other hand, according to the principles of the unsteady-state, data for modifying the shapes and sizes of the billets are provided.
The deformation principles of the steady-state and the unsteady-state of open-die cold extrusion for involute spline shafts are analyzed by means of experiments. On one hand, based on the deformation principles of the steady-state, data for determining structural parameters of the die, the size of the billet and the constraint condition of this technique are given. On the other hand, according to the principles of the unsteady-state, data for modifying the shapes and sizes of the billets are provided.
1996, 10(1).
Abstract:
A CAD tools environment is described to support cincurrent collaborative design. The environment has four components: shared design representation, design process control, CAD tools, designer interface. Some related issues for the construction, such as form feature handling, constraint satisfaction, design process control, STEP based information ntegration, are discussed in more detail.
A CAD tools environment is described to support cincurrent collaborative design. The environment has four components: shared design representation, design process control, CAD tools, designer interface. Some related issues for the construction, such as form feature handling, constraint satisfaction, design process control, STEP based information ntegration, are discussed in more detail.
1996, 10(1).
Abstract:
Backward spinning is analyzed by 3D rigid-plastic FEM. A 3D mechanical model for backward spinning is presented. The distributions are obtained of strain-rate and stress in the contact area of the roller and its adjacent area. The results can well interpret the principle of deformation of backward spinning. The relationship between the roller angle and three components of spinning force is found out, and the optimum roller angle, when the general spinning force gets to the minimum value, is calculated. The distributions of deformation area obtained by FEM agree with the experimental result well.
Backward spinning is analyzed by 3D rigid-plastic FEM. A 3D mechanical model for backward spinning is presented. The distributions are obtained of strain-rate and stress in the contact area of the roller and its adjacent area. The results can well interpret the principle of deformation of backward spinning. The relationship between the roller angle and three components of spinning force is found out, and the optimum roller angle, when the general spinning force gets to the minimum value, is calculated. The distributions of deformation area obtained by FEM agree with the experimental result well.
1996, 10(1).
Abstract:
The construction kinematics and no reverse error property of heterotype single cycloid steel ball transmission are studide and its engagement pairs structure as well as force analysis are also presented. It provides a kind of high property driver of large transmission ratio and compact construction and has theoretical and practical significance for application of the steel ball transmission.
The construction kinematics and no reverse error property of heterotype single cycloid steel ball transmission are studide and its engagement pairs structure as well as force analysis are also presented. It provides a kind of high property driver of large transmission ratio and compact construction and has theoretical and practical significance for application of the steel ball transmission.
1996, 10(1).
Abstract:
The lubrication behavior of double enveloping hourglass worm gearing is studied experimently. The effects of rotational speed of the worm and load on the formation of the fluid film between engagement tooth surfaces are investigated in detail, and working angle of this worm gearing is also analyzed. Some beneficial results are obtained.
The lubrication behavior of double enveloping hourglass worm gearing is studied experimently. The effects of rotational speed of the worm and load on the formation of the fluid film between engagement tooth surfaces are investigated in detail, and working angle of this worm gearing is also analyzed. Some beneficial results are obtained.
1996, 10(1).
Abstract:
A new method adding planar cams for the complete shaking moment balancing of spatial linkages is presented. This method is simple, practical, and has universal practicability for the spatial linkages which have input links with revolute kinematic pairs. Therefore, it has important significance in balancing theory and practicality. As an illustrative example, the method is used to balance a RSS'R spatial linkage.
A new method adding planar cams for the complete shaking moment balancing of spatial linkages is presented. This method is simple, practical, and has universal practicability for the spatial linkages which have input links with revolute kinematic pairs. Therefore, it has important significance in balancing theory and practicality. As an illustrative example, the method is used to balance a RSS'R spatial linkage.
1996, 10(1).
Abstract:
It is expounded that ρωh2/η is the Reynolds number form of thrust bearings and effects of the centrifugal forces can be judged by its magnitude. Three methods improving the configuration of pads are given out to overcome the harmful influence of the centrifugal forces on the performance of bearing, and the optimzed parameters for three kinds of high-speed thrust bearings are provided by solving the varying-viscositied three-dimensional Reynolds equation.
It is expounded that ρωh2/η is the Reynolds number form of thrust bearings and effects of the centrifugal forces can be judged by its magnitude. Three methods improving the configuration of pads are given out to overcome the harmful influence of the centrifugal forces on the performance of bearing, and the optimzed parameters for three kinds of high-speed thrust bearings are provided by solving the varying-viscositied three-dimensional Reynolds equation.
1996, 10(1).
Abstract:
Trivalent Cr layers are studied by direct current brush-plating and pulse current brush-palting. Under the SEM, the appearance, the morphology of cross sections and normal sections of the layers are observed and analysed, the hardness, bond intensities and corrosion-resistance are measured. Then the election-probe and X ray diffraction instruments are used to study the bond and harden mechanism of layers. The result of research shows that: the harden effect of the layers if caused by the extra-fine grains and internal stress in the layers. And the layers and basis are joined by mechanical bond, metal bond and diffuse bond. All these kinds of bonds lie on different places of interface, they make the layers and base metal unit well.
Trivalent Cr layers are studied by direct current brush-plating and pulse current brush-palting. Under the SEM, the appearance, the morphology of cross sections and normal sections of the layers are observed and analysed, the hardness, bond intensities and corrosion-resistance are measured. Then the election-probe and X ray diffraction instruments are used to study the bond and harden mechanism of layers. The result of research shows that: the harden effect of the layers if caused by the extra-fine grains and internal stress in the layers. And the layers and basis are joined by mechanical bond, metal bond and diffuse bond. All these kinds of bonds lie on different places of interface, they make the layers and base metal unit well.
1996, 10(1).
Abstract:
The expressions for calculating the values of the workspace areas of 2-DOF parallel planar manipulators (PPM) is derived. By the aid of computer, the values are calculated and plotted on the physical model of the solution space of the 2-DOF PPMs, so the workspace-area-property atlas is obtained. The atlas delineates the relationship between the workspace areas and the link lengths of the 2-DOF PPMa all sidedly. It is very useful for designers overall to understand and know well the relationship.
The expressions for calculating the values of the workspace areas of 2-DOF parallel planar manipulators (PPM) is derived. By the aid of computer, the values are calculated and plotted on the physical model of the solution space of the 2-DOF PPMs, so the workspace-area-property atlas is obtained. The atlas delineates the relationship between the workspace areas and the link lengths of the 2-DOF PPMa all sidedly. It is very useful for designers overall to understand and know well the relationship.