Tilting pad gas journal bearing is one of the most widely used types of aerodynamic bearings due to its inherent excellent stability in high speed applications.A practical method for analyzing and calculating the per-...Tilting pad gas journal bearing is one of the most widely used types of aerodynamic bearings due to its inherent excellent stability in high speed applications.A practical method for analyzing and calculating the per- formances of such bearings is presented as well as its rotordynamics based on the computer aided technique.The method of calculation and the philosophy of programming with a microcomputer for the computer aided analysis are highlighted.展开更多
A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder...A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder has a higher H(?) and lower σ,than one made up of spherical Fe_O_4.展开更多
A technique of detecting cutting tool fracture and ultimate wear by si- multaneously monitoring both the spindle motor current and cutting process related acoustic emission(AE)in the cutting process is reported.The te...A technique of detecting cutting tool fracture and ultimate wear by si- multaneously monitoring both the spindle motor current and cutting process related acoustic emission(AE)in the cutting process is reported.The technique can detect breakage of drills having diameter over 0.8mm,turning cutter crack of area over 0.2mm,and the ultimate wear.The principle,system construction,experimental method and result of the technique are discussed.The ratio of success in detection approaches 96% or higher.展开更多
Based on an analysis of the relative shaft-to-hole position and attiude errors, as well as of the mechanics and Kinematics in the process of automatic assembly of industrial robots, the paper studies the principle of ...Based on an analysis of the relative shaft-to-hole position and attiude errors, as well as of the mechanics and Kinematics in the process of automatic assembly of industrial robots, the paper studies the principle of construction of dynamic wrists. Type I-3 and Ⅱ-6 dynamic compliant wrists have been designed and made. Prblems in the production of compliant elements and the connection between compliant elements and wrists were also solved. A study on the results of tests of the function of two kinds of dynamic compliant wrists shows that the dynamic compliant wrist's compliancy function can be improved by adding metallic materials having higher longitudinal and transverse rigidity into the softer elstomer. And the design Principle is proved to be feasible and practicable. It can be expected that the use of dynamic compliant wrist will greatly lower the technical requirements of the shaft-hole assembly and the requirements in the resetting accuracy.展开更多
Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip f...Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip friction coefficient and machining quality by comparing them with those of WC based cemented carbides. The cutting data and the regressed empirical formulae would be useful to promote proper application of cermet cutting tool materials.展开更多
Introduces a new monitoring method in FMS explicated in some detail by means of the MSF(Monitoring System of FMS)under development by the au- thors.In order to push FMS technology forword,enhance machining flexibility...Introduces a new monitoring method in FMS explicated in some detail by means of the MSF(Monitoring System of FMS)under development by the au- thors.In order to push FMS technology forword,enhance machining flexibility and the flexibility of human operaters and equipment in a FMS,the authors have made some breakthroughs in traditional ways of single item,unit monitoring and self-han- dling,and suggested the idea of integrated inspection and put the MSF into more practicability.The working status of FMS can be monitored on the CRT of a micro- computer of the MSF,system troubles will be shown with icons,by the flash of the system characteristic symbol or by alarming,and so on.This explores a new way for FMS inspection in a wholly integrated manner.展开更多
The dynamic performances of floating-ring bearing with hydrodynamic/hydrostatic gas lubrication are studied theoretically and some calculated charts of dynamic coefficients are given in the paper. The method of stabil...The dynamic performances of floating-ring bearing with hydrodynamic/hydrostatic gas lubrication are studied theoretically and some calculated charts of dynamic coefficients are given in the paper. The method of stability analysis is also presented and it is proved that the high speed stability of such bearings is better than other types of gas bearings.展开更多
文摘Tilting pad gas journal bearing is one of the most widely used types of aerodynamic bearings due to its inherent excellent stability in high speed applications.A practical method for analyzing and calculating the per- formances of such bearings is presented as well as its rotordynamics based on the computer aided technique.The method of calculation and the philosophy of programming with a microcomputer for the computer aided analysis are highlighted.
文摘A kind of superfine Fe_3O_4 cubic powder has been prepared chemi- cally.Its formation is related with the concentration of Na^(+1) in the chemical reaction.Given the same particle size,a superfine Fe_3O_4 cubic powder has a higher H(?) and lower σ,than one made up of spherical Fe_O_4.
文摘A technique of detecting cutting tool fracture and ultimate wear by si- multaneously monitoring both the spindle motor current and cutting process related acoustic emission(AE)in the cutting process is reported.The technique can detect breakage of drills having diameter over 0.8mm,turning cutter crack of area over 0.2mm,and the ultimate wear.The principle,system construction,experimental method and result of the technique are discussed.The ratio of success in detection approaches 96% or higher.
文摘Based on an analysis of the relative shaft-to-hole position and attiude errors, as well as of the mechanics and Kinematics in the process of automatic assembly of industrial robots, the paper studies the principle of construction of dynamic wrists. Type I-3 and Ⅱ-6 dynamic compliant wrists have been designed and made. Prblems in the production of compliant elements and the connection between compliant elements and wrists were also solved. A study on the results of tests of the function of two kinds of dynamic compliant wrists shows that the dynamic compliant wrist's compliancy function can be improved by adding metallic materials having higher longitudinal and transverse rigidity into the softer elstomer. And the design Principle is proved to be feasible and practicable. It can be expected that the use of dynamic compliant wrist will greatly lower the technical requirements of the shaft-hole assembly and the requirements in the resetting accuracy.
文摘Through systematic cutting experiments, characteristics of the cutting performance of Ti(C, N) based cermets is identified. The experiments were designed to study their resistance,toughness, cutting force, tool-chip friction coefficient and machining quality by comparing them with those of WC based cemented carbides. The cutting data and the regressed empirical formulae would be useful to promote proper application of cermet cutting tool materials.
文摘Introduces a new monitoring method in FMS explicated in some detail by means of the MSF(Monitoring System of FMS)under development by the au- thors.In order to push FMS technology forword,enhance machining flexibility and the flexibility of human operaters and equipment in a FMS,the authors have made some breakthroughs in traditional ways of single item,unit monitoring and self-han- dling,and suggested the idea of integrated inspection and put the MSF into more practicability.The working status of FMS can be monitored on the CRT of a micro- computer of the MSF,system troubles will be shown with icons,by the flash of the system characteristic symbol or by alarming,and so on.This explores a new way for FMS inspection in a wholly integrated manner.
文摘The dynamic performances of floating-ring bearing with hydrodynamic/hydrostatic gas lubrication are studied theoretically and some calculated charts of dynamic coefficients are given in the paper. The method of stability analysis is also presented and it is proved that the high speed stability of such bearings is better than other types of gas bearings.
