Macro-deformation characteristics of continuous drive friction welded mild steel joints were examined by using one deformable workpiece (objective) and the other undeformable one (rigid). The microstructure evolut...Macro-deformation characteristics of continuous drive friction welded mild steel joints were examined by using one deformable workpiece (objective) and the other undeformable one (rigid). The microstructure evolution and hardness change across the joint were studied. The results show that the axial shortening and radial increment of joints increase with increasing the frictiou time at l 200 rpm. The cementite particles of pearlites in the weld center are uniformly distributed on the ferrite matrix, while the cementites of the pearlite in the thermal-mechanically affected zone are broken and discontinuously dispersed in the pearlite. The hardness decreases rapidly from the weld center to the parent metal under the coupled effects of heat and deformation during the rapid heating and cooling processes.展开更多
The friction drive elevators the influence of the braking distance has very high significance to meet certain safety regulations and comfort.During the emergency braking the delay for the system a frame and a cabin sh...The friction drive elevators the influence of the braking distance has very high significance to meet certain safety regulations and comfort.During the emergency braking the delay for the system a frame and a cabin should be within the range from 0.2 to 9.81 m/s~2.However,there are no specialist literatures regarding the issues connected with emergency braking of elevating devices either.The results of the own empirical research work are presented regarding the influence of design changes on the working parameters of the friction drive elevator gears.ASG100,KB 160,PP16,PR2000UD and CHP2000 types of safety progressive gears are analyzed.ASG100,KB 160,PP16,PR2000UD type progressive gears are already produced by European manufacturers.CHP2000 type gears are established as the alternative option for the already existing solutions.The unique cam system has been used in the CHP 2000 gears.The cam leverage gives the chance to unblock,in a very easy way,the clamed gears after braking.Thus,it is a key aspect to perform laboratory tests over the braking process of a newly created solution.The proper value of the braking distance has a significant influence on the value of delay in terms of binding standards.The influence of loading on the effective braking distance and the value of the falling elevator cabin speed are analyzed and the results are presented.The results presented are interesting from lift devices operation and a new model of CHP 2000progressive gear point of view.展开更多
The aim of present study is introducing a method by subdividing friction welding phases into three steps according to the temperature change during continuous drive friction welding operation. Thermal curve allowable ...The aim of present study is introducing a method by subdividing friction welding phases into three steps according to the temperature change during continuous drive friction welding operation. Thermal curve allowable subdividing of the friction welding phase's time into three distinct periods, while the microstructure evolution during friction welding goes through three different situations. The effects of three distinct periods were achieved by macro-microscopy, microhardness HV_(0.1), tensile tests and scanning electronic microscopy(SEM).The results clearly show that the microstructure during the friction phase goes through three completely different situations which mechanically influenced on microstructure, tensile strength and ductility of the welded joint.展开更多
On basis of the finite element software DEFORM, the 2D coupled thermo-mechanical model of continuous drive friction welding of ring parts is established. The temperature and the flashes during the welding process are ...On basis of the finite element software DEFORM, the 2D coupled thermo-mechanical model of continuous drive friction welding of ring parts is established. The temperature and the flashes during the welding process are investigated. The results of numerical simulation show that the temperature of friction surface is higher than that of other region and the peak temperature increases with the increase of welding time. During the process of friction stage, no flash appears because of the low temperature and the small axial friction pressure. At the forging stage, the flashes appear, whose dimensions and bending degree increase with the increase of welding temperature. Moreover, with the increase of rotational velocity and axial forging pressure, the dimensions and the bending degree of flashes of continuous drive friction welding increase.展开更多
This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr...This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.展开更多
文摘Macro-deformation characteristics of continuous drive friction welded mild steel joints were examined by using one deformable workpiece (objective) and the other undeformable one (rigid). The microstructure evolution and hardness change across the joint were studied. The results show that the axial shortening and radial increment of joints increase with increasing the frictiou time at l 200 rpm. The cementite particles of pearlites in the weld center are uniformly distributed on the ferrite matrix, while the cementites of the pearlite in the thermal-mechanically affected zone are broken and discontinuously dispersed in the pearlite. The hardness decreases rapidly from the weld center to the parent metal under the coupled effects of heat and deformation during the rapid heating and cooling processes.
基金Nova Trading Company from Torun and Rywal-RHC Company from Lublin for the financial support owing to which it was possible to perform the research study and tests presented in the compilation.
文摘The friction drive elevators the influence of the braking distance has very high significance to meet certain safety regulations and comfort.During the emergency braking the delay for the system a frame and a cabin should be within the range from 0.2 to 9.81 m/s~2.However,there are no specialist literatures regarding the issues connected with emergency braking of elevating devices either.The results of the own empirical research work are presented regarding the influence of design changes on the working parameters of the friction drive elevator gears.ASG100,KB 160,PP16,PR2000UD and CHP2000 types of safety progressive gears are analyzed.ASG100,KB 160,PP16,PR2000UD type progressive gears are already produced by European manufacturers.CHP2000 type gears are established as the alternative option for the already existing solutions.The unique cam system has been used in the CHP 2000 gears.The cam leverage gives the chance to unblock,in a very easy way,the clamed gears after braking.Thus,it is a key aspect to perform laboratory tests over the braking process of a newly created solution.The proper value of the braking distance has a significant influence on the value of delay in terms of binding standards.The influence of loading on the effective braking distance and the value of the falling elevator cabin speed are analyzed and the results are presented.The results presented are interesting from lift devices operation and a new model of CHP 2000progressive gear point of view.
文摘The aim of present study is introducing a method by subdividing friction welding phases into three steps according to the temperature change during continuous drive friction welding operation. Thermal curve allowable subdividing of the friction welding phase's time into three distinct periods, while the microstructure evolution during friction welding goes through three different situations. The effects of three distinct periods were achieved by macro-microscopy, microhardness HV_(0.1), tensile tests and scanning electronic microscopy(SEM).The results clearly show that the microstructure during the friction phase goes through three completely different situations which mechanically influenced on microstructure, tensile strength and ductility of the welded joint.
基金Acknowledgement This work is supported by the National Natural Science Foundation of China (No. 51204111 ) and the Education Department Foun- dation of Liaoning Province (No. L2012047).
文摘On basis of the finite element software DEFORM, the 2D coupled thermo-mechanical model of continuous drive friction welding of ring parts is established. The temperature and the flashes during the welding process are investigated. The results of numerical simulation show that the temperature of friction surface is higher than that of other region and the peak temperature increases with the increase of welding time. During the process of friction stage, no flash appears because of the low temperature and the small axial friction pressure. At the forging stage, the flashes appear, whose dimensions and bending degree increase with the increase of welding temperature. Moreover, with the increase of rotational velocity and axial forging pressure, the dimensions and the bending degree of flashes of continuous drive friction welding increase.
基金supported by JSPS KAKENHI Grant Numbers JP 15H05759 and JP 20H00211。
文摘This paper presents a compact XYZ micro-stage driven by an impact driving mechanism.A moving body is translationally actuated along the X-,Y-,and Z-axes in millimeter-scale range and with nanometer-scale resolution.Cr-N thin-film strain sensors are integrated into the micro-stage for closed-loop positioning.Closed-loop control is also carried out.The motion errors in six degrees of freedom are also investigated for this micro-stage.It is clarified by analysis of finite element method that rotational motion errors around the driving axis are caused by torques due to tensions from the elastic hinges of microstage.The mechanical structure of XYZ micro-stage to cancel out the torque generated is proposed and the second prototype is fabricated.Although the rotational motion error is successfully suppressed in the second prototype,a rotational motion error of more than 0.1°remains due to remaining torque and assembly error of the elastic hinges.Then,in order to reduce the rotational motion error,the prototype is designed in which the location of elastic hinges is single-layered.By designing a mechanical structure in which torque is suppressed,all rotational motion errors are successfully reduced to less than 0.05°in the prototype with single-layer hinges.