Durning the design process of hydrostatic rotary worktable,the processing and assembly tolerance,(the offset of worktable and the gap of the oil film’s thickness)is ignored.But it will cause that the real bearing o...Durning the design process of hydrostatic rotary worktable,the processing and assembly tolerance,(the offset of worktable and the gap of the oil film’s thickness)is ignored.But it will cause that the real bearing of oil pocket deviates from the initial design value,and then the performance of rotary worktable will be reduced significantly.Up to now,no effort is found toward the research of influence of the processing and assembly tolerance on the performance of the rotary worktable.So the hydrostatic oil film is assumed as the elastomer in this paper,and then the bearing capacity of the oil pocket is studied with and without the mass offset of the worktable by taking an expression between the bearing capacity and the oil film’s thickness of the oil pocket as the deform compatibility equation.The influence of the processing tolerance of the oil sealing belt’s gap on the bearing capacity of the oil pocket is analyzed.In the light of the liquid hydrostatic worktable of Gantry Moving Milling Center using on the scene,the oil pocket’s pressure of the worktable is tested using Rotary Worktable Test System under the circumstance of the mass offset of the worktable and the gap tolerance of the oil sealing belt,and then the equivalent offset of worktable,the average pressure of the oil pocket and the actual thickness of the oil film are analyzed respectively.The test results show that the bearing capacity component of the oil pocket caused by G is consistent,and the component caused by M is relative to the position of the oil pocket.When the oil sealing belt’s gap is larger than the theoretical value,the bearing capacity of the oil pocket is smaller than the others;whereas the bearing capacity of the oil pocket is larger than the others.The maximum and minimum equivalent offsets are 0.256 4 mm and 0.047 5 mm,respectively,and the average oil pocket pressure varies from 0.345 MPa to 0.460 MPa,the maximum and minimum value of the actual oil film thickness are 109.976?m(No.7 oil pocket)and 93.467?m(No.展开更多
Common fluid film bearing issues(mainly high bearing temperature)preventing reliable operation of turbomachinery will be addressed.Atheoretical review of radial and thrust bearing performance will be included for a ba...Common fluid film bearing issues(mainly high bearing temperature)preventing reliable operation of turbomachinery will be addressed.Atheoretical review of radial and thrust bearing performance will be included for a basic understanding on how to handle the bearing issues.Some theoretical plots will be presented to demonstrate the effect of key bearing design parameters on bearing performance.Advanced bearing materials beyond babbitt will also be introduced as bearing upgrade options to overcome bearing issues.Case studies on radial and thrust bearing upgrades to mitigate or eliminate the bearing issues will be shared.Some of the common vibration problems preventing reliable operation of turbomachinery will also be described with suggestions on how to eliminate or mitigate the problems via changes to bearing design features or new bearing technology.A couple of case studies representing each vibration problem will be presented.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51075348)Hebei Provincial Natural Science Foundation of China(Grant No.E2011203151)Research Fund for Doctoral Program of Higher Education of China(Grant No.20101333110002)
文摘Durning the design process of hydrostatic rotary worktable,the processing and assembly tolerance,(the offset of worktable and the gap of the oil film’s thickness)is ignored.But it will cause that the real bearing of oil pocket deviates from the initial design value,and then the performance of rotary worktable will be reduced significantly.Up to now,no effort is found toward the research of influence of the processing and assembly tolerance on the performance of the rotary worktable.So the hydrostatic oil film is assumed as the elastomer in this paper,and then the bearing capacity of the oil pocket is studied with and without the mass offset of the worktable by taking an expression between the bearing capacity and the oil film’s thickness of the oil pocket as the deform compatibility equation.The influence of the processing tolerance of the oil sealing belt’s gap on the bearing capacity of the oil pocket is analyzed.In the light of the liquid hydrostatic worktable of Gantry Moving Milling Center using on the scene,the oil pocket’s pressure of the worktable is tested using Rotary Worktable Test System under the circumstance of the mass offset of the worktable and the gap tolerance of the oil sealing belt,and then the equivalent offset of worktable,the average pressure of the oil pocket and the actual thickness of the oil film are analyzed respectively.The test results show that the bearing capacity component of the oil pocket caused by G is consistent,and the component caused by M is relative to the position of the oil pocket.When the oil sealing belt’s gap is larger than the theoretical value,the bearing capacity of the oil pocket is smaller than the others;whereas the bearing capacity of the oil pocket is larger than the others.The maximum and minimum equivalent offsets are 0.256 4 mm and 0.047 5 mm,respectively,and the average oil pocket pressure varies from 0.345 MPa to 0.460 MPa,the maximum and minimum value of the actual oil film thickness are 109.976?m(No.7 oil pocket)and 93.467?m(No.
文摘Common fluid film bearing issues(mainly high bearing temperature)preventing reliable operation of turbomachinery will be addressed.Atheoretical review of radial and thrust bearing performance will be included for a basic understanding on how to handle the bearing issues.Some theoretical plots will be presented to demonstrate the effect of key bearing design parameters on bearing performance.Advanced bearing materials beyond babbitt will also be introduced as bearing upgrade options to overcome bearing issues.Case studies on radial and thrust bearing upgrades to mitigate or eliminate the bearing issues will be shared.Some of the common vibration problems preventing reliable operation of turbomachinery will also be described with suggestions on how to eliminate or mitigate the problems via changes to bearing design features or new bearing technology.A couple of case studies representing each vibration problem will be presented.