Study On Elastohydrodynamic Oil Lubrication Design Theory Of Arbitrary Intersecting Line Gear Pair

In the previous research,the geometric designs of line gear(LG)with arbitrary intersecting and arbitrary skew have been completed.Meanwhile,the researches on manufacturing technology of LG have also made remarkable achievements.And some practicability results indicated that LG can meet the requirements of small and medium conventional power transmission.However,to be widely used,the related research on lubrication design of LG is needed.This dissertation studied the oil lubrication design theory of arbitrary intersecting LG(AILG).In order to make a LG pair has an ideal service life,the full-film lubrication should be formed as far as possible while the line gears are running.The LG pair is the point contact friction pair,thus the ideal lubrication state should be the EHL.The formation of lubricant film is directly related to the geometric morphology of the contact area and the operating conditions.In this dissertation,precise geometrical modeling method of line teeth of the AILG was studied.On the basis of modeling method,the geometric morphology of the contact area of AILG pair was analyzed and the geometric design of line teeth was corrected based on the analysis result so that the AILG are easier to achieve EHL.Finally,through the numerical calculation of EHL and the verified experiments of lubricant film thickness measurement,the method to select the applicable operating conditions of the AILG was studied.The specific research contents of this dissertation are summarized as the following four aspects.1.Precise geometrical model of line teeth of the AILG was established.On the basis of the previous research of the AILG and the characteristics of 3D CAD software,the equation of driven center curve was corrected,and the profile equations of the line teeth of the AILG were deduced.The precise geometrical model of line tooth was built by using Pro/E software which is theoretically the same as the geometric model described by profile equations of the line teeth of the AILG.Finally,the kinematical simulation results showed that the corrected tooth do not affect the meshing of the AILG pair.2.The corrected design method of contact model based on the AILG EHL design was establised.The parameters of the equivalent ellipsoid model of the AILG were calculated.On the basis of the calculation,the elliptical contact area of the AILG pitch point was analyzed and the methods to correct geometric morphology of the elliptical contact area were proposed.The methods are summarized as follows: 1)increase line teeth radius to increase the radius of the short axis of contact ellipse;2)change the position of the circular section of driving line teeth to reduce the radius of the long axis of contact ellipse;3)change the position of the circular section of driven line teeth to further increase the radius of the short axis of contact ellipse.Finally,examples were provided to show that the new design method of the line tooth can effectively improve the elliptical contact area and make the EHL easier to be formed while the AILG pair are running.3.The AILG parameters design criterias based on EHL design were established.Semi-quantitative analysis of the relationship between the parameters of the AILG and the parameters of the equivalent ellipsoid model were presented,and the AILG parameters design criterias were proposed according to the analysis results.And based on that,a cross section design method of the AILG was proposed.Examples were provided to show that the elliptical contact area was further improved by using the parameters design criterias.Finally,on the basis of the AILG corrected design method and the parameters design criterias,the 3D model of the AILG pair was built,and the kinematical simulation by using the Pro/E was accomplished.The results proved the applicability and reliability of the corrected design method and the parameters design criterias for AILG.4.The selection criterias for operating conditions of the AILG EHL were establisged.An external oil supply system was designed to improve the optics EHL test rig.The experiments of lubricant film thickness measurement by using the test rig were accomplished to verify the accuracy of numerical calculation.The parameters of the equivalent ellipsoid model of the commonly used AILG were calculated and listed as schedule,that could provide a reference to industry.The conditions to form EHL were discussed,and the oil film thickness map was drawn by numerical calculation.Finally,an example was provided to show that how to choose the applicable conditions of EHL for the AILG in practical application.