Research On Transmission Performance Of Segmented And Deformed Elliptic Gear

The segmented and deformed elliptic gear has the advantage of high efficiency and torque in transmission as same as the cylindrical gearing.Moreover,it is also compact-sized.The variable-ratio and gear ratio motion can be realized.It is widely used in various machines such as machine tool,agricultural machinery and pump and so forth.The study on it is with wide application foreground.The expression of pitch curve in polar coordinates for the segmented and deformed elliptic gear is shown,so is the conjugate tooth.The two-segmented and deformed elliptic gear and the three-segmented are taken for examples.The study lays the foundation of geometric modeling and analytical calculation for the segmented and deformed elliptic gear,so do the designing and manufacturing.The mathematical model of the cutter and slotting cutter are set up.The location of the teeth-cutter is controlled by program programed by VBA language,and then the gear billet of segmented and deformed elliptic gear is subtracted using it.Thus the manufacturing is realized.The VBA is the secondary development language in Solidworks software.The three-dimension model of the gear is gained through the method mentioned above.The force analysis for the non-circular gear pair is carried out afterward.The force analysis for the pair is conducted,and then a single gear as well.The force forced on the gear is obtained,which lays basis for gear intensity check.The formula used to calculate the bending stress and the contact stress of the non-circular gear is obtained on the basis of intensity analysis method for the cylindrical gear.At the same time the parameters are modified.The method mentioned above is quick,but the accuracy is low.The strength of the gear is analyzed using finite element software.The result shows that the maximum bending stress is 2e7Pa under the condition of?=900°.The maximum contact stress is 4.8e6Pa under the condition of?=15°.Compared with the calculated method of multi-tooth meshing,the result calculated by the method of single tooth meshing is bigger.However,the computing resource is saved and it is fast using this method when the carrying capacity of the gear is checked.The kinematical properties for the segmented and deformed elliptic gear are analyzed.The result shows that the rangeability of the angular velocity and angular acceleration increases along with the increase of eccentricity ratio.When the value of deformation coefficient is 1,the transmission of the gear is smooth.When the value of deformation coefficient departs from 1 further,the changing amplitude of angular velocity and angular acceleration is larger.When the segments of the gear exceed 3 and the value of each segment is not equal,the accelerated speed of the driven wheel changes suddenly.The analysis provides evidence for the appropriate design of the gear system.The.geometric model of an elliptical gear and a gear pair are built by using Solidworks software,UG(Unigraphics)software and ADAMS software.The corresponding finite element model is established in the ANSYS Workbench software.The inherent characteristic of the gear is analyzed,including the first six natural frequencies and mode of vibration.The variation range of the natural frequency for an elliptical gear pair is obtained by analyzing its natural frequency in different engage position.A method analyzing the modal of an elliptical gear pair is provided.The natural vibration characteristics of the gear can be analyzed accurately,which lays the foundation of the structure optimization and the noise control.