Design Of The Logix Gear And Its Research On Strength

The main research contents of the paper conclude:(1) The principle and process of forming the logix rack is introduced. According to the equation of the tooth profile of the logix rack and the relationship which the logix rack and the logix gear is meshed, the equation of the tooth profile out of the pitch circle of the logix gear is obtained. Combined with the equation of the tooth profile of the logix gear, the coordinates of the logix points which relative curvature is zero at the tooth profile are calculated by matlab programming, then one side of the tooth profile of the logix gear is fitted and the whole profile figure of tooth is drawn out. Then, the three tooth profile parameters are changed respectively to make different profile figures of tooth so as to analyse the influence on the tooth profile of the logix gear and the number of the logix point of the tooth profile parameters.(2) The formula of the addendum radius of the logix rack cutter of single fillet is established, then the relationship between the addendum radius and the connecting logix point is acquired, and the equations of the addendum curve of logix rack cutters of single fillet and two fillets are established. According to the relationship which the logix rack and the logix gear is meshed, the equation of the dedendum transition curve of the logix gear is got, then through programming, the points of the dedendum transition curve of the logix gear are calculated, and the 2D drawings of the logix gear is drawn out. 3D models of the logix gears under two kinds of logix rack cutters is established, then the static finite element analysis of logix gears which single tooth is meshed is done by using workbench, the stress distribution of logix gears is obtained, which shows that bending strength of the logix gear under the dedendum transition curve of the logix rack cutter of single fillet is better.(3) In order to get the appropriate tooth profile parameters of the logix gear, with reference to the tooth thickness of the addendum circle of the involute gear under the same condition, multiple sets of tooth profile parameters which the initial pressure angle is in the range of 2 °-12° is calculated. By comparing the tooth profile characteristics, and combined with the stress analysis of the logix gears which is meshed at the pitch circle under certain working conditions, a method to choose the tooth profile of the logix gear is promoted, which can ensure bending strength and contact strength at the same time. That is, the smaller the initial pressure angle is, the better the result is. It is concluded that the tooth profile parameters which the initial pressure angle is 2° should be adopted.(4) The involute gear model under the involute rack cutter in the same way is established. The meshing process of the logix gears is analyzed, which pointed out that the maximum stress of the root occurs at the highest point of the single-teeth meshing area. The root stress of the logix gears of several groups of tooth profile parameters and the involute gear which are meshed at the pitch circle and the highest point of the single-teeth meshing area are analyzed by using the Workbench, which concluded more accurately that bending strength of the logix gear is better than the involute gear, and the correctness of the above result is also verified.