| Cyclo-Palloid spiral bevel gears are the key components of the large or heavy mechanical equipment for transmitting motion and power between intersecting axes. At present, CNC machining equipment and digital manufacturing technologies of Cyclo-Palloid spiral bevel gears are still owned by Klingelnberg Corporation in Germany. But in the field of CNC machining equipment and manufacturing technologies, the domestic companies are still in the initial stage. In order to improve the independent innovation capacity of CNC machining equipment and enhance the digital manufacturing level of Cyclo-Palloid spiral bevel gears, the CNC machining equipment and key technologies for realizing digital manufacturing has been studied in this paper. The main research results are as follows.1. Based on the meshing theory of spiral bevel gears, the shortcomings of the existing machine-settings calculation algorithm of Cyclo-Palloid spiral bevel gears have been improved. By setting the major axis length of the instantaneous contact ellipse and according to the curvature parameters at reference point of engaged tooth surface, the offset value EXB of the axis of outer cutter head for modifying tooth lengthwise curvature is determined using iterative algorithm. By controlling the offset distance EXF of the axis of outer cutter head to ensure the tooth thickness, avoiding the helical angle and curvature deviation generated by the existing algorithms. Based on the KN3028, KN3030 standards and the improved algorithms, computer-aided design software is developed, and the software calculation results are verified through examples.2. Based on the gear meshing theory, the tooth surface equation and the calculation method for tooth surface curvature parameters of Cyclo-Palloid spiral bevel gears is established. According to the tooth surface equation and the curvature parameters of the gearset, tooth contact analysis method for Cyclo-Palloid spiral bevel gears is established. It can not only analyze the contacting status of gearset at the theoretical installation location, but also obtain the shape of contact pattern, the curve of transmission error and the adjusting value of V, H while the gearset engaging at heel, midpoint and toe location. The machine-settings calculation algorithm and tooth contact analysis method are verified through the actual processing experiments.3. Based on the tooth surface equation, the formulas are given for calculating the position vector and normal vector of the discrete points, while the discrete points are in the machine adjusting location or the generating location. An accurate method for calculating start and end generating cradle angle is proposed. Furthermore, a tooth form analysis method is proposed and the influence rule and its extent of various machine setting parameters on the tooth form is analyzed. On this basis, a method for modifying the tooth form errors is presented. According to the measured data, we can obtain the correction value of machine-setting parameters by which modify the tooth form errors generated by machining errors or compensate the tooth deformation generated by heat treatment.4. Based on the CNC machining principle of Cyclo-Palloid spiral bevel gears, a new structure for workpiece spindle is proposed. It can realize the adjustment of offset distance and the continuous changes of direction angle of outer cutter head axis. Based on the motion transforming principle between CNC machine and mechanical machine and the machining coordinate system of H1600K CNC cutting machine, the mathematical model for CNC machining is established. By using this mathematical model and the "electronic gear" function of numerical control system, NC code can be generated, thus achieving CNC machining of Cyclo-Palloid spiral bevel gears.5. Based on the model of H1600K CNC Cyclo-Palloid spiral bevel gear cutting machine, the structure of the on-machine measuring system is proposed. Considering the shortcomings of measuring principle of CMM and gear measuring center when inspecting the pinion, an on-machine measuring method of tooth forms errors based on generating principle is proposed. The tooth form errors can be measured without interference by using the probe with smaller diameter. The on-machine measuring procedure and data processing method for indexing precision and tooth form errors are given. Based on the secondary development platform of AutoCAD, simulation software is developed. By comparing the simulated measuring results with theoretical analysis results, the correctness of the on-machine measuring principle is verified.
|
PDF Full Text Request