| Bevel gears include spiral bevel gears and hypoid gears. They are used for transmitting the rotational motion of the crossing or interleaving axes with the constant transmission ratio. Due to its performance, such as the high carrying capacity, the big overlap coefficient, the high stability, the low noise and vibration, spiral bevel gears are widely used as a key part on machines of many industry fields, such as aviation, shipbuilding, vehicle, machine equipment and petrochemical machinery. So the bevel gears possess a very important position in the modern machinery. Nowadays its production is mainly finished by the special gear machine tool. But because of the complexity of geometry characteristic and the engagement locomotion of spiral bevel gears, a lot of machining problems still remained. On the one hand the manufacture is complex, time-spending and costly , on the other hand the structure and size of the existing machine tool is limited, which make it impossible to machine some big dimension gear pairs.How to solving the conflict between machine tool size and gear workpiece's, and how to predict the tooth flank and tooth contact pattern, has become the focus of scholars in gear researching field.Based on above problems, the developing team deeply researched on the digitization manufacturing technology of spiral bevel gears, which is fit for machining on multi-axial machine tool. This thesis mainly researched on entity model, which is the the first stage work of this digitization manufacturing technology, and a new modeling method was brought forward. The 3D model of spiral bevel gears was build in this method, and by tooth flank optimize design, the controlling of tooth contact pattern was realized, the production time circle was shorten, the cost was reduced, the tooth flank and tooth contact pattern were predicted. In some meaning, this thesis offered a new research tool and method for the main learning issues, such as production simplification, tooth flank and contact pattern prediction. At the same time, by utilizing the technology, the R&D period was reduced, facility investment was cut down and the core competitive ability of corporation was promoted. This technology is especially fit for the digitization design and manufactureing of large modulus gears.The main contents of this thesis are as follows:1. The basic concept and related theory of spiral bevel gears were briefly introduced.2. The tooth cutting calculation principle was clarified.3. The structure of Gleason No.116 Machine tool and locomotion principle were introduced and its setting process was analyzed. Then the SF and SB Summary of Gleason machine settings were programd by using Visual Basic 6.0.4. Base on UG and GRIP redevelop kit, the Spiral Gear modeling system was developed. Using the geometry size getting from part drawing and setting parameters from Summary, the cutting simulation of bevel gears was accomplished. By adjusting of setting parameters, the actively controlling of tooth contact pattern on wheel was achieved.5. The unsmooth flank was rebuild and then the TCA was carried on. In order to validate the feasibility of the modeling method introduced by this thesis, an experiment of steel workpiece was processed on multi-axial CNC center. |
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