Active Precision Design Of Gear Shaping Machine

Gear is widely used in automotive, aviation, shipbuilding, military and other fields as the most widely used drive device. As the key drive components of all types of machinery, the manufacturing processes of the gear products and its quality directly affect the quality of complete machines. Therefore, the precision of gear shaping machine directly affects the machining accuracy, and the transmission performance and noise of gears further. Machine precision design, an important step in machine design, is the key to determine the price quality and success of the products. The traditional precision design method is primarily to calculate the precision of every machine tool parts in the transmission chain based on the given precision of machine tool's terminal actuators. It is the precision design which is oriented to the manufacturing equipments, but it can't meet the machining precision requirement of super-precision machining. Therefore, this paper explores the issues on gear shaping machine tool's precision design from the requirement of the gear precision and machining mechanism. Main contents and results are as follows.1. The gear precision requirement-oriented active precision design method of gear shaping machine tool is proposed. It designs gear shaping machine precision from the mechanical precision requirement of gears and machining mechanism. The basic idea of this method is to establish the mapping model according to the gear shaping machine tool's motion error and the gear machining error, and then to establish the gear mechanical precision model based on the error mapping model. Finally, transform the requirement of the gear precision to the motion precision of three CNC controlled axis according to the machining precision model.2. According to the principles of conjugating tooth, it establishes the tooth surface model of the involutes cylindrical gear, and the tooth model is validated.3. With the analysis of the influence factors of gear tooth surface machining error, it analysis the impact of the motion error of the NC axis on the errors of the discrete points according to the involutes gear tooth surface model; it establishes a processing error model after selecting pitch variation as the test items.4. The machine precision model is established based on the machining error mapping model. The sensitivity of the single NC axis is obtained after the analysis of the machine precision model. The active precision design model is also established taking the accuracy distribution and the precision reserve principle into account.5. The active precision design model is applied to the precision design of YKW51250 CNC gear shaping machine developed by Tianjin No.1 Machine Tool Works. And the design reference value of the three NC axes of the CNC gear shaping machine is figured out when the machining precision grade of the involutes cylindrical gear is six.