Research On Pitch Process Technology Of Gear-grinding For Ultra-precision Master Gear

Gear is one of the most commonly used parts in mechanical equipment. It is widely used in mechanical driving devices. With the development of machine building industry, gear-precision must be higher. The gear-manufacturing accuracy also is an important indication of a nation’s manufacturing level. So it is very important to carry out ultra-precision master gear project to develop our gear manufacturing industry.The profile and lead accuracy, radial runout accuracy and pitch accuracy are the main accuracy indexes of ultra-precision master gear. Pitch accuracy affects exactitude and stability of gear transmission directly. It is the major index for transmission accuracy. This paper analyzed all the factors that affected pitch accuracy of the ultra-precision master gears, and discussed the errors generating during the manufacturing procedure of gear withY7125gear grinding machine, including the errors caused by gear installation, geometric eccentricity and indexing positioning.1. Gear Installation ErrorDuring the gear installed process, synthetically geometric eccentricity occurs. It will directly affect the pitch accuracy of the ultra-precision master gear. The problem can be solved by increasing the accuracy of indexing system. It is convenient. Meanwhile, grinding gear is an effective way to improve gear geometric accuracy.2. Indexing Plate Installation ErrorIndexing plate is the leading part to locate of machine tools. Its accuracy is passed to the manufacturing gear directly. In this paper, the indexing plate with high accuracy was used. In the other hand, sine compensation method was used to adjust the installing-center of the indexing plate and the accumulated pitch errors of gear were reduced.3. End-tooth Indexing PlateRecently, the highest accurate mechanical indexing device is the end-tooth indexing plate. End-tooth indexing principle can be used to reduce accumulated pitch errors of indexing plate, but it has nothing to do with single pitch error. The maximum precision of end-tooth indexing plate is±0.05". End-tooth indexing plate was used to increase the pitch accuracy of gear. This method also reduced the amount of work in indexing plate installation and setting up. Through the analysis above, how to improve the pitch accuracy was studied. In this paper, the problems during the practical manufacturing process of ultra-precision master gear were studied and solved. The proposed methods increased the measurement efficiency and accuracy.