Principle and technology of on machine measurement of large gear

Gear is famous for its complex shape all the time, and its various error inspection items are not only various, but also technically difficult, which has become a topic concerned by the engineering circles for nearly a century. Over the years, more than 100 kinds of gear measuring instruments have been developed at home and abroad, and the products have developed from pure mechanical to NC, CNC electronic. In the 60’s and 70’s, the leading products of gear measuring instrument are mechanical generating involute gear tester, lead tester, universal gear tester, etc. With the development of mechatronics, optoelectronics and computer technology, the above products are gradually replaced by the electronic generating involute gear tester with advanced technology, perfect function, high precision and high reliability. Since the mid-1980s, CNC gear measuring center based on CNC technology has gradually become the mainstream of gear measuring instruments. In recent years, the United States and Japan have developed a new type of non-contact gear measuring instrument, the key technology is the non-contact (optical) probe equipment, which further shows that the modern gear measuring technology is an integrated technology of mechatronics and optoelectronics.

It can be seen from many research results that there are many kinds of precision measuring instruments for medium and small modulus gears and medium diameter gears, and the functions are complete. among

The most representative should be the desktop gear measuring center, which uses advanced CNC technology, CAA technology, precision detection technology, etc., and absorbs some of the latest technical achievements of CMM, and has gradually become the main measuring means for medium and small modulus gears and medium diameter gears. At the same time, the development of gear measuring technology in China is also very rapid, and various precision gear measuring instruments have been developed one after another, such as the gear measuring instruments of Harbin Measuring Tool and cutting tool factory and the gear measuring instruments of Chengdu Tool Research Institute.

It can be seen that the precision measurement technology for small and medium modulus and gear with diameter less than 2.5m is quite mature, and various measuring instruments dominated by gear measuring machine can complete the precision measurement of various errors.

The further development of gear measurement technology is tending to the extension of two poles, that is, the measurement of micro gear with very small modulus and diameter and the measurement of large gear with very large modulus and diameter, which has become the development frontier of gear measurement technology. In the long-term plan of 2000, the state also takes them as two directions of key development. This is also an urgent problem to be solved in the development of micro precision machinery and large precision equipment. As far as large high precision gears are concerned, they are mainly used in transportation, energy, metallurgy, mining, building materials, national defense, aerospace and other important departments. At present, the manufacturing technology of large gears in the world is constantly improving, and the varieties and specifications are gradually expanding. The gear diameter processed by hobbing machine has reached Φ 12500 mm, the gear diameter processed by gear shaper machine has reached Φ 15000nun。 The diameter of the block combined gear used in the space tracking mechanism has been calculated in Φ 24500mm~ Φ 30500mm. With the emergence of 600000 HP aircraft carrier, million ton oil tanker, 1.5 million KW generator set and 15m ore autogenous mill, larger gears are needed. David Brown has made 100 tons of gears and m η= 80 mm gears have also been processed by lufhin industries of the United States η= 68mm gear. In terms of accuracy, the maximum diameter of the “super silent” submarine gear manufactured by michelgan tool company of the United States is Φ The precision of pitch and helix angle is 0.0038 mm and 0.002 mm / 100 mm respectively Φ The accumulated pitch error of 6200ram gear is less than 0.004mm, which indicates that the high-precision measurement of large gear becomes more and more urgent and important.