Abstract: To improve the precision of common gear-hobbing machine and develop high-precision worm gear cutting machine, the errors are decomposed and analyzed for each part of the transmission chain based on the transmission error transfer theory, and a system correction method is presented for the transmission chain of gear-hobbing machine. According to the results of accurate measurement and error frequency-spectrum analysis obtained by the developed testing system for machine tool, three main error sources are found, namely, short-term errors introduced by bevel gears of machine tool, short-term errors introduced by worm of worktable, and long-term errors brought by worm gears of worktable. With computer-aided manufacturing technology for eccentric wheel and cam, the main errors are corrected one by one. After a series of test - correction - test cycle, the test results of machine tool in situ are that transmission error is 7.55, periodic error is 4.23 and cumulative error is 3.41. Experimental results show that a common gear-hobbing machine is refined to a high-precision worm gear cutting machine, being a top level one in China.

Key words: Error analysis, Error correction, High-precision, Machine tool, Worm gear